Chronic kidney disease as a global public health problem: approaches and initiatives - a position statement from Kidney Disease Improving Global Outcomes

Advances in glomerular filtration rate-estimating equations

PURPOSE OF REVIEW

Estimated glomerular filtration rate (eGFR) is now commonly reported by clinical laboratories. Here, we review the performance of current creatinine and cystatin C-based estimating equations as well as demonstration of their utility in public health and clinical practice.

RECENT FINDINGS

Lower levels of GFR are associated with multiple adverse outcomes, including acute kidney injury and medical errors. The new Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation improves performance and risk prediction compared with the Modification of Diet in Renal Disease study equation. Current cystatin C-based equations are not accurate in all populations, even in those with reduced muscle mass or chronic illness, in which cystatin C would be expected to outperform creatinine. eGFR reporting has led to a greater number of referrals to nephrologists, but the increased numbers do not appear to be excessive or burdensome. The Modification of Diet in Renal Disease study equation appears to be able to provide drug dosage adjustments similar to the Cockcroft-Gault equation.

SUMMARY

Estimated GFRs and their reporting can improve and facilitate clinical practice for chronic kidney disease. Understanding strengths and limitations facilitates their optimal use. Endogenous filtration markers, alone or in combination, which are less dependent on non-GFR determinants of the filtration markers, are necessary to lead to more accurate eGFRs.

A challenge to chronic kidney disease in Asia: The report of the second Asian Forum of Chronic Kidney Disease Initiative

BACKGROUND

The Asian Forum of Chronic Kidney Disease Initiative started in 2007 in Hamamatsu, Japan when delegates from 16 countries joined together to facilitate collaboration in studying chronic kidney disease (CKD) in the Asia-Pacific region. Based on the outcome of the first meeting, the second meeting was organized as a consensus conference to frame the most relevant issues, and develop research recommendations and action plan.

PROCEEDINGS

The meeting was held on 4 May 2008 as a pre-conference meeting to the 11th Asian Pacific Congress of Nephrology in Kuala Lumpur. This meeting consisted of three sessions: Session I was dedicated to the estimation of glomerular filtration rate and the standardization of serum creatinine measurements. Session II discussed specific considerations in the aetiology of and risk factors for end-stage renal disease in Asia. We concluded that there were regional specific problems that might lead to a very high prevalence of end-stage renal disease. Session III discussed the issue of facilitation of coordination and integration of the CKD initiative between developed and developing countries in the Asia-Pacific region.

CONCLUSION

The following action plans were formulated: (i) validating the existing global estimated glomerular filtration rate equation or creating a new one using serum creatinine standardized by a central laboratory; (ii) establishing a pan-Asian CKD registry to facilitate risk analysis of CKD and its comorbidities; (iii) adapting existing clinical practice guidelines for CKD detection and management to address specific problems in this region; and (iv) working closely with other international professional organizations to promote manpower development and education in different aspects of CKD in developing countries.

Genome-wide association studies in nephrology research

Kidney diseases constitute a serious public health burden worldwide, with substantial associated morbidity and mortality. The role of a genetic contribution to kidney disease is supported by heritability studies of kidney function measures, the presence of monogenic diseases with renal manifestations, and familial aggregation studies of complex kidney diseases, such as chronic kidney disease. Because complex diseases arise from the combination of multiple genetic and environmental risk factors, the identification of underlying genetic susceptibility variants has been challenging. Recently, genome-wide association studies have emerged as a method to conduct searches for such susceptibility variants. They have successfully identified genomic loci that contain variants associated with kidney diseases and measures of kidney function. For example, common variants in the UMOD and PRKAG2 genes are associated with risk of chronic kidney disease; variants in CLDN14 with risk of kidney stone disease; and variants in or near SHROOM3, STC1, LASS2, GCKR, NAT8/ALMS1, TFDP2, DAB2, SLC34A1, VEGFA, FAM122A/PIP5K1B, ATXN2, DACH1, UBE2Q2/FBXO22, and SLC7A9, with differences in glomerular filtration rate. The purpose of this review is to provide an overview of the genome-wide association study method as it relates to nephrology research and summarize recent findings in the field. Results from genome-wide association studies of renal phenotypes represent a first step toward improving our knowledge about underlying mechanisms of kidney function and disease and ultimately may aid in the improved treatment and prevention of kidney diseases.

The finding of reduced estimated glomerular filtration rate is associated with increased mortality in a large UK population

BACKGROUND

CKD as defined by KDIGO/KDOQI has been shown to affect ~ 8.5% of the UK population. The prevalence of CKD in the UK is similar to that in the USA, yet incident dialysis rates are dramatically different. This retrospective cohort study investigates the association between reduced kidney function and mortality in a large UK population.

METHODS

All serum creatinine results covering Northern Ireland's 1.7 million population were collected between 1 January 2001 and 31 December 2002. Estimated glomerular filtration rates (eGFR) were calculated for all serum creatinine measurements using four-variable MDRD equation (IDMS aligned). Patients were followed up for both all-cause and cardiovascular mortality data until the end of December 2006. Patients on renal replacement therapy were excluded. Subgroup analysis in the 75,345 subjects enrolled within a parallel primary care study permitted additional survival analysis with adjustment for traditional cardiovascular risk factors.

RESULTS

A total of 1,967,827 serum creatinine results from 533,798 patients were collected. During the period of follow-up, 59,980 deaths occurred. In multivariate survival analysis, using eGFR as a time-varying covariate, a graded association between CKD (defined by eGFR) and all-cause mortality was identified. Compared with participants with an eGFR of > 60 mL/min/1.73 m(2), the adjusted hazard ratios (and 95% confidence intervals) for participants with an eGFR of 45-59 mL/min/1.73 m(2) was 1.02 (0.99-1.04), an eGFR of 30-44 mL/min/1.73 m(2) was 1.44 (1.40-1.47), an eGFR of 15-29 mL/min/1.73 m(2) was 2.12 (2.05-2.20) and an eGFR of < 15 mL/min/1.73 m(2) was 3.46 (3.24-3.70). Significantly, increased all-cause mortality was associated with an eGFR < 45 mL/min/1.73 m(2) following adjustment for age and gender. The association between cardiovascular mortality and reduced renal function continued to be significant for participants with an eGFR of 45-65 mL/min/1.73 m(2). Subgroup analysis in 75,345 individuals with more detailed clinical information available confirmed this association following adjustment for traditional cardiovascular risk factors in addition to age and gender.

CONCLUSIONS

This study demonstrates a graded association between reduced renal function as represented by eGFR and mortality in a UK population. The all-cause and cardiovascular mortality risk increases sharply when estimated GFR falls < 45 mL/min/1.73 m(2). The association between an eGFR measured between 45 and 65 mL/min/1.73 m(2) and cardiovascular mortality persists in this cohort and highlights the ongoing uncertainty in accurately categorizing renal dysfunction.

Kidney function, albuminuria, and all-cause mortality in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study

BACKGROUND

Chronic kidney disease and albuminuria are associated with increased risk of all-cause mortality.

STUDY DESIGN

Prospective observational cohort study.

SETTING & PARTICIPANTS

17,393 participants (mean age, 64.3 ± 9.6 years) in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) Study.

PREDICTOR

Estimated glomerular filtration rate (eGFR), urinary albumin-creatinine ratio (ACR).

OUTCOME

All-cause mortality (710 deaths); median duration of follow-up, 3.6 years. MEASUREMENTS & ANALYSIS: Categories of eGFR (90 to <120, 60 to <90, 45 to <60, 30 to <45, and 15 to <30 mL/min/1.73 m(2)) and urinary ACR (<10 mg/g or normal, 10 to <30 mg/g or high normal, 30 to 300 mg/g or high, and >300 mg/g or very high). Cox proportional hazards models were adjusted for demographic factors, cardiovascular covariates, and hemoglobin level.

RESULTS

The background all-cause mortality rate for participants with normal ACR, eGFR of 90 to <120 mL/min/1.73 m(2), and no coronary heart disease was 4.3 deaths/1,000 person-years. Higher ACR was associated with an increased multivariable-adjusted HR for all-cause mortality within each eGFR category. Decreased eGFR was associated with a higher adjusted HR for all-cause mortality for participants with high-normal (P = 0.01) and high (P < 0.001) ACRs, but not those with normal or very high ACRs.

LIMITATIONS

Only 1 laboratory assessment for serum creatinine and ACR was available.

CONCLUSIONS

Increased albuminuria was an independent risk factor for all-cause mortality. Decreased eGFR was associated with increased mortality risk in those with high-normal and high ACRs. The mortality rate was low in the normal-ACR group and increased in the very-high-ACR group, but did not vary with eGFR in these groups.

Impact of reduced kidney function on cardiopulmonary fitness in patients with systolic heart failure

BACKGROUND

Decreased renal function has been consistently associated with increased mortality among patients with systolic heart failure. The relationship between estimated glomerular filtration rate (eGFR) and other high-risk features including reduced cardiorespiratory fitness has not been previously reported in this patient population.

METHODS

The HF-ACTION trial was a prospective, randomized trial of exercise therapy versus usual care in patients with systolic heart failure. Patients with class 2-4 heart failure and a left ventricular ejection fraction of ≤ 35% were recruited. Serum creatinine was measured up to 1 year prior to entry. The 4-variable modified Modification of Diet in Renal Disease equation was used to calculate eGFR. Peak oxygen consumption (peak VO(2)) was directly measured using gas exchange analysis during progressive exercise testing to volitional fatigue or adverse signs/symptoms.

RESULTS

Of 2,091 subjects (mean age 59 ± 13 years, with serum creatinine available at baseline), 72% were men, and 61, 33, and 5% were Caucasians, African Americans, and others, respectively. Older age, diabetes, and hypertension were all more frequent with declining eGFR. The Pearson correlation between eGFR and peak VO(2) was 0.22 (p < 0.0001). Age was negatively correlated with both eGFR (r = -0.44, p < 0.0001) and peak VO(2) (r = -0.27, p < 0.0001). The peak VO(2) tended to decline across decreasing levels of eGFR. Individuals with an eGFR <30 ml/min/1.73 m(2) had, on average, 2.1 high-risk features including peak VO(2) <14 ml/kg/min, age >75 years, diabetes, and functional class 3-4 symptoms. Conversely, those with an eGFR >90 ml/min/1.73 m(2) had relatively few (1.0) high-risk characteristics.

CONCLUSIONS

Reduced renal filtration is associated with impaired cardiorespiratory fitness and a clustering of high-risk features in systolic heart failure patients which portend a more complicated course and higher all-cause mortality.

Hyperuricemia as an independent risk factor of chronic kidney disease in middle-aged and elderly population

INTRODUCTION

Hyperuricemia in the general population remains controversial, in terms of it being considered a risk factor for chronic kidney disease (CKD). Within this context, we evaluated the effects of hyperuricemia on renal function in older Taiwanese adults.

METHODS

From January 2002 to December 2006, we conducted a community-based medical screening program involving 31,331 subjects older than 40 years. According to the National Kidney Foundation guidelines, stage 3 to 5 patients with CKD were included for analysis. Age, body mass index, systolic blood pressure, fasting plasma glucose, triglyceride, cholesterol and proteinuria were considered potential confounders.

RESULTS

Participants with hyperuricemia tended to have higher systolic blood pressure, sugar levels, body mass index, and cholesterol and triglyceride levels but lower estimated glomerular filtration rate (eGFR) levels; eGFR negatively correlated with serum uric acid level. By using multiple logistic regression models before and after adjusting for any confounding factors, we noted that participants with hyperuricemia had a 4.036-fold (odds ratios = 4.036) and 3.649-fold (odds ratios = 3.649) increased risk for CKD, respectively, compared with the control group. We used multiple linear regression analysis to examine the association of serum uric acid level and eGFR at different stages of CKD; significance was found only in participants with stage 3 CKD and not in participants with stages 4 or 5.

CONCLUSIONS

Hyperuricemia is an independent risk factor for CKD in middle-aged and elderly Taiwanese adults. Thus, an effective screening program that identifies people with hyperuricemia is warranted.

Association of estimated glomerular filtration rate and albuminuria with all-cause and cardiovascular mortality in general population cohorts: a collaborative meta-analysis

BACKGROUND

Substantial controversy surrounds the use of estimated glomerular filtration rate (eGFR) and albuminuria to define chronic kidney disease and assign its stages. We undertook a meta-analysis to assess the independent and combined associations of eGFR and albuminuria with mortality.

METHODS

In this collaborative meta-analysis of general population cohorts, we pooled standardised data for all-cause and cardiovascular mortality from studies containing at least 1000 participants and baseline information about eGFR and urine albumin concentrations. Cox proportional hazards models were used to estimate hazard ratios (HRs) for all-cause and cardiovascular mortality associated with eGFR and albuminuria, adjusted for potential confounders.

FINDINGS

The analysis included 105,872 participants (730,577 person-years) from 14 studies with urine albumin-to-creatinine ratio (ACR) measurements and 1,128,310 participants (4,732,110 person-years) from seven studies with urine protein dipstick measurements. In studies with ACR measurements, risk of mortality was unrelated to eGFR between 75 mL/min/1.73 m(2) and 105 mL/min/1.73 m(2) and increased at lower eGFRs. Compared with eGFR 95 mL/min/1.73 m(2), adjusted HRs for all-cause mortality were 1.18 (95% CI 1.05-1.32) for eGFR 60 mL/min/1.73 m(2), 1.57 (1.39-1.78) for 45 mL/min/1.73 m(2), and 3.14 (2.39-4.13) for 15 mL/min/1.73 m(2). ACR was associated with risk of mortality linearly on the log-log scale without threshold effects. Compared with ACR 0.6 mg/mmol, adjusted HRs for all-cause mortality were 1.20 (1.15-1.26) for ACR 1.1 mg/mmol, 1.63 (1.50-1.77) for 3.4 mg/mmol, and 2.22 (1.97-2.51) for 33.9 mg/mmol. eGFR and ACR were multiplicatively associated with risk of mortality without evidence of interaction. Similar findings were recorded for cardiovascular mortality and in studies with dipstick measurements.

INTERPRETATION

eGFR less than 60 mL/min/1.73 m(2) and ACR 1.1 mg/mmol (10 mg/g) or more are independent predictors of mortality risk in the general population. This study provides quantitative data for use of both kidney measures for risk assessment and definition and staging of chronic kidney disease.

FUNDING

Kidney Disease: Improving Global Outcomes (KDIGO), US National Kidney Foundation, and Dutch Kidney Foundation.

Nephrogenic systemic fibrosis: a survey of nephrologists' perceptions and practices

BACKGROUND AND OBJECTIVES

Nephrogenic systemic fibrosis (NSF) is a disorder that can affect patients with renal dysfunction exposed to a gadolinium-based contrast agent (GBCA). Given the unique role nephrologists play in caring for patients at risk to develop NSF, this study surveyed their perceptions and practices regarding NSF.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

An internet-based, cross-sectional survey of clinical nephrologists in the United States was performed. Perceptions and self-reported practices regarding NSF and local facility policies were assessed concerning GBCA use in renal dysfunction.

RESULTS

Of the 2310 eligible nephrologists e-mailed to participate in the survey, 171 (7.4%) responded. Respondents spent 85% of their time in direct patient care and 83% worked in private practice; 59% had cared for a patient with NSF. Although over 90% were aware of the morbidity and mortality associated with NSF, 31% were unaware of an association with specific GBCA brand and 50% believed chronic kidney disease stage 3 patients were at risk to develop NSF. Changes in facility policies concerning GBCA use in renal dysfunction were widespread (>90%). Most nephrologists (56%) felt that enacted policies were appropriate, yet 58% were uncertain if the changes had benefited patients.

CONCLUSIONS

These results indicate that nephrologists are generally familiar with the risk factors and consequences of NSF, but their perceptions do not always align with current evidence. Local policy changes in GBCA use are pervasive. Most nephrologists are comfortable with these policy changes but have mixed feelings regarding their effectiveness.

Surveillance of chronic kidney disease around the world: tracking and reining in a global problem

In recent years, there has been a general recognition of the importance of tackling noncommunicable chronic diseases throughout the world and not just in developed nations. Chronic kidney disease (CKD) is increasingly recognized as a public health threat, based on its high prevalence, rising incidence, associated complications, and cost. It is imperative that nations develop screening and surveillance programs related to CKD. This article provides a global perspective on existing and emerging CKD surveillance efforts. A variety of programs are described, ranging from cross-sectional screening studies to determine CKD prevalence; targeted screening of high-risk populations presenting for voluntary testing; to more systematic surveillance within the scope of integrated health care systems in many developed nations. The choice of surveillance programs for many countries will depend on available resources and competing health care priorities. Integration with surveillance programs for other major chronic diseases such as diabetes, hypertension, and obesity is highly desirable and could be a key to the prevention of CKD. Finally, we propose the model of integrated health systems as one that is perhaps best suited to systematic, longitudinal surveillance of many chronic diseases, a model based on a national electronic health care record with linkage across primary care and hospital-based programs. Robust health education efforts and timely dissemination strategies will remain the key to the success of disease surveillance. It is gratifying to note that more and more countries are developing and adopting CKD surveillance programs as part of national disease prevention strategies.

Risk factors and screening for chronic kidney disease

The asymptomatic nature of chronic kidney disease (CKD) makes explicit screening strategies for individuals at risk as the only means of early detection. This will allow more time for interventions to alter the natural history of the disease by delaying or preventing kidney disease progression and its complications. Patient awareness of CKD remains low. Utilization of CKD tests for patients at risk and interpretation of those tests to detect CKD by primary care physicians remain suboptimal. There is insufficient evidence to support general population screening. Diabetes, hypertension, and age 60 or greater are the primary CKD screening target conditions, based on assessments representative of the general populations in America and Norway. Although cardiovascular disease, family history of CKD, and ethnic and racial minorities are important predictors of CKD risk, they do not contribute significantly beyond the scope of diabetes, hypertension, and older age. Challenges remain to define the roles in the community of the primary physician and nephrologist to implement intensive blood pressure control, use of renin-angiotensin system blockers for proteinuric patients and nephrology referral as indicated. The electronic medical record holds the most promise in CKD screening through improvements in the flow of information and application of clinical decision support.

Chronic kidney disease and cancer: a troubling connection

Chronic kidney disease (CKD) and cancer are connected in a number of ways in both directions: cancer can cause CKD either directly or indirectly through the adverse effects of therapies; CKD may, conversely, be a risk factor for cancer; and both may be associated because they share common risk factors, often toxins. In this review, we briefly address the issue of paraneoplastic nephropathies as well as that of toxin-related cancers and CKD, including analgesic and aristolochic acid nephropathies. We then focus on the links between the various stages of CKD and cancer incidence, and critically examine major epidemiologic surveys in the field. Compared with the general population, kidney transplant recipients have a threefold to fourfold increase in overall cancer risk, and relative risks higher than 3 for about 20 specific tumors, most, but not all, of which are known or suspected to be caused by viral agents. After dialysis, cancer risk increases 10% to 80% according to studies, with relative risks significantly higher than in the general population, for about 10 cancer sites. There is emerging evidence for an excess risk of cancer in patients in early CKD stages.

Awareness of chronic kidney disease among patients and providers

Earlier recognition of chronic kidney disease (CKD) could slow progression, prevent complications, and reduce cardiovascular-related outcomes. However, current estimates of CKD awareness indicate that both patient- and provider-level awareness remain unacceptably low. Many of the factors that are possibly associated with CKD awareness, which could help guide implementation of awareness efforts, have yet to be fully examined. Also, little is known regarding whether increased patient or provider awareness improves clinical outcomes, or whether there are possible negative consequences of awareness for CKD patients. Further research is necessary to continue to design and refine awareness campaigns aimed at both patients and providers, but there is an immediate need for dissemination of basic CKD information, given both the high prevalence of CKD and its risk factors and the low estimated awareness of CKD.

Alcohol consumption and kidney function decline in the elderly: alcohol and kidney disease

BACKGROUND

Alcohol consumption appears to be protective for cardiovascular disease; however, its relationship with kidney disease is unclear.

METHODS

This prospective cohort study included 4343 subjects from the Cardiovascular Health Study, a longitudinal, community-based cohort of persons aged ≥65 from four US communities. We used previously defined categories based on weekly alcohol consumption: none, former, <1 drink, 1-6 drinks, 7-13 drinks and ≥14 drinks. Cystatin C was measured at baseline, year 3 and year 7; eligible subjects had at least two measures. Estimated GFR(cys) was calculated from cystatin C. The primary outcome was rapid kidney function as an annual estimated GFR (eGFR(cys)) loss >3 mL/min/1.73 m(2)/year.

RESULTS

Eight percent of the cohort reported former alcohol use and 52% reported current alcohol consumption. During a mean follow-up of 5.6 years, 1075 (25%) participants had rapid kidney function decline. In adjusted logistic regression models, there was no association between alcohol use and kidney function decline (odds ratio, 95% confidence interval: none = reference; former = 1.18, 0.89-1.56; <1 drink = 1.20, 0.99-1.47; 1-6 = 1.18, 0.95-1.45; 7-13 = 1.10, 0.80-1.53; >14 = 0.89, 0.61-1.13). Results were similar with kidney function decline as a continuous outcome.

CONCLUSIONS

Our results suggest that moderate alcohol consumption has neither adverse nor beneficial effects on kidney function. Although clinicians will need to consider the potential deleterious effects associated with alcohol consumption, there does not appear to be a basis for recommending that older adults discontinue or initiate light to moderate alcohol consumption to protect against kidney disease.

New loci associated with kidney function and chronic kidney disease

Chronic kidney disease (CKD) is a significant public health problem, and recent genetic studies have identified common CKD susceptibility variants. The CKDGen consortium performed a meta-analysis of genome-wide association data in 67,093 individuals of European ancestry from 20 predominantly population-based studies in order to identify new susceptibility loci for reduced renal function as estimated by serum creatinine (eGFRcrea), serum cystatin c (eGFRcys) and CKD (eGFRcrea < 60 ml/min/1.73 m(2); n = 5,807 individuals with CKD (cases)). Follow-up of the 23 new genome-wide-significant loci (P < 5 x 10(-8)) in 22,982 replication samples identified 13 new loci affecting renal function and CKD (in or near LASS2, GCKR, ALMS1, TFDP2, DAB2, SLC34A1, VEGFA, PRKAG2, PIP5K1B, ATXN2, DACH1, UBE2Q2 and SLC7A9) and 7 loci suspected to affect creatinine production and secretion (CPS1, SLC22A2, TMEM60, WDR37, SLC6A13, WDR72 and BCAS3). These results further our understanding of the biologic mechanisms of kidney function by identifying loci that potentially influence nephrogenesis, podocyte function, angiogenesis, solute transport and metabolic functions of the kidney.

Genetic loci influencing kidney function and chronic kidney disease

Using genome-wide association, we identify common variants at 2p12-p13, 6q26, 17q23 and 19q13 associated with serum creatinine, a marker of kidney function (P = 10(-10) to 10(-15)). Of these, rs10206899 (near NAT8, 2p12-p13) and rs4805834 (near SLC7A9, 19q13) were also associated with chronic kidney disease (P = 5.0 x 10(-5) and P = 3.6 x 10(-4), respectively). Our findings provide insight into metabolic, solute and drug-transport pathways underlying susceptibility to chronic kidney disease.

Early recognition and prevention of chronic kidney disease

Chronic kidney disease is a common disorder and its prevalence is increasing worldwide. Early diagnosis on the basis of presence of proteinuria or reduced estimated glomerular filtration rate could permit early intervention to reduce the risks of cardiovascular events, kidney failure, and death that are associated with chronic kidney disease. In developed countries, screening for the disorder is most efficient when targeted at high-risk groups including elderly people and those with concomitant illness (such as diabetes, hypertension, or cardiovascular disease) or a family history of chronic kidney disease, although the role of screening in developing countries is not yet clear. Effective strategies are available to slow the progression of chronic kidney disease and reduce cardiovascular risk. Treatment of high blood pressure is recommended for all individuals with, or at risk of, chronic kidney disease. Use of angiotensin-converting-enzyme inhibitors or angiotensin-receptor blockers is preferred for patients with diabetic chronic kidney disease or those with the proteinuric non-diabetic disorder. Glycaemic control can help prevent the onset of early stages of chronic kidney disease in individuals with diabetes. Use of statins and aspirin is beneficial for most patients with chronic kidney disease who are at high cardiovascular risk, although research is needed to ascertain how to best prevent cardiovascular disease in this cohort. Models of care that facilitate delivery of the many complex aspects of treatment simultaneously could enhance management, although effects on clinical outcomes need further assessment. Novel clinical methods to better identify patients at risk of progression to later stages of chronic kidney disease, including kidney failure, are needed to target management to high-risk subgroups.

Early detection of Balkan endemic nephropathy in Bosanska Posavina

Balkan endemic nephropathy (BEN) is a chronic tubulointersticial nephropathy that is diagnosed in a few agrarian regions of Balkan. Even tough numerous dilemmas and conflicting opinions regarding BEN etiology are encountered in literature, prevailing theory is that BEN is caused by chronic poisoning with aristolochic acid ingested by food in people with genetic predisposition to this disease. BEN is categorized as a toxic tubulointerstitial nephropathy, with clinical picture and disease progression not differing from other tubulointerstitial nephropathies, but with insidious and gradual progression to end stage renal disease. There is no specific and sensitive diagnostic biomarkers for BEN and we use epidemiological and functional diagnostic criteria. It is considered that BEN affects up to 10% of population in endemic region. According to Renal Register of Bosnia and Herzegovina, there are around 15% of BEN patients on chronic dialysis program, but no official data on the number of predialysis BEN patients, because of lack of adequate demographic data and screening or systematic examinations of the population living in the affected region since 1991. The members of the Society of nephrology, dialysis and transplantation of Bosnia and Herzegovina organized screening in two villages of Bosanska Posavina, as a part of the "Program Program of detection of chronic kidney diseases in high-risk population in Bosnia and Herzegovina", project which was approved from International Society of nephrology. In this paper we analyze preliminary results of that Program and discuss previous studies about BEN in Bosnia and Herzegovina, particularly diagnostic criteria and biomarkers of BEN.

Prevalence of chronic kidney disease in persons with undiagnosed or prehypertension in the United States

Hypertension is both a cause and a consequence of chronic kidney disease, but the prevalence of chronic kidney disease throughout the diagnostic spectrum of blood pressure has not been established. We determined the prevalence of chronic kidney disease within blood pressure categories in 17 794 adults surveyed by the National Health and Nutrition Examination Survey during 1999-2006. Diagnosed hypertension was defined as self-reported provider diagnosis (n=5832); undiagnosed hypertension was defined as systolic blood pressure > or = 140 mm Hg or diastolic blood pressure > or = 90 mm Hg, without report of provider diagnosis (n=3046); prehypertension was defined as systolic blood pressure > or = 120 and <140 mm Hg or diastolic blood pressure > or = 80 and <90 mm Hg (n=3719); and normal was defined as systolic blood pressure <120 mm Hg and diastolic blood pressure <80 mm Hg (n=5197). Chronic kidney disease was defined as estimated glomerular filtration rate <60 mL/min per 1.73 m(2) or urinary albumin:creatinine ratio >30 mg/g. Prevalences of chronic kidney disease among those with prehypertension and undiagnosed hypertension were 17.3% and 22.0%, respectively, compared with 27.5% with diagnosed hypertension and 13.4% with normal blood pressure, after adjustment for age, sex, and race in multivariable logistic regression. This pattern persisted with varying definitions of kidney disease; macroalbuminuria (urinary albumin:creatinine ratio >300 mg/g) had the strongest association with increasing blood pressure category (odds ratio: 2.37 [95% CI: 2.00 to 2.81]). Chronic kidney disease is prevalent in undiagnosed and prehypertension. Earlier identification and treatment of both these conditions may prevent or delay morbidity and mortality from chronic kidney disease.

Raising awareness of chronic kidney disease in a Brazilian urban population

The incidence and prevalence of chronic kidney disease have been increasing in recent years in developing countries. The aim of this study was to report the results of a general chronic kidney disease awareness program applied to an urban population in a large Brazilian city. From January 2002 to January 2005 a total of 8883 individuals in the city of Curitiba (PR, Brazil) were screened for hypertension, body mass index, hematuria, and proteinuria. A family history and previous medical diagnosis of hypertension and diabetes mellitus (DM) were also recorded. Of the 8883 individuals assessed, 56% were women, subject median age was 47 years (range: 17-93 years) and more than 90% were Caucasian. Thirty percent had signs of hematuria, 6% had proteinuria, and 3% had hematuria and proteinuria. The median of mean arterial pressure values was 93 mmHg (range: 71-135 mmHg) and 16% of the population screened had a history of hypertension. A significant positive family history of both hypertension or DM was present in 42% (P < 0.0001; chi-square = 83.18) and 7% (P < 0.0001; chi-square = 161.31) of the hypertensive group, respectively. Finally, the prevalence of hypertension and DM was significantly higher in older individuals with proteinuria. In the present study, a higher prevalence of hematuria and proteinuria was found in older individuals with hypertension and diabetes compared to the general population. These data confirm the need for public awareness of renal disease in high-risk individuals.

Prevalence and risk factors for CKD in spouses and relatives of hemodialysis patients

BACKGROUND

A higher prevalence of chronic kidney disease (CKD) has been found in genetic relatives of patients with end-stage renal disease. However, the risk of CKD in nongenetic spouses of patients with end-stage renal disease is still unknown.

STUDY DESIGN

Cross-sectional study.

SETTING & PARTICIPANTS

196 first- and second-degree relatives and 95 spouses of 178 hemodialysis (HD) patients were enrolled. Two sex- and age-stratified matched counterpart controls were randomly selected from the population of a community screening program for CKD.

PREDICTORS

Relatives or spouses of HD patients and kidney disease risk factors.

OUTCOMES

Prevalence of CKD (albuminuria or low estimated glomerular filtration rate).

MEASUREMENT

Albuminuria (urine albumin-creatinine ratio > or = 30 mg/g), low estimated glomerular filtration rate (<60 mL/min/1.73 m(2)), and kidney disease risk factors of age, hypertension, diabetes mellitus, metabolic syndrome, and lifestyle.

RESULTS

A significantly higher prevalence of CKD was found in relatives (15.8% vs 7.5%; P = 0.01) and spouses (41.1% vs 15.8%; P < 0.001) of HD patients compared with their counterpart controls. Multiple logistic regression analysis showed that age (OR, 1.05) and hypertension (OR, 3.13) were significant independent risk factors for CKD in relatives of HD patients, whereas diabetes mellitus (OR, 3.51) was a significant risk factor for CKD in spouses of HD patients. For all pooled participants, being relatives (OR, 2.55) or spouses (OR, 2.80) of HD patients, age (OR, 1.06), female sex (OR, 1.81), diabetes mellitus (OR, 3.95), hypertension (OR, 1.85), and hyperuricemia (OR, 2.06) were independent significant risk factors for CKD.

LIMITATIONS

Cross-sectional research design, single laboratory measurement, and limited numbers of participants.

CONCLUSIONS

A comprehensive screening program for CKD is equally important in both relatives and spouses of HD patients, especially for participants with the renal risk factors of older age, hypertension, and diabetes mellitus. Spousal concordance of CKD suggests that the shared environmental factors and health behaviors might have important roles in the development of CKD.

Human recombinant ACE2 reduces the progression of diabetic nephropathy

OBJECTIVE

Diabetic nephropathy is one of the most common causes of end-stage renal failure. Inhibition of ACE2 function accelerates diabetic kidney injury, whereas renal ACE2 is downregulated in diabetic nephropathy. We examined the ability of human recombinant ACE2 (hrACE2) to slow the progression of diabetic kidney injury.

RESEARCH DESIGN AND METHODS

Male 12-week-old diabetic Akita mice (Ins2(WT/C96Y)) and control C57BL/6J mice (Ins2(WT/WT)) were injected daily with placebo or with rhACE2 (2 mg/kg, i.p.) for 4 weeks. Albumin excretion, gene expression, histomorphometry, NADPH oxidase activity, and peptide levels were examined. The effect of hrACE2 on high glucose and angiotensin II (ANG II)-induced changes was also examined in cultured mesangial cells.

RESULTS

Treatment with hrACE2 increased plasma ACE2 activity, normalized blood pressure, and reduced the urinary albumin excretion in Akita Ins2(WT/C96Y) mice in association with a decreased glomerular mesangial matrix expansion and normalization of increased alpha-smooth muscle actin and collagen III expression. Human recombinant ACE2 increased ANG 1-7 levels, lowered ANG II levels, and reduced NADPH oxidase activity. mRNA levels for p47(phox) and NOX2 and protein levels for protein kinase Calpha (PKCalpha) and PKCbeta1 were also normalized by treatment with hrACE2. In vitro, hrACE2 attenuated both high glucose and ANG II-induced oxidative stress and NADPH oxidase activity.

CONCLUSIONS

Treatment with hrACE2 attenuates diabetic kidney injury in the Akita mouse in association with a reduction in blood pressure and a decrease in NADPH oxidase activity. In vitro studies show that the protective effect of hrACE2 is due to reduction in ANG II and an increase in ANG 1-7 signaling.

The views of patients and carers in treatment decision making for chronic kidney disease: systematic review and thematic synthesis of qualitative studies

OBJECTIVE

To synthesise the views of patients and carers in decision making regarding treatment for chronic kidney disease, and to determine which factors influence those decisions.

DESIGN

Systematic review of qualitative studies of decision making and choice for dialysis, transplantation, or palliative care, and thematic synthesis of qualitative studies.

DATA SOURCES

Medline, PsycINFO, CINAHL, Embase, social work abstracts, and digital theses (database inception to week 3 October 2008) to identify literature using qualitative methods (focus groups, interviews, or case studies). Review methods Thematic synthesis involved line by line coding of the findings of the primary studies and development of descriptive and analytical themes.

RESULTS

18 studies that reported the experiences of 375 patients and 87 carers were included. 14 studies focused on preferences for dialysis modality, three on transplantation, and one on palliative management. Four major themes were identified as being central to treatment choices: confronting mortality (choosing life or death, being a burden, living in limbo), lack of choice (medical decision, lack of information, constraints on resources), gaining knowledge of options (peer influence, timing of information), and weighing alternatives (maintaining lifestyle, family influences, maintaining the status quo).

CONCLUSIONS

The experiences of other patients greatly influenced the decision making of patients and carers. The problematic timing of information about treatment options and synchronous creation of vascular access seemed to predetermine haemodialysis and inhibit choice of other treatments, including palliative care. A preference to maintain the status quo may explain why patients often remain on their initial therapy.

Metabolic syndrome and risk of development of chronic kidney disease: the Niigata preventive medicine study

BACKGROUND

The metabolic syndrome consists of a cluster of cardiovascular risk factors, many of which have also been implicated in the genesis of chronic kidney disease. We studied the impact of the metabolic syndrome on chronic kidney disease in general population.

METHODS

The Niigata Preventive Medicine Study was community-based prospective observational cohort study based upon the annual health examinations in Japan. We studied the association of the metabolic syndrome with a risk of development of kidney dysfunction and proteinuria in 34 986 participants without baseline kidney disease.

RESULTS

The metabolic syndrome was present in 3679 subjects (11%). During a follow-up of 5.8 years, kidney dysfunction developed in 184 subjects with metabolic syndrome (5.0%) and 746 subjects without metabolic syndrome (2.4%). The metabolic syndrome was associated with development of kidney dysfunction (hazard ratio [HR], 2.12). All of the metabolic syndrome components were associated with risk of kidney dysfunction. The risk of kidney dysfunction increased across a number of the fulfilled metabolic syndrome components. The association of metabolic syndrome with kidney dysfunction remained significant in subjects without hypertension, diabetes, or cardiovascular disease (HR, 1.99) and in those < or =60 years without hypertension, diabetes, or cardiovascular disease (HR, 2.11). The metabolic syndrome was similarly associated with the development of proteinuria in all subjects (HR, 1.67), in those without hypertension, diabetes, or cardiovascular disease (HR, 1.64) and in those < or =60 years without hypertension, diabetes, or cardiovascular disease (HR, 2.14).

CONCLUSIONS

The metabolic syndrome was associated with kidney disease even in subjects without major classical risk factors for chronic kidney disease.

Kidney disease: improving global outcomes

Kidney Disease: Improving Global Outcomes (KDIGO) is an independent organization with the mission to improve care and outcomes of patients with kidney disease worldwide through the development and coordination of clinical practice guidelines. KDIGO has established firm links with other organizations that have previously produced clinical practice guidelines in the field of kidney disease. The first three KDIGO guidelines--treatment of hepatitis C, management of bone and mineral disease, and care of kidney transplant recipients--have been finalized and the next three--acute kidney injury, management of glomerulonephritis, and management of blood pressure in chronic kidney disease--are under development. The ultimate goal is to cover most major aspects of care for patients with kidney disease. Corner stones of KDIGO's guideline development process are independent, multidisciplinary, international work groups, close collaboration with professional methodology experts who perform systematic evidence reviews, and open public review of each guideline. Grades of Recommendation Assessment, Development, and Evaluation (GRADE) methodology is applied for grading the quality of evidence and strength of recommendations. International conferences organized by KDIGO support the coordination of guideline development, assess the suitability of guideline topics and help to establish global consensus on definitions and policies.

Chronic kidney disease in long-term survivors of myeloablative allogeneic haematopoietic cell transplantation: prevalence and risk factors

BACKGROUND

Chronic kidney disease (CKD) seems to be common in long-term survivors of haematopoietic cell transplantation (HCT). However, the range of its frequency is very wide, likely due to variability in the definitions of CKD and the periods of follow-up.

METHODS

We conducted a cross-sectional and retrospective study in 158 adults who received myeloablative allogeneic HCT for lymphohaematologic malignancies at least 3 years ago and are alive today. The mean survival time was 6.15 +/- 4.88 years (range: 3-16 years). CKD was defined as a sustained decrease in glomerular filtration rate (GFR) or persistent proteinuria for a period more than 3 months. GFR was calculated based on serum creatinine (Cr) using the Modification of Diet in Renal Disease formula. Serum Cr and proteinuria were measured at least on three occasions separated by one or more months before the investigation. CKD was classified according to the National Kidney Foundation CKD staging. Proteinuria was defined as positive dipstick test > or =1+. The factors associated with the presence of CKD with a decrease of GFR (CKD > or = stage 3) were examined using multivariate logistic regression analysis, adjusted for demographic and clinical characteristics.

RESULTS

The prevalence of proteinuria was found in 36 out of 158 patients (22.8%). The prevalence of each CKD stage was as follows: Stage 0 (no CKD), 98 patients (62.0%); Stage 1, 18 patients (11.4%); Stage 2, 15 patients (9.5%); Stage 3, 8 patients (5.1%); Stage 4, 10 patients (6.3%) and Stage 5, 9 patients (5.7%). Initiation of chronic dialysis treatment or transplant was performed in seven CKD stage-5 patients (4.4%) at a mean of 10.9 +/- 3.72 years after HCT. Multivariate analysis identified acute kidney injury with HCT [odds ratio (OR), 9.920; 95% confidence interval (CI), 2.084-39.68; P = 0.0051], hypertension after HCT (OR, 4.031; 95% CI, 1.044-13.06; P = 0.0346) and survival time after HCT (OR, 4.275; 95% CI, 2.823-23.04; P = 0.0481) as significant factors associated with the presence of CKD > or = stage 3.

CONCLUSIONS

A remarkably high percentage of long-term survivors had evidence of proteinuria and all stages of CKD. CKD in transplant recipients may result from incomplete recovery from acute renal insults, hypertension and increasing longevity. The CKD cohort should be at a great risk for end-stage renal disease and cardiovascular morbidity and mortality. The burden of CKD should be recognized as a significant public health problem.

A systematic review of factors influencing decision-making in adults living with chronic kidney disease

OBJECTIVE

To identify factors influencing patient involvement in decision-making in the context of chronic kidney disease (CKD) and effective interventions to support their decision-making needs.

METHODS

A systematic review included studies and decision support tools that involved: (1) adults with CKD, (2) studies published from 1998-2008; and (3) a focus on patient decision-making needs, and/or barriers and facilitators to shared decision-making. Studies were quality appraised.

RESULTS

Forty studies were appraised. These studies mainly focused on the decisions patients with CKD faced around the choice of renal replacement therapy and withholding/withdrawing dialysis. Moreover, studies typically focused on health care professional's provision of information about the decision rather than identifying decisional conflict and supporting patients in decision-making. No studies were found that identified the patient's point of view about factors that might influence or inhibit quality decision-making. Factors influencing CKD patient's participation in decision included: (1) interpersonal relationships; (2) preservation of current well being, normality and quality of life; (3) need for control; and (4) personal importance on benefits and risks. Of the four patient decision aids identified, none had been evaluated for effectiveness.

CONCLUSION

Patients with CKD face decisions that are likely to cause decisional conflict. Most studies focused on information needs related to renal replacement therapy and withdrawing or withholding dialysis. There was less focus on other decision-making needs in the context of those choices and across the trajectory of CKD. Although patient decision aids and implementation of shared decision-making have been evaluated in patients with other medical conditions, little is known about interventions to support patients with CKD making quality decisions.

PRACTICE IMPLICATIONS

Patients with CKD have decision-making needs across the trajectory of their illness. Although little is known about supporting patients with CKD decision-making, support could be provided with protocols and tools that have been developed for other chronic illness situations. Development of CKD-specific clinical practice guidelines that include decision support best practices could benefit CKD patients. Research priorities include development and evaluation of CKD focused decision support tools and processes.

High prevalence of undiagnosed chronic kidney disease among at-risk population in Kinshasa, the Democratic Republic of Congo

Background

There is limited knowledge of Chronic Kidney Disease (CKD) among high risk populations, especially in the developing countries. We report our study of testing for CKD in at-risk subjects.

Methods

In a cross-sectional study, 527 people from primary and secondary health care areas in the city of Kinshasa were studied from a random sample of at-risk out-patients with hypertension, diabetes, obesity, or HIV+. We measured blood pressure (BP), blood glucose level, proteinuria, body mass index, and estimated glomerular filtration rate (eGFR by MDRD equation) using calibrated creatinine levels based on one random measurement. The associations between health characteristics, indicators of kidney damage (proteinuria) and kidney function (<60 ml/min/1.73 m²) were also examined.

Results

The prevalence of CKD in this study was 36%, but only 12% were aware of their condition. 4% of patients had stage 1 CKD, 6% stage 2, 18% stage 3, 2% stage 4, and 6% had stage 5. 24 hour quantitative proteinuria (>300 mg/day) was found in 19%. In those with the at-risk conditions, the % of CKD was: 44% in patients with hypertension, 39% in those with diabetes; 16% in the obese and 12% in those who were HIV+. 82% of those with a history of diabetes had elevated serum glucose levels at screening (≥ 126 mg/dl). Only 6% of individuals with hypertension having CKD had reduced BP to lower than 130/80 mmHg. In multivariate analysis, diabetes, proteinuria and hypertension were the strongest determinants of CKD 3+.

Conclusion

It appears that one out of three people in this at-risk population has undiagnosed CKD and poorly controlled CKD risk factors. This growing problem poses clear challenges to this developing country. Therefore, CKD should be addressed through the development of multidisciplinary teams and improved communication between traditional health care givers and nephrology services. Attention to CKD risk factors must become a priority.

Proteinuria as a surrogate outcome in CKD: report of a scientific workshop sponsored by the National Kidney Foundation and the US Food and Drug Administration

Changes in proteinuria have been suggested as a surrogate outcome for kidney disease progression to facilitate the conduct of clinical trials. This report summarizes a workshop sponsored by the National Kidney Foundation and US Food and Drug Administration (FDA) with the following goals: (1) to evaluate the strengths and limitations of criteria for assessment of proteinuria as a potential surrogate end point for clinical trials in chronic kidney disease (CKD), (2) to explore the strengths and limitations of available data for proteinuria as a potential surrogate end point, and (3) to delineate what more needs to be done to evaluate proteinuria as a potential surrogate end point. We review the importance of proteinuria in CKD, including the conceptual model for CKD, measurement of proteinuria and albuminuria, and epidemiological characteristics of albuminuria in the United States. We discuss surrogate end points in clinical trials of drug therapy, including criteria for drug approval, the definition of a surrogate end point, and criteria for evaluation of surrogacy based on biological plausibility, epidemiological characteristics, and clinical trials. Next, the report summarizes data for proteinuria as a potential surrogate outcome in 3 broad clinical areas: early diabetic kidney disease, nephrotic syndrome, and diseases with mild to moderate proteinuria. We conclude with a synthesis of data and recommendations for further research. At the present time, there appears to be sufficient evidence to recommend changes in proteinuria as a surrogate for kidney disease progression in only selected circumstances. Further research is needed to define additional contexts in which changes in proteinuria can be expected to predict treatment effect. We recommend collaboration among many groups, including academia, industry, the FDA, and the National Institutes of Health, to share data from past and future studies.

White/black racial differences in risk of end-stage renal disease and death

BACKGROUND

End-stage renal disease disproportionately affects black persons, but it is unknown when in the course of chronic kidney disease racial differences arise. Understanding the natural history of racial differences in kidney disease may help guide efforts to reduce disparities.

METHODS

We compared white/black differences in the risk of end-stage renal disease and death by level of estimated glomerular filtration rate (eGFR) at baseline in a national sample of 2,015,891 veterans between 2001 and 2005.

RESULTS

Rates of end-stage renal disease among black patients exceeded those among white patients at all levels of baseline eGFR. The adjusted hazard ratios for end-stage renal disease associated with black versus white race for patients with an eGFR > or = 90, 60-89, 45-59, 30-44, 15-29, and <15 mL/min/1.73 m2, respectively, were 2.14 (95% confidence interval [CI], 1.72-2.65), 2.30 (95% CI, 2.02-2.61), 3.08 (95% CI, 2.74-3.46), 2.47 (95% CI, 2.26-2.70), 1.86 (95% CI, 1.75-1.98), and 1.23 (95% CI, 1.12-1.34). We observed a similar pattern for mortality, with equal or higher rates of death among black persons at all levels of eGFR. The highest risk of mortality associated with black race also was observed among those with an eGFR 45-59 mL/min/1.73 m2 (hazard ratio 1.32, 95% CI, 1.27-1.36).

CONCLUSION

Racial differences in the risk of end-stage renal disease appear early in the course of kidney disease and are not explained by a survival advantage among blacks. Efforts to identify and slow progression of chronic kidney disease at earlier stages may be needed to reduce racial disparities.

Factors associated with low bone mass in the hemodialysis patients--a cross-sectional correlation study

BACKGROUND

Low bone mass is common in end-stage renal disease patients, especially those undergoing hemodialysis. It can lead to serious bone health problems such as fragility fractures. The purpose of this study is to investigate the risk factors of low bone mass in the hemodialysis patients.

METHODS

Sixty-three subjects on hemodialysis for at least 6 months were recruited from a single center for this cross-sectional study. We collected data by questionnaire survey and medical records review. All subjects underwent a bone mineral density (BMD) assay with dual-energy x-ray absorptiometry at the lumbar spine and right hip. Data were statistically analyzed by means of descriptive analysis, independent t test and one way analysis of variance for continuous variables, Pearson product-moment correlation to explore the correlated factors of BMD, and stepwise multiple linear regression to identify the predictors of low bone mass.

RESULTS

Using WHO criteria as a cutoff point, fifty-one subjects (81%) had a T-score lower than -1, of them 8 subjects (13%) had osteoporosis with the femoral neck most commonly affected. Regarding risk factors, age, serum alkaline phosphatase (ALP) level, and intact parathyroid hormone (iPTH) level had significant negative correlations with the femoral neck and lumbar spine BMD. On the other hand, serum albumin level, effective exercise time, and body weight (BW) had significant positive correlations with the femoral neck and lumbar spine BMD. Age, effective exercise time, and serum albumin level significantly predicted the femoral neck BMD (R(2) x 0.25), whereas BW and the ALP level significantly predicted the lumbar spine BMD (R(2) x 0.20).

CONCLUSION

This study showed that advanced age, low BW, low serum albumin level, and high ALP and iPTH levels were associated with a low bone mass in the hemodialysis patients. We suggest that regular monitoring of the femoral neck BMD, maintaining an adequate serum albumin level and BW, and undertaking an exercise program are important to improve bone health in the patients undergoing hemodialysis.

Multiple loci associated with indices of renal function and chronic kidney disease

Chronic kidney disease (CKD) has a heritable component and is an important global public health problem because of its high prevalence and morbidity. We conducted genome-wide association studies (GWAS) to identify susceptibility loci for glomerular filtration rate, estimated by serum creatinine (eGFRcrea) and cystatin C (eGFRcys), and CKD (eGFRcrea < 60 ml/min/1.73 m(2)) in European-ancestry participants of four population-based cohorts (ARIC, CHS, FHS, RS; n = 19,877; 2,388 CKD cases), and tested for replication in 21,466 participants (1,932 CKD cases). We identified significant SNP associations (P < 5 × 10(-8)) with CKD at the UMOD locus, with eGFRcrea at UMOD, SHROOM3 and GATM-SPATA5L1, and with eGFRcys at CST and STC1. UMOD encodes the most common protein in human urine, Tamm-Horsfall protein, and rare mutations in UMOD cause mendelian forms of kidney disease. Our findings provide new insights into CKD pathogenesis and underscore the importance of common genetic variants influencing renal function and disease.

What types of cancers are associated with immune suppression in HIV? Lessons from solid organ transplant recipients

PURPOSE OF REVIEW

To examine recently published evidence of cancer risk after solid organ transplantation to gain insight into cancers that are associated with immune suppression in HIV.

RECENT FINDINGS

Data from several population-based studies comparing cancer risk in recipients of solid organ transplants with that in the general population have demonstrated increased risk for a broad range of cancers, predominantly those with a known or suspected infectious cause. This increase in risk is independent of cohort aging and probably independent of established behavioral and other risk factors for cancer. Epidemiological risk factor data are limited but appear to indicate a relationship with severity and duration of immune suppression. A recent meta-analysis indicates a striking similarity in the pattern of cancer occurrence in transplant recipients and people with HIV/AIDS.

SUMMARY

The similarity of the increased risk of cancer in these two immunosuppressed populations, who differ with respect to their underlying conditions and lifestyles, is compelling evidence that these cancers are associated with immune deficiency. The mechanisms are not fully understood but appear to be related to impaired immune surveillance. These data challenge the classification of only a narrow range of cancers as associated with immune suppression in people with HIV/AIDS.