Data collection
Baseline patients’ characteristics were collected on admission, including age, gender, specific pathogenesis, Epstein-Barr virus (EBV), complete blood cell count (CBC), fibrinogen (FIB), lactate dehydrogenase (LDH), triglycerides (TG), albumin, calcium, β2-microglobulin (β2 -MG), ferritin, serum soluble interleukin-2 receptor (sIL-2R, sCD25), fever, splenomegaly and serum 25-(OH)D. Our previous studies have revealed clinical significance of PET-CT in diagnosing lymphoma-associated HLH (LHLH) 17,18. Therefore, in this study, lymphoma with lymph node or bone marrow biopsy and suspected by PET/CT were regarded as LHLH.
The evaluation of baseline vitamin D level was performed in the clinical laboratory of our hospital and assayed by electrochemiluminescence immunoassay (Rochee 170, Roche Co. Ltd. Shanghai, China). 25-(OH)-D levels were categorized according to a cut-off value of a published literature:30nmol/L19.