Background Hemophagocytic syndrome (HS) is a severe, potentially life-threatening, hyperinflammatory disorder. It is difficult to distinguish reactive HS (RHS) form other diseases such as sepsis, rheumatic diseases, and malignancies. Recently, Fardet et al have developed a score called HScore to help clinicians in the differential diagnosis of RHS.
Objectives Our aim was to analyze the performance of HScore (with and without bone marrow criteria) for RHS diagnosis in rheumatic diseases and to determine the best cut-off values for this subgroup of patients.
Methods We have retrospectively reviewed the medical records of patients with the diagnosis of RHS and rheumatic disorders who were evaluated in Departments of Rheumatology and Pediatric Rheumatology at Hacettepe University, Ankara, Turkey between 2002-2014. The first group (n=32) consisted of patients who had RHS and the control group (n=64) included patients with rheumatic diseases but not RHS. We have applied the HScore and examined the performances of different cut-off values. SPSS 15.0 for Windows is used for statistical analysis.
Results We have included a total of 32 patients in the RHS group. Of these patients, 14 (43.75%) had AOSD, 10 (31.25%) SJIA, six (18.75%) SLE, and two (6.25%) had vasculopathies. The control group (n=64) was consisted of 32 AOSD, 13 SJIA and 19 SLE patients who did not have RHS. Adult/pediatric patient ratios were 20/12 for RHS and 47/17 for control group. The HScore parameters and numbers of patients according to the categories of each parameter were summarized in Table 1. The best cut-off value was 190.5 with a sensitivity of 96.9% and specificity of 98.4%. In adult and pediatric subgroups, it had a sensitivity of 95% and 100%, and specificity of 97.9% and 100%, respectively. A lower cut-off value of 155.5 seemed to perform better with a sensitivity of 96.9% and specificity of 84.4% when we excluded the bone marrow item of the HScore. This cut-off value had a sensitivity of 95% and 100%, and specificity of 80.9% and 94.1% in adult and pediatric groups respectively. Of note, in the pediatric subgroup, a higher cut-off value of 169.5 performed better with a sensitivity and specificity of 100%.
Conclusions According to the original study, the best cut-off value for the HScore was 169; however, in our study group, 190.5 performed better. Our results indicate that different cut-off values should be determined for RHS according to the different underlying disorders. We do not always perform bone marrow aspiration to determine hemophagocytosis for RHS diagnosis, especially in patients with rheumatic diseases. Thus, it may be more proper to use the HScore set without the bone marrow item especially in this subset of patients. Further prospective studies are needed to evaluate the strength and potential practical usefulness of the HScore in different patient group.
Fardet L, Coppo P, Kettaneh A, Dehoux M, Cabane J, Lambotte O. Low glycosylated ferritin, a good marker for the diagnosis of hemophagocytic syndrome. Arthritis Rheum 2008;58(5):1521-7
Disclosure of Interest None declared