Vitamin D Deficiency and Its Association with Inflammatory Markers, Lipid Profile and Regulatory T-cells in Pediatric Sickle Cell Disease Patients

We investigated vitamin D deficiency in pediatric sickle cell disease patients and its association with selected bone, lipid and inflammatory parameters. The study included 64 patients (33 SS and 31 SB) and 21 carriers (AS). Blood was obtained to assess levels of vitamin D, WBC, CRP, Ca, P, ALP, PTH, triglyceride, total cholesterol, LDL, VLDL, HDL, IL-2, IL-12, TNF-α, IL-4, IL-6, IL-10 and regulatory T cells. The patients were grouped according to their genotype (SS, SB) and vitamin D status (low or normal). Carriers were also grouped as low or normal vitamin D. Laboratory findings were similar between low and normal Vit D groups in SS, SB and AS genotypes except a lower IL-12 in SB-low vitamin D compared SB-normal vitamin D group. Acute chest syndrome was more frequent in SS-low Vit D (63%) compared to SS-normal Vit D (25%), SB-low Vit D (21%) and SB-normal Vit D (33%) (P = 0.045). Both SS and SB with low vitamin D had higher VLDL (P = 0.006 and P = 0.022), TNF-α (P = 0.001) and regulatory T cells (P = 0.000) compared to AS-low vitamin D. Both SS and SB with normal vitamin D had higher levels of regulatory T cells (P = 0.000) compared to AS-normal vitamin D. Vit D was not a modifier of selected inflammation, bone and lipid parameters in sickle cell disease. Acute chest syndrome was comparably more frequent in SS-low vitamin D. Increase of regulatory T cells in the patients was a result of chronic inflammation in sickle cell disease.