Effects of Intravenous Immunoglobulin therapy and Fc gamma receptor polymorphisms on BK Virus Nephropathy in Kidney Transplant Recipients.

Background BK virus nephropathy (BKVN) is a major complication in kidney transplant patients. This study aimed to investigate the efficacy of intravenous immunoglobulin (IVIG) therapy against persistent BKVN and to evaluate the association between persistent BKVN and Fc gamma receptor (Fc gamma R) single nucleotide polymorphisms (SNPs). Methods A total of 86 patients out of 279 kidney recipients with BKVN were investigated in a single-center retrospective study. The majority of 86 patients were Hispanic and Asian (69.8% and 17.4%). Patients were treated with adjunctive IVIG or standard therapy (controls). Subgroup analysis was performed between IVIG responders and non-responders. BK virus copy number and serum creatinine (SCr) were measured to evaluate the impact of IVIG. We analyzed the association between the response to IVIG and genotype at Fc gamma R3A (rs396991) and Fc gamma R2A (rs1801274) SNPs. Results Viral load in IVIG non-responders was significantly higher than in responders at the time of diagnosis (219 271.8 vs 29 816.3 copies/mL, P = .015) and after 6 months of IVIG use (12 789.5 vs 1369.5 copies/mL, P < .001). However, analyses SNP of Fc gamma R2A (OR = 0.807, CI = 0.435-1.496 P = .495) and Fc gamma R3A (OR = 0.997, CI = 0.505-1.970, P = .993) SNPs showed no significant differences between the 2 groups. Conclusion IVIG appears to lower BK DNA viral load significantly in patients with persistent BKVN. However, no associations were identified between BKVN and Fc gamma R2A or Fc gamma R3A SNPs.