Study patients
A total of 54 adult cases with newly diagnosed sHLH at the First
Affiliated Hospital of Nanjing Medical University from November 2015 to
December 2020 was enrolled. All the diagnosis of sHLH was based on the
2004 HLH Diagnostic Criteria16. The NK cells
cytotoxicity assay was not applicable due to the limitation of
technology. Excluded criteria included (1) history of rickets; (2)
history of parathyroid or metabolic diseases; (3) use of
over-the-counter or prescribed vitamin complements; (4) history of
severe liver and kidney dysfunction.