Reactive hemophagocytic lymphohistiocytosis: Epidemiological, clinico-biological and etiological profile

Hemophagocytic lymphohistiocytosis (HLH) is an hyperinflammatory state resulting from increased secretion of proinflammatory cytokines, which are responsible for clinical, biological and cytological manifestations.

The aim of our study is to describe the epidemiological, clinical, biological, etiological and evolutionary profile of HLH in Tunisia.

A retrospective study that involved patients, with images of hemophagocytosis in myelograms analyzed at the laboratory of biological hematology of the University Hospital "Hédi-Chaker" of Sfax-Tunisia, followed at these departments: hematology, internal medicine, department of infectious-diseases and department of gastroenterology, (June2017- May2021). First, we identified all patients with hemophagocytosis images. Secondly, we selected the patients who fulfilled the diagnostic criteria of the HLH-2004-score.

Nineteen patients were included in this study. Nine men and 10 women with a mean age of 37.95 years. Fever was present in all patients. Organomegaly was described in 74% of cases. The most frequent cytopenia was anemia (100%). Hypertriglyceridemia was noted in 79% of cases and hyperferritinemia (> 500 ng/mL) was ubiquitous. In myelogram, 68% of patients had slides showing numerous or very numerous images of hemophagocytosis. The infectious pathology was the most common cause of HLH (42%). No cause was found in 10% of cases. The corticosteroid therapy at a dose of 1 mg/kg/day was prescribed in 89% of our patients. The overall evolution was favorable in 58% of cases. The mortality was not associated with the causal pathology (p=0.218).

Secondary HLH is likely to be under-recognized, which contributes to its high morbidity and mortality. Early recognition is crucial for any reasonable attempt at curative therapy.