Microalbuminuria predicts overt proteinuria among patients with HIV infection

BACKGROUND

This study examines the association between microalbuminuria and the development of proteinuria among HIV-infected persons.

METHODS

A total of 948 subjects provided urine samples for albumin, protein and creatinine measurements semiannually. Microalbuminuria was defined as an albumin-to-creatinine ratio of >30 mg/g. Proteinuria was defined as a protein-to-creatinine ratio of > or =0.350 mg/mg. The progression from microalbuminuria to proteinuria was described.

RESULTS

At baseline, 69.4% of the subjects had no detectable proteinuria, 20.2% had microalbuminuria, and 10.4% had proteinuria. Subjects with microalbuminuria and proteinuria were more likely to be black (P=0.02), have lower CD4 cell counts (P=0.02 comparing subjects without abnormal urine protein excretion to subjects with microalbuminuria; P=0.0001 comparing subjects with microalbuminuria to subjects with proteinuria), and have a higher HIV RNA level (P=0.08 and 0.04, respectively). Among 658 subjects with normal urine protein, 82.7% continued to have no abnormality, 14.3% developed microalbuminuria, and 3.0% developed proteinuria. Subjects without baseline proteinuria (i.e. either normal protein excretion or microalbuminuria) who developed proteinuria were more likely to have microalbuminuria (P=0.001), a lower CD4 cell count (P=0.06), and a higher plasma HIV RNA (P=0.03) than those who did not progress to proteinuria. In multivariate analysis, only microalbuminuria remained associated with the development of proteinuria (odds ratio 2.9; 95% confidence interval 1.5, 5.5; P=0.001).

CONCLUSION

Microalbuminuria predicts the development of proteinuria among HIV-infected persons. Because proteinuria has been linked to poorer outcomes, strategies to affect microalbuminuria should be tested.

Research in HIV-related renal diseases lags behind their burden to the 'positive' community

Although outcomes for persons with HIV infection and renal disease have improved, the analysis by Choi et al. suggests that they remain similar to or worse than outcomes for persons with diabetes mellitus. This study should be used to frame the research resources that we devote to furthering knowledge in this area.

Association of intradialytic blood pressure changes with hospitalization and mortality rates in prevalent ESRD patients

The relationship between blood pressure (BP) and clinical outcomes among hemodialysis patients is complex and incompletely understood. This study sought to assess the relationship between blood pressure changes with hemodialysis and clinical outcomes during a 6-month period. This study is a secondary analysis of the Crit-Line Intradialytic Monitoring Benefit Study, a randomized trial of 443 hemodialysis subjects, designed to determine whether blood volume monitoring reduced hospitalization. Logistic regression was used to estimate the association between BP changes with hemodialysis (Deltasystolic blood pressure=postdialysis-predialysis systoic BP (SBP) and the primary outcome of non-access-related hospitalization and death. Subjects whose systolic blood pressure fell with dialysis were younger, took fewer blood pressure medications, had higher serum creatinine, and higher dry weights. After controlling for baseline characteristics, lab variables, and treatment group, subjects whose SBP remained unchanged with hemodialysis (N=150, DeltaSBP -10 to 10 mm Hg) or whose SBP rose with hemodialysis (N=58, DeltaSBP > or =10 mm Hg) had a higher odds of hospitalization or death compared to subjects whose SBP fell with hemodialysis (N=230, DeltaSBP < or =-10 mm Hg) (odds ratio: 1.85, confidence interval: 1.15-2.98; and odds ratio: 2.17, confidence interval: 1.13-4.15). Subjects whose systolic blood pressure fell with hemodialysis had a significantly decreased risk of hospitalization or death at 6 months, suggesting that hemodynamic responses to dialysis are associated with short-term outcomes among a group of prevalent hemodialysis subjects. Further research should attempt to elucidate the mechanisms behind these findings.

Associations between CMS's Clinical Performance Measures project benchmarks, profit structure, and mortality in dialysis units

Prior studies observing greater mortality in for-profit dialysis units have not captured information about benchmarks of care. This study was undertaken to examine the association between profit status and mortality while achieving benchmarks. Utilizing data from the US Renal Data System and the Centers for Medicare & Medicaid Services' end-stage renal disease (ESRD) Clinical Performance Measures project, hemodialysis units were categorized as for-profit or not-for-profit. Associations with mortality at 1 year were estimated using Cox regression. Two thousand six hundred and eighty-five dialysis units (31,515 patients) were designated as for-profit and 1018 (15,085 patients) as not-for-profit. Patients in for-profit facilities were more likely to be older, black, female, diabetic, and have higher urea reduction ratio (URR), hematocrit, serum albumin, and transferrin saturation. Patients (19.4 and 18.6%) in for-profit and not-for-profit units died, respectively. In unadjusted analyses, profit status was not associated with mortality (hazard ratio (HR)=1.04, P=0.09). When added to models with profit status, the following resulted in a significant association between profit status (for-profit vs not-for-profit) and increasing mortality risk: URR, hematocrit, albumin, and ESRD Network. In adjusted models, patients in for-profit facilities had a greater death risk (HR 1.09, P=0.004). More patients in for-profit units met clinical benchmarks. Survival among patients in for-profit units was similar to not-for-profit units. This suggests that in the contemporary era, interventions in for-profit dialysis units have not impaired their ability to deliver performance benchmarks and do not affect survival.

The predictive value of self-report scales compared with physician diagnosis of depression in hemodialysis patients

The prevalence of depression in end-stage renal disease (ESRD) patients on hemodialysis has not been definitively determined. We examined the prevalence of depression and the sensitivity, specificity, positive, and negative likelihood ratios (+LR and -LR) of self-report scales using the physician-administered Structured Clinical Interview for Depression (SCID) as the comparison. Ninety-eight consecutive patients completed the Beck Depression Inventory (BDI) and the Center for Epidemiological Study of Depression (CESD) scales. A physician blinded to BDI and CESD scores administered the SCID. Receiver/responder operating characteristic curves determined the best BDI and CESD cutoffs for depression. Depressed patients had more co-morbidities and lower quality of life, P<0.05. The prevalence of depression by SCID was 26.5% and of major depression was 17.3%. The CESD cutoff with the best diagnostic accuracy was 18, with sensitivity 69% (95% confidence interval (CI) (51%, 87%)), specificity 83% (95% CI (74%, 92%)), positive predictive value (PPV) 60%, negative predictive value (NPV) 88%, +LR 4.14, and -LR 0.37. The best BDI cutoff was 14, with sensitivity 62% (95% CI (43%, 81%)), specificity 81% (95% CI (72%, 90%)), PPV 53%, NPV 85%, +LR 3.26, and -LR 0.47. Self-report scales have high +LR but low -LR for diagnosis of depression. When used for screening, the threshold for depression should be higher for ESRD compared with non-ESRD patients. Identifying depression using physician interview is important, given the low -LR of self-report scales.

Outcomes of patients with chronic renal insufficiency in the bypass angioplasty revascularization investigation

BACKGROUND

Although severe chronic kidney disease (CKD) is an independent predictor of mortality among patients with coronary artery disease, the impact of mild CKD on morbidity and mortality has not been fully defined.

METHODS AND RESULTS

Morbidity and mortality for the 3608 patients with multivessel coronary artery disease enrolled in the Bypass Angioplasty Revascularization Investigation randomized trial and registry were compared on the basis of the presence and absence of CKD, defined as a preprocedure serum creatinine level of >1.5 mg/dL. Seventy-six patients had CKD. Patients with renal insufficiency were older and more likely to have a history of diabetes, hypertension, and other comorbidities. Among patients undergoing PTCA, patients with CKD had a greater frequency of in-hospital death and cardiogenic shock (P<0.05 and 0.01, respectively). There was a trend toward a larger proportion of patients with CKD experiencing angina at 5 years (P=0.079). Patients with CKD had more cardiac admissions (P=0.003 and <0.0001 for patients undergoing PTCA and CABG, respectively) and a shorter time to subsequent CABG after initial revascularization than patients without CKD (P=0.01). CKD was associated with a higher risk of death at 7 years, both of all causes (relative risk 2.2, P<0.001) and of cardiac causes (relative risk 2.8, P<0.001).

CONCLUSIONS

CKD is associated with an increased risk of recurrent hospitalization, subsequent CABG, and mortality. This increased risk of death is independent of and additive to the risk associated with diabetes.

Protease inhibitors are associated with a slowed progression of HIV-related renal diseases

AIMS

While angiotensin-con-verting enzyme inhibitors and zidovudine may improve the course of the most common HIV-related renal disease, HIV-associated nephropathy (HIVAN), the effect of anti-retroviral combination therapy on this and other HIV-related renal diseases has not been assessed. This study describes the clinical course of HIV-related renal diseases and the effect of protease inhibitors on their progression.

METHODS

This retrospective cohort study reviews the clinical course of 19 patients with a clinical or biopsy-proven diagnosis of HIVAN or other HIV-related renal diseases. Groups progressing and not progressing to ESRD were compared using longitudinal analyses to assess the association between creatinine clearance and clinical and therapeutic factors.

RESULTS

The cohort consisted of 16 African-Americans, 2 Caucasians and 1 Native American. Their modes of HIV infection were intravenous drug use (7), a history of men having sex with men (3) and heterosexual behavior (5). Patients were followed for a median of 16.6 months. Seven patients reached ESRD. Loss of creatinine clearance over time did not differ among genders, races, or patients with different modes of HIV infection. Longitudinal analyses demonstrated an association between protease inhibitors and prednisone and a slower decline in creatinine clearance in multivariable models (p = 0.04 and 0.003, respectively).

CONCLUSIONS

The epidemiology and clinical course of HIV-related renal diseases is more heterogeneous than previously described. This study suggests a benefit to the use of protease inhibitors and prednisone on the progression of these nephropathies.

Long-term outcomes of revascularization for peripheral vascular disease in end-stage renal disease patients

The occurrence of peripheral vascular disease (PVD) and atraumatic lower-extremity amputations is significantly greater in patients with end-stage renal disease (ESRD) than those with normal renal function. Moreover, the mortality for dialysis patients undergoing atraumatic lower-extremity amputations is far greater. Because PVD requiring amputation is an extreme form of PVD, we tested the hypothesis that mortality and intermediate outcomes for patients with ESRD undergoing lower-extremity revascularization, a less extreme form of PVD, would be equivalent to that for patients without ESRD. This is a retrospective case-control analysis of lower-extremity revascularization in patients with ESRD. Procedures in patients with ESRD were matched with procedures in non-ESRD controls for patient age, sex, race, diabetes mellitus, and hospital setting. Patient survival, graft survival, and limb salvage rates were determined using Kaplan-Meier analysis. Subjective interpretation of functional and symptomatic improvement was determined by telephone interviews with patients or relatives. Thirty-one procedures were performed on 20 patients with ESRD and 64 matched procedures were performed on 57 patients without ESRD. In the ESRD group, median patient survival was 1.72 years compared with 5.17 years for the control group (P < 0.001). Time to 50% limb loss was 1.24 years in the ESRD group and longer than 5.65 years in the control group (P < 0.001). Time to 50% graft patency loss was 0.70 years in the ESRD group and longer than 5.5 years in the control group (P < 0.05). Subjective improvement was less in patients with ESRD. Outcomes of lower-extremity revascularization in patients with ESRD are inferior to those in non-ESRD controls. The mortality rate for patients with ESRD who undergo revascularization is extremely high. Patient-related variables (eg, increased prevalence of hypertension and cardiovascular disease) and/or provider-specific factors (eg, timing of surgery in the course of PVD) may be responsible for poorer outcomes.

Renal diseases associated with human immunodeficiency virus infection: epidemiology, clinical course, and management

Human immunodeficiency virus (HIV)--associated nephropathy (HIVAN) and other glomerular lesions (e.g., immunoglobulin A nephropathy and immune complex glomerulonephritis) are frequent complications of HIV infection. These renal diseases usually present as a nephrotic syndrome with progressive loss of renal function and an increased risk of mortality. The prevalence and epidemiology of these renal lesions remain largely undefined; however, most studies agree that black race is a major risk factor for HIVAN. Observational studies have suggested that antiretroviral medications and angiotensin-converting enzyme inhibitors have beneficial effects on slowing the progression of renal disease among patients with HIVAN; however, little is known about the effect of these therapies on other renal lesions. Future research should focus on gaining a better understanding of the distribution and determinants of renal disease among HIV-infected patients as well as on performing controlled studies to test treatment strategies.

Hypertension and medication-related renal dysfunction in the HIV-infected patient

Given the improved life expectancy with highly active antiretroviral therapy among patients with human immunodeficiency virus (HIV)-infection, the treatment of medical problems such as hypertension will become increasingly more important. Although HIV-infected patients are at increased risk for the development of pulmonary hypertension, there is little data to suggest they are at increased risk for systemic hypertension or secondary causes of hypertension. Multiple potential drug interactions exist between antiretroviral medications, particularly the protease inhibitors and antihypertensive medications. Additionally, certain antiretroviral medications have frequent and important side effects relating to the kidneys and urinary system. Knowledge of these interactions and side effects is essential toward caring for the patient with HIV-infection.

Differential survival after coronary revascularization procedures among patients with renal insufficiency

BACKGROUND

Acute myocardial infarction, cardiac arrest, and other cardiac events are the major cause of mortality among patients with renal insufficiency. Previous studies of interventions for coronary artery disease among patients with renal insufficiency have not controlled for potentially confounding factors such as coronary artery disease severity and left ventricular function. This study investigates the comparative survival for patients with renal insufficiency and coronary artery disease following coronary artery bypass graft (CABG) surgery as compared with percutaneous coronary artery intervention (PCI), while controlling for confounding factors.

METHODS

This retrospective cohort study of patients undergoing CABG surgery or PCI discharged between 1993 and 1995 uses the New York Department of Health databases and Cox proportional hazards analyses to estimate the mortality risk associated with CABG as compared with PCI for patients with renal insufficiency. Renal function was categorized as creatinine <2.5 mg/dL (N = 58,329), creatinine > or =2.5 mg/dL (N = 840), and end-stage renal disease (ESRD) requiring dialysis (N = 407).

RESULTS

Patients with either ESRD or serum creatinine > or =2.5 mg/dL had more severe coronary artery disease and a greater frequency of comorbid conditions as compared with patients with creatinine <2.5 mg/dL. Creatinine > or =2.5 mg/dL and ESRD were both associated with an increased mortality risk among all distributions of coronary artery disease anatomy. Among patients with ESRD, the risk ratio (RR) of mortality for patients undergoing CABG compared with PCI was 0.39 (95% CI, 0.22 to 0.67, P = 0.0006). Among patients with creatinine > or =2.5 mg/dL, CABG surgery did not convey a survival benefit over PCI (RR, 0.86, 95% CI, 0.56 to 1.33, P = 0.50).

CONCLUSIONS

This study demonstrates a survival benefit among patients with ESRD undergoing CABG surgery as compared with PCI, while controlling for severity of coronary artery disease, left ventricular dysfunction, and other comorbid conditions. These results suggest that management decisions among patients with coronary artery disease should be made in the context of not only location and severity of coronary artery lesions, but also on the presence and severity of renal dysfunction.

Changing hemodialysis thresholds for optimal survival

BACKGROUND

The urea reduction ratio (URR), a measure quantitating solute removal during hemodialysis, is the fractional reduction of the blood urea concentration during a single hemodialysis treatment. The URR is the principal measure of hemodialysis dose in the United States. Based on studies of patients dialyzed prior to 1994, a minimum URR value of 65% was recommended to optimize survival. Because of new hemodialysis technologies and evolving demographics of the hemodialysis population, the relationship between the amount of hemodialysis and mortality was examined in contemporary cohorts.

METHODS

This retrospective cohort included> 15,000 patients per year receiving hemodialysis during 1994 through 1997. Each patient's URR was averaged for the three months prior to the beginning of each year. Mortality odds ratios were calculated for patients by URR. To determine the URR value above which no further improvement in mortality was seen ("threshold"), spline functions were tested in logistic regression models, both unadjusted and adjusted for case mix measures. The strength of fit for URR, defined by a range of candidate thresholds from 55 to 75%, was evaluated in increments of 1% for each year using spline functions.

RESULTS

The median URR was 63.2, 65.4, 67.4, and 68.1% for 1994 through 1997, respectively. The median length of hemodialysis treatments increased only six minutes from the beginning to the end of the period of analysis. Using spline functions, the threshold URR values were 61.1, 65.0, 68.0, and 71.0% for 1994 through 1997 in models adjusted for case mix. The ratio of median URR to URR threshold decreased from 1.03 in 1994 to 0.97 in 1997.

CONCLUSIONS

From 1994 to 1997, the median URR and the URR threshold for mortality benefit increased. Although an increased need in the amount of hemodialysis may be a consequence of changes in patients' demographic characteristics, the likely explanation(s) is a change in the dialysis procedure and/or blood sampling favoring higher URR values without changing the amount of dialysis provided. The recommended minimum URR of 65% appears to be too low to confer an optimal mortality benefit in the context of current practices.

Racial inequity in America's ESRD program

The end-stage renal disease (ESRD) program has a significant overrepresentation of racial and ethnic minority groups. The increased susceptibility of nonwhite populations to ESRD has not been fully explained and probably represents a complex interplay of genetic, cultural, and environmental influences. Because the program delivers care under a uniform health care payment system, it represents a unique environment in which to explore variation in health care delivery. A number of disparities in outcomes and delivery of ESRD care have been noted for racial minority participants. These include possible overdiagnosis of hypertensive nephrosclerosis, decreased provision of renal replacement therapy, limited referral for home dialysis modalities, underprescription of dialysis, increased use of synthetic grafts rather than fistulas as permanent angioaccess, and delayed wait-listing for renal transplantation. Transplantation inequities mean that black patients are likely to remain on dialysis relatively longer, so that their susceptibility to less than optimal processes of care increases disproportionately. Improved survival and quality of life (QOL) for blacks with ESRD may have encouraged provider complacency about racial disparities in the ESRD program and in particular about referral for transplantation. It is also apparent that minority ESRD patients may, similar to their non-ESRD counterparts, be referred less frequently for invasive cardiovascular (CV) procedures. Despite these observations of inequality in ESRD care, the adjusted mortality for minority participants in the ESRD program are better than for the majority population. This seeming paradox may define an opportunity to improve outcomes for minorities with ESRD even more.

Effect of anti-lymphocyte antibody induction therapy on renal allograft survival

Our two meta-analyses show that antilymphocyte antibody induction therapy extends allograft survival when compared to induction therapy with cyclosporine, azathioprine, and prednisone with the majority of the benefit seen during the first 2 years after transplant. The benefit of induction therapy with respect to allograft survival is particularly important among patients with pretransplant panel reactive antibodies greater than 20%. Although our understanding of the role of antilymphocyte antibody induction therapy continues to evolve, these two meta-analyses provide evidence for its use in clinical renal transplantation.

The effect of antilymphocyte induction therapy on renal allograft survival. A meta-analysis of individual patient-level data. Anti-Lymphocyte Antibody Induction Therapy Study Group

PURPOSE

Randomized, controlled trials have not shown that the perioperative use of antilymphocyte antibodies (induction therapy) improves survival of cadaveric kidney allografts. This study combined individual patient-level data from published trials to examine the effect of induction therapy on allograft survival.

DATA SOURCES

Randomized, controlled trials identified from MEDLINE.

STUDY SELECTION

Published trials that compared adult recipients of cadaveric renal allografts who did and did not receive antilymphocyte antibodies in the perioperative period were selected if individual patient-level data were available.

DATA EXTRACTION AND ANALYSIS

Individual patient-level data were collected for each of 628 study patients. Multivariable Cox proportional hazards regression was used to estimate the effect of induction therapy on allograft survival.

RESULTS

The adjusted rate ratio for allograft failure with induction therapy compared with conventional therapy was 0.62 (95% CI, 0.43 to 0.90) (P = 0.012) over 2 years and 0.82 (CI, 0.62 to 1.09) (P = 0.17) over 5 years. The effect of induction therapy on allograft survival diminished over time; no benefit overall was seen after 2 years after transplantation (rate ratio, 1.13 [CI, 0.72 to 1.78]) (P > 0.2). Greater HLA-DR mismatch, delayed allograft function, diabetes mellitus in the recipient, African-American ethnicity of the recipient, and presensitization (panel-reactive antibody levels > or = 20%) were significantly associated with allograft failure at 5 years. Among high-risk patients, only those who were presensitized benefited from induction therapy at 2 years (rate ratio, 0.12 [CI, 0.03 to 0.44]) (P = 0.001). Results were similar at 5 years.

CONCLUSIONS

Using individual-level data, this study showed a benefit of induction therapy at 2 years, particularly among presensitized patients. Although the benefit of this therapy subsequently waned, presensitized patients continued to have benefit at 5 years.

Effect of anti-lymphocyte induction therapy on renal allograft survival: a meta-analysis

Induction immunosuppression with antilymphocyte antibodies has not been shown to improve cadaveric kidney allograft survival in randomized, controlled trials despite widespread use. This meta-analysis of randomized, controlled trials assessed the effectiveness of induction therapy in prolonging allograft survival. Studies of induction therapy were identified in Medline (1986 through 1996), using the terms "monoclonal antibodies" or "antilymphocyte serum," and "kidney transplantation," "human," and "clinical trial." Bibliographies, pharmaceutical manufacturers, the United Network for Organ Sharing, National Institutes of Health, and study authors were also consulted. Seven of 247 identified studies met the following inclusion criteria: (1) an adult study population; (2) assessment of antilymphocyte antibodies in the immediate posttransplant period; (3) a control arm of cyclosporine, azathioprine, and prednisone in the immediate posttransplant period; and (4) presentation of survival data. Two readers independently extracted protocol and survival data from each study. Summary odds ratios (fixed and random effects) and a rate ratio from proportional hazards regression at 2 yr were estimated to examine the effect of induction therapy on allograft survival. The summary odds ratios were both 0.66 (confidence interval [CI], 0.45 to 0.96; P = 0.03), and the rate ratio was 0.69 (CI, 0.49 to 0.97; P = 0.03), indicating a beneficial effect of induction therapy on allograft survival. Allograft survival was 85.6% (CI, 82.1 to 89.1%) in the induction therapy group and 79.6% (CI, 75.6 to 83.6%) in the conventional therapy group. These results were stable in a sensitivity analysis based on study quality. Allograft survival was prolonged with induction therapy compared with conventional immunosuppression. These data indicate a potential role for the routine use of induction therapy in renal transplantation to optimize the survival of cadaveric allografts.