Background:  Acute renal failure is an important complication of HIV infection, yet remains poorly studied. It is unclear whether HIV care, including HAART and prophylaxis against opportunistic infections, affects the risk of developing acute renal failure. We studied the incidence of acute renal failure in a large multi-ethnic cohort of HIV infected patients.

Methods:  All HIV-infected patients attending King’s College Hospital, London, United Kingdom, who experienced an estimated glomerular filtration rate (eGFR) <60 mL/minute between January 1998 and December 2005 were studied. Patients were assessed for acute renal failure by applying 3 eGFR-based or serum creatinine-based criteria:  confirmed eGFR <60 mL/minute, nadir eGFR >40% reduced from baseline, and duration of renal failure (eGFR <60 mL/min) <3 months; or confirmed raised serum creatinine (>120 μM/L [1.36 mg/dL]), peak serum creatinine >50% increased over baseline, and duration of renal failure (raised serum creatinine) <3 months. In addition, patients with chronic kidney disease (eGFR <60 mL/min for >3 months) were included as acute on chronic renal failure if they experienced a confirmed >40% reduction in eGFR in <3 months. Acute renal failure episodes were classified as early-onset if they occurred <3 months of initiating HIV care, and late-onset if they occurred >3 months after initiating care.

Results:  During the study period, 130 of 2274 patients (5.7%) developed 144 episodes of acute renal failure. The etiology of acute renal failure was diverse and included opportunistic and non-opportunistic infections, malignancy, or liver disease in 35%, 42%, 17%, and 12% of patients, accompanied by reduced renal blood flow (70%), use of nonsteroidal anti-inflammatory drugs (27%), or exposure to potentially nephrotoxic anti-microbial or anti-neoplastic agents (67%). The incidence rates of early-onset and late-onset acute renal failure were 19.3 (95%CI 15.4 to 24.1) and 1.1 (0.83 to 1.49) episodes per 100 person-years, respectively (rate ratio 17.4, 12.0 to 25.2, p <0.001). In multivariate analysis, nadir CD4 T cell count <100 x 10⁹ cells/L (OR 6.7, 2.5 to 18.3), and AIDS (OR 6.7, 3.4 to 13.3) were associated with early-onset acute renal failure, while intravenous drug use (OR 4.8, 1.3 to 17.7), hepatitis C co-infection (OR 3.4, 1.3 to 8.6), and nadir CD4 T cell count <100 x 10⁹ cells/L (OR 5.8, 2.5 to 13.4) were associated with late-onset acute renal failure.

Conclusions:  Acute renal failure was common among patients initiating HIV care, and associated with advanced immunodeficiency. The incidence of acute renal failure declined more than 10-fold in patients who had received HIV care for >3 months.