C‐reactive protein as a novel biomarker for vitamin D deficiency in alopecia areata

Abstract Background Alopecia areata (AA) is an autoimmune condition characterized by sudden and unpredictable hair loss, with a lifetime incidence of 2%. AA can be divided into three categories: patchy alopecia, alopecia totalis, and alopecia universalis. It can affect a person's psychological health and overall quality of life. Elevated C‐reactive protein (CRP) levels in the liver may indicate an inflammatory response in autoimmune diseases. Vitamin D, essential for immune system control and skin health, may be related to AA. Hair follicles contain vitamin D receptors, which control immunological responses in the skin. However, no study has found a relationship between CRP and vitamin D in AA patients in our region. Subjects and Methods An analytical cross‐sectional study with a case‐control design research investigation of 82 AA patients and 81 healthy controls was carried out. Both groups’ medical histories were taken. Biochemical analysis was done for both groups as well as the serum vitamin D levels, and CRP. Genetic analysis for CDX2 rs11568820 variant detected by PCR (T‐ARMS‐PCR) method and vitamin D receptor (VDR) gene expression measured by real‐time PCR analysis for both patients and healthy subjects. Results CRP levels are higher in AA patients, AA patients with G/G genotypes exhibited higher concentrations of CRP when compared to those with A/A and A/G genotypes while patients with A/A genotypes have higher levels of Serum vitamin D as compared to the A/G and G/G genotypes. G allele was more abundant in AA patients. VDR gene expression was lower in AA compared to control and lower in ophiasis compared to localized and multiple patchy AA. An important inverse linear correlation was observed between vitamin D and CRP levels in ophiasis AA. Conclusion CRP concentrations were found to be elevated in AA patients. The considerable accuracy of CRP in the diagnosis of AA is substantiated by a statistically significant al. A noteworthy inverse linear association was observed between serum vitamin D and CRP concentrations in ophiasis AA.