A convenient and practical index for predicting the induction response in adult patients with hemophagocytic lymphohistiocytosis: ferritin/platelet ratio.

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome with high mortality rate. The response to induction therapy is an important factor affecting survival. The purpose is to investigate laboratory predictors for induction response in adult patients with HLH, which are convenient, practical, and timeliness. Clinical data from January 2017 to December 2020 was retrospectively analyzed, and 269 patients were included. Patients were divided into remission and non-remission groups according to their induction response, 177 in the remission group, and 92 in the non-remission group. We reviewed general characteristics and analyzed the predictive value of serum ferritin, triglycerides, alanine aminotransferase (ALT), and blood cells before and 1-4 weeks after induction therapy for induction response by univariate analysis, ROC curves, etc. There was a correlation between serum ferritin, ALT, leukocytes, neutrophils, hemoglobin, platelets, and induction response (P < 0.05). Serum ferritin and platelets 1-4 weeks after induction therapy, respectively, might be a good predictor for induction response in adults with HLH, with AUC values close to or greater than 0.7. We established a new clinical model of the ferritin/platelet ratio. The results showed that the ferritin/platelet ratio at 1-4 weeks after induction therapy might be a practical index for predicting induction response, which significantly improved the area under the ROC curve (AUC > 0.75). Patients with a ferritin/platelet ratio > 16.08 at 2 weeks after induction therapy may have a relatively poor induction response. Ferritin/platelet ratio after induction therapy can be a good predictor for induction response in adult patients with HLH.