Hacettepe Üniversitesi Tıp Fakültesi Çocuk Hematoloji Ünitesi'nde İzlenen Familyal Hemofagositik Lenfohistiyositoz Hastalarının Değerlendirilmesi

Abstract

Familial hemophagocytic lymphohistiocytosis (FHL) is an autosomal recessive, life-threatening condition characterized by deficient immune response. The major underlying defect in FHL is impaired Natural Killer (NK) cell and T lymphocyte degranulation and/or cytotoxicity, and the only curative treatment is hematopoetic stem cell transplantation (HSCT). In this study, we aimed to evaluate the FHL patients’ clinical and laboratory findings, factors affecting the response to treatment, prognosis and survival. A retrospective analysis was performed on 57 patients diagnosed with FHL at Hacettepe University İhsan Doğramacı Children’s Hospital Pediatric Hematology Unit, between November 1994 and December 2012. Median age of these patient’s was 18 months. Mutation analysis were performed in 37 patients and of these, 11 had UNC13D, 10 had PRF1 and three had STX11 gene mutation. Fourty four persent of the patients had central nervous system (CNS) involvment on admission and spinal cord involvement was also seen on five patients. Remission was achieved in 24 patients with the treatment protocols, HLH-1994 and HLH-2004, in a median time of 76 days (minimum-maximum:15-705 days). When factors affecting the remission time were evaluated, remission time was prolonged 3.1 times in patients with ferritin level ≥1500 mg/dL. When patients were grouped according to their ages [Group 1 (0-24 months) and Group 2 (>24 months)]; patients in Group 1 had higher ferritin and AST levels whereas lower leukocyte and fibrinogen levels. Survival rate was also lower in these patients. In Group 1, survival rates were lower in patients with hepatic involvement. HSCT was performed in 18 patients (%32) and five year survival rate was %44. In conclusion, FHL is a disease with high mortality rates and the only curative treatment is HSCT. When FHL is suspected, genetic studies should be done and not only CNS but also spinal cord imaging should be performed as well. Treatment must be started immediately in patients who has poor prognostic factors v including, age above two years, ferritin level above 1500 mg/dL, and spinal cord, bone marrow or hepatic involvement. After FHL is diagnosed with genetic studies, donor search for HSCT must be started and HSCT should be performed as soon as possible after the remission.