Assessment of the HScore for reactive haemophagocytic syndrome in patients with rheumatic diseases

Reactive haemophagocytic syndrome (RHS) is a hyperinflammatory disorder often occurring in the background of several disorders such as infections, malignancies, and rheumatic diseases. Recently, a score known as the HScore was developed for the diagnosis of RHS. In the original study, most of the patients had underlying haematological malignancy or infection and the best cut-off value for the HScore was 169 (sensitivity 93%; specificity 86%). In this study we aimed to analyse the performance of the HScore in rheumatic disease-related RHS.

The patients with rheumatic disorders evaluated in the Departments of Rheumatology and Paediatric Rheumatology at Hacettepe University, Ankara, Turkey between 2002 and 2014 were reviewed retrospectively. The first group (n = 30) consisted of patients with RHS; the control group (n = 64) included patients with active rheumatic diseases without RHS.

In the RHS group, 14 (46.7%) had adult-onset Still's disease (AOSD), 10 (33.3%) systemic juvenile idiopathic arthritis (SJIA), and six (20%) systemic lupus erythematosus (SLE). The control group (n = 64) consisted of 32 (50%) AOSD, 13 (20.3%) SJIA, and 19 (29.7%) SLE patients. Applying the HScore to the RHS patients, the best cut-off value was 190.5 with a sensitivity of 96.7% and specificity of 98.4%. When we excluded the patients from the control group who had not had bone marrow aspiration (n = 23), the same cut-off (190.5) performed best (sensitivity 96.7%; specificity 97.6%). Applying the 2004 haemophagocytic lymphohistiocytosis (HLH-2004) criteria gave a sensitivity of 56.6% and a specificity of 100% in the whole study group.

In our study, a cut-off value for the HScore different from the original study performed better. Further studies are warranted to determine optimum cut-off values in different studies.