Racial and socioeconomic factors in glomerular disease

APOL1 Genotype, Kidney and Cardiovascular Disease, and Death in Older Adults

OBJECTIVE

We sought to evaluate the cardiovascular impact of coding variants in the apolipoprotein L1 gene APOL1 that protect against trypanosome infection but have been associated with kidney disease among African Americans.

APPROACH AND RESULTS

As part of the Cardiovascular Health Study, a population-based cohort of Americans aged ≥65 years, we genotyped APOL1 polymorphisms rs73885319 and rs71785153 and examined kidney function, subclinical atherosclerosis, and incident cardiovascular disease and death over 13 years of follow-up among 91 African Americans with 2 risk alleles, 707 other African Americans, and 4964 white participants. The high-risk genotype with 2 risk alleles was associated with 2-fold higher levels of albuminuria and lower ankle-brachial indices but similar carotid intima-media thickness among African Americans. Median survival among high-risk African Americans was 9.9 years (95% confidence interval [CI], 8.7-11.9), compared with 13.6 years (95% CI, 12.5-14.3) among other African Americans and 13.3 years (95% CI, 13.0-13.6) among whites (P=0.03). The high-risk genotype was also associated with increased risk for incident myocardial infarction (adjusted hazard ratio 1.8; 95% CI, 1.1-3.0) and mortality (adjusted hazard ratio 1.3; 95% CI 1.0-1.7). Albuminuria and risk for myocardial infarction and mortality were nearly identical between African Americans with 0 to 1 risk alleles and whites.

CONCLUSIONS

APOL1 genotype is associated with albuminuria, subclinical atherosclerosis, incident myocardial infarction, and mortality in older African Americans. African Americans without 2 risk alleles do not differ significantly in risk of myocardial infarction or mortality from whites. APOL1 trypanolytic variants may account for a substantial proportion of the excess risk of chronic disease in African Americans.

Apolipoprotein L1 (APOL1) Variants (Vs) a possible link between Heroin-associated Nephropathy (HAN) and HIV-associated Nephropathy (HIVAN)

In 1970s, Heroin-associated Nephropathy (HAN), one form of focal and segmental glomerulosclerosis (FSGS), was a predominant cause of End-stage Kidney Disease (ESKD) in African-Americans (AAs). In 1980s, with the surge of Acquired Immune Deficiency Syndrome (AIDS) in AAs, HAN more or less disappeared, and the incidence of Human Immunodeficiency Virus associated Nephropathy (HIVAN) markedly increased. Recent studies in AAs have identified APOL1 variants (Vs) as a major risk factor for the development and progression of non-diabetic kidney diseases including idiopathic FSGS and hypertension-attributed nephrosclerosis. These observations have also offered partial insights into the mechanisms of development, and higher rate of occurrence of both HAN and HIVAN in AAs. AAs with APOL1Vs develop idiopathic FSGS at four-fold higher rate compared to European Americans (EAs). Similarly, HIV infected AAs with APOL1Vs (if not on antiviral therapy), risk a 50% (10-fold greater) chance of developing HIVAN. It has been suggested that APOL1Vs expression may render podocytes more vulnerable to various types of injury: bacterial, viral, and others. However, in addition to genetic variants, additional factors such as persistence of a second hit may determine the nature and severity of glomerular disease. In patients with HAN, heroin or contaminants may have been the offending second insult(s) which caused renal disease in susceptible AA patients. In the 80's, since heroin-induced second hit was neither consistent nor sustained (depending on drug availability in the street), the disease was masked or replaced HIV infected patients (especially in untreated subjects), by an overwhelming second hit by the virus which was both intense as well as persistent. It appears that APOL1Vs may be one of the links between the disappearance of HAN and emergence of HIVAN in AA patients.

Early-life course socioeconomic factors and chronic kidney disease

Kidney failure or ESRD affects approximately 650,000 Americans, whereas the number with earlier stages of CKD is much higher. Although CKD and ESRD are usually associated with adulthood, it is likely that the initial stages of CKD begin early in life. Many of these pathways are associated with low birth weight and disadvantaged socioeconomic status (SES) in childhood, translating childhood risk into later-life CKD and kidney failure. Social factors are thought to be fundamental causes of disease. Although the relationship between adult SES and CKD has been well established, the role of early childhood SES for CKD risk remains obscure. This review provides a rationale for examining the association between early-life SES and CKD. By collecting data on early-life SES and CKD, the interaction with other periods in the life course could also be studied, allowing for examination of whether SES trajectories (eg, poverty followed by affluence) or cumulative burden (eg, poverty at multiple time points) are more relevant to lifetime CKD risk.

Analysis of clinicopathologic correlations in Iranian patients with lupus nephritis

OBJECTIVE

To determine clinical features of different histopathological presentations in patients with lupus nephritis (LN).

METHODS

Clinical and pathological features of 71 biopsy-proven LN patients were analyzed in a cross-sectional study during 2005-2011.

RESULTS

Sixty-five women (91.5%) and six men (8.5%) were studied. The mean Activity Index (AI) and Chronicity Index (CI) were 6.2 ± 3.1 and 1.7 ± 1.5, respectively. The most common histopathologic presentation of kidneys was class IV (52.1%). Patients with more advanced International Society of Nephrology and the Renal Pathology Society (ISN/RPS) classes, had longer disease duration (P = 0.007), higher levels of blood urea nitrogen (P = 0.004) and serum creatinine (P = 0.035). The most frequent active lesion seen in renal biopsies was endocapillary hypercellularity (83.1%) while glomerular sclerosis was the most common chronic lesion (52.1%). Patients with chronic lesions, including glomerular sclerosis (P = 0.032), fibrous crescent (P = 0.001), interstitial fibrosis (P = 0.025) and tubular atrophy (P = 0.049) had higher serum creatinine levels. Hypertension was mainly seen in patients who had interstitial fibrosis and tubular atrophy (P = 0.026, 0.002 respectively). Moreover, subjects with renal failure had been more frequently involved with fibrinoid necrosis/karyorrhexis (P = 0.003), interstitial inflammation (P = 0.009), fibrous crescents (P = 0.041), tubular atrophy (P = 0.008) and interstitial fibrosis (P < 0.001).

CONCLUSION

We found that both histopathologic classification (ISN/RPS criteria) and histopathologic grading (US National Institutes of Health activity and chronicity indices) correlate to some clinical manifestations of LN. Considering these correlations may help to determine the patients' clinicopathologic status, prognosis and the need to immediate treatment. Nevertheless, it is necessary to clarify the accuracy of these findings in larger-scale prospective studies.

HIV-associated nephropathy in Caucasians: case report and review of literature

HIV-associated nephropathy (HIVAN) is almost exclusively seen in African-Americans (AA) and is rare in Caucasians. The mechanisms responsible for the predilection of HIVAN in AA are not well understood. In transgenic mouse studies, genetic background plays a vital role in the development of the HIVAN phenotype. Larger studies in humans have been initiated to study genetic polymorphisms responsible for HIVAN. As our case illustrates, HIVAN should be considered in Caucasian patients with HIV infection complicated by nephrotic syndrome and renal failure.

Membranous glomerulonephritis: treatment response and outcome in children

The aim of this study was to characterize clinical features, treatment response, and outcome of idiopathic membranous glomerulonephritis (MGN) in a single-center cohort of children. A retrospective review of biopsy-proven idiopathic MGN in 12 children (mean age 11.9 years) was undertaken. Presentation was nephrotic syndrome (NS) (75%), hematuria/proteinuria (17%), and asymptomatic proteinuria (8%). Ten patients (83%) with NS and nephrotic range proteinuria (NRP) were treated with prednisone, and two patients with non-NRP were not treated with immunosuppressive medications. Steroid response in the treated patients was complete (10%), partial (40%), and absent (50%), respectively. Oral cyclophosphamide was used in seven patients of whom five were steroid resistant, one was steroid dependent, and one was partially responsive. At the mean follow up of 27 months, outcome parameters included an estimated glomerular filtration rate of 128 cc/min per 1.73 m(2), albumin of 4.2 gm/dL, and a urine protein/creatinine ratio of 0.87 [median 0.16 (range 0.02-6.52)]. Remission was complete in 75% of the patients and partial in 17%. One patient (8%) with chronic kidney disease (stage 2) was unresponsive to therapy. Complete remission was significantly associated with the absence of chronic histological changes (p = 0.03). In conclusion, children with NS and/or NRP associated with MGN appear to have a good prognosis when treated with a combination of corticosteroids and cyclophosphamide.

Glomerular diseases in a Hispanic population: review of a regional renal biopsy database

CONTEXT AND OBJECTIVE

Epidemiological data provide useful information for clinical practice and investigations. This study aimed to determine glomerular disease frequencies in a region of Colombia and it represents the basis for future studies.

DESIGN AND SETTING

Single-center retrospective analysis at the University of Antioquia, Colombia.

METHODS

All native renal biopsies (July 1998 to December 2007) were reviewed, but only glomerular diseases were analyzed. The diagnosis of each case was based on histological, immunopathological and clinical features.

RESULTS

A total of 1,040 biopsies were included. In 302 cases (29.0%), the patient's age was

CONCLUSIONS

As among Afro-Americans, FSGS is the most frequent type of glomerulopathy in our population, but in our group, there are more cases of IgAN. The reasons for these findings are unclear. This information is an important contribution towards understanding the prevalence of renal diseases in Latin America.

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Key Words

• epidemiology
• glomerulonephritis
• hispanic americans
• database
• biopsy
• epidemiología
• glomerulonefritis
• hispanoamericanos
• base de datos
• biopsia

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MESH Headings

• Adult
• Age Distribution
• Aged
• Biopsy
• Colombia/epidemiology
• Databases, Factual
• Female
• Glomerulonephritis, IGA/epidemiology
• Glomerulosclerosis, Focal Segmental/epidemiology
• Glomerulosclerosis, Focal Segmental/pathology
• Humans
• Infant
• Infant, Newborn
• Kidney/pathology
• Male
• Middle Aged
• Retrospective Studies
• Young Adult

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Affiliation(s)

Luis Fernando Arias Department of Pathology, PRYT Group, School of Medicine, University of Antioquia, Medellín, Colombia.
Jorge Henao
Rubén Darío Giraldo
Nelson Carvajal
Joaquin Rodelo
Mario Arbeláez

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Pharmacotherapy for human immunodeficiency virus-associated nephropathy

Approximately 10% of adult patients with human immunodeficiency virus (HIV) infection have HIV-associated nephropathy (HIVAN). This condition, a leading cause of renal failure, is characterized by damage to specific areas of the renal filtration system. It manifests with increased serum creatinine levels, overt proteinuria, and in some patients, end-stage renal disease (ESRD). The mortality rate for HIVAN-related ESRD is high-30% within the first year of onset. Most instances of HIVAN occur in patients of African descent. Although advances in defining the pathology have been made, the optimal treatment strategy remains unclear. Potential benefits of potent combination antiretroviral therapy, angiotensin-converting enzyme (ACE) inhibitors, and corticosteroids have been reported in small clinical trials and case reports. Cyclosporine is another option, but clinical experience with this agent in managing HIVAN is limited. Few conclusions can be drawn from the limited body of available evidence. Antiretroviral therapy, ACE inhibitors, and corticosteroids are possibly associated with reversal of serum creatinine level increases and proteinuria, but studies are necessary to further define the role of these agents in therapy. Close monitoring is advised when treating any patient with HIVAN.

Ethnic disparities in patients with systemic lupus erythematosus

Ethnic disparities in health care have been historically well documented, but their causes still remain poorly explained. In the US, ethnic minorities have a higher incidence and prevalence of systemic lupus erythematosus and also experience less favorable outcomes when compared with the Caucasian majority. These discrepancies can be explained, at least in part, by genetic-related ethnic factors; however, nongenetic factors emerging from differences in socioeconomic status and related individual social (poverty, limited access to quality health care) and cultural characteristics (inadequate health belief patterns, distrust in medical institutions) are also likely to contribute to these discrepancies. A comprehensive recognition of current unfavorable, but modifiable, circumstances will provide the framework to develop strategic approaches toward eliminating existent disparities in health, including those occurring in patients with systemic lupus erythematosus.

Environmental epidemiology and risk factors for autoimmune disease

It has long been recognized that environmental influences play an important role in the risk of developing chronic rheumatic disease. Defining specific pathogenic environmental mediators that may trigger the development or progression of autoimmune disease remains a focus of increasing investigative effort. Factors promoting disease may not be identical to factors that influence the severity or progression of the disorder. Human monozygotic twin studies, animal studies, and genetic models demonstrate that genetic influences strongly determine whether one will develop autoimmunity, however, genes affecting the metabolism of exogenous agents that may trigger disease expression have only recently drawn attention. In this article the authors review recent reports that advance our understanding of previously recognized environmental risk factors and challenge accepted beliefs that increased estrogenic exposures predate the incidence of autoimmune disorders, systemic lupus erythematosus in particular.