Kidney disease in antiretroviral-naïve HIV-positive adults with high CD4 counts: prevalence and predictors of kidney disease at enrolment in the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

OBJECTIVES

HIV infection has been associated with an increased risk of chronic kidney disease (CKD). Little is known about the prevalence of CKD in individuals with high CD4 cell counts prior to initiation of antiretroviral therapy (ART). We sought to address this knowledge gap.

METHODS

We describe the prevalence of CKD among 4637 ART-naïve adults (mean age 36.8 years) with CD4 cell counts > 500 cells/μL at enrolment in the Strategic Timing of AntiRetroviral Treatment (START) study. CKD was defined by estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2) and/or dipstick urine protein ≥ 1+. Logistic regression was used to identify baseline characteristics associated with CKD.

RESULTS

Among 286 [6.2%; 95% confidence interval (CI) 5.5%, 6.9%] participants with CKD, the majority had isolated proteinuria. A total of 268 participants had urine protein ≥ 1+, including 41 with urine protein ≥ 2+. Only 22 participants (0.5%) had an estimated glomerular filtration rate < 60 mL/min/1.73 m(2) , including four who also had proteinuria. Baseline characteristics independently associated with CKD included diabetes [adjusted odds ratio (aOR) 1.73; 95% CI 1.05, 2.85], hypertension (aOR 1.82; 95% CI 1.38, 2.38), and race/ethnicity (aOR 0.59; 95% CI 0.37, 0.93 for Hispanic vs. white).

CONCLUSIONS

We observed a low prevalence of CKD associated with traditional CKD risk factors among ART-naïve clinical trial participants with CD4 cell counts > 500 cells/μL.

Glomerular filtration rate estimated using creatinine, cystatin C or both markers and the risk of clinical events in HIV-infected individuals

OBJECTIVES

The accuracy and precision of glomerular filtration rate (GFR) estimating equations based on plasma creatinine (GFR(cr)), cystatin C (GFR(cys)) and the combination of these markers (GFR(cr-cys)) have recently been assessed in HIV-infected individuals. We assessed the associations of GFR, estimated by these three equations, with clinical events in HIV-infected individuals.

METHODS

We compared the associations of baseline GFR(cr), GFR(cys) and GFR(cr-cys) [using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations] with mortality, cardiovascular events (CVEs) and opportunistic diseases (ODs) in the Strategies for the Management of Antiretroviral Therapy (SMART) study. We used Cox proportional hazards models to estimate unadjusted and adjusted hazard ratios per standard deviation (SD) change in GFR.

RESULTS

A total of 4614 subjects from the SMART trial with available baseline creatinine and cystatin C data were included in this analysis. Of these, 99 died, 111 had a CVE and 121 had an OD. GFR(cys) was weakly to moderately correlated with HIV RNA, CD4 cell count, high-sensitivity C-reactive protein, interleukin-6, and D-dimer, while GFR(cr) had little or no correlation with these factors. GFR(cys) had the strongest associations with the three clinical outcomes, followed closely by GFR(cr-cys), with GFR(cr) having the weakest associations with clinical outcomes. In a model adjusting for demographics, cardiovascular risk factors, HIV-related factors and inflammation markers, a 1-SD lower GFR(cys) was associated with a 55% [95% confidence interval (CI) 27-90%] increased risk of mortality, a 21% (95% CI 0-47%) increased risk of CVE, and a 22% (95% CI 0-48%) increased risk of OD.

CONCLUSIONS

Of the three CKD-EPI GFR equations, GFR(cys) had the strongest associations with mortality, CVE and OD.

Factors associated with failure to list HIV-positive kidney transplant candidates

With improved survival in the antiretroviral era, data from ongoing studies suggest that HIV patients can be safely transplanted. The disproportionate burden of HIV-related end-stage renal disease in minority populations may impose additional obstacles to successful completion of the transplant evaluation. We retrospectively reviewed 309 potentially eligible HIV patients evaluated for kidney transplant at our institution since 2000. Only 20% of HIV patients have been listed, compared to 73% of HIV-negative patients evaluated over the same period (p < 0.00001). Failure to provide documentation of CD4 and viral load (36% of candidates) was the most common reason for failure to progress beyond initial evaluation. Other factors independently associated with failure to complete the evaluation included CD4 < 200 at initial evaluation (OR 15.17; 95% CI 1.94-118.83), black race (OR 2.33; 95% CI 1.07-5.06), and history of drug use (OR 2.56; 95% CI 1.22-5.37). More efficient medical record sharing and an awareness of factors associated with failure to list HIV-positive transplant candidates may enable transplant centers to more effectively advocate for these patients.

Factors associated with failure to list HIV-positive kidney transplant candidates

With improved survival in the antiretroviral era, data from ongoing studies suggest that HIV patients can be safely transplanted. The disproportionate burden of HIV-related end-stage renal disease in minority populations may impose additional obstacles to successful completion of the transplant evaluation. We retrospectively reviewed 309 potentially eligible HIV patients evaluated for kidney transplant at our institution since 2000. Only 20% of HIV patients have been listed, compared to 73% of HIV-negative patients evaluated over the same period (p < 0.00001). Failure to provide documentation of CD4 and viral load (36% of candidates) was the most common reason for failure to progress beyond initial evaluation. Other factors independently associated with failure to complete the evaluation included CD4 < 200 at initial evaluation (OR 15.17; 95% CI 1.94-118.83), black race (OR 2.33; 95% CI 1.07-5.06), and history of drug use (OR 2.56; 95% CI 1.22-5.37). More efficient medical record sharing and an awareness of factors associated with failure to list HIV-positive transplant candidates may enable transplant centers to more effectively advocate for these patients.