Diagnosis and manifestation of hemophagocytic lymphohistiocytosis: A single centre experience

Abstract

Hemophagocytic lymphohistiocytosis (HLH) is an inflammatory hyperactivity disorder that can potentially endanger one’s life. We revised all HLH cases diagnosed at Kaunas Clinics paediatric onco-haematology centre in 2010-2023 based on HLH-2004 criteria, analysed clinical manifestations, laboratory tests, aetiology, and outcomes. We found 12 cases, (3 boys and 9 girls) with a median age of 9,08 years. All the patients had fever, splenomegaly was diagnosed in 8 (66,7%). Laboratory findings included anaemia (61,5%), neutropenia (91,6 %), thrombocytopenia (75%), hypertriglyceridemia (45.5 %), hypofibrinogenemia (63,6 %). Hemophagocytosis was discovered in 7 (58.3%): bone marrow (41,6 %), liver (33,3%), skin (8.3%), three patients had hemophagocytosis in more than one site. Serum ferritin concentration varied from 102 to 20000 μg/L; with ≥500 μg/L occurring in 8 (66.7 %) cases. Soluble CD25 and natural killer activity were performed in 7 and 4 patients respectively, and all of them were abnormal. Other manifestations that were not included in HLH criteria were hepatitis in 8, rash and/or arthralgia in 4 and neurological damage in 2 cases. Primary HLH was diagnosed in 2 cases, while secondary HLH occurred in the setting of macrophage activation syndrome (4), Langerhans cell histiocytosis (1), Ebstein-Barr viral infection (1), unknown (4). Altogether, 5 deaths were registered, the last one in 2015. We conclude that the diagnosis of HLH is always problematic because of the diversity of presentation and variability of laboratory tests. Tests such as NK-cell activity, and soluble CD25 levels are not always possible to perform and receive in time for diagnosis confirmation. Hepatitis and neurological damage, although not included in the criteria, can help to suspect this syndrome and start treatment in time. Acknowledgment of HLH is essential for diagnosis and immediate treatment leading to improved prognosis.