Granulomatous interstitial nephritis on renal biopsy in human immunodeficiency virus positive patients: Prevalence and causes in Cape Town, South Africa

Abstract

South Africa continues to be burdened by human immunodeficiency virus (HIV) and tuberculosis (TB). In Cape Town, the epidemic of HIV‐TB co‐infection is as high as 70%. Granulomatous interstitial nephritis (GIN) has increased in frequency on renal biopsy. This study aimed to determine GIN prevalence and causes in HIV‐positive patients as well as renal outcomes, patient survival and associated factors. This observational cohort study reviewed HIV‐positive renal biopsies for GIN from 2005 to 2012. Causes of GIN (medications, TB, fungal and other), and baseline characteristics were analysed. A comparison of baseline data, renal function and survival was made between GIN and non‐GIN cohorts. There were 45/316 biopsies demonstrating GIN. TB was the likely cause of GIN in 27 (60%) and 9 (20%) were due to a drug. Low estimated glomerular filtration rate was a statistically significant factor associated with mortality in both GIN (P = 0.045) and non‐GIN cohorts (P < 0.000). In the GIN group, there were 12 (26.7%) deaths. Mortality for all patients was greatest in the first 6 months (P = 0.057). TB co‐infection in both cohorts was associated with a higher mortality. The multivariate logistic regression demonstrated that a higher urine protein/creatinine ratio (uPCR) and lower estimated glomerular filtration rate were statistically associated with death. GIN is common in HIV‐positive renal biopsies in Cape Town. TB‐GIN was the commonest cause and associated with a high early mortality. GIN should be considered in HIV‐positive patients with acute kidney injury, its presence conveys a survival benefit. There is a need for improved diagnostic accuracy and treatment strategies of TB‐GIN.

Causes of granulomatous inflammation in native and allograft kidneys: case series from a single center and a review of the literature

“…Timely diagnosis and early treatment of tuberculosis is associated with more favorable outcomes (42). GIN due to tuberculosis is even more common among subjects infected with HIV, and is associated with increased mortality in that case (45). None of our cases were HIVpositive.…”

The Evolving Spectrum of Kidney Histology in HIV-Positive Patients in South Africa

“…The substantially higher proportion of cases with TID in our series may reflect the exceptionally high prevalence of TB (42%), which can result in granulomatous interstitial nephritis in the kidney, TB drug-induced interstitial nephritis, or ATI from kidney hypoperfusion in those with severe systemic illness. 25 , 26 Furthermore, the greater degree of immunodeficiency in our patients may have resulted in increased susceptibility to other infections and increased exposure to nephrotoxic agents. Of note, about half of the patients with HIV/TB had initiated ART within 3 months of kidney biopsy, raising the possibility that some kidney pathology may have been the result of immune reconstitution inflammatory syndrome in the kidney.…”

Chronic kidney disease (CKD) and associated risk in rural South Africa: a population-based cohort study

“…The study confirmed known associations with HIV infection, hypertension, and diabetes 2,30,31 , but one third of participants with CKD had none of these risk factors. Potential contextspecific risk for kidney disease not accounted for in this study include endemic malaria, endemic genitourinary schistosomiasis, genitourinary tuberculosis, ingestion of traditional and overthe-counter medicines, and environmental exposures such as agricultural pesticides and heavy metal toxins [32][33][34] . Such exposures might result in repeated bouts of acute, or acute-on-chronic kidney injury, or comprise the "second hit" needed for APOL1-induced kidney injury.…”