The value of nailfold capillaroscopy in Raynaud s phenomenon in daily clinical practice

Transcription

1 The value of nailfold capillaroscopy in Raynaud s phenomenon in daily clinical practice Berber de Boer, Facultair begeleider: M.M. Zandbelt, reumatoloog Deventer Ziekenhuis Extern begeleider: J. Meijs, arts-onderzoeker LUMC/professor Huizinga, reumatoloog LUMC Locatie: Leids Universitair Medisch Centrum, afdeling reumatologie 1

2 Abstract Objective: To assess the necessity of a follow-up capillaroscopyin patients with Raynaud s phenomenon (RP), and to assess the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of capillaroscopy for the development of systemic sclerosis (SSc). Methods: Patients with RP with a capillaroscopy at the outpatient clinic at least six months ago were invited for a follow-up capillaroscopy. Patients were evaluated for new symptoms using a questionnaire and a physical examination. Results: The study population consisted of 107 patients with RP; 71 were available for followup. At baseline, 28% of the 71 patients had a normal/aspecific pattern, 42% showed borderline changes and 30% showed an SSc-pattern.The mean duration of follow-up was 12 months (range 6-25 months). In 21 (30%) patients capillaroscopy changed during follow-up, in 6 (8%) patients the capillaroscopy pattern worsened. All patients with a progressive capillaroscopy pattern had an established diagnosis at baseline or were still classified as suspected for secondary RP. Thirteen patients were diagnosed with SSc. An SSc-pattern had a sensitivity of 69%, a specificity of 84%, a PPV of 50% and a NPV of 92% for the development of SSc. Conclusion: Repeated capillaroscopy did not yieldnew diagnoses in patients with RP presenting at an academic outpatient clinic. Our study confirmed that capillaroscopy has a valuable role in the distinction between PRP and SRP due to SSc. Based on the findings of this study, a followup capillaroscopy after a year in all RP patients cannot be advocated. Samenvatting Doel: Doel van deze studie is om het belang van een follow-up capillairoscopiebij patiënten met het fenomeen van Raynaud (RP) vast te stellen en om de sensitiviteit, specificiteit, positief voorspellende waarde (PVW) en negatief voorspellende waarde (NVW) van capillairoscopie voor systemische sclerose (SSc) te bepalen. Methode: Patiënten met RP die minstens zes maanden geleden een capillairoscopie kregen op de polikliniek werden uitgenodigd voor een follow-up capillairoscopie. Om nieuwe symptomen op te sporen, vulden patiënten een vragenlijst in en werd een lichamelijk onderzoek verricht. Resultaten: De studiepopulatie bestond uit 107 patiënten met RP: 71 waren beschikbaar voor follow-up. Tijdens het baseline bezoek had 28% van de 71 patiënten een normaal/aspecifiek patroon, 42% toonde een secundair patroon en 30% had een SSc-patroon. De gemiddelde followupduur was twaalf maanden (spreiding van 6-25 maanden). Bij 21 (30%) patiënten veranderde het capillairoscopiepatroon tijdens de follow-up; bij 6 (8%) patiënten verslechterde het patroon. Alle patiënten met een verslechterde capillairoscopie hadden al een diagnose bij het baseline bezoek of waren bij follow-up nog steeds verdacht voor een secundair RP. Dertien patiënten hadden SSc. Een SSc-patroon had een sensitiviteit van 69%, een specificiteit van 84%, een PVW van 50% en een NPV van 92% voor het ontwikkelen van SSc. Conclusie: Herhaling van capillairoscopie heeft niet tot nieuwe diagnosen geleid bij patiënten met RP op de polikliniek. Deze studie bevestigt dat capillairoscopie een belangrijke rol heeft in het onderscheid tussen een PRP en SRP door SSc. Gebaseerd op deze resultatenkan een followup capillairoscopie na één jaar bij alle patiënten met RP niet worden aanbevolen. 2

3 Table of contents Introduction and objectives 4 Methods 6 Results 10 Conclusion and discussion 15 References 20 Appendix A: vragenlijst 24 Appendix B: Raynaud s Condition Score 26 3

4 Introduction and objectives Raynaud s phenomenon (RP) is a vasospastic disorder characterized by color changes indicating ischemia, cyanosis and hyperemia of predominantly the fingers in response to cold or emotional factors (figure 1). RP is a relatively common condition in the general population (1-3). RP can be distinguished in primary and secondary RP. Primary RP (PRP) is diagnosed in patients with a combination of a normal capillaroscopy, absence of autoantibodies and absence of clinical characteristics suggestive for an underlying disease (4). Secondary RP (SRP) is diagnosed in patients with an underlying disease, predominantly connective tissue diseases (CTDs). SRP is only in a small proportion of patients present, with systemic sclerosis (SSc) as the most common underlying disease (5;6). Figure 1: Ischemia in Raynaud s phenomenon SSc is a CTD with a wide range of clinical manifestations. The most typical manifestation is skin thickening and hardening (sclerosis). The pathogenesis of the disease is characterized by a triad of changes in microvasculature, fibrosis and immune activation (1). Almost all organs can be involved in the more advanced stages of the disease, including the lungs (interstitial lung disease), kidneys (renal crises) and heart. RP is often the first manifestation of the disease. The prevalence of RP in SSc is as high as 98% according to several studies (7). Due to microvascular alterations, problems in the hands of patients are common, for example digital ulcers or pitting scars. Until some decades ago, there was limited interest inthe distinction between the two Raynaud phenomena. There were no treatment options to prevent progression of an underlying disorder, so early diagnosis did not improve the prognosis. Nowadays, several drugs are available with effects on vascular remodeling: angiotensin-converting enzyme inhibitors, prostanoids, and endothelin 1 receptor antagonists(2). Consequently, early detection of SSc (which means diagnosing SSc before other symptoms than RP develop) is important for a better prognosis (3). Nailfold capillaroscopy (capillaroscopy) is a commonly used tool to differentiate between a PRP and SRP. Previous studies evaluated the role of capillaroscopy in the differential diagnosis of patients with RP (8). The essence of this tool is to examine the morphology of the nailfold capillaries (9). Since changes in microvasculature play an important role in the pathogenesis of SSc (10), capillaroscopy is a useful screening tool in patients with RP (8;11;12). Patients with PRP have no evidence of microvascular disease on capillaroscopy. Patients with a RP due to SSc show a typical pattern, consisting of the presence of enlarged/giant capillaries, haemorrhages and loss of capillaries, also known as a scleroderma pattern (or SSc-pattern) (9). This pattern recognition is a qualitative scoring system. It is used in everyday clinical practice and is a fast way to evaluate presence of microvascular damage.another way to examine the nailfold capillaries is using a (semi-)quantitative scoring system. The different parameters are counted per millimeter, in order to assess the extent of microvascular change. This quantitative 4

5 Figure 2: Severe cutaneous involvement in SSc. Note the flexion contractures of the fingers, the distal pulp loss, deformity of the nails and the scleroderma.copyright 2009, American College of Rheumatology assessment has a possible role in monitoring/predicting disease severity, disease progression and response to therapy, but this role has to be further investigated. Although patients with a normal capillaroscopy and no other signs of a CTD are considered to have a PRP, transition from PRP to SRP over time is previously reported. The negative predictive value of abnormal nailfold capillaries is as high as 93% (4), but Koenig et al. (8) showed that in a mean followup duration of four years, 12.6% of patients progressed from isolated RP to definite SSc. Moreover, Herrick and Cutolo (2) stated that there is often a long delay between the onset of RP and the diagnosis. Cutolo et al. suggested that patients with PRP should be evaluated (semi)annually by capillaroscopy in order to detect transition to SRP as early as possible (13;14), since progression does occur in some patients. It is not known whether standardized (semi)annually follow-up capillaroscopy in absence of new clinical features is advocated. This means that more clinical studies are needed investigating change over time in patients presenting with RP, particularly with respect to the microvasculature as assessed by capillaroscopy (2). Thirty years ago, the first paper describing the specific capillaroscopic patterns in SSc was published (5). Since then the diagnostic criteria for SSc have been changed several times. Nowadays it is possible to diagnose SSc even before the development of any organ involvement, since nailfold changes at capillaroscopy in combination with RP can be sufficient to diagnose early SSc. Those changes usually precede clinically recognizable SSc by years (6). More recently, the ACR and Eular proposed new classification criteria (the ACR/EULAR classification criteria), based on a scoring system(7). In this scoring system an abnormal capillaroscopy is one of eight possible features leading to the classification of patients as having SSc.The importance of nailfold capillaroscopy is well reflected by those criteria. In the current study the value of repeated capillaroscopy will be evaluated in a cohort of patients with RP referred to an academic center in The Netherlands. It will be assessed whether patients showed transition from PRP to SRP during follow up, defined as development of new symptoms or worsened capillaroscopy pattern. Consequently, the usefulness of repeated capillaroscopy in a rheumatologic practice will be assessed. Furthermore, the importance of capillaroscopy will be evaluated; the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of capillaroscopy in patients with RP referred to our hospital will be calculated. The role of a quantitative scoring 5

6 system will be assessed and it will be assessed whether capillaroscopy had an essential role in diagnosis. Patients will also be evaluated for fulfillment of the ACR/EULAR classification criteria, since capillaroscopy has a role in these criteria. Methods Study design For the current study consecutive patients with RP who had had a capillaroscopy in the Leiden University Medical Center (a tertiary care center) between November 2011 and October 2013 were included. Their medical files were evaluated in order to obtain information about the patients, for example onset of RP, presence of autoantibodies, findings at physical examination, diagnosis made by the rheumatologists and therapy for RP. Ethical approval for this study was obtained from the Institutional Review Board of the Leiden University Medical Center. Patients Patients were evaluated and diagnosed by rheumatologists. Diagnosis was based on the combination of clinical evaluation, laboratory results and capillaroscopy pattern. RP was defined as a history of at least two of three phases of color change (white, blue, red), induced by cold exposure, and involving at least one finger of each hand (6). PRP was defined according to the definition of LeRoy and Medsger (8). PRP is characterized as episodic attacks of acral pallor or cyanosis, strong and symmetric peripheral pulses, no evidence of digital pitting, ulceration, or gangrene, normal nailfold capillaries, negativity for antinuclear antibodies (ANA), and a normal erythrocyte sedimentation rate (ESR). SRP was defined as RP associated with a CTD. SSc was diagnosed as diffuse or limited cutaneous SSc classified according to the American College of Rheumatology (ACR) (9) or LeRoy (10)criteria for early SSc. The recently published ACR/EULAR classification criteria (7) were additionally evaluated(table 1). Diagnosis of the other CTDs were based on the combination of diagnostic/classification criteria and expert opinion: systemic lupus erythematosus (SLE) according to the ARA-criteria (11), undifferentiated CTD (UCTD) according to the Mosca criteria (12), mixed CTD (MCTD) according to the Alarcón-Segovia or Kahn criteria (13), Sjögren s syndrome according to the AECG criteria (14), dermatomyositis (DM) according to the criteria proposed by Bohan and Peter (15) and rheumatoid arthritis (RA) according to the 2010 ACR/Eular criteria (16). Patients with RP who did not fulfill the criteria for PRP or SRP were defined as suspected for SRP, meaning RP with abnormalities in capillaroscopyand/or in laboratory parameters, but no definite secondary disorder. For the follow-up evaluation patients younger than 18 years old were excluded, as were patients who recently (less than six months ago based on earlier studies (17)) had had their first evaluation by capillaroscopy. 6

7 Table 1: ACR/EULAR classification criteria Item Sub-item(s) Weight/ score Skin thickening of the fingers of both hands extending proximal to the metacarpophalangeal joints (sufficient criterion) - 9 Skin thickening of the fingers (only count the higher score) Puffy fingers 2 Sclerodactyly of the fingers (distal to the metacarpophalangeal joints but proximal 4 to the proximal interphalangeal joints) Fingertip lesions (only count the higher score) Digital tip ulcers 2 Fingertip pitting scars 3 Telangiectasia - 2 Abnormal nailfold capillaries - 2 Pulmonary arterial hypertension and/or interstitial lung disease Pulmonary arterial hypertension 2 (maximum score is 2) Interstitial lung disease Raynaud s phenomenon - 3 SSc-related autoantibodies (anticentromere, anti-topoisomerase I (anti- Scl-70), anti-rna polymerase III) (maximum score is 3) Anticentromere 3 Anti-topoisomerase I Anti-RNA polymerase III These criteria are applicable to any patient considered for inclusion in an SSc study. The criteria are not applicable to patients with skin thickening sparing the fingers or to patients who have a scleroderma-like disorder that better explains their manifestations (e.g., nephrogenic sclerosing fibrosis, generalized morphea, eosinophilic fasciitis, scleredema diabeticorum, scleromyxedema, erythromyalgia, porphyria, lichen sclerosis, graft-versus-host disease, diabetic cheiroarthropathy). The total score is determined by adding the maximum weight (score) in each category. Patients with a total score of 9 are classified as having definite SSc. Assessment methods Baseline visit The first evaluation was done in the context of clinical practice as done by a rheumatologist. This evaluation consisted of a medical history, physical examination, laboratory investigations (presence of auto-antibodies) and capillaroscopy. The first visits were conducted between November 2011 and August Follow-up visit In order to evaluate new symptoms or alterations in capillaroscopy pattern, patients were invited by B.d.B. for a second evaluation. During the follow-up visit, a second capillaroscopy was performed. After assessment with capillaroscopy, the patients were evaluated for new symptoms using a self-conducted (non-validated) questionnaire, in order to explore common symptoms in SSc (for example; skin involvement, gastro-intestinal involvement and cardiopulmonary complaints). The Raynaud s Condition Score (18) was used for measuring severity of the RP. The Dutch questionnaire and Raynaud s Condition Score are provided in Appendix A and B, respectively. A physical examination was performed, evaluating the presence of puffy fingers, scleroderma, telangiectasia, pitting scars and digital ulcers. The follow-up visits were conducted between January 6 and February by B.d.B. Auto-antibodies Measurement of auto-antibodies included antinuclear antibody (ANA), measured by indirect immunofluorescence on HEP-2000 cells (Biomedical Diagnostics, Antwerpen, Belgium) and anti-topoisomerase I (anti-scl-70) and anti-centromere (ACA) were measured with an ELIA (Enzyme Linked Immuno Assay) technique (Immunocap 250, ThermoFisher Scientific, Nieuwegein, The Netherlands). Anti-RNA polymerase III (anti-rnap III) was measured 7

8 externally (ELISA; Sanquin, Amsterdam, The Netherlands) in case of negative ANA, ACA and anti-scl-70 in order to determine the presence of at least one SSc-related auto-antibody. Capillaroscopy Capillaroscopy was performed by experienced observers (baseline capillaroscopy by A.J.M.S or J.M. and follow-up capillaroscopy by B.d.B) using a videocapillaroscope (Videocap 3.0, DS Medica). The second, third, fourth and fifth finger of both hands were investigated, after application of a drop of oil on the nailfold bed. Four fields per nail were studied, observing only the distal row of capillaries. Observers were blinded to patient characteristics and diagnosis. Capillaroscopy images were classified into three categories: normal/aspecific, SSc-pattern or borderline changes (17). An SSc-pattern is characterized by loss of capillaries, presence of microhaemorrhages (extracapillary brown masses of erythrocytes) and giant capillaries (enlargement of the capillary lumen > 50 micrometer). Early, active and late SSc-patterns were defined according to previous studies (19).The early pattern is characterized by the appearance of a few giant capillaries, a few haemorrhages, and no decrease in capillary density. In the active phase large numbers of giant capillaries, haemorrhages and a moderate loss of capillaries are found. The late pattern is characterized by severe loss of capillaries, distinctive morphologic alterations (neoangiogenesis) and few or absent giant capillaries and haemorrhages (figure 3). Figure 3: Different capillaroscopy patterns. Cutolo, Rheumatology (Oxford) A: early SSc-pattern, characterized by few giant capillaries, few haemorrhages and no obvious loss of capillaries. B: active SSc-pattern, characterized by a lot of giant capillaries, a lot of haemorrhages and loss of capillaries. C: late SSc-pattern: severe loss of capillaries, neoangiogenesis, almost no giant capillaries and haemorrhages. D: normal capillaroscopy: no loss of capillaries, normal morphology, no enlargement of capillaries. 8

9 Images with a regular distribution of capillaries with a normal size (diameter of less than 20 micrometers) without capillary loss and a morphology without abnormalities, were classified as a normal pattern. A normal pattern has a density of between 9 and 14 capillaries per mm (17). Images with minimal abnormalities were classified as aspecific.images were considered to have borderline changes in two scenarios, as defined by Cutolo and Smith (17). First, when abnormal shapes (i.e., neo-angiogenesis, shapes differing form the normal (hairpin) and nonspecific variations (tortuosities or crossing)) occurred in high prevalence within one patient. Second, when several of the following abnormalities occurred together: shape abnormalities (neoangiogenesis), confluent haemorrhages or variations in dimension. Both the SSc-pattern and the borderline pattern were considered as an abnormal capillaroscopy and therefore patients with those patterns were considered not to have PRP. Inter observer agreement of the three observers was high (κ = 0.812). Quantitative assessment. The quantitative scoring system performed in this study is a slightly modified version of the system described before by Sulli et al (20). Two fields of the distal capillary row of 1 mm per nailfold were scored. Parameters that were scored, were amount of capillaries per mm, amount of enlarged and giant capillaries, amount of haemorrhages and amount of abnormal capillaries (neoangiogenesis). For each patient the mean score per finger for each of these parameters was obtained from the analysis of the second, third, fourth and fifth fingers of both hands, using the scoring system described above. In order to evaluate the role of quantitative scoring, the relationship between the capillaroscopic parameters and different diagnostic groups and different CTDs was determined. Statistical analysis. Descriptive statistics were used to summarize baseline characteristics. According to their distribution, continuous variables were either presented as mean and standard deviation (SD) or medians with interquartile range (IQR). All continuous variables were compared the different groups of capillaroscopy pattern using ANOVA or Kruskal-Wallis test. Categorical variables were calculated as frequencies with percentages and compared between patients with the different patterns using Chi-square analyses where applicable.p values less than 0.05 were considered statistically significant. Inter observer agreement was calculated as kappa or intraclass correlation coefficient. All statistical analyses were executed using SPSS 20.0 software (SPSS Inc., Chicago, USA). 9

10 Results Capillaroscopy patients N=130 RP N=107 No RP N=23 18 years N=104 < 18 years N=3 Capillaroscopy > 6 months ago N=96 Capillaroscopy < 6 months ago N=8 Follow-up patients N=71 Lost to follow-up N=25 Normal/Aspecific N=20 Borderline changes N=30 SSc-pattern N=21 PRP N=8 SSRP N=9 MCTD N=1 UCTD N=1 RA N=1 SSRP N=19 SSc N=3 SLE N=3 UCTD N=4 Sjögren N=1 SSRP N=7 SSc N=9 SLE N=1 MCTD N=2 UCTD N=2 Figure 4: Flowchart of patients with capillaroscopy and diagnosis after baseline. RP Raynaud s phenomenon, PRP primary RP, SSRP suspected secondary RP, MCTD mixed connective tissue disease, UCTD undifferentiated connective tissue disease, RA rheumatoid arthritis, SSc systemic sclerosis, SLE systemic lupus erythematosus. Baseline characteristics According to clinical practice, 130 patients were investigated by capillaroscopy in the outpatient clinic, as presented in the flowchart. Twenty-three patients did not have RP and were excluded. The study population consisted of 107 patients with RP, 82 (77%) of them were female as presented in table 2. The median duration of RP was four years (interquartile range 1-11) and the median age of onset of RP was 38 years (interquartile range 20-52). ANA positivity was found in 59 (55%) of patients and 21 (20%) of patients had an SSc-specific autoantibody; 1 patient tested positive for anti-scl-70, 11 for ACA and 10 for anti-rnap III. Capillaroscopy pattern was normal/aspecific in 30 (28%) of the patients, 43 (40%) of the patients had borderline changes and 34 (32%) of the patients had an SSc-pattern. Significant differences in baseline characteristics between the different patterns were found for ENA positivity and anti-ssa, due to the association between these autoantibodies and the different underlying diseases.rp was classified as PRP in 15 (14%) patients and SRP in 19 (36%) patients. The diagnosis SSc was made in 16 (15%) patients, SLE in 5 (5%) patients, 10

11 MCTD in 6 (6%) patients, UCTD in 10 (9%) patients, RA in 1 (1%) patient and Sjögren s syndrome in 1 (1%) patient. Fifty (47%) patients were suspected for SRP, but no definite diagnosis could be made. In three patients no information regarding the diagnosis was available. Table 2. Baseline characteristics Total Normal/Aspecific Borderline SSc p-value N= 107 N= 30 (28%) N= 43 (40%) N= 34 (32%) Age, years, mean (SD) 46 (16) 48 (12) 42 (15) 49 (20) 0,110 Female, N (%) 82 (77) 24 (80) 32 (74) 26 (77) 0,857 RP duration, years, median (IQR) 4 (1-11) 7 (1-18) 2 (1-7) 4 (2-18) 0,504 Onset of RP, years, median (IQR) 38 (20-52) 39 (20-53) 37 (20-50) 36 (19-56) 0,990 Physical examination Digital ulcers, N (%) 1 (1) 0 (0) 0 (0) 1 (3) 0,338 Pitting scars, N (%) 7 (7) 1 (3) 3 (7) 3 (9) 0,668 Sclerodactyly/puffy fingers, N (%) 17 (16) 3 (13) 5 (12) 8 (24) 0,330 Autoantibodies, N (%) ANA, N (%) 59 (55) 16 (53) 20 (47) 23 (68) 0,175 ENA, N (%) 25 (23) 3 (10) 6 (14) 16 (47) 0,000 Anti-Scl-70, N (%) 1 (1) 0 (0) 0 (0) 1 (3) 0,338 Anti-centromere, N (%) 11 (10) 2 (7) 3 (7) 6 (18) 0,231 Anti-RNP-polymerase III, N (%) 10 (9) 1 (3) 3 (7) 6 (18) 0,115 Anticardiolipine, N (%) 1 (1) 0 (0) 0 (0) 1 (3) 0,338 Anti-SSA, N (%) 9 (8) 0 (0) 3 (7) 6 (18) 0,036 Anti-SSB, N (%) 5 (5) 0 (0) 2 (5) 3 (9) 0,248 Anti-Jo1, N (%) 1 (1) 0 (0) 1 (2) 0 (0) 0,472 Anti-Sm, N (%) 3 (3) 0 (0) 2 (5) 1 (3) 0,495 RP Raynaud's phenomenon, ANA antinuclear antibody, ENA extractable nuclear antigens <10% missing Follow-up evaluation Eleven patients were excluded for the current study, including three children and eight patients with a recent capillaroscopy, resulting in 96 patients who were invited for the follow-up evaluation. Of those 96 patients, 71 patients (74%) were able to participate in our study (figure 4). Of the 71 patients re-evaluated, 55 (77%) were female. The median duration of RP was four years, with a range of 0-43 years. The severity of RP symptoms, measured by the Raynaud s Condition Score (RCS), showed no significant difference between the different capillaroscopy patterns. The RCS also did not differ between the clinical diagnoses. Patients who were lost tofollow-up did not differ in baseline characteristics and capillaroscopy pattern compared to patients with a follow-up evaluation (data not shown). The duration of follow-up varied from 6 to 25 months, with a mean duration of 12 months. The capillaroscopy at follow-up resulted in a normal/aspecific pattern in 26 (37%) patients, borderline changes in 27 (38%) patients and an SSc-pattern in 18 (25%). The capillaroscopy pattern changed in 21 (30%) patients. Particularly, in 6 (8%) patients the capillaroscopy pattern worsened; three patients progressed from normal to borderline changes and three patients progressed from borderline changes to an SSc-pattern (table 3). Changes in capillaroscopy pattern did not yield new diagnoses. Of the patients with a worsened capillaroscopy pattern, four were diagnosed with SSc or UCTD based on other findings than capillaroscopy at baseline, one still had SRP without a definite diagnosis and one had progressed to SSc before the capillaroscopy had changed. 11

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13 Table 3. Patients with a worsened capillaroscopy Patient Capillaroscopy Diagnosis number Baseline Follow-up Baseline Follow-up Comments 1 Normal/aspecific Borderline PRP SSc Diagnosis based on sclerodactyly before follow-up capillaroscopy 2 Normal/aspecific Borderline Suspected SRP Suspected SRP - 3 Normal/aspecific Borderline UCTD UCTD - 4 Borderline SSc SSc SSc - 5 Borderline SSc SSc SSc - 6 Borderline SSc UCTD UCTD - PRP primary Raynaud s phenomenon, SSc systemic sclerosis, SRP secondary Raynaud s phenomenon, UCTD undifferentiated connective tissue disease The definite diagnosis changed in five patients during follow-up. One patient progressed from PRP to SSc based on clinical findings before the follow-up capillaroscopy was performed. One patient progressed from suspected SRP to DM. This patient still had borderline changes at follow-up capillaroscopy. Three patients had suspected SRP at baseline based on capillaroscopy abnormalities and a normal capillaroscopy at follow-up, so were diagnosed as PRP at follow-up. The rate of progression from PRP to SRP was 12.5% (one of eight patients) and the rate of progression from suspected SRP to SRP was 3% (one of 35 patients). Of the 21 patients with an SSc-pattern, progression from an early to an active pattern was found in one patient during 21 months of follow-up, and progression from an early to a late pattern was seen in one patient during 16 months of follow-up. Progression from an active to a late pattern was found in one patient during 6 months of follow-up. Finally, 10 (14%) patients were diagnosed as PRP and 30 (42%) patients as SRP. The definite diagnosis was SSc in 13 (18%) patients, SLE in 4 (6%) patients, MCTD in 3 (4%) patients, UCTD in 7 (10%) patients, DM in 1 (1%) patients, RA in 1 (1%) patient and Sjögren s syndrome in 1 (1%) patients. The remaining 31 (44%) patients were diagnosed as suspected SRP (table 4). Table 4. Capillaroscopy and diagnosis at follow-up Normal/aspecific Borderline changes SSc-pattern Total PRP (14%) SSc (17%) SLE (6%) MCTD (4%) UCTD (10%) DM (1%) Sjögren s syndrome (1%) RA (1%) Suspected SRP (44%) Total PRP primary Raynaud s phenomenon, SSc systemic sclerosis, SLE systemic lupus erythematosus, MCTD mixed connective tissue disease, UCTD undifferentiated connective tissue disease, DM dermatomyositis, RA rheumatoid arthritis, SRP secondary Raynaud s phenomenon, UCTD undifferentiated connective tissue disease 13

14 Value of capillaroscopy Based on our study, an SSc-pattern at capillaroscopy had a sensitivity of 69% for SSc, a specificity of 84%, a PPV of 50% and a NPV of 92%. This was calculated based on the followup capillaroscopy and the follow-up diagnosis. Based on the baseline capillaroscopy and the follow-up diagnosis, the specificity and PPV were slightly lower (79% and 43%, respectively). An abnormal capillaroscopy (borderline changes or an SSc-pattern) had a sensitivity 100%, specificity 45%, PPV of 29% and NPV of 100% for SSc. All patients were evaluated to assess whether the capillaroscopy had an essential role in their diagnosis. In the 16 patients with SSc at baseline, capillaroscopy had no role indiagnosis in1 patient and did help in diagnosis of 15 patients. In 10 patients with UCTD, capillaroscopy had no role in 1 patient, an essential role in 4 patients and did help in 5 patients. In 6 patients with MCTD, capillaroscopy had no role in 2 patients and did help in diagnosis of 4 patients. In 5 patients with SLE, capillaroscopy had norole in diagnosis in 3 patients and it did help in diagnosis of 2 patients. In 67 patients with no diagnosis, but with RP, a normal capillaroscopy led to the diagnosis of PRP in 14 patients. Twelve patients had a normal capillaroscopy but were ANA positive, 27 had suspected SRP based on capillaroscopy findings alone and 14 based on a combination of ANA positivity and capillaroscopy abnormalities.in these last two groups capillaroscopy had a role in classifiying these patients in this study as suspected SRP, not in a definite diagnosis. Quantitative scoring All baseline capillaroscopies of 102 patients with RP were scored quantitatively (by B.d.B). Of the remaining five patients with RP, the capillaroscopy images were lost. The images of 15 patients were scored by two observers (J.M and B.d.B). Intraclass correlation coefficients are listed in table 5. The number of capillaries, enlarged capillaries and giants had almost perfect agreement, number of neoangiogenesis had a moderate agreement and the number of haemorrhages had a fair agreement. Table 5: Inter observer agreement quantitative scoring Mean number of capillaries Mean number of enlarged capillaries (20-50 micrometer) Mean number of giants Mean number of neoangiogenesis Mean number of haemorrhages Intraclass correlation coefficient Per patient the mean of each characteristic was calculated per finger. Themedians of the quantitative scores for number of capillaries, haemorrhages, enlarged capillaries, giant capillaries and neoangiogenesis were calculated per patient group (PRP, suspected SRP and SRP).In table 6 the results are listed. The number of capillaries was almost normal in PRP patients, slightly decreased in suspected SRP and definitely decreased in SRP patients. This difference was statistically significant. In both suspected SRP and SRP significantly more haemorrhages and enlarged capillaries were seen than in PRP patients.giant capillaries occur predominantly in patients with an SRP. Neoangiogenesis was rare in the whole population; it did not occur in PRP patients, and only in small quantity in some patients with suspected SRP. 14

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16 Table 6. Quantitative characteristics per diagnostic group PRP (N=12) Suspected SRP (N=53) SRP (N=37) p-value Capillaries, median (IQR) ( ) ( ) ( ) Haemorrhages, median (IQR) ( ) ( ) ( ) Enlarged capillaries, median (IQR) ( ) ( ) ( ) Giant capillaries, median (IQR) ( ) ( ) ( ) Neoangiogenesis, median (IQR) ( ) ( ) ( ) The quantitative characteristics were also evaluated for the different diagnosis. Results are shown in table 7. Patients with PRP show some loss of capillaries, patients with SLE and UCTD show a moderate loss and patients with SSc and MCTD show the most severe loss. Giant capillaries are found in highest quantity in SSc patients, but also occur in patients with SLE, MCTD and UCTD. Neoangiogenesis is rare in all diagnoses. The most apparent differences occurred between the group of PRP patients and all the other groups. Table 7. Quantitative characteristics per diagnosis PRP (N=12) SSc (N=14) SLE (N=5) MCTD (N=6) UCTD (N=10) p- value Capillaries, median (IQR) ( ( ( ( ( ) 7.786) 7.688) 7.813) 8.100) Haemorrhages, median (IQR) ( ) ( ) ( ) ( ) ( ) Enlarged capillaries,median (IQR) ( ) ( ) ( ) ( ) ( ) Giant capillaries, median (IQR) ( ) ( ) ( ) ( ) ( ) Neoangiogenesis, median (IQR) ( ) ( ) ( ) ( ) ( ) Finally, the quantitative characteristics were evaluated for the different SSc-patterns. These characteristics were available for 32 patients. Only one of them had a late SSc-pattern. Therefore, the characteristics were only compared between the groups of early and active SScpattern. The results are listed in table 8. Significant differences were found for capillary loss, enlarged capillaries and giant capillaries. Table 8. Quantitative characteristics per SSc-pattern Early (N=19) Active (N=12) p-value Capillaries, median (IQR) ( ) ( ) Haemorrhages, median (IQR) ( ) ( ) Enlarged capillaries, median (IQR) ( ) ( ) Giant capillaries, median (IQR) ( ) ( ) Neoangiogenesis, median (IQR) ( ) ( )

17 Evaluation of the ACR/EULAR criteria To evaluate the recently published ACR/EULAR classification criteria, all SSc patients in the baseline cohort were retrospectively evaluated. Eleven of the sixteen patients fulfilled the ACR/EULAR criteria. Six of these patientswould not have fulfilled the criteria without an abnormalcapillaroscopy. The remaining fivepatients were diagnosed withssc based on expert opinion. One had 8 points and had a sicca syndrome. One patient got 8 points, and developed more symptoms (and therefore more points) later in the disease course. One patient got five points and had extensive calcinosis and a sicca syndrome. One patient got five points and had a hypertensive crisis, cerebral vasculopathy and renal failure. A multidisciplinary team, consisting of neurologists and a rheumatologist diagnosed this patient with SSc. The last patient was initially diagnosed as having SSc, but was considered to have MCTD at follow-up. Conclusion and discussion This follow-up study mainly focused on changes in capillaroscopy over time. No new diagnoses in our patients based on follow-up capillaroscopy were made. Based on these findings, a followup capillaroscopy after a year in all RP patients cannot be advocated. The secondary aim of this study was to evaluate the role of capillaroscopy in the distinction between PRP and SRP. In line with previous studies, NPV was higher compared to PPV for the development of SSc (6;22). Our study confirmed that capillaroscopy has a valuable role in this distinction, especially in differentiation between PRP and SSc. We did not find an additional value for the quantitative scoring system in this differentiation. The exact prevalence of RP in the general population is not known. Estimates range from 2% to 20% of the general population (23-25). Only a small percentage of RP patients seek medical consultation for their complaints (4). As known from other studies, patients with SRP have often more serious symptoms than patients with PRP and therefore are more likely to present their symptoms at a hospital (26). In our study no statistically significant difference in severity of RP symptoms between the different diagnoses was found. In the general RP population, approximately 20% of patients have an underlying disease (26;27), whereas in our population 42% had an underlying disorder. This confirms that patients who seek medical consultation for their complaints are more likely to have an underlying disease.this is one of the reasons for the high percentage of patients who had capillaroscopy abnormalities at baseline (72%). Other studies reported a lower percentage of baseline abnormalities, but patients with a definite diagnosis at baseline were excluded in those studies (6). In line with other studies, patients with normal capillaries most likely do not progress to a CTD over time; patients with an SSc-pattern most likely have a CTD or will progress to SSc or another CTD (6). We had expected a relatively high rate of progression in our study population, since patients with RP presenting at a hospital, a tertiary care center, are more likely to have an underlying disease than the general RP population. However, only two of 43 patients (5%) with PRP or suspected SRP developed a definite CTD in follow-up. The differences in definitions of SRP make it difficult to compare our findings with other studies. Hirschl et al (28) define PRP as RP without an underlying disorder, SRP as RP with an established underlying disorder and suspected SRP as RP with findings suggesting an underlying disorder. Cutolo (29) defines SRP as RP with abnormal nailfold capillaries, which leads to a 17

18 transition from PRP to SRP of 14.6% over a mean period of 29.4 months. In this study, RP with capillaroscopy abnormalities alone was not considered to be SRP, but was classified as suspected SRP. Since symptoms of an underlying disorder are more clinically relevant than nailfold abnormalities alone, we consider progression to a definite CTD as the most important outcome measure. Moreover, patients who show an early SSc-pattern may show less significant changes at follow-up. Consequently, it may be harmful to diagnose these patients with SSc or SRP based on nailfold abnormalities alone, since they possibly will never experience SSc-symptoms. This is illustrated by the study of Koenig(6). Seventy-nine percent of patients with an SSc-specific autoantibody and an SSc-pattern at capillaroscopy at baseline visit developed SSc in 15 years of follow-up. This indicates a high risk of SSc in this subgroup of patients. On the other hand, 21% of this high risk group does not progress to SSc, and therefore rheumatologists should be careful in diagnosing SSc purely based on capillaroscopic and laboratory findings. In our study population, diagnosis of SSc was made by a rheumatologist, taking into account the ACR, LeRoy or ACR/EULAR criteria. In all patients with SSc in this cohort, diagnosis was based on more than just a capillorscopy and RP.Even without the capillaroscopy findings, these patients would have been diagnosed with SSc. This is important to emphasize, since conform the LeRoy criteria, patients can be diagnosed as having early SSc based on objective RP and an SScpattern at capillaroscopy. The values calculated for sensitivity and specificity would have been unreliable if patients would have been diagnosed with SSc purely based on capillaroscopy. In our study population, only 11 of the 16 SSc patients fulfilled the ACR/EULAR classification criteria. This result can be explained. First of all, the ACR/EULAR classification criteria are aimed to include SSc patients in studies, not at diagnosing patients. Therefore, the diagnosis can be clear without the patient fulfilling the ACR/EULAR classification criteria. Furthermore, some of the patients who did not fulfill the criteria showed less typical symptoms. Diagnosis was not easy in those cases. However, the classification criteria are aimed to include a homogenous group of patients with SSc in studies. Five of 16 patients with established SSc would not have been included if we had used the classification criteria. For creating a homogenous SSc cohort, comparable to other studies, the classification criteria are valuable, but not for dividing a population with RP into different diagnostic groups. Although we did not find an additional value of repeated capillaroscopy in our cohort, we see value of follow-up capillaroscopy in subgroups of RP patients. Patients who show a minimal early SSc-pattern (for example, one giant) should have a follow-up capillaroscopy. It is possible that they show less significant abnormalities in follow-up, in which case they do not require follow-up. If they show a progressive SSc-pattern, they have to be monitored more closely. The same can be advised for patients with borderline changes. Patients who show a clear SSc-pattern and have SSc-specific autoantibodies have a high risk of developing SSc. Therefore, they do not require a follow-up capillaroscopy. Close monitoring for SSc-related symptoms has more value. Patients with PRP (so normal nailfold capillaries and ANA negativity) will not require a followup capillaroscopy, based on findings in our study and based on the study by Koenig (6). The value of capillaroscopy in the diagnosis of SSc is well established, as reflected by the fact that an abnormal capillaroscopy is one of the recently published ACR/EULAR classification criteria for systemic sclerosis (7). However, the value of capillaroscopy in diagnosing other 18

19 CTDs is less important. The role of borderline changes is less clear and more research is needed. In this study population, two thirds of patients who showed borderline changes did not have an underlying disease at follow-up. Patients who showed an SSc-pattern almost all did have an established CTD at follow-up. Other patterns than the SSc-pattern have been described, some with acceptable sensitivity and specificity (30). However, in daily rheumatologic practice the different described patterns are notused, expect for the SSc-pattern (31). Until today capillaroscopy is mostly used in order to detect SSc and to monitor disease progression in SSc (17). We also looked at the possible role of a quantitative scoring system in daily practice. Although PRP patients have a normal/aspecific capillaroscopy, it was seen that almost all PRP patients had some loss of capillaries in at least one finger. Those changes are not as obvious as those seen in a late SSc-pattern and definitely not present in all images of all nails, but there was evident loss. This is conform earlier studies (32;33). Some abnormalities are not confined to patients with SRP, but also occur in patients with PRP. Moreover, even healthy subjects often show some abnormalities. Hoerth et al found that altered capillaries occur frequently among healthy individuals and should be interpreted as normal unless a suspicious increase in their frequency is determined by reference to the scoring system. Giant capillaries and diffuse loss of capillaries were not found in healthy individuals and seem to be of specific diagnostic value. A perfectly normal capillaroscopy pattern in healthy subjects is rare and occurs in only 15% of subjects(34). Our other populations (PRP, SLE, MCTD, and UCTD) were relatively small. Therefore, obvious quantitative characteristics at capillaroscopy were hard to establish in these subgroups of patients. However, we did find that SSc patients show the typical giant capillaries and haemorrhages. Some of the patients with the other CTDs also showed an SSc-pattern. This explains the number of SSc-specific abnormalities, especially giants, seen in the other CTDs. What was found, is that some of the other CTDs show more enlarged capillaries and haemorrhages than SSc, but based on quantitative findings it is impossible to establish the diagnosis. However, the quantitative scoring system is mostly aimed at monitoring disease progression and response to therapy in SSc patients, and the value for this role is therefore not limited by our findings. Quantitative parameters such as number of capillaries and number of neoangiogenesis in a patient can be monitored to assess, for example, response to endothelin receptor antagonists. Treatment is often aimed to prevent worsening of the micovascular damage, especially in the fingers, and consequently to prevent development of digital ulcers. Capillary loss is a direct reflection of microvascular involvement and therefore can be helpful in monitoring response to therapy or disease progression. The quantitative scoring system may even be more precise than the distinction in early, active and late SSc-pattern, what is done in daily practice. We found, as expected, that an active pattern has more loss of capillaries and that giant capillaries are more frequent in an active than in an early SSc-pattern. A difference between an early and an active SSc-pattern was not found for haemorrhages or neoangiogenesis. Therefore, using the quantitative characteristics may be more valuable than defining broad categories of SSc-patients, in which patients with slightly different quantitative characteristics fall into the same SScpattern. One problem we had with the quantitative scoring system was the difference between observers regarding haemorrhages. The ICC was only Of course, if a quantitative scoring system 19

20 will be used in daily practice or for research purposes, a high inter observer reliability is needed. The low ICC can be explained by the difficulty of counting punctiformhaemorrhages. These can present as small brown dots. Sometimes it is impossible to determine whether a dot on a capillaroscopy image is a haemorrhage or dirt and this leads to different interpretations between different observers. A solution for this problem would be to only count the obvious haemorrhages, in particular comb-like haemorrhages. These haemorrhages are hard to miss and a typical feature of an SScpattern or borderline changes.small brown dots in the images should not be counted as haemorrhages. The ICC of neoangiogenesis was not optimal either (0.585). It can be hard to determine whether a capillary has a slightly abnormal morphology or should be considered as neoangiogenesis, especially when visibility is poor. This leads to alimitation for using a quantitative system. In daily practice, especially in SSc-patients, visibility can be poor. Often just a few fingers can be evaluated, while in the other fingers severe fibrosis makes it impossible to visualize the capillaries. Since it is known that all the different quantitative parameters can differ a lot between different fingers, this gives a limited and possible wrong result. Of course limited visibility is a problem in the qualitative scoring system as well. The biggest difference is that if important characteristics like giants can be detected in the few available images, qualitative evaluation of those images can be sufficient and reliable. In a quantitative scoring system, the mean of all fingers is calculated and therefore it can have considerable consequences if not all fingers with abnormal quantitative characteristicscan be evaluated. The most obvious role for capillaroscopy is early detection of a possible SSc. This does not mean that it is the only role. In SSc, it is used to monitor disease progression. SSc patients normally progress from an early through an active to a late SSc-pattern, reflecting different stages of disease (35). Other roles of capillaroscopy have been described in literature. Capillaroscopy is used in SSc patients to predict future organ involvement (36;37). Other examples are different scoring systems based on capillaroscopy to predict the risk for development of digital ulcers (38-40). Since several treatment options are available to prevent the development of new digital ulcers, this score has clinical value in predicting which patients may benefit from this treatment. This study has several limitations which should be taken into account. First, the mean follow-up duration was 12 months, which is lower compared to previous studies (6;22;28). However, patients were instructed to return to the hospital in case they experience new SSc-related symptoms in order to avoid a considerable delay in diagnosing SSc. Second, the rate of progression from patients presenting at our outpatient clinic is probably an overestimation of progression from PRP to SRP in all RP patients, as reflected by the high proportion of patients with an underlying disorder (42%). The generalizability of the progression rates is therefore limited to patients with RP who present at an outpatient clinic. Third, in our cohort a test for anti-rnap III was performed according to clinical suspicion of a CTD, but not measured in all patients due to practical and financial issues. The biggest strength of this study is that it focuses on capillaroscopy in daily clinical practice. This study gives a clear indication of the value of capillaroscopy for a rheumatologist at the outpatient clinic, since the population of this study is a direct reflection of that at an outpatient clinic. Superiorly to other studies, we included the total population of patients with RP 20

21 presenting at the outpatient clinic, and did not exclude patients who already had a diagnosis after baseline measurement. Findings in this study and the current literature lead to some interesting roles of capillaroscopy that have to be further investigated. First of all, capillaroscopy can be used to predict future organ involvement or digital ulcers in SSc patients. A second possibility is to look at capillaroscopy patterns and changes over time in other CTDs. Besides further research regarding capillaroscopy, another interesting aspect has to be addressed, namely defining other risk factors for the development of SSc than an SSc-pattern and SSc-specific autoantibodies, since these two risk factors do not fully predict which patients will develop SSc. In conclusion, we found that capillaroscopy has a valuable role in the distinction between PRP and SRP due to SSc and follow-up capillaroscopy after 6 months to 2 yearsof follow-up did not yield new diagnoses. 21