Journal of Pediatric Critical Care P - ISSN: E - ISSN: Year: 2017 Volume: 4 Issue: 3 DOI /

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1 Journal of Pediatric Critical Care P - ISSN: E - ISSN: Year: 2017 Volume: 4 Issue: 3 DOI / Case Report Hemophagocytic lymphohistiocytosis presenting as septic shock in a neonate Mary Jacqueline Saviour* Praveen Khilnani** * Pediatric hospitalist **Consultant Pediatric intensivist, Mediclinic City Hospital, Dubai Health Care City, Dubai, UAE Received: 13-May-17/Accepted: 27-Jun-17/Published online: 20-Jul-17 Correspondence: Dr. Mary Jacqueline Saviour, MBBS, DCH (Glasgow), MRCPCH (LONDON Pediatric hospitalist, Mediclinic city hospital, P.O. Box , Dubai, UAE Phone: , E mail: Mary.Saviour@mediclinic.ae ABSTRACT: hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening disease that usually occurs in infants and young children. It is characterized by severe hyper inflammation due to uncontrolled proliferation of activated lymphocytes and monocytes which are morphologically normal cells. This can lead to production and release of immense number of cytokines referred to as cytokine storm. It is typically a systemic disease with multiorgan involvement. Here we report a case of HLH in a twenty-eight days old baby presenting a clinical picture of septic shock, persistent metabolic acidosis multiple organ failure and disseminated intravascular coagulation (DIC). Keywords: HLH, hemophagocytic lymphohistiocytosis, Neonate, Septic shock, Neonatal sepsis, Introduction HLH is an infrequent clinical syndrome which brings about unusual proliferation of histiocytes in tissues and organs. Two forms of HLH are described, the inherited form which include the primary or familial HLH due to a known genetic defect, perforin gene which is inherited in a autosomal recessive pattern 1 and the other one associated with immunodeficiency syndrome like Gricellie syndrome, linked lymphoproliferative syndrome and Chediak Higashi syndrome, a rare autosomal recessive disorder that arises from a mutation of a lysosomal trafficking regulator protein, characterized by partial oculocutaneous albinism (OCA), immunodeficiency, and a mild bleeding tendency. Approximately 85% of affected children develop the accelerated phase, a lymphoproliferative infiltration of the

2 bone marrow and reticuloendothelial system. 2 Frequently HLH can be the first presentation of other primary immunodeficiency syndromes. 3 Usually there may not be a family history of genetic disease as the inheritance is autosomal recessive. 2,3 The incidence of primary HLH is I in 50,000 population. About 80% of cases present before 1 year of age and among this, only 10 % present in the neonatal period. 1 There are five subtypes of familial HLH, and each is associated with a specific gene. 4 It is found that, if not treated, approximately 95% of children will die of the disease 5, even though spontaneous partial regression has also been described. 6 Secondary HLH also known as acquired HLH is associated with infections such as viral bacterial fungal and parasitic infections,collagen vascular diseases and malignancies. 3 The most prominent among viral infections is the Epstein Barr viral (EBV) Infection. 7 Other viruses include Herpes virus group, Cytomegalovirus,Human immunodeficiency virus,influenza virus and Rubella viruses. 8,9 The disease occurs more commonly in summer. 10 Acquired HLH associated with malignancy, mainly lymphoma, can occur before or during treatment of the disease. HLH that happens along with autoimmune diseases is mentioned as MAS- macrophage activating syndrome. The outcome of secondary hemophagocytic lymphohistiocytosis varies. It can be very difficult to distinguish between primary and secondary HLH. Infection could be a triggering factor in both the cases. Prompt diagnosis and management is essential for the survival of the patient and the great hurdle being, the delay in diagnosis itself, because of the rarity of the disease as such, different clinical presentations and the lack of specificity in clinical and laboratory findings. We present an early case of HLH in a neonate presenting as clinical picture of severe septic shock and multiple organ involvement with no positive bacteriological or viral evidence. Case report Twenty-eight days old male Indian baby of nonconsanguineous marriage was admitted through emergency with history of fever and poor feeding for 2 days. Baby was born full term 39 weeks by vaginal delivery with assisted vacuum with an Apgar score of 8 at 1 minute and 9 at 5 minutes, birth weight of 4 kg, Length 57 cm and head circumference 36 cm. New born examination was within normal limits. Antenatal period was uneventful. There was no history of maternal fever or history of Group B streptococcal (GBS) colonization during this pregnancy or the previous one. Mother had known hypothyroidism under control and her thyroxine requirement did not increase during pregnancy. Thyroid function tests for the baby were normal. Baby had one sibling seven years old -a healthy male child. There was no family history of autoimmune disorders, immunodeficiency disorders or early child hood death. Baby received BCG and hepatitis B vaccine and new born metabolic screening was normal. Baby had been exclusively breast fed. During the time of admission mother also had mild fever and rhinitis with a slight hoarseness of her voice. On admission baby had a fever of 38.5 degree Celsius. Clinical examination was unremarkable except for the seborrheic dermatitis over the scalp in plenty and a peculiar greasy yellowish flake resembling seborrheic dermatitis seen on the eyebrows and external ear in a streaky linear pattern as if outpouring from the external auditory meatus in both ears. Baby had black hair and there was no occulocutaneous albinism. As there was no obvious focus of infection full septic screening (Complete and differential blood counts, C reactive protein(crp), chest radiograph as well as cerebrospinal fluid(csf) and urine cultures were done) and was commenced on intravenous cefotaxime.

3 Table 1: Shows the results of all the investigations done which were essentially within normal limits. leucocytes 8.85x10^9/L hemoglobin 12.2g/dl hematocrit 34.6% neutrophil 1.3X10^9/L lymphocyte 5.7X10^9/L monocyte 1.5X10^9/L platelet 171,000/mm Chest x-ray normal C- reactive protein 10mg/L Blood culture No growth Urine culture No growth Influenza AandB negative swabs CSF test result red blood cells 12cells/mm3 white blood cells 5cells/mm3 glucose 3.2mmol/L protein 477mg/L colour clear Gram stain No organisms seen Bacterial culture No growth Baby received intravenous antibiotics for 3 days. Apart from few colic episodes baby was hemodynamically stable and clinically doing fine, discharged on oral antibiotics and was advised follow up after 2 days expecting full recovery within a period of 48 hours. At home baby developed fever again, was not taking feeds at all, had tachypnea and respiratory distress and was readmitted the following day in a critical state. Course after Readmission; Upon readmission from the emergency room baby was extremely sick looking, pale, jaundiced and lethargic. Initial Vitals revealed a respiratory rate of 70/min, Heart rate 150/min, oxygen saturation(spo2)- 96% with 3 liters of oxygen by nasal cannula, capillary refill time 5 seconds and a rectal temperature of 39 degree Celsius with clinical evidence of edema. Patient was in respiratory distress with grunting, nasal flaring, chest recessions and head nodding. Abdomen was distended with hepatomegaly and splenomegaly. Arterial blood gas showed severe metabolic acidosis (ph7.0) and concomitant hypoglycemia (blood sugar 1.05 mmol/l) and Hyperkalemia (6.5 meq/l) Baby was clinically in septic shock with multiorgan failure. After the initial resuscitation with saline bolus, intravenous dextrose and antibiotics, baby was admitted to PICU and was placed on mechanical ventilation and needed inotropic support with Dopamine and epinephrine infusion. Supportive care was continued in the Pediatric intensive care unit a working diagnosis of fulminant sepsis with multiorgan failure, broad spectrum antibiotics intravenous ceftriaxone, intravenous meropenem and intravenous acyclovir were started along with intravenous hydrocortisone in view of catecholamine resistant septic shock and persistent metabolic acidosis. Patient also received

4 multiple transfusions of packed red cells, platelets and fresh frozen plasma in view of worsening clinical condition and active bleeding from the puncture sites, from urethra and fresh blood seen in the nasogastric tube. In spite of all the intensive care efforts and supportive measures the baby continued to be hypotensive, having severe DIC with no improvement in metabolic acidosis. Serum Potassium had normalized. Despite all efforts baby expired within a period of 24 hours of admission. All cultures remained negative including viral serology. Laboratory blood investigations revealed a high ferritin level, deranged liver functions, Picture of DIC (Disseminated intravascular coagulation),prolonged activated partial thromboplastin time,thrombocytopenia, hypofibrinogenemia, a high CRP, procalcitonin level a high creatinine level and a normal serum ammonia level.. Differential count revealed a relatively higher monocyte count. (See Table 2) Peripheral smear revealed leucocytes increased in number with marked lymphocytosis, monocytosis and neutrophilia. Lymphocytes were with reactive with atypical features and rare vacuolated monocytes were also seen. There were no blast cells. Red cells were decreased in number with normocytic normochromic mild polychromasia. Platelets were decreased in number. No satelettosis was seen. Chest x-ray showed ill-defined patchy areas of consolidation over the right upper lobe and paucity of gas shadows in the intestine with predominant gas in the abdomen. Ultra sound abdomen revealed hepatosplenomegaly with moderate ascites and fluid level in the urinary bladder suggestive of active hemorrhage. Echocardiogram revealed moderately depressed cardiac function with no evidence of congenital heart condition. Discussion Hemophagocytic lymphohistiocytosis (HLH) is a rare potentially fatal systemic disorder involving multiple organs. It is characterized by prolonged fever, hepatosplenomegaly, skin rashes and multiorgan dysfunction and abnormal laboratory findings like cytopenias, high ferritin, high c-reactive protein, high ESR, high triglycerides, low fibrinogen, elevated D- dimer, multiorgan dysfunction usually involving the liver. Abnormal liver function test and hemophagocytic histiocytosis are seen in bone marrow spleen liver and lymphatic nodes Clinically HLH can present as fever, shock, capillary leak, thrombocytopenia, delirium, disseminated intravascular coagulation and multiorgan failure. Even through the exact mechanism of this severe pathogenesis is not fully understood but basic sciences research evidence points to role of perforin and NK cells in the HLH subtypes. 3, 14,15 Natural killer (NK) cells are part of the inborn immune system and perform an important role in triggering the immune system in response to an infection and suppressing the immune system when the infection is abolished. 16 In HLH, NK cells are not capable of removing the infected cells or to suppress the activated component of the inborn immune system, resulting in persistent stimulation of the inflammatory cascade and an uninhibited systemic inflammatory syndrome. 17 When stimulated, NK cells release granules that contain perforin granzymes which forms death inducing pores in the cell membrane of target cells leading to osmotic lysis and protein degradation and is responsible for the cytotoxicity. Perforin or pore forming protein is a major cytolytic protein contained in granules. 2 Impaired perforin function due to gene mutation plays an important role in Familial HLH as reported in the literature. 18

5 Table 2 -Laboratory investigations on second admission Test Result Normal range Intepretation sodium 130mmol/L mmol/L potassium 6.5mmol/L mmol/L Chloride 101mmol/L /mmol/L Bicarbonate 6mmol/L 12-mmol/L Blood urea nitrogen 12.30mmol/L mmol/L Creatinine 61.64umol/L 35-58umol/L Glucose 1.05mmol/L mmol/L C-reactive protein 141mg/L 0-5mg/L White blood cell count 142X10^9/L 5-19X19^9/L Red blood cell count 2.77M/ul 3-5.4Mm/ul Hemoglobin 9g/dl 10-18g/dl Hematocrit 26% 31-55% Platelet 52x10^9/L X10^9/l Neutrophils 14.7X10^9/L 1-9x10^9/L Lymphocytes 108x10^9/L X10^9/L Monocytes 18.1x10^ x10^9/L Fibrinogen <60mg/dl mg/dl Total Bilirubin 149µmol/L µmol/L Direct Bilirubin 114µmol/L µmol/L Alanine Aminotransferase 521IU/L 0-55IU/L Aspartate Aminotransferase 2198IU/L 5-34IU/L Gamma Glutamyltrasferase 132IU/L 12-64IU/L Prothrombin >120 seconds seconds INR > Activated partial >180 seconds seconds thromboplastin time Procalcitonin 3.55ng/ml <0.05ng/ml Ferritin >40,000ng/ml ng/ml Lactate dehydrogenase 3614U/L U/L Ammonia 61umol/L 16-60umol/L Blood culture No growth Urine culture No growth serology Rubella negative Toxoplasma negative Cytomegalovirus negative Epstein Barr virus negative Coxsackie virus negative

6 The first case of HLH was reported in 1952 by Farquhar and Claireaux. 19 HLH has equal distribution in males and females. 3 There should be a suspicion of HLH in all cases of sudden onset of unexplained systemic inflammatory response including fever, malaise,hepatosplenomegaly, jaundice, generalized lymphadenopathy and cytopenias % of pediatric cases show central nervous symptoms which include irritability, mental status changes, meningitis, encephalopathy, Seizures, hemiplegia, cranial nerve palsies and ataxia. 20 The diagnosis of HLH can be challenging as the symptoms are nonspecific and the disease is easily under recognized as in this case. The current (2004) diagnostic criteria for HLH which have been adapted from Henter et al. 12 are; 1. A molecular diagnosis consistent with HLH. These include the identification of pathologic mutations of PRF1, UNC13D, or STX11. OR 2. Fulfillment of five out of the eight criteria below: Fever (>100.4 F, >38 C) Splenomegaly Cytopenias affecting at least two of three lineages in the peripheral blood: Hemoglobin <9 g/100 ml (in infants <4 weeks: hemoglobin <10 g/100 ml) Platelets < /L Neutrophils < /L Hypertriglyceridemia (fasting, greater than or equal to 265 mg/100 ml) and/or hypofibrinogenemia ( 150 mg/100 ml) Ferritin 500 ng/ml Hemophagocytes in the bone, spleen or lymph nodes Low or absent natural killer cell activity Soluble CD25 (soluble IL-2 receptor) >2400 U/ml (or per local reference laboratory) In addition, in the case of familial HLH, no evidence of malignancy should be present. In neonates, clinical presentation of HLH can be in a different manner. Commonly as fever is not present in this age group, absence of fever should not delay the clinician from making the diagnosis of HLH. 21 In the same way, it has been reported that only 14% of neonates show hypertriglyceridemia, although it has been frequently reported in adults. This difference has been attributed to age related differences in lipid metabolism. 21 On the other hand, coagulopathy hepatomegaly and cytopenias should raise the suspicion of HLH in neonates, 2 Neonatal HLH presenting as fulminant liver failure is very rare but it has been reported. 3 In

7 this challenging case presenting with signs and symptoms of severe sepsis and septic shock the history was somewhat suggestive of HLH. Initial admission as mild fever, full septic screening was done, and no cause was identified and later presenting as severe sepsis like picture with DIC. Various types of skin rashes have been described in HLH as erythroderma generalized purpuric macules and papules morbilliform eruptions and are present in more than half of the patients including scaly and waxy lesions on the scalp and behind the ears. 19 This scaly and waxy lesion was seen on this baby and had a linear and streaky pattern. Ferritin is a positive acute phase reactant, exhibiting increased levels in blood during the acute phase response. Ferritin is a useful and convenient screen in suspected cases of HLH. Ferritin levels has been studied in pediatric patients and it has been found that, a ferritin level of >10,000microgram/L was 90% sensitive and 96%specific for HLH. 22 This high cut off level of ferritin significantly increases the specificity as ferritin can also be elevated other inflammatory condition but the increase is typically not up to this high levels. Ferritin can be measured conveniently at almost all hospitals as a rapid test and our case had a value of >40,000 micro gram/l. Our case satisfied all the five diagnostic criteria with fever more than 38 degrees Celsius, splenomegaly, cytopenias in two cell lines, low hemoglobin, low platelets, hypofibrinogenemia and high ferritin. There was no evidence of malignancy; peripheral smear did not reveal any blast cells despite the high cell count. In addition to the above, other biochemical parameters were high including CRP, LDH, D- dimer, and abnormal liver function test. Initially there was a thought of metabolic disorder as there was fulminant liver failure, but the new born metabolic screening was normal and the blood ammonia level was within normal limits. This case presented as fulminant sepsis and received steroids for catecholamine resistant shock and not with the target to treat HLH. In a report, 60% of patients with severe sepsis, HLH was demonstrable, but was unable to fulfill criteria for HLH. There was another report which showed that, one-third of the patients who died in the intensive care unit with sepsis and multiorgan failure had microscopic evidence of HLH. 23,24 This can well be explained by the fact that suppression of the function of NK cells occurs in severe sepsis, particularly in sepsis associated with viral infections. 25,26 Raised scd25/sil-2r was also noticed in these patients. Thus, these findings propose that a significant overlap occurs in severe sepsis and HLH, with an ultimate common pathway leading to hemophagocytosis. These observations imply that at least even some cases of infection-associated HLH are just the ultimate end of the inflammatory spectrum of sepsis. 27,28 It is essential to start the treatment early to suppress the exaggerated immune response by using immunosuppressive agents. The 2004 treatment protocol formulated at the second international meeting of The Histiocyte Society recommends an 8-week induction therapy with corticosteroids, cyclosporine A and etoposide treatment. 12 Corticosteroids are used to suppress the hypercytokinemia, Cyclosporin A adds the inhibition of T-cell activation, and etoposide further blocks cell division and cell proliferation. Allogenic stem cell transplant (SCT) is indicated in selected cases (with genetic defect) in which the defective immune systems replaced by a healthy one from a different person. Treatment with SCT improves 3-year survival from 0% to 50% in familial cases 29 and with reduced intensity regimes showing better results. 30 Cases have been reported to be cured with

8 SCT In acquired or secondary HLH the immediate treatment of the underlying disease is indicated. 3 The prognosis of genetic HLH without treatment is uniformly poor, with a median survival of 1 to 2 months 11 and a less than 10% probability that the patients survive for 3 years. 14 At present there are no precise methods to avoid Primary HLH. Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy. Genetic counseling will help to weigh the risks before planning for a child if there is a family history of the condition Vigorous research is presently being done to discover the promises for treatment and prevention of inherited and acquired genetic diseases. Even though HLH cannot be prevented, a few methods that can help decrease the occurrence of the condition include proper sanitation thereby restricting the contact to pathogens, pursuing medical care promptly during a progressive deteriorating illness, initial management and ongoing treatment to guarantee a better prognosis. 32 Conclusion HLH is a very rare and perhaps an underdiagnosed disease. Physicians face a critical challenge in establishing a timely diagnosis of HLH. It is a real medical emergency at all ages. In a new born, HLH should be considered in the differential diagnosis if there is multisystem organ involvement especially in the absence of metabolic or infective cause. Awareness of this condition is extremely important for the pediatricians as the early commencement of therapy is crucial to control the hypercytokinemia and if not, may lead to end organ failure and death. Acknowledgement The authors are grateful to the medical and nursing staff, Pediatric intensive care unit of Mediclinic City Hospital, Dubai. Conflict of Interest: None Source of Funding: None References: 1. Stepp SE, Dufourcq-Lagelouse R, Le Deist F. Perforin gene defects in familial hemophagocytic lymphohistiocytosis.science 1999;286(446): Freeman HR Ramanan AV. Review of hemophagocytic lymphohistiocytosis. Arch Dis Child 2011;96: Janka GE. Familial and acquired hemophagocytic lymphohistiocytosis. Annu Rev Med 2012;63: Kejian Z, Alexandra FH, Judith J, Rebecca MA, Joyce V.Hemophagocytic Lymphohistiocytosis, Familial. Gene Reviews. National Center for Biotechnology Information PMID NBK Henter JI, Elinder G, Ost A. Diagnostic guidelines for hemophagocytic lymphohistiocytosis. The FHL Study Group of the Histiocyte Society. Semin Oncol 1991;18: Larroche C, Scieux C, Honderlick P. Spontaneous resolution of hemophagocytic syndrome associated with acute parvovirus B19 infection and concomitant Epstein-Barr virus reactivation in an otherwise healthy adult. Eur J ClinMicrobiol Infect Dis 2002; 21: Imashuku.S. Clinical features and treatment strategies of Epstein-Bar virus-associated hemophagocyticlymphohistiocytosis. Crit Rev Oncol Hematol 2002; 44:

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