Incidence of BK Virus in HIV-positive Kidney Transplant Recipients: Case Series From South Africa

Background BK virus-associated nephropathy (BKVN) is a viral complication after kidney transplantation and an important cause of graft dysfunction and loss. Its impact on HIV-positive kidney transplant recipients (KTRs), who are at increased risk for opportunistic infections, remains poorly understood. Methods This single-center case series in South Africa describes BKVN incidence and outcomes in HIV-positive KTRs who received kidneys from HIV-positive donors between 2008 and 2025. A screening protocol and schedule were implemented in 2021, and BKVN was classified as possible, probable, or presumptive according to The Second International Consensus Guidelines. Results Over the study period, there were 63 KTRs and 34 donors; 2 recipients with primary graft failure were excluded. The remaining 61 recipients had a median age of 40 y, 54% were male, and 93% were of Black African ethnicity. Median CD4 count at transplantation was 439 cells/mm 3 , and all KTRs had suppressed HIV viral load on antiretroviral therapy. HIV-associated nephropathy was the most common cause of end-stage kidney disease. Hypertension was prevalent (89%), and one-third had a history of treated tuberculosis. All patients received antithymocyte globulin induction at transplant. Seventeen recipients had no BKVN screening data, 36 maintained negative BK viral loads, while 8 developed BK polyomavirus viremia and/or viruria. Of these, 2 (3%) had polymerase chain reaction-confirmed viremia, and 6 (10%) met criteria for possible (n = 1), probable (n = 2), or presumptive BKVN (n = 3). BK polyomavirus viremia and/or viruria occurred either within 6 mo or between 1 and 2 y posttransplant. Management consisted of reducing immunosuppression. Possible and probable cases (5%) maintained functioning grafts. All 3 (5%) presumptive cases had biopsy-proven disease, with one resulting in graft loss (1.6%). Conclusions Despite limited resources and delayed routine screening, the BKVN incidence was low (5%), and most affected recipients achieved viral control and preserved graft function.