Adult onset haemophagocytic lymphohistiocytosis prognosis is affected by underlying disease: analysis of a single-institution series of 174 patients

BACKGROUND: Haemophagocytic lymphohistiocytosis (HLH) is a rare clinical syndrome characterised by activation of the mononuclear phagocytic system, and often leads to progressive multiple organ failure. The diagnosis of HLH is made late by most physicians. METHODS: To confirm the diagnosis of acquired HLH made in a single-institution series of adult patients with HLH-04 criteria, we applied the HScore and evaluated prognostic factors associated with clinical outcome. RESULTS: A total of 174 patients with a median age of 51 years (range 17-90) were included. Male/female ratio was 111/63. In 92/174 (52.9%) patients, there were potential haematological diseases (4 acute leukaemia, 1 thrombotic thrombocytopenic purpura, 3 Hodgkin's lymphoma [HL], 17 B-cell non-Hodgkin's lymphoma [NHL], 67 T-cell NHL including 22 natural killer / T-cell NHL [NK/t-cell NHL). Six (3.4%) patients had autoimmune disease and 76 (43.7%) undiagnosed underlying disease. There were 44 (25.3%) patients with Epstein-Barr virus infection, 11 (6.3%) with cytomegalovirus, 1 (0.5%) syphilis, 9 (5.2%) hepatitis B virus and 3 (1.7%) human immunodeficiency virus. More than 95% of patients had hyperferritinaemia, high lactate dehydrogenase, fever and low albumin, whereas 89.1% of patients had bone marrow phagocytosis. By the HScore, 4/174 patients had a > 50% and 16/174 patients had a > 90% probability of not having HLH. All 174 patients fulfilled more than five of the HLH-04 diagnostic criteria, but 16 of them had a low probability of HLH by the HScore. In a multivariate analysis, lymphopenia and hypofibrinogenaemia were independent prognostic factors for death. CONCLUSION: In our study, viral infection was not an independent prognostic factor. NK/T-cell - NHL was associated with worse prognosis compared with B-cell NHL and T-cell NHL (p = 0.036) and similar to other aetiologies.