A RETROSPECTIVE REVIEW OF THE SPECTRUM OF HIV-RELATED KIDNEY PATHOLOGY AT A TERTIARY CENTRE IN SOUTH AFRICA

South Africa has one of the highest prevalences of human immunodeficiency virus (HIV) infection worldwide. Kidney disease is a common and important complication of HIV, and a wide spectrum of kidney pathology associated with HIV infection has been described, with human immunodeficiency virus-associated nephropathy (HIVAN) the most well-characterised and historically the most prevalent. However, since the rollout of antiretroviral therapy (ART) in South Africa in 2004, the patterns of HIV-related kidney pathology have changed. This study aims to describe the spectrum of kidney pathology among people living with HIV who underwent kidney biopsy over a 29-year period at a tertiary centre in Cape Town, South Africa, and to describe patterns of kidney pathology before and after the rollout of ART.

This retrospective descriptive study included people living with HIV who underwent native kidney biopsy at Tygerberg Hospital during the period of 1 January 1992 to 31 December 2020. Patients were categorised by biopsy year into a pre-ART rollout period (before 2004) and a post-ART rollout period (2004 or later). We described the frequencies and proportions of histopathological patterns of kidney injury in the overall cohort and compared their distribution before and after the rollout of ART. In addition, clinical, demographic and laboratory characteristics were summarised and compared between the two periods. The most common non-HIVAN histopathological patterns were also identified.

The cohort consisted of 554 people living with HIV who underwent kidney biopsy during the study period. Most biopsies were performed after ART rollout (499/554, 90.1%). The mean age at biopsy was 36.5 years, with a relatively equal distribution by sex. Data on ART use were unavailable for patients in the pre-ART period, but were available for most patients in the post-ART rollout period, of whom 54.8% (232/423) were using ART at the time of biopsy. HIV-associated nephropathy (HIVAN) was diagnosed in 45.7% of all patients (253/554), with one-third of those with HIVAN (84/253, 33.2%) having an additional histopathological pattern of kidney injury. In the pre-ART rollout period, HIVAN was the most prevalent diagnosis (33/55, 60.0%), whereas a lower prevalence was observed post-ART rollout (220/499, 44.1%). During the post-ART rollout period, more than half of the patients (279/499, 55.9%) exhibited only non-HIVAN kidney pathology. The most frequently observed non-HIVAN histopathological patterns were immune complex-mediated glomerulonephritis (206/385, 53.5%) and tubulointerstitial disease (153/385, 39.7%). In an exploratory analysis, ART use was associated with lower odds of isolated HIVAN (aOR=0.39, 95% CI 0.24-0.64) after adjustment for the case mix.

This study describes the spectrum of kidney pathology among patients with HIV at a tertiary centre in Cape Town, South Africa, over nearly three decades, demonstrating a substantial burden of HIVAN overall. Unsurprisingly, we observed a lower proportion of patients with HIVAN in the post-ART rollout period compared to the period before ART rollout. An increase in the proportion of patients with non-HIVAN pathology, most notably immune complex-mediated glomerulonephritis and tubulointerstitial disease, accompanied the decrease in the proportion of patients with HIVAN in the period after ART rollout.