Clinical and Histopathological Findings in HIV-positive to HIV-positive Kidney Transplant Recipients

Background. The spectrum of histological findings in transplanted kidneys from HIV-positive donors to HIV-positive recipients is relatively unexplored. This study describes the type and timing of histological diagnoses observed in this unique cohort. Methods. Adequate biopsies were analyzed at implantation and posttransplant between September 2008 and May 2022. Histological disease spectrum, distributions over time, and relevant clinical characteristics and management were reported for both for-cause and protocol biopsies. Results. Twenty-four implantation biopsies from 31 deceased donors and 179 allograft biopsies (100 for-cause, 79 protocol) from 50 recipients were analyzed. Most rejection episodes occurred in the first year posttransplant. Eighteen recipients (36%) had at least 1 episode of biopsy-confirmed acute/chronic T cell–mediated rejection (TCMR) or active antibody-mediated rejection (AMR). Protocol biopsies showed no active AMR or acute/chronic TCMR. However, 9 of 79 biopsies identified borderline/suspicious TCMR. Common nonrejection diagnoses were interstitial fibrosis and tubular atrophy, ascending pyelonephritis, and calcineurin inhibitor toxicity. Classic and suspected HIV-associated nephropathy (HIVAN) were identified in 3 and 6 patients, respectively. Protocol biopsies diagnosed 1 case of classic HIVAN and 6 cases of suspected HIVAN. AMR most adversely affected kidney function and significantly contributed to graft failure. Conclusions. The histological findings in this cohort of HIV-positive kidney transplant recipients who received grafts from unmatched HIV-positive donors revealed a spectrum of abnormalities. Protocol biopsies added to surveillance on borderline rejection and assisted in the recognition of HIVAN. Confirmed rejection occurred in 18 recipients (36%). Understanding the factors contributing to this may assist in the optimization of immunosuppressive protocols in the future.