Risk Prediction Scores Aid Management of Chronic Kidney Disease in HIV

Older age and lower baseline estimated glomerular filtration rate (eGFR) in individuals with HIV may be predictive of increased risk for chronic kidney disease (CKD) according to a recently published study in AIDS.¹

HIV-positive individuals have an almost 4-fold increased risk of CKD when compared with HIV-negative age-matched controls. In developed countries, the proportion of HIV-positive individuals aged ≥50 years is predicted to rise from 28% in 2010 to 73% by 2030. Since the development of CKD is strongly associated with increasing age, this will likely lead to significant increases in the incidence of CKD in HIV-positive individuals.

In the setting of HIV infection, CKD is often the result of traditional risk factors such as diabetes and hypertension, as well as the effects of HIV and antiretroviral (ARV) therapy. Unfortunately, the assessment of individual risk is challenging; therefore, several risk prediction scores have been proposed. 

This retrospective cohort study validated and compared 2 HIV-specific CKD risk prediction scores, one from the Data Collection on Adverse Effects of Anti-HIV Drugs (D:A:D) study group and one proposed by Scherzer et al.² This study also aimed to identify factors associated with the development of CKD and rate of decline in renal function.¹

Between 2008 and 2009, patients (n=748) at the Alfred Hospital in Melbourne, Australia, were included in the study if they were HIV positive with at least 2 measurements of eGFR documented. Exclusion criteria included pre-existing CKD (baseline eGFR <60 mL/min) or less than 5 eGFR results being available during the follow-up period. Participants were predominantly male (90.9%) and the median age was 46 years.  Multivariate regression analysis was performed to determine factors associated with development of CKD, defined as 2 consecutive eGFR measurements <60 mL/min. Performance of CKD risk scores proposed by the Short D:A:D and Scherzer et al was estimated by the area under the receiver operator curve (AUROC).

A total of 7 (5%) individuals developed CKD, which occurred at a median of 4.7 years and was associated with older age (P =.02) and lower baseline eGFR of 60 to 89 mL/min (P <.001). Antiretroviral use at baseline was not found to be associated with the subsequent development of CKD. Additionally, multivariate analysis showed a trend toward more rapid deterioration in renal function in participants with diabetes (P =.08) or established proteinuria (P =.14). The Short D:A:D and Scherzer CKD risk scores were validated, with the Short D:A:D score appearing more robust (a high score [>5] was strongly correlated with an increased risk of CKD). 

However, it should be noted that the Scherzer score was originally designed for use in treatment-naive men. The significant prior exposure to antiretroviral treatment that occurred in participants in this study may have affected the AUROC generated. Although neither risk score is currently recommended in international guidelines, results suggest that they may be helpful in identifying individuals with intermediate eGFR results (60-89 mL/min) most likely to progress to CKD.

Overall, the study authors concluded that “risk prediction tools can assist clinicians to stratify those at highest risk, with most to gain from increased monitoring, judicious [antiretroviral]  selection and aggressive management of risk factors.”

References

1. Woolnough EL, Hoy JF, Cheng AC, et al (2018) Predictors of chronic kidney disease and utility of risk prediction scores in HIV positive individuals [published online May 28, 2018]. AIDS. doi: 10.1097/QAD.0000000000001901
2. Scherzer R, Gandhi M, Estrella MM, et al. A chronic kidney disease risk score to determine tenofovir safety in a prospective cohort of HIV-positive male veterans. AIDS 2014;28(9):1289-1295.