Platelet-derived alpha-granules are associated with inflammation in patients with NK/T-cell lymphoma-associated hemophagocytic syndrome.

Due to the variable overlap of multiple symptoms, accurate early diagnosis of NK/T-cell lymphoma-associated hemophagocytic syndrome (NK/T-LAHS) is difficult, making the prognosis extremely poor. Hemophagocytic syndrome (HPS) is now diagnosed primarily based on the hemophagocytic lymphohistiocytosis (HLH)-2004 diagnostic criteria, and platelet count is one of the baseline evaluations. However, in our study, the data showed that decreased platelets were not only a clinical feature of HPS but also the key cells that regulate inflammation by releasing α-granules containing upregulated platelet factor 4 (PF4) and downregulated platelet-derived growth factors (PDGFs). Furthermore, we found that angiopoietin-4 (ANG-4), which has significant differential expression, has been less reported, that may affect hematopoiesis and proinflammatory responses and can be used as diagnostic biomarkers together with PF4 and PDGFs.