Hemophagocytic Lymphohistiocytosis in a Extremely Low Birth Weight Infant Presenting with a Neonatal Thrombocytopenia.

INTRODUCTION: Hemophagocytic lymphohistiocytosis(HLH) is a potentially fatal disease presenting at an young children. Symptoms and physical findings include fever, rash and pancytopenia associated with histiocytic infiltration of bone marrow, liver and spleen. Its occurrence in neonates is very rare. We describe a female infant diagnosed with HLH, who was born at 24 week 3 days of gestational age(GA) weighing 666 gm. The infant expired due to aggravating thrombocytopenia and hepatosplenomegaly leading to multiple organ failure associated with suspected sepsis. Autopsy findings lead to a confirmation of HLH.

CASE: The baby, weighing 666gm, was born from a 36 year-old mother at GA 24 weeks 3 days, by emergency cesarian section due to vaginal bleeding. The mother came from the Republic of Kyrgystan and didn’t receive any antenatal care. The mother had a history of 8 prior abortions due to incompetence of internal os cervix (0–5–3/0–0). CBC on the first day was normal, but on the third day itg showed thrombocytopenia (Hb 11.2 g/dL, WBC 11,700/mm³, Platelet 78x10³/mm³). Antibiotics were administered for suspected sepsis. On the 47th day, abdominal ultrasonography was performed due to abdominal distension and TPN-induced conjugated hyperbilirubinemia. GB wall edema and hepatomegaly were noted. Thrombocytopenia persisted and on the 55th day the patient became hypotensive and develped metabolic acidosis. Laboratory work up for persistent thrombocytopenia included anti-platelet antibody(−), TORCH(−), parvovirus-B19 PCR(-), CMV PCR (−), EBV infection(−). Bone marrow biopsy was not done. The patient expired from sepsis and multiorgan failure on the 61st day. Autopsy findings showed histiocyte infiltration of all tissue including the liver, spleen and brain. Bone marrow biopsy also showed infiltration of abundant hemophagocytic histiocytes consistent with a diagnosis of HLH.

CONCLUSION: A premature newborn with HLH described here presented with thrombocytopenia. Therefore, HLH should be included in the differential diagnosis of neonatal thrombocytopenia.