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, 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.