Khaled Mahmoud Mohiedeen and Akram Deghedy*Tropical medicine and clinical pathology departments* Alexandria faculty of medicine ABSTRACT

Transcription

1 Original Article Use Of Anti-Cyclic Citrullinated Peptide Antibodies to Distinguish Hepatitis C Virus (HCV) Associated Arthropathy from Concomitant Rheumatoid Arthritis In Patients with Chronic HCV Infection Khaled Mahmoud Mohiedeen and Akram Deghedy*Tropical medicine and clinical pathology departments* Alexandria faculty of medicine ABSTRACT Differentiating those patients whose symptoms are an extrahepatic manifestation of HCV from patients who have concomitant Rheumatoid arthritis (RA) is essential for appropriate management. Objectives: To investigate that Cyclic Citrullinated Peptide Antibodies (CCP antibodies), in contrast to Rheumatoid factor (RF), might be a candidate biomarker for concurrent Rheumatoid arthritis in chronic HCV patients. Methods: Fifty non arthritic patients with chronic viral hepatitis C were included. Testing for autoantibodies was performed using ELISA kits for IgG anti-ccp, IgG-RF and IgM-RF. Results: CCP antibodies were positive in only two patients (4%), whereas, RF was elevated in the serum of 60% of the patients. IgG- RF was detected more frequently (56%), followed by IgM-RF (30%). There was no statistically significant correlation between CCP antibody level and serum IgG-RF (R 2 = 0.030), or IgM-RF (R 2 = 0.016). Conclusion: Anti-CCP may be more useful than RF for the diagnosis or literally the exclusion of Rheumatoid arthritis in patients with chronic HCV infection. Introduction Chronic HCV infection is associated with extra hepatic immune mediated conditions inclu-ding vacuities, glomerulonephritis, thyroiditis, and sialoadenitis (1, 2). Arthralgias are common, and (3, 4) oligo or polyarthritis have been reported. Arthralgia and arthritis in patients with chronic hepatitis C can mimic rheumatoid arth-ritis (RA), and discrimination is really difficult without observing the erosions. (5) Differentiating those patients whose symptoms are an extra hepatic manifestation of HCV from patients who have concomitant RA is essential for appropriate management. Patients with virus induced symptoms require antiviral therapy; while patients with RA benefit from disease modifying anti rheumatic drugs. (4) Fifty to seventy percent of patients with HCV infection may have rheumatoid factor (RF). The increased prevalence of RF in patients with HCV infection diminishes the diagnostic specificity of serum RF for rheumatoid arthritis (RA) in this group of patients. Therefore, the presence of RF mostly does not help in distinguishing between RA and HCV-associated rheumatic symptoms. (6) Antibodies to cyclic citrullinated peptide (anti- CCP) are recent serological marker available for the diagnosis of RA. It is tested by commercially available ELISA kit that has comparable sensitivity and is more specific than Rheumatoid factor for the diagnosis of RA. The clinical usefulness of anti- CCP in diagnosis of early arthritis is established and these antibodies represent an important addition to the diagnostic (7, 8) armamentarium in RA. Patients and Methods Patients. Fifty patients with chronic hepatitis C infection were included in this study after obtaining their consent. Patients who satisfied

2 the inclusion/exclusion criteria were recruited in this study and selected from patients attending the outpatient clinic or admitted to the inpatient ward of Tropical Medicine Department, Alexandria Main University Hospital. Detailed history taking and thorough clinical examination were done for all patients. Patients were included after confirmation that HCV is the etiological agent of their chronic liver disease and obtaining an evidence of persistent infection by either liver biopsy or abnormal transaminases. The exclusion criteria included concomitant hepatitis B infection, known RA or the presence of a history or clinically evident arthritis, or current use of antiviral therapy. Laboratory method: Serum samples were tested for anti-hepatitis C antibodies by commercial ELISA testing and were confirmed by HCV RNA polymerase chain reaction amplification. Testing for autoantibodies was performed using ELISA kits for IgG anti-ccp, IgG-RF and IgM- RF. All tests were performed according to the manufacturer s recommendations. Prediluted control and diluted patient sera are added to the microwell plates coated with the antigen. Unbound sample was washed away and an enzyme labeled anti-human IgG or IgM, was added to each well to detect IgG-RFor IgM-RF respectively, or enzyme labeled anti-human IgG for CCP antibodies detection. The results of anti- CCP ELISA were considered negative in samples with results < 25 U/mL and are defined as positive in samples with results 25 U/mL. For RF, patients were considered to be seropositive if serum RF was > 6 IU for all isotypes. Comparison of CCP antibody and RF concentrations was done. The study protocol was approved by the ethics committee. Results Fifty HCV patients were included in the study. The characteristics of the patients are presented in Table 1. Subjects had a mean age of 45 years; there were 34 men and 16 women. No patients were receiving antiviral therapy. Sixty six percent of patients were treatment-naive and 34% were treatment failures. RF was elevated in the serum of 60% of the patients. IgG-RF was detected more frequently (56%), followed by IgM-RF (30%). CCP antibodies were positive in only two patients (4%) (Figure.1). Compared to CCP antibodies seropositivity, there was a statistically significant increase in the number of patients with elevations of IgG, and IgM RF. Correlation of serum RF with serum anti-ccp levels was examined by simple regression. In this group of patients, there was no statistically significant association between CCP antibody level and serum IgG-RF (R 2 = 0.306), IgM-RF (R 2 = 0.016) (Figures 2,3). Age Range: Mean: 45 y Sex Males: 34 Females: 16 Treatment history naive: 66% Treatment failure: 34% Table.1 Patients demographic characteristics

3 Figure 1 Prevalence of autoantibodies in HCV patients (% seropositivity) IgG RF IgM RF ACCP Figure 2: Correlation between ACCP and IgG RF Figure 3: Correlation between ACCP and IgM RF Discussion Rheumatoid arthritis (RA) and hepatitis C virus (HCV) infection are 2 distinct chronic diseases that share several intriguing similarities. Each illness is associated with immune system activation, autoantibody and cryoglobulin production, secondary vasculitis and Sjögren s syndrome, and an increased risk of B cell lymphoma (9, 10) Although it is not always possible to identify a specific pattern of HCV-related arthropathy, two different clinical subsets of arthritis have mainly been described; a mono articular,oligoarticular intermittent arthritis aff- ecting large and medium-sized joints and almost invariably associated with the presence of mixed cryoglobulinaemia and a polyarticular symmetrical arthritis closely resembling RA with metacarpophalangeal, proximal interphalangeal and wrist joints involvement. (3,11) Arthritis associated with mixed cryoglobulins or secondary to immune complex deposition related to the chronic viral infection might respond to interferon- α. (4) However, induction or exacerbation of arthritis with interferon therapy in some HCV patients has been noted. (12) These patients might respond better to therapy directed

4 specifically to RA. Immunosuppressants are generally avoided in chronic HCV infection due to potential exacerbation of viral replication or direct hepatotoxicity. (13) In this study, RF was elevated in the serum of 60% of chronic HCV patients. IgG-RF was detected more frequently (56%), followed by IgM-RF (30%). This is in accordance with other studies which reported even higher percentages for the positivity of RF in similar cohorts of patients. (14,15) This high rate of RF seropositivity in patients with chronic HCV infection presents diagnostic and therapeutic difficulties for the clinician. Recently, Anti-cyclic citrullinated peptide (anti-ccp) antibody testing was found to be particularly useful in the diagnosis of rheumatoid arthritis, with high specificity, presence early in the disease process, and ability to identify patients who are likely to have severe disease and (16) irreversible damage. Unlike RF, CCP antibody levels were not elevated in nonarthritic patients with chronic hepatitis C included in this study. In the two patients with CCP antibody above the upper limit of normal, the level was in the mild positive range. This is in agreement with the results reported by Lienesch et al (17) who detected a marginally elevated CCP antibody in a single patient (2%). They also did not find a correlation between anti CCP and RF positivity which was also reported in the present study. In a study on nonarthritic patients with HCV, Orge et al (6) have found that, the sensitivity, specificity and positive predictive value of the anti-ccp test was superior to the RF test and concluded that; Cyclic citrullinated peptide antibody is a more useful test than RF among patients with chronic HCV infection without arthritis. Moreover, Ezzat et al (18) reported that Anti-CCP antibodies were positive in 4.5% in patients with HCV and polyarthropathy and in 83.3% of patients with RA. RF was positive in 81.1% of HCV patients with polyarthropathy and in 90% of RA patients. They concluded that, anti-ccp antibodies are reliable laboratory markers to differentiate between RA and HCV-related polyarthropathy. This observation may let us conclude that most of the cases of chronic HCV associated polyarthropathy with positive RF testing are not really due to Rheumatoid arthritis. Lienesch et al explained that the HCV associated B cell activity responsible for RF production does not result in an increased production of antibodies against CCP. Considering these data, a possible interpretation of the presence of CCP antibodies in HCV patients with arthritis could be that the synovitis is secondary to concomitant RA. Supporting this hypothesis is the lack of CCP antibody production in other conditions associated with inflammatory arthropathy. (18) Similarly, measurement of anti-ccp antibodies was also reported to be better than RF detection to discriminate HBV-associated arthropathy from concomitant RA in patients with chronic HBV infection (19). The present study suggest that, CCP antibodies unlike RF are not produced in response to HCV infection, and therefore Anti-CCP may be more useful than RF for the diagnosis or literally the exclusion of Rheumatoid arthritis in this group of patients. References 1. Ramos-Casals M, Trejo O, Garcia-Carrasco M, Font J. Therapeutic management of extra-hepatic manifestations in patients with chronic. hepatitis C virus infection. Rheumatology 2003; 42: Pawlotsky JM, Roudot-Thoraval F, Simm-onds P, et al. Extrahepatic immunologic manif-estations in chronic hepatitis C and hepatitis C virus serotypes. Ann Intern Med 1995;122: Lovy MR, Starkebaum G, Uberoi S. Hepatitis C infection presenting with rheumatic manife-stations: a mimic of rheumatoid arthritis. J Rhe-umatol 1996; 23:

5 4. Zuckerman E, Keren D, Rozenbaum M, et al. Hepatitis C virus related arthritis: characteristics and response to therapy with interferon alpha. Clin Exp Rheumatol 2000; 18: Palazzi C, D'Angelo S, Olivieri I. Hepatitis C virusrelated arthritis. Autoimmunity Reviews 2008; 8: Örge J, Çefle A, Yazıcı A, Gürel-Polat N, Hulagu S. The positivity of rheumatoid factor and anti-cyclic citrullinated peptide antibody in nonarthritic patients with chronic hepatitis c infection. Rheumatol Int 2010;30: Jansen LM, van Schaardenburg D, van der Horst- Bruinsma I, van der Stadt R, De Koning M, Dijkmans BA. The predictive value of anti-cyclic citrullinated peptide antibodies in early arthritis. J Rheumatol 2003; 30: Khosla P, Shankar S, Duggal L. Anti CCP antibodies in Rheumatoid arthritis. J Indian Rheumatol Assoc 2004 : 12 : Alter MJ. Hepatitis C virus infection in the United States. J Hepatol 1999; 31 Suppl 1: Lawrence RC, Hochberg MC, Kelsey JL, et al. Estimates of the prevalence of selected arthritic and musculoskeletal diseases in the United States. J Rheumatol 1989; 16: Olivieri I., Palazzi C., Padula A. Hepatitis C virus and arthritis. Rheum Dis Clin North Am 2003;29: Nesher G, Ruchiemer R Alpha - interferon - induced arthritis: clinical presentation, treatme-nt, and prevention. Semin Arthritis Rheum 1998;27: Wener MH, Johnson RJ, Sasso EH, Gretch DR.Hepatitis C virus and rheumatic disease. J Rheumatol1996; 23: Clifford BD, Donahue D, Smith L, et al. High prevalence of serological markers of autoi-mmunity in patients with chronic hepatitis C. Hepatology 1995;21: Nocente R, Ceccanti M, Bertazzoni G, Cammarota G, Silveri NG, Gasbarrini G. HCV infection and extrahepatic manifestations. Hep-atogastroenterology 2003; 50: Niewold TB, Harrison MJ, Paget SA Anti-CCP antibody testing as a diagnostic and prog-nostic tool in rheumatoid arthritis. QJM. 2007; 100 (4): Lienesch D, Morris R, Metzger A, Debuys P, Sherman K. Absence of Cyclic Citrullinated Peptide Antibody in Nonarthritic Patients with Chronic Hepatitis C Infection. J Rheumatol 2005;32: Niewold TB, Harrison MJ, Paget SA. Anti-CCP antibody testing as a diagnostic and prognostic tool in rheumatoid arthritis. QJM. 2007; 100(4): Lim MK, Sheen DH, Lee YJ, Mun YR, Park M, Shim SC. Anti-cyclic citrullinated peptide antibodies distinguish hepatitis B virus (HBV)-associated arthropathy from concomitant rheum-atoid arthritis in patients with chronic HBV infection. J Rheumatol 2009; 36(4):712-6.