Society of Diabetic Nephropathy Prevention Journal of Nephropharmacology 2345-4202 15 2 2026 07 01 Prevalence and genotyping of BK polyomavirus in kidney transplant recipients; a cross-sectional study in Chaharmahal and Bakhtiari province, Iran e12840 e12840 10.34172/npj.12840 EN Gholam Abbas Kaydani https://orcid.org/0000-0003-0324-3238 Niloufar Afrough https://orcid.org/0009-0000-1357-6453 Majid Shirani https://orcid.org/0000-0003-4084-4403 Parisa Dehghan Journal Article 10.34172/npj.12840 2025 12 07 2026 06 02 Introduction: BK polyomavirus (BKV) presents a significant challenge in renal transplantation, as it is strongly associated with nephropathy and subsequent graft loss. Although four genotypes have been identified based on VP1 region nucleotide sequences, genotype I remains the most prevalent globally. Objectives: This study investigated the prevalence and viral subtypes of BKV among kidney transplant recipients in Chaharmahal and Bakhtiari province, Iran. Patients and Methods: This is a cross-sectional, descriptive-analytical study. Urine samples were collected from 37 kidney transplant recipients. Viral DNA was isolated and analyzed using polymerase chain reaction (PCR). Phylogenetic analysis was performed using MEGA 6.0 software to identify viral subtypes and construct a phylogenetic tree. Results: BKV DNA was detected in 17 of the 37 samples (46%). Sequence analysis identified subtype I as the dominant genotype in this region. While prevalence was higher in patients over 45 years of age, no statistically significant correlation was found between BKV positivity and age or gender. Conclusion: Given the high prevalence of BKV in this cohort and the absence of specific antiviral therapies, routine pre- and post-transplant screening for both donors and recipients is strongly recommended to prevent BK virus-associated nephropathy (BKVN) and graft rejection.