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

Vitamin D level, lipid profile, and vitamin D receptor and transporter gene variants in sickle cell disease patients from Kurdistan of Iraq

Introduction

Sickle cell disease (SCD) patients are susceptible to the development of vitamin D deficiency (VDD). Vitamin D through binding to vitamin D receptor (VDR) exerts its function and affects gene transcription in target tissues. VDR gene variants affect bone mineral density.

Methods

In a case‐control study, 101 SCD patients including 61 sickle cell anemia (SCA), 39 S/β‐thalassemia, and 1 HbS/HbD (SD) along with 110 healthy individuals from Kurdistan of Iraq were studied. The lipid profile, vitamin D level, FokI, and TaqI variants of VDR and group‐specific component (GC) were detected using the standard enzymatic method, the immunodiagnostic systems limited EIA kit and PCR‐RFLP methods, respectively.

Results

Around 93% and 82% of SCA and S/β‐thalassemia patients, respectively, had VDD compared to 83% of healthy individuals. Severe VDD (<10 ng/ml) was detected in 78.7% of patients with HbSS. Plasma levels of total cholesterol, HDL‐C, and LDL‐C in SCD patients were significantly lower compared to controls. Vitamin D levels were negatively correlated to TG and positively correlated to total cholesterol and HDL‐C. The frequencies of the C allele of FokI were 81.7% (p = 0.003), 80.3% (p = 0.034), and 84.6% (p = 0.011) in all SCD, SCA, and S/β‐thalassemia patients, respectively, compared to 69.1% in controls. However, no significant difference was detected comparing the frequencies of VDR TaqI and GC polymorphisms between SCD patients and controls.

Conclusion

In the present study, we found hypocholesterolemia, high prevalence of VDR FokI C allele, and low vitamin D levels among children and adults with SCD from Kurdistan of Iraq.