Abstract
Background: Hemophagocytic lymphohistiocytosis (HLH) is a rare immune
disease, accompanied by high mortality. Vitamin D (VD), as a marker of
inflammation, plays an important role in the regulation of the immune
system by binding to receptors of immune cells (T and B cells). The
purpose of this study was to investigate the expression level of vitamin
D in HLH and to clarify its relationship with prognosis. Method: We
conducted a retrospective analysis of 54 adult sHLH cases from November
2015 to December 2020. Results: Among the cohort, 49 (90.7%) patients
with sHLH had VD insufficiency (25-hydroxy vitamin D [25-(OH)D]
<50nmol/L) and median level was 23.95 (range: 7.5-90.8)
nmol/L. Classified by 30nmol/L as the threshold value, there were no
significant differences on baseline characteristics between two groups,
except triglycerides (TG). Level of 25-(OH)D was significantly
associated with TG (r=-0.34, P=0.011) and ferritin (r=-0.26, P=0.055).
Patients with lower 25-(OH)-D level acquired shorter overall survival
(28 vs. 125 days P=0.041). After multivariable adjustment, 25-(OH)-D was
identified as an independent factor of survival (HR 0.364;95% CI
0.183-0.724; P=0.004). A significant interaction was discovered at
25-(OH)-D with ferritin (P=0.009) through subgroup analysis. Vitamin D
is more likely to predict survival in elderly, male, MHLH, EBV
infection, hemoglobin<90g/L, platelet<100×109/L,
fibrinogen<1.5g/L, triglyceride, ferritin
>10000ug/l, sCD25>20000ng/l group.
Conclusions: Patients with sHLH almost had vitamin D insufficiency and
vitamin D is an important prognostic protective factor for sHLH.