Performances of the H-Score for Diagnosis of Hemophagocytic Lymphohistiocytosis in Adult and Pediatric Patients

Objectives: In this study, we compared the performances of adapted hemophagocytic lymphohistiocytosis (HLH)-2004 guidelines with those of the new diagnostic H-score to identify patients with HLH in a multicenter cohort consisting of adult and pediatric cases of suspected HLH. Methods: The study sample consisted of 147 cases, including 20 adults and 16 children with HLH. Two sets of biological data were evaluated: at presentation and the maximal values reached during the episode. Results: At presentation, for both children and adults, the H-score was more efficient than adapted HLH-2004 guidelines to identify HLH. The diagnostic sensitivity and specificity were respectively 100% and 80% for children and 90% and 79% for adults. However, for adults, performances became comparable between adapted HLH-2004 guidelines and H-score as patient clinical status worsened. The specificity decreased to 73% for the same sensitivity. Conclusions: The adapted HLH-2004 guidelines seem less powerful and H-score seems to be more appropriate for children, which may be due to less significantly marked biological features. For adults, H-score performances are better when determined at presentation. The cutoff value of the H-score should be adapted depending on the target population to obtain optimal specificity.