Blog entry by Meguid El Nahas
Issue 2, 2011
Renal Disease Associated with Antiretroviral Therapy (ART) in the Treatment of HIV
(R.D. Cooper, M. Tonelli, Edmonton, Canada; Nephron Clin Pract 2011;118:262-268). In this review, the authors highlight the impact but also the potential nephrotoxicity of antiretroviral agents. They urge those treating HIV-positive individuals to discriminate between drug-related nephrotoxicity and other causes of HIV-associated kidney injury. They also stress that renal dysfunction should not be considered a contraindication to initiation of ART. However, it is important to bear in mind that kidney function at ART initiation is an independent predictor of death in HIV-infected individuals, especially in those with a history of AIDS. There is little doubt that close monitoring of renal function is essential to minimize complications and improve outcomes in HIV-infected individuals. Kidney damage related to ATR is typically reversible with early recognition and timely discontinuation of the offending agent. Nephrologists should be familiar with the potential toxicity of these agents to avoid delays in diagnosis.
The Burden of Chronic Kidney Disease (CKD) on Developing Nations: A 21st Century Challenge in Global Health
(R.A. Nugent and colleagues, USA and UK; Nephron Clin Pract 2011;118:269-277). In this review, Nugent from the Center for Global Development and her colleagues highlight issues related to the impact of CKD on health in emerging economies. Such countries are the subject of a triple hit that leads to the development of CKD and impacts on population health and survival, i.e. poverty, infectious (communicable) disease as well as westernization with the sharp rise in noncommunicable chronic disease. The latter, as highlighted in the review, includes obesity with its impact on the development of diabetes, hypertension and cardiovascular disease (CVD). Moreover, life expectancy is rising in developing countries, which is associated with increased life course exposure to risk factors that lead to CKD and CVD. Cost-effective detection and management approaches are also advocated, stressing that they have to be adjusted to meet the local needs and means and also have to take into consideration access to care and related cost. The 21st century with advances in telecommunication may open new and exciting opportunities to access healthcare in emerging countries. After all, before too long most people in those countries will have a mobile phone, but few will have access to a doctor! Perhaps, Mobile Health can be one way forward...
Clinical Characteristics of Kidney Disease in Japanese HIV-Infected Patients
(N. Yanagisawa and colleagues, Japan; Nephron Clin Pract 2011;118:285-291). The authors have studied prevalence of CKD in HIV-infected Japanese patients. They report that microalbuminuria, macroalbuminuria and proteinuria were present in 13.2, 4.55 and 9.52% of patients, respectively. The prevalence of CKD of any stage and CKD stage 3 and above was 15.4 and 9.70%, respectively. Multivariate analysis showed significant associations between the coexistence of diabetes, hypertension and hepatitis C infection with either proteinuria or albuminuria, which was significantly related to the presence of renal dysfunction. Lower CD4 cell count was associated with the presence of renal dysfunction, but higher HIV-RNA level was not. These figures bear striking similarities to those published elsewhere with a high prevalence of microalbuminuria. Care should be taken not to confound microalbuminuria due to infection, inflammation and associated with poverty in these individuals with intrinsic CKD. All too often Nephrologists do not fully appreciate that microalbuminuria is a sensitive marker of systemic infections and associated inflammation, that is reversible when the condition is treated. Caution should also be exerted when prevalence estimates are derived from single cross-sectional sampling as CKD diagnosis needs confirmatory testing to ascertain the chronic nature of the renal dysfunction. Finally, 90% of the patients reported in this study were treated with ART, which, as highlighted in the review by Cooper and Tonelli, can be associated with renal toxicity.
Proteinuria Thresholds Are Irrational: A Call for Proteinuria Indexing
(T.J. Ellam, M. El Nahas, UK; Nephron Clin Pract 2011;118:217-224). The authors draw the reader’s attention to the notion that current CKD guidelines are based on absolute thresholds of proteinuria/albuminuria, with no reference to the residual renal function. They argue that this is illogical as the severity of proteinuria is a direct reflection of the number of residual filtering nephrons as well as their pathology and the capacity of the tubules to reabsorb filtered protein/albumin. The current simplistic approach to proteinuria may also compromise its usefulness in diagnosis and prognosis of CKD. The routine measurement of the urinary protein/albumin:creatinine ratio (PCR/ACR) and estimated glomerular filtration rate (eGFR) gives rise to the opportunity to index proteinuria for renal function (i.e. a PCR:eGFR or ACR:eGFR ratio). The authors advocate consideration of the benefits of indexing PCR/ACR for eGFR to optimize treatment decisions based on proteinuria/albuminuria. Consideration should also be given to correcting urinary creatinine values (for ACR/PCR calculation) to age and gender in order to adjust for creatinine generation as already done with serum creatinine estimation and calculation of eGFR.