Association Between Circulating 25-Hydroxy Vitamin D Receptor and Molecular Response in Multiple Myeloma.

<b>Background and Objective:</b> Vitamin D Receptor (VDR) regulate several body processes related to metabolism, immunological function and oncogenesis. Low vitamin D levels are recognized as associated with a higher incidence of hematologic malignancies and poor outcomes. This study aims to determine whether vitamin D levels and VDR contribute to multiple myeloma (MM). <b>Materials and Methods:</b> This study enrolled twenty-five patients diagnosed with MM. Ages and gender were matched between patients and healthy groups. Serum Protein Electrophoresis (SPEP) was detected for all patients. Also, serum 25-hydroxy vitamin D levels were recorded. The PCR products were submitted to Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and Sanger sequencing to detect VDR gene polymorphism including (FokI, ApaI and Tru9I). <b>Results:</b> This study revealed that an M spike was detected in five patients newly diagnosed with MM. According to vitamin D levels 84% of patients had a vitamin D deficiency. In the RFLP technique, FokI CT, ApaI AA and Tru9I GG genotypes were highly distributed in patients. Additionally, the MM group had a significant frequency of the T allele in the FokI (44.0%), the A allele in the ApaI (68.0%) and the A allele in the Tru9I (30.0%). <b>Conclusion:</b> The SPEP is an easy-to-perform laboratory test that can be used to detect and quantify monoclonal proteins. Low vitamin D level of less than 20 ng mL¹ is associated with an increased prevalence of MM and a worse response to treatment. In addition, VDR gene polymorphisms may be a molecular marker of MM risk.