Clinical Course of Adult FSGS and Minimal Change Disease in North American and Japanese Cohorts

Key Points

Data from different geographical regions highlighted the differences in clinical manifestations and treatment response of adult FSGS/minimal change disease. There were shared factors that were associated with treatment response across the cohorts: FSGS, higher BP, and lower eGFR. Recognizing geographical difference allows us better understanding of disease biology, risk prediction, and design of future clinical trials.

Background

Regional differences in presentation and clinical course of nephrotic syndrome (NS) have not been studied well because few studies directly compared the data from different intercontinental regions.

Methods

We included adult nephrotic patients with FSGS and minimal change disease (MCD) who received immunosuppressive therapy (IST) in a North American (Nephrotic Syndrome Study Network [NEPTUNE], N =89) or Japanese (Nagoya Kidney Disease Registry [N-KDR], N =288) cohort. Baseline characteristics and rates of complete remission (CR) were compared. Factors associated with time to CR were evaluated by Cox regression models.

Results

NEPTUNE participants had more FSGS (53.9 versus 17.0%) and family history of kidney disease (35.2 versus 3.2%). N-KDR participants were older (median 56 versus 43 years) and demonstrated greater levels of urine protein creatinine ratio (7.73 versus 6.65) and hypoalbuminemia (1.6 versus 2.2 mg/dl). N-KDR participants showed higher proportion of CR (overall: 89.2 versus 62.9%; FSGS: 67.3 versus 43.7%; MCD: 93.7 versus 85.4%). A multivariable model showed that FSGS (versus MCD: hazard ratio [HR], 0.28; 95% confidence interval [CI], 0.20 to 0.41), systolic BP (per 10 mm Hg: HR, 0.93; 95% CI, 0.86 to 0.99), and eGFR (per 10 ml/min per 1.73 m2: HR, 1.16; 95% CI, 1.09 to 1.24) were associated with time to CR. There were significant interactions in patient age (P = 0.004) and eGFR (P = 0.001) between the cohorts.

Conclusions

The North American cohort had more FSGS and more frequent family history. Japanese patients showed more severe NS with better response to IST. FSGS, hypertension, and lower eGFR were shared predictors of poor treatment response. Identifying shared and unique features across geographically diverse populations may help uncover biologically relevant subgroups, improve prediction of disease course, and better design future multinational clinical trials.

A Multicenter Cohort Study of Histologic Findings and Long-Term Outcomes of Kidney Disease in Women Who Have Been Pregnant

BACKGROUND AND OBJECTIVES

For many women pregnancy is the first contact with health services, thus providing an opportunity to identify renal disease. This study compares causes and long-term renal outcomes of biopsy-proven renal disease identified during pregnancy or within 1 year postpartum, with nonpregnant women.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Native renal biopsies (1997-2012), in women of childbearing age (16 to <50 years), from 21 hospitals were studied. The pregnancy-related diagnosis group included those women with abnormal urinalysis/raised creatinine identified during pregnancy or within 1 year postpartum. Pregnancy-related and control biopsies were matched for age and ethnicity (black versus nonblack).

RESULTS

One hundred and seventy-three pregnancy-related biopsies (19 antenatal, 154 postpregnancy) were identified and matched with 1000 controls. FSGS was more common in pregnancy-related biopsies (32.4%) than controls (9.7%) (P<0.001) but there were no differences in Columbia classification. Women with a pregnancy-related diagnosis were younger (32.1 versus 34.2 years; P=0.004) and more likely to be black (26.0% versus 13.3%; P<0.001) than controls, although there were no differences in ethnicities in women with FSGS. The pregnancy-related group (excluding antenatal biopsies) was more likely to have a decline in Chronic Kidney Disease Epidemiology Collaboration eGFR in the follow-up period than the control group (odds ratio, 1.67; 95% confidence interval, 1.03 to 2.71; P=0.04), and this decline appeared to be more rapid (-1.33 versus -0.56 ml/min per 1.73 m2 per year, respectively; P=0.045). However, there were no differences between groups in those who required RRT or who died.

CONCLUSIONS

Pregnancy is an opportunity to detect kidney disease. FSGS is more common in women who have been pregnant than in controls, and disease identified in pregnancy or within 1 year postpartum is more likely to show a subsequent decline in renal function. Further work is required to determine whether pregnancy initiates, exacerbates, or reveals renal disease.

Long-Term Outcome of Kidney Transplantation in Recipients with Focal Segmental Glomerulosclerosis

BACKGROUND AND OBJECTIVES

FSGS can recur after kidney transplantation and is associated with poor graft outcomes. We aimed to assess the incidence of FSGS recurrence post-transplant and determine the effect of graft source on recurrence and graft survival in patients with biopsy-proven FSGS.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using the Australian and New Zealand Dialysis and Transplant Registry, we assessed incidence of FSGS, the influence of donor type on the risk of FSGS recurrence, and graft loss in recipients with ESRD caused by primary FSGS using Kaplan-Meier and logistic regression analyses.

RESULTS

Between 1992 and 2011, 736 first kidney transplants were performed in 666 adults and 70 children (≤20 years old) with biopsy-proven primary FSGS. FSGS recurred in 76 (10.3%) patients. Younger age (P<0.001), nonwhite ethnicity (P=0.02), and having a live donor (P=0.02) were independent risk factors associated with recurrence. Median graft survival was significantly better for live donor compared with deceased donor grafts (14.8 versus 12.1 years; P<0.01). Disease recurrence predicted poor graft outcomes, with 52% (95% confidence interval, 40% to 63%) 5-year graft survival in the recurrence group compared with 83% (95% confidence interval, 79% to 86%) in the group without recurrent disease (P<0.001).

CONCLUSIONS

FSGS recurrence after kidney transplantation was more common in live donor kidneys. Despite this, graft survival in live donor recipients was significantly better for both children and adults with FSGS. We propose that live donor transplantation should not be avoided in patients with FSGS.

Focal segmental glomerulosclerosis is associated with a PDSS2 haplotype and, independently, with a decreased content of coenzyme Q10

Focal segmental glomerulosclerosis (FSGS) and collapsing glomerulopathy are common causes of nephrotic syndrome. Variants in >20 genes, including genes critical for mitochondrial function, have been associated with these podocyte diseases. One such gene, PDSS2, is required for synthesis of the decaprenyl tail of coenzyme Q10 (Q10) in humans. The mouse gene Pdss2 is mutated in the kd/kd mouse model of collapsing glomerulopathy. We examined the hypothesis that human PDSS2 polymorphisms are associated with podocyte diseases. We genotyped 377 patients with primary FSGS or collapsing glomerulopathy, together with 900 controls, for 9 single-nucleotide polymorphisms in the PDSS2 gene in a case-control study. Subjects included 247 African American (AA) and 130 European American (EA) patients and 641 AA and 259 EA controls. Among EAs, a pair of proxy SNPs was significantly associated with podocyte disease, and patients homozygous for one PDSS2 haplotype had a strongly increased risk for podocyte disease. By contrast, the distribution of PDSS2 genotypes and haplotypes was similar in AA patients and controls. Thus a PDSS2 haplotype, which has a frequency of 13% in the EA control population and a homozygote frequency of 1.2%, is associated with a significantly increased risk for FSGS and collapsing glomerulopathy in EAs. Lymphoblastoid cell lines from FSGS patients had significantly less Q10 than cell lines from controls; contrary to expectation, this finding was independent of PDSS2 haplotype. These results suggest that FSGS patients have Q10 deficiency and that this deficiency is manifested in patient-derived lymphoblastoid cell lines.

Hypertension and chronic kidney disease: controversies in pathogenesis and treatment

The relationship between hypertension and chronic kidney disease (CKD) has long been the subject of controversy. The pathogenetic mechanisms of nephropathy in non-diabetic individuals with hypertension, as well as optimal hypertension treatment targets in populations with nephropathy remain important clinical concerns. This manuscript reviews breakthroughs in molecular genetics that have clarified the complex relationship between hypertension and kidney disease, answering the question of which factor comes first. An overview of the potential roles that hyperuricemia plays in the pathogenesis of hypertension and CKD and current blood pressure treatment guidelines in populations with CKD are discussed. The ongoing National Institutes of Health-sponsored Systolic Blood Pressure Intervention Trial (SPRINT) is underway to help answer these important questions. Enrollment of 9250 hypertensive SPRINT participants will be completed in 2013; important results on ideal blood pressure control targets for reducing nephropathy progression, cardiovascular disease end-points, and preserving cognitive function are expected. As such, many of the controversial aspects of hypertension management will likely be clarified in the near future.

Idiopathic collapsing focal segmental glomerulosclerosis in pediatric patients

The aim of this study was to evaluate the clinical outcome of our patients with idiopathic collapsing focal segmental glomerulosclerosis (FSGS) as compared to those with non-collapsing FSGS. The study included a total of 39 patients with idiopathic FSGS. Of these, 11 had collapsing FSGS and the remaining 28 were collectively grouped as non-collapsing FSGS. The mean ages, gender ratio (M:F), and percentage of African-American patients in collapsing versus non-collapsing FSGS groups were 12.7+/-3.1 and 8.9+/-5.1 years, 1.2:1 and 4.6:1, and 90.9 and 53.6%, respectively. After a mean followup period of 31.5+/-22.3 months, 8 patients (73%) with collapsing FSGS had chronic renal impairment as compared to 8 (29%) patients with non-collapsing FSGS group after a mean follow-up period of 18.7+/-12.9 months. However, the cumulated renal survival at 30 months did not reveal a significant difference. In comparison to non-collapsing FSGS, collapsing FSGS in our study was equally common in females as in males and occurred predominantly in African Americans. The outcome of our patients with collapsing FSGS at 30 months was better than in previous reports.

NPHS2 gene, nephrotic syndrome and focal segmental glomerulosclerosis: A HuGE review

Nephrotic syndrome, characterized by edema, proteinuria, hyperlipidemia and low serum albumin, is a manifestation of kidney disease involving the glomeruli. Nephrotic syndrome may be caused by primary kidney disease such as focal segmental glomerulosclerosis. Mutations in the podocin gene, NPHS2, have been shown in familial and sporadic forms of steroid-resistant nephrotic syndrome, including focal segmental glomerulosclerosis. Podocin is an integral membrane protein located at the slit diaphragm of the glomerular permeability barrier. Complete information is lacking for the population frequency of some NPHS2 variants for all racial and ethnic groups. The most frequently reported variant, R229Q, is more common among European-derived populations than African-derived populations. We calculated crude odds ratios and 95% confidence intervals of childhood nephrotic syndrome and focal segmental glomerulosclerosis associated with R229Q heterozygosity using data from five studies. The R229Q variant is not associated with focal segmental glomerulosclerosis in the US population of African descent. In contrast, the R229Q variant is associated with a trend toward increased focal segmental glomerulosclerosis risk in European-derived populations, with an estimated increased risk of 20-40%. Our insight into the association between NPHS2 variants and nephrotic disease is hampered by the limitations of the existing studies, including small numbers of affected individuals and suboptimal control groups. Nevertheless, the available data suggest that large epidemiological case-control studies to examine the association between NPHS2 variants and nephrotic syndrome are warranted.

Effects of Steroids in Focal Segmental Glomerulosclerosis in a Predominantly African-American Population

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) is a common primary glomerulopathy in African Americans. Prolonged treatment with steroids is recommended for FSGS in those with nephrotic-range proteinuria, but strong evidence for this recommendation, especially in African-American adults, is lacking. We reviewed our experience with steroids in FSGS in a predominantly African-American cohort.

METHODS

Patients with primary FSGS were identified and their charts were retrospectively reviewed for demographic data, characteristics of renal biopsy, blood pressure, and use of steroids. End-stage renal disease and doubling of creatinine were end-points.

RESULTS

Seventy-two patients (65 African Americans) were identified with 48.3 months of follow-up. Patients receiving steroids (n=43) had higher urine protein excretion than those who did not. Seventeen patients reached end-stage renal disease and 26 doubled their creatinine concentration. Factors significant for renal survival on Cox proportional hazards model were initial creatinine level, severity of renal lesion, and blood pressure over the follow-up period. Treatment with steroids did not affect renal survival. About one third of patients receiving steroids developed complications consisting of diabetes (n=4) and greater than 5 kg weight gain (n=10).

CONCLUSION

Renal function, severity of the renal lesion, and blood pressure determine renal survival in FSGS. A beneficial effect of steroids was not observed in this predominantly African-American adult cohort.

Variants in the Wilms' tumor gene are associated with focal segmental glomerulosclerosis in the African American population

Wilms' tumor gene (WT1) is important for nephrogenesis and gonadal growth. WT1 mutations cause Denys-Drash and Frasier syndromes, which are characterized by glomerular scarring. To test whether genetic variations in WT1 and WIT1 (gene immediately 5' to WT1) associate with focal segmental glomerulosclerosis (FSGS), patients with biopsy-proven idiopathic and HIV-1-associated FSGS were enrolled in a multicenter study. We genotyped SNP rs6508 located in WIT1 exon 1, three SNPs (rs2301250, rs2301252, rs2301254) in the promoter shared by WT1 and WIT1, rs2234590 in exon 6, rs2234591 in intron 6, rs16754 in exon 7, and rs1799937 in intron 9 of WT1. Cases (n = 218) and controls (n = 281) were compared in the African American population. Stratification by HIV-1 infection status showed that SNPs rs6508, rs2301254, and rs1799937 were significantly associated with FSGS [rs6508 odds ratio (OR) 1.82, P = 0.006; rs2301254 OR 1.65, P = 0.049; rs1799937 OR 1.91, P = 0.005] in the non-HIV-1 group and rs2234591 (OR 0.234, P = 0.011) in the HIV-1 group. Haplotype analyses in the population revealed that seven SNPs were associated with FSGS; five SNPs had the highest contingency score [-log10(P value) = 13.57] in the HIV-1 group. This association could not be explained by population substructure. We conclude that SNPs in WT1 and WIT1 genes are significantly associated with FSGS, suggesting that variants in these genes may mediate pathogenesis by altering WT1 function. Furthermore, HIV-1 infection status interacts with genetic variations in both genes to influence this phenotype. We speculate that nephropathy liability alleles in WT1 pathway genes cause podocyte dysfunction and glomerular scarring.

The differential effect of race among pediatric kidney transplant recipients with focal segmental glomerulosclerosis

BACKGROUND

Given the differential effect of race on focal segmental glomerulosclerosis (FSGS) progression in native kidneys, recurrence of FSGS in the transplanted kidney, and allograft source, the authors conducted this study to evaluate the influence of FSGS by race and allograft source.

METHODS

Data from 8,065 pediatric renal transplant recipients (n = 620 FSGS) between 1987 and 1997 from the United Network for Organ Sharing registry were used for this study. Stratified analysis by race and allograft source allowed independent assessment of the effect of FSGS on transplant survival.

RESULTS

Among black children, allograft survival was not different between FSGS and non-FSGS patients adjusted for recipient age, recurrent disease, allograft source, zero antigen mismatch, and acute rejection (hazard ratio [HR], 1.15; 95% confidence interval [95% CI], 0.93 to 1.42; P = 0.22). Among nonblack children, the risk of allograft failure in children with FSGS was 1.31 times higher than other causes of end-stage renal disease (ESRD) in multivariate analysis (95% CI, 1.04 to 1.64; P = 0.02). Despite the impact of disease recurrence in the nonblack children with FSGS, the risk of graft failure was less for living donor recipients (HR, 1.51; 95% CI, 1.08 to 2.10) than for cadaveric recipients (HR, 1.80; 95% CI, 1.32 to 2.44) compared with the lowest risk group (nonblack, non-FSGS, living donor).

CONCLUSION

The effect of FSGS on renal allograft survival in children differs between racial groups. Children of nonblack races with FSGS have a worse allograft survival rate compared with other causes of ESRD. Within nonblack children with FSGS, living donor transplants convey a better allograft survival than cadaveric transplants.

Racial and ethnic differences in the incidence and progression of focal segmental glomerulosclerosis in children

Idiopathic focal segmental glomerulosclerosis (FSGS) is a common cause of nephrotic syndrome in pediatric and adult patients. Most children with FSGS do not respond to any form of therapy and progress to end-stage renal disease (ESRD). FSGS reoccurs in the transplanted kidney in approximately one third of initial transplants and in a substantially higher percentage of subsequent transplants once FSGS has recurred in an earlier transplant. Thus, FSGS is a disease with substantial morbidity. Over the past several years, the incidence of FSGS in adults and children appears to be increasing, particularly in certain racial groups and ethnic populations. Several recent studies in adult and pediatric patients suggest that the incidence of FSGS is increasing particularly in the black population. In addition, some studies have also demonstrated a more rapid progression of FSGS to ESRD in black patients compared to other ethnic groups. Racial and ethnic background is likely to have a substantial influence on the incidence and progression of FSGS in children and adults. It is likely that specific genes or a combination of genes influence the different clinical manifestations of FSGS in racial and ethnic groups. Genetic mutations in NPHS1 gene, which encodes nephrin, have been found to cause congenital nephrotic syndrome. Genetic mutations in the NPHS2 gene, which encodes podocin, recently have been shown to be strongly associated with a recessive form of steroid-resistant nephrotic syndrome. Mutations in the ACTN4 gene that encodes actinin 4 has also been associated with familial nephrotic syndrome. A role for ACE polymorphisms in the progression of FSGS has been found in some studies. Future investigations to identify polymorphisms that influence the development of FSGS, the progression of FSGS, and the response to therapy will greatly improve understanding of the pathogenesis and management of FSGS.

Focal segmental glomerulosclerosis in African Americans

Focal segmental glomerulosclerosis (FSGS), the leading glomerular cause of the nephrotic syndrome among African Americans, is typically associated with edema, proteinuria, hypertension, microscopic hematuria, and renal insufficiency. Recent studies suggest that either the incidence of FSGS has increased or an increased number of biopsies of African American patients have made the diagnosis more common. The collapsing variant of FSGS, which occurs more commonly in African Americans than in whites, carries an especially poor prognosis with respect to renal survival. Although the pathogenesis of FSGS is not well understood, the fact that it frequently recurs early after transplantation has led to speculation that patients with FSGS may have a circulating factor that leads to increased glomerular permeability. There are no randomized control trials of treatment regimens for FSGS. Steroids, alkylating agents, and cyclosporin have all been used with variable results to treat FSGS.

Racial and socioeconomic factors in glomerular disease

The influence of racial and socioeconomic factors on the incidence, prognosis, and response to therapy of many diseases has long been noted. Although glomerular diseases comprise 10% to over 16% of the dialysis and renal transplant populations, respectively, only recently have racial and socioeconomic factors been evaluated. Several glomerular diseases are associated with a striking African-American predominance. These include idiopathic focal sclerosis, and especially its collapsing variant, human immunodeficiency virus (HIV)-associated nephropathy, and severe lupus nephritis. In many of these entities the renal disease is also more aggressive and rapidly progressive than in other populations. Recent data points to genetic-biologic as well as social and economic factors that may be responsible for these findings. Studies dealing with the therapy of glomerular lesions must be stratified for racial and social background differences to avoid bias in outcome. Whether racial and socioeconomic data should be used in treating individual patients, and how, remains an area of controversy.

Recurrent focal segmental glomerulosclerosis following renal transplantation in Korean pediatric patients

The recurrence of focal segmental glomerulosclerosis (FSGS) in transplants is a well-known problem in pediatric renal transplantation (Tx). Recently, the race of the recipient was recognized as a major variable associated with disease recurrence. In view of this finding, we report on our single-center experience of FSGS recurrence in Korean children, an ethnically homogeneous Far East Asian population. Clinical records and renal biopsy specimens, both native and graft, were reviewed for all pediatric renal Txs (recipient age < or = 18 yr) performed at Seoul National University Hospital from 1984 to 1999. Twenty-two children with primary FSGS received 22 allografts for renal replacement. The mean age of disease onset in these patients was 5.9 yr. The grafts were from 12 living-related, six living-unrelated, and four cadaveric donors, and all recipients were immunosuppressed with cyclosporin A (CsA)-based regimens. Post-transplant recurrence of FSGS was confirmed in nine patients (41%). Long-term graft survival in recurrent and non-recurrent groups was not significantly different. Risk factor analysis showed that patients with a disease duration shorter than 48 months (odds ratio 11.7, 95% CI 1.53-89.1) and a glomerulosclerosis percentage of < 55% by renal biopsy (odds ratio 16.0, 95% CI 1.45-176) were at greater risk of disease recurrence. These results suggest that Korean children are similar to non-African-American youngsters in the USA and Europe with respect to post-transplant recurrence of FSGS. The same may be true of other Far Eastern Asian children.

Proteinuria and focal segmental glomerulosclerosis in severely obese adolescents

OBJECTIVE

To describe the clinical and laboratory features of obesity associated proteinuria and focal segmental glomerulosclerosis.

STUDY DESIGN

The patients were seen over a 12-year period at two large children's hospitals. Renal biopsies, performed for the diagnosis of unexplained heavy proteinuria and prepared for light, immunofluorescent, and electron microscopy, were read independently by two pediatric pathologists. Blood pressure, body mass index, serum levels of creatinine, albumin, and cholesterol, and 24-hour urinary protein were measured.

RESULTS

Seven African American adolescents were identified with obesity-associated proteinuria, which was characterized by severe obesity (120 +/- 30 kg), markedly elevated body mass index (46 +/- 11), mild hypertension (134/74 +/- 10/18 mm Hg), slightly low to normal serum albumin levels (3.6 +/- 0.2 g/dL), moderately elevated serum cholesterol levels (196 +/- 60 mg/dL), and elevated 24-hour protein excretion (3.1 +/- 1.3 g/dL). Calculated creatinine clearance was normal in 6 patients and decreased in one. Typical renal histologic features included glomerular hypertrophy, focal segmental glomerulosclerosis, increased mesangial matrix and cellularity, relative preservation of foot process morphology, and absence of evidence of inflammatory or immune-mediated pathogenesis. One patient showed a dramatic reduction in proteinuria in response to weight reduction. Three patients who were given angiotensin-converting enzyme inhibitors had reduced urinary protein losses from 2.9 g to 0.7 g per day. One patient developed end-stage renal disease.

CONCLUSION

Obese adolescents should be monitored for proteinuria, which has distinct clinical and pathologic features and may be associated with significant renal sequelae. Such proteinuria may respond to weight reduction and/or treatment with angiotensin-converting enzyme inhibitors.

Why is there so much end-stage renal failure of undetermined cause in UK Indo-Asians?

There is a high incidence of end-stage renal failure (ESRF) of undetermined cause in the Indo-Asian population of the UK. We studied patients presenting from the district of Brent and Harrow, which has a large Indo-Asian community, and whose renal services are largely provided by our centre. The diagnosis and ethnicity of patients starting renal replacement therapy and/or undergoing renal biopsy were collated. The incidences of ESRF, rates of renal biopsy and underlying diagnoses were calculated for Indo-Asians and Caucasians. Requirement for renal replacement therapy in Indo-Asians presenting to our centre from Brent and Harrow was 221/10(6)/year; no underlying diagnosis was identified in 77/10(6)/year. Renal biopsy rate in these patients was 456/10(6)/year, and the diagnostic categories significantly over-represented compared to Caucasians were: hypertension and ischaemia, focal segmental glomerulosclerosis (FSGS), idiopathic interstitial nephritis (IIN), diabetic nephropathy, minor glomerular abnormality, lupus nephritis and non-specific advanced chronic renal disease (p<0.001). The first three of these had a combined incidence of 135/10(6)/year in Indo-Asians and 31/10(6)/year in Caucasians. ESRF of undetermined cause is common in UK Indo-Asians, as is requirement for renal biopsy. Hypertension with ischaemia, FSGS and IIN are over-represented in the Indo-Asian population, and should be targeted for early diagnosis and treatment in this group.

Graft loss due to recurrent focal segmental glomerulosclerosis in renal transplant recipients in the United States

Rates of and risk factors for graft loss and graft loss resulting from recurrent focal segmental glomerulosclerosis (FSGS) have not been studied in a national population. A retrospective analysis was performed on a national registry (1999 United States Renal Data System) of 101,808 renal transplant recipients (October 1, 1987, to December 31, 1996). Of these, 3,861 recipients of solitary renal transplants who had end-stage renal disease resulting from FSGS met inclusion criteria. Outcomes were graft loss and graft loss resulting from recurrent FSGS. As a percentage of all graft loss, recurrent FSGS accounted for 18.7% in living donor recipients and 7.8% in cadaveric recipients. In white recipients, the corresponding figures were 27% and 13%. In multivariate analysis, factors associated with graft loss resulting from recurrent FSGS were white recipient, donor African-American kidney in white recipient, younger recipient age, and treatment for rejection. African-American recipients had higher rates of graft loss overall. A living donor was associated with superior overall graft survival. Among renal transplant recipients with FSGS, white recipients had a higher risk of graft loss resulting from recurrent FSGS, disproportionately seen in recipients of African-American kidneys. The role of donor/recipient race pairing on graft loss resulting from recurrent FSGS should be validated. Living donor had no association with graft loss from recurrent FSGS after correction for other factors. African-American recipients with FSGS may have the most to gain from a living donor, given their improved graft survival and decreased risk of graft loss resulting from recurrent FSGS. This is a US government work. There are no restrictions on its use.

Glomerular size and glomerulosclerosis in Australian aborigines

We have previously described the prevalence of glomerulomegaly in biopsy specimens from Australian Aborigines with renal disease, a phenomenon documented in a number of other indigenous populations. Many of the biopsy specimens showed variable degrees of focal and segmental glomerulosclerosis (FSGS). Correlations between glomerular size and FSGS have been described in various animal models, as well as studies of humans. The aim of this study is to determine whether a relation exists between glomerular volume and severity of FSGS in biopsy specimens from Australian Aboriginals in the Northern Territory and Aboriginal inhabitants of the Tiwi Islands (Bathurst Island and Melville Island, Northern Territory, Australia). Consecutive clinical biopsy specimens were obtained from 78 non-Tiwi and 72 Tiwi Aboriginals. Glomerular volume was estimated using the stereological method of Weibel and Gomez. FSGS was graded from 0 to 4; 0 indicates no sclerosis and 4 indicates severe sclerosis. A biphasic relationship between glomerular size and severity of FSGS was identified. As the severity of FSGS increased from grade 0 to grade 3, glomerular size also increased. For both populations studied, glomeruli scored as grades 1, 2, and 3 were approximately 50% (P< 0.001), 65% (P< 0.001), and 100% (P< 0.001) larger than normal glomeruli, respectively. However, in glomeruli with grade 4 FSGS, glomerular size decreased to the size of normal glomeruli. These results show a biphasic relationship between severity of FSGS and glomerular size in Australian Aborigines.

Focal segmental glomerulosclerosis in African Americans: effects of steroids and angiotensin converting enzyme inhibitors

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) is a common primary glomerulopathy in African Americans. In this report, we present data on 40 African American patients with FSGS from our medical center.

METHODS

Patients were identified from a review of all charts seen in our conservative management renal clinic in 1996, a review of renal biopsy rolls (1994-1998), and a review of patients entering the end-stage renal disease (ESRD) program with a primary diagnosis of FSGS (1993- 1997). Charts were reviewed for demographic, biopsy, and treatment data. Patients who were observed for at least 4 months (range, 4-125 months) were included. ESRD was used as the primary endpoint (n = 12). Data were analyzed using univariate and multivariate Cox hazards and Kaplan-Meier survival analysis. Twenty-four patients were treated with angiotensin-converting enzyme (ACE) inhibitors. Similarly, 24 patients were treated with corticosteroids for a mean of 8.75 +/- 2.6 months and a total dose of 9.3 +/- 2.2 g.

RESULTS

On univariate analysis, factors found to be significant determinants for reaching ESRD were the initial creatinine (P = 0.0001), interstitial fibrosis (P = 0.032), the percentage of globally sclerosed glomeruli (P = 0.0018), and the mean arterial blood pressure over the course of follow-up (P = 0.05). Neither the ACE inhibitors nor the corticosteroids had a significant impact on reaching ESRD. The patients reaching ESRD (n = 12) were analyzed separately. The mean time from biopsy to ESRD was 24.7 +/- 9.8 months. ACE inhibitors prolonged renal survival (P = 0.023), but steroids did not. Initial creatinine was the only factor found to be a significant determinant for ESRD.

CONCLUSIONS

We conclude that FSGS is common in African Americans. Early diagnosis and blood pressure control are important, but the beneficial effects of steroids and ACE inhibitors in this population are still unclear.

Nephrotic syndrome in Namibian children

BACKGROUND AND OBJECTIVES

Patterns of nephrotic syndrome vary between regions and countries, and influence approaches to management. In the mid-1970s the University of Stellenbosch became involved in providing tertiary care to Namibia, including a paediatric nephrology service. The aim of this study was to document the clinical, pathological and outcome features of nephrotic syndrome in Namibian children.

SUBJECTS

Seventy black Namibian children with nephrotic syndrome were managed from 1975 to 1988. Sixty-eight renal specimens (67 biopsies and 1 autopsy specimen) were evaluated.

RESULTS

Twenty-nine of the 70 children (41.4%) were hepatitis B virus (HBV) carriers, of whom 25 (86.2%) were male. Of the 29, 26 had predominantly membranous glomerulonephritis (MGN), 1 mesangiocapillary glomerulonephritis (MCGN), and 1 focal segmental glomerulosclerosis (FSGS); 1 child in advanced renal failure was not biopsied. Five children (7.4%) showed minimal change disease (MCD), 11 (16.2%) FSGS and 15 (22.1%) diffuse mesangial proliferative glomerulonephritis (DMP). The remaining 10 children showed diffuse glomerulosclerosis (6), MCGN (3) and endocapillary proliferative GN (1). Four of the 5 children with MCD went into remission on immunosuppressive treatment. Of the 15 with DMP, 4 improved spontaneously and only 1 of those treated did not improve. Only 2 of those with FSGS improved on treatment. The children with HBV-associated MGN and MCGN were offered symptomatic rather than specific treatment. Thirteen children presented with degrees of chronic renal failure. Eight are known to have died, 3 of relentless nephrotic syndrome and 4 (of whom 3 were HBV carriers) of end-stage renal failure. One child died of penicillin anaphylaxis.

CONCLUSIONS

The pattern of nephrotic syndrome in black Namibian children differed greatly from the non-African pattern elsewhere in that MCD was uncommon and HBV-associated GN was the most common single group. The most frequent pattern of HBV-associated GN was MGN with some mesangiocapillary features showing marked male predominance. MCD and DMP were potentially treatable and could only be identified by biopsy. HBV carrier rates exert a major influence on the proportions of morphological subgroups of nephrotic syndrome in children. As these HBV carrier rates alter in future due to the influence of vaccination and urbanisation, the relative size of nephrotic subgroups seems likely to alter.

Changing patterns in the histopathology of idiopathic nephrotic syndrome in children

BACKGROUND

It is widely accepted that minimal change nephrotic syndrome (MCNS) is the most common cause of nephrosis in children. Recent studies have demonstrated an increasing incidence of focal segmental glomerulosclerosis (FSGS) in adults.

METHODS

To determine possible changes in the etiology of childhood nephrosis, the clinical charts of 152 pediatric patients diagnosed with idiopathic nephrotic syndrome between 1978 and 1997 were reviewed. Histopathological diagnosis was available in 105 patients.

RESULTS

MCNS was present in 35% of all biopsies, whereas FSGS was observed in 31%. Even if we assume that all patients without a histological diagnosis had MCNS (presumptive MCNS), the total incidence of MCNS (biopsy proven + presumptive) in our population was only 55%. We observed a dramatic increase in the incidence of FSGS during recent years. Before 1990, FSGS was diagnosed in 23% of all renal biopsies but increased to 47% afterward (P = 0.02). This pattern was observed in all ethnic groups. In African Americans, there was a trend for an increase in the incidence of FSGS from 38% before 1990 to 69% after 1990. A similar trend was observed in Caucasians (from 20 to 45%) and Hispanics (from 8 to 33%) Hispanics had the highest incidence of MCNS (biopsy proven + presumptive: 73%), followed by Caucasians (53%) and African Americans (37%). The mean age for presentation of nephrotic syndrome in African Americans (8.0 +/- 0.9 years) was higher than in Caucasians (4.1 +/- 0.05) and Hispanics (3.3 +/- 0.5).

CONCLUSIONS

Our study showed that the incidence of FSGS in children with idiopathic nephrotic syndrome has increased recently. Furthermore, in African American children. FSGS is the most common cause of nephrotic syndrome. These findings may have significant implications in the management of childhood nephrotic syndrome.

[Racial differences between patients with focal segmental glomerulosclerosis and membranoproliferative glomerulonephritis from the State of Bahia]

OBJECTIVE

To assess the association between race and type of glomerulonephritis, taking into account age, gender and the presence of hepatosplenic schistosomiasis mansoni.

METHODS

Patients from the Renal Service of the Federal University of Bahia, Brazil, 80 with focal segmental glomerulosclerosis (FSG) and 50 with membranoproliferative glomerulonephritis (MPGN) were compared regarding the distribution of the racial types (black, mulatto, white). Patients with systemic lupus erythematosus or any kind of autoimmune disease were not included in the present analysis. Adjusted comparisons were performed using the Mantel-Haenszel method and a multivariate logistic regression model.

RESULTS

Race was significantly associated with histologic type; the odds of being classified as black or mulatto were approximately 2.4 times higher (odds ratio = 2.43; IC 95% = 1.09-5.45) in patients with FSG than in those with MPGN. The association between race and histologic type was not influenced by the potential effects of age, gender and hepatosplenic schistosomiasis. In the multivariate logistic regression model, race was significantly associated (p = 0.037) with type of glomerulonephritis (odds ratio = 2.54; IC 95% = 1.06-6.06).

CONCLUSION

A higher frequency of negroes and mulattoes in the FSG group (compared with MPGN) in this sample from the State of Bahia is consistent with findings of previous studies from the United States. The data support the possibility of a greater susceptibility to FSG among negroes and mulattoes, independently of age, gender and schistosomiasis. The identification of the mechanisms that determine this racial difference represents an important question for future investigations.

High incidence of focal segmental glomerulosclerosis in nephrotic syndrome of childhood

In recent adult literature, there have been reports of an increasing incidence of focal segmental glomerulosclerosis (FSGS) among patients with nephrotic syndrome. To examine whether this observation is also relevant to the pediatric population we utilized our hospital computerized database to analyze the data on children with primary nephrotic syndrome seen first between the years 1984 and 1995. A questionnaire was also sent to all metropolitan Kansas City pediatricians to identify possible patients outside the database. The inclusion criteria were clinical nephrotic syndrome or proteinuria with a kidney biopsy. A total of 148 patients (group A) were identified; 86 of them from metropolitan Kansas City (group B). In group A the incidence of minimal change disease (MCD) and FSGS was 52.7% [95% confidence interval (CI) 44%-60%] and 23.0% (95% CI 16-29%), respectively and in group B 54.7% (95% CI 44%-65%) and 24.5% (95% CI 15%-33%), respectively. Those numbers were significantly different from the International Study of Kidney Disease in Children (IS-KDC) reported incidence of 76.4% for MCD and 6.9% for FSGS. Similar to the ISKDC, in our population children over 6 years had a higher incidence of FSGS than younger children (32.8% vs. 16.7%, P = 0.028). The annual incidence rate for nephrotic syndrome in group B was 2.2 cases/10(5) children per year, of which MCD comprised 1.22 cases/10(5) children per year and FSGS 0.5 cases/10(5) children per year. The annual incidence rates of both primary nephrotic syndrome (3.6) and FSGS (1.6) were significantly higher in African-Americans, than Caucasians (1.8 and 0.3 cases/10(5) children per year, respectively). Our study indicates nearly no change in the annual incidence of pediatric primary nephrotic syndrome, but a higher incidence of FSGS with reciprocal decline in the incidence of MCD. The possibility of primary nephrotic syndrome being caused by a non-MCD entity is further raised among African-American and in children over 6 years. We conclude that our perception of primary nephrotic syndrome of childhood as a benign condition has to be carefully reexamined and a more-guarded prognostic approach adopted in our geographic area.

HIV-associated nephropathy: outcome and prognosis factors. Groupe d' Etudes Néphrologiques d'Ile de France

Records of 102 patients with biopsy-proven HIV-associated nephropathy (HIVAN) admitted to 18 hospitals in the Paris area from 1984 through 1996 were retrospectively reviewed. Demographics and clinical and laboratory features of the cohort were determined, and prognostic factors of renal and patient survival were analyzed. Renal and patient survival curves were estimated with the actuarial method. Prognostic factors were assessed by uni- and multidimensional analyses based on Cox regression models. Values were expressed as median with interquartile. The total population (median age 34) included 97% blacks and 71.5% males. Median patient follow-up was 165 d (range, 43 to 493). At the time of renal biopsy, median values of serum creatinine, proteinuria, and CD4+ cell count were 496 micromol/L, 6.5 g/24 h, and 48.5 cells/mm3, respectively. Fifteen patients were given steroids after the onset of HIVAN. Overall patient survival at 0.5, 1, and 3 yr was 73 +/- 5, 55 +/- 6, and 38 +/- 7%, respectively. The proportion of patients free of dialysis at 0.5, 1, and 3 yr was 73 +/- 5, 60 +/- 7, and 18 +/- 10%, respectively. Predictors of poor patient prognosis were a low CD4+ cell count (relative risk [RR; per 50 cells/mm3 decrease] 1.35; confidence interval [CI], 1.13 to 1.6) and antiretroviral therapy before the onset of HIVAN (RR 1.9; CI, 1.05 to 3.6). Main independent factors associated with better renal outcome were: steroid therapy (RR 0.29; CI, 0.1 to 0.9); low proteinuria level (RR [per 50% decrease] 0.7; CI, 0.5 to 0.98); low serum creatinine (RR [per 1.1 mg/dl decrease] 0.78; CI, 0.7 to 0.87); and hemoglobin level (RR [per g/dl increase] 0.76; CI, 0.58 to 1.00). HIVAN is not a rare nephropathy in Paris and its suburbs. Renal prognosis and patient survival are better than what was reported previously. Steroids may delay the downward course of HIVAN. It is not certain that in the new era of HIV therapy, the possible renal benefits of corticosteroids outweigh their potential risks. The only reliable predictor of patient survival is the intensity of immunodeficiency.

Age and ethnicity affect the risk and outcome of focal segmental glomerulosclerosis

In patients with proteinuria, African-American (AA) ethnicity is reported to be a risk factor for focal segmental glomerulosclereosis (FSGS) and its progression to end-stage renal disease (ESRD). We reviewed our single-center experience to determine the probability of FSGS and its progression to ESRD based on ethnicity and age at presentation in children with proteinuria with or without nephrotic syndrome. Proteinuria without systemic disease or acute glomerulonephritis was the presenting feature in 17% (236/1,403) of children in the renal patient database of Texas Children's Hospital, Baylor College of Medicine. Histopathological diagnoses were established in 107 of 236 patients (45%). FSGS was identified in 65 patients, accounting for 28% of all patients with proteinuria and 61% of patients who underwent renal biopsy. FSGS was more prevalent in AA (45%) than in non-AA patients (22%) (P=0.001), and AA patients with FSGS were older at presentation (12.7+/-4.4 years) than non-AA patients (5.6+/-4.6 years) (P<0.001). Among patients who underwent renal biopsy, increasing age at presentation increased the probability of having FSGS in AA but not non-AA patients (P=0.04). Five-year actuarial renal survival of FSGS was worse in AA (8%) than in non-AA patients (31%) (P=0.01). These data suggest an increased risk and worse outcome of FSGS in AA compared with non-AA children.

Paediatric nephrotic syndrome in Auckland, New Zealand

OBJECTIVE

To review children with nephrotic syndrome in Auckland, New Zealand.

METHODS

All children admitted to Auckland Children's Hospital between January 1984 and December 1994 with nephrotic syndrome and a renal biopsy had their charts retrospectively reviewed and the appropriate information summarised.

RESULTS

Fifty-seven children biopsied with nephrotic syndrome were available for review. The mean age at diagnosis was 5.4 years, standard deviation (SD) 3.9 years, with mean follow-up of 5.7 years. The histologies of the renal biopsies were: minimal change nephrotic syndrome (MCNS) in 37%, focal segmental glomerulosclerosis in 19%, membranoproliferative glomerulonephritis (MPGN) in 23% and other causes in 21%. Maori children were most likely to have MPGN. Steroid resistance was present in 66% of children. End stage renal failure developed in 26% of patients and chronic renal failure in 4% of patients.

CONCLUSION

In this series the proportion of children with MCNS is low and significant numbers of children with nephrotic syndrome progressed to chronic renal failure and end stage renal failure.

Hemodialysis vascular access: variable thrombus-free survival in three subpopulations of black patients

Hemodialysis vascular access-related problems account for most hospitalizations in chronic hemodialysis patients. Although some co-morbid risk factors for early fistula failures have been described, a great deal of unknown exists as to why access survival is favorable in some patients. In this longitudinal study, fistulae patency and thrombosis episodes were monitored from placement date in three groups of end-stage renal disease (ESRD) patients who have been on dialysis for > or =90 days. Thirty-six patients (29 male; 80%) with a mean age of 42+/-2 years were monitored. The groups consisted of eight patients with biopsy-confirmed focal segmental glomeruloscierosis (FSGS), 13 with acquired immunodeficiency syndrome-related nephropathy (human immunodeficiency virus [HIV]), and 15 with hypertensive ESRD (hypertensive nephrosclerosis [HTN]) who served as controls. Diabetics and patients aged > or =64 years were excluded. Twenty-five of 36 (69%) fistulae were prosthetic (AVG), while 11 (31%) were native (AVF). The FSGS group was more likely to have an AVG (87.5%), while 54% of the HIV group had an AVG. The thrombosis event rate was significantly greater among the FSGS patients (3/patient-year) than the HIV (0.15/patient-year) and HTN (0.5/patient-year) patients (P < 0.0001 and P < 0.002, respectively). The mean thrombosis-free duration for both AVG and AVF among the HIV and HTN groups were 318.5+/-17 days and 311.7+/-22.5 days, respectively. These were significantly greater than in the FSGS group (26.5+/-7 days; P < 0.0001). The cumulative 1-year patency rate for AVG among the HIV and HTN groups was 85% and 65%, respectively, while that of the FSGS group was 0%. Kaplan-Meier hazard analysis showed that all groups were at risk of access thrombosis as time progressed, but the FSGS group had the highest risk of access thrombosis, which began from the date of placement and increased exponentially with time. The increased thrombosis rate among the patients in the FSGS group correlated with their weight (R = 0.8, P = 0.003) and pre-ESRD 24-hour urinary protein excretion (R = 0.9, P = 0.001). The HIV status appeared to confer enhanced hemodialysis access survival. This may be related to the high rate of native fistulae placement and favorable vascular reactivity to shear stress. Accelerated atherosclerosis and small caliber vessels may be responsible for the poor fistulae outcome among the FSGS group. More studies will be necessary to further explore these findings.

Variants of alpha 1-proteinase inhibitor in black and white South African patients with focal glomerulosclerosis and minimal change nephrotic syndrome

OBJECTIVE

To determine the prevalence and biochemical characteristics of certain alleles of alpha 1-proteinase inhibitor in black and white South African patients with two common types of pathology causing the nephrotic syndrome.

DESIGN

A cross sectional study of black and white patients with focal glomerulosclerosis (FGS) or minimal change disease (MCNS) and black and white controls.

SETTING

The patients were drawn from the Paediatric Nephrology Units at the Johannesburg and Baragwanath Hospitals and the controls were drawn from the South African Blood Transfusion Service and the Paediatric Nephrology Clinic in Johannesburg.

RESULTS

There was a significant increase in the prevalence of the V allele in black patients with FGS (12%) as compared to black controls (1%) (p = 0.01). None of the white patients with FGS had the V allele but two out the five coloured (mixed race) patients had the V allele (20%). An increase in the prevalence of the S allele of alpha 1PI was found in white patients with FGS and MCNS (10%) as compared to white controls (2%). The plasma elastase inhibitory capacity (EIC) associated with the phenotypes (PI) M1 (Ala213)S, M1 (Ala213) V, and M1 (Ala213) M1 (Ala213) was significantly decreased as compared to the EIC associated with PI M1 (Val213) M1 (Val213) (p = 0.006, p = 0.004, and p = 0.025, respectively). Twelve of 13 patients with FGS and infected with tuberculosis had either the M1 (Ala213) V or F alleles and required transplantation owing to the severity of the disease. All of these patients were either black or coloured. However, eight of 12 patients with FGS who had the M1 (Ala213) V or S alleles but were PPD negative did not require transplantation.

CONCLUSION

It is possible that the combination of functionally less efficient alpha 1PI and an inflammatory challenge associated with an infection such as tuberculosis could predispose black and coloured nephrotic patients to more aggressive scarring in FGS.

Focal segmental glomerulosclerosis in adult African Americans

We have previously shown that idiopathic focal segmental glomerulosclerosis (FSGS) is the most common non-proliferative primary glomerulopathy in adult African Americans. In this report we present our experience with treated FSGS in 15 such patients followed over five years. They were all treated with prednisone 60 mg daily for three months, followed by a slow tapering. In addition, two patients later had cyclophosphamide, and five had enalapril. At entry hypertension was present in 73% of the patients, nephrotic syndrome in 87%, and elevated serum creatinine (> or = 1.4 mg/dl) in 40%. Five of the 15 patients (33%) developed end-stage renal failure (ESRF), one of them having a "malignant" course after the advent of pregnancy. Two patients (13%) have chronic renal insufficiency (CRI; serum creatinine > 2.5 mg/dl); three (20%) have mild renal insufficiency (serum creatinine 1.4-2.5 mg/dl), and five patients (33%) have normal renal function. The cumulative renal survival was 93% at five years, but only 26% at eight years. At last follow-up all the ten patients who did not develop ESRF were in partial remission (urinary protein of 1.3 g/day +/- 1.21), but 4 of the 5 patients who did not develop ESRF had no prolonged partial remission of nephrotic syndrome. Neither the initial clinical parameters not the use of enalapril correlated with the renal outcome (univariate analysis). However, 4 of the 5 patients who developed ESRF had elevated serum creatinine at entry, versus only 2 of the 10 not developing ESRF (p = 0.09 by two-sided, and 0.045 by one-sided Fisher's exact test). We conclude that the short-term renal outcome in nephrotic adult African Americans with treated FSGS is comparable to that of the non-African Americans, but their long-term prognosis may be poorer. Patients developing ESRF were more likely to present with elevated serum creatinine. Enalapril did not seem to modify the course of renal disease, but its utility and that of other ACE inhibitors in the treatment of FSGS must await prospective randomized studies.

Intravenous methylprednisolone and oral alkylating agent therapy of prednisone-resistant pediatric focal segmental glomerulosclerosis: a long-term follow-up

Prednisone-resistant nephrotic syndrome (NS) due to focal segmental glomerulosclerosis (FSGS), the most common acquired disease requiring chronic dialysis and transplantation in children, has a low likelihood of response to alkylating agent therapy. This report summarizes the results of a 0.75-12.5 (average 6.33) year follow-up of 32 pediatric cases of prednisone-resistant FSGS treated with a regimen of high-dose intravenous methylprednisolone (M-P) and alternate-day prednisone, plus an alkylating agent in 25/32. On last followup: 21/32 were in remission [urine protein-to-creatinine ratios (Pru/Cru) < or = 0.2]; 3/32 had mild proteinuria (Pru/Cru > 0.2-0.5); 2/32 had moderate proteinuria (Pru/Cru > 0.5-1.9); and 6/32 remained nephrotic (Pru/Cru > or = 2.0). Of the incomplete or nonresponders; 3/11 progressed to end-stage renal failure; 5/11 had decreased creatinine clearances (CrCl): and 3/11 had persistent proteinuria with normal CrCl. All of the persistently nephrotic children, but none of the complete responders, developed decreased CrCl. All of the complete responders were able to stop treatment; four relapsed but responded well to retreatment.

CONCLUSIONS

This regimen of methylprednisolone and alternate-day prednisone, with or without an alkylating agent, is effective in achieving sustained remissions and preserving normal renal function in the great majority of children with FSGS and prednisone-resistant NS.

Impact of tuberculosis in children with idiopathic nephrotic syndrome

Forty black South African children (mean age 4.7 +/- 2.6 years) with idiopathic nephrotic syndrome due to focal glomerulosclerosis (FSGS) were evaluated. Tuberculosis (TB) was found in 37.5% of children with FSGS (FSGS-TB) compared with 6% of a comparable group with minimal lesion nephrotic syndrome. No significant differences were found in the initial mean serum albumin, cholesterol, triglyceride and creatinine levels in FSGS-TB compared with children with glomerulosclerosis but without TB (FSGS-nonTB). The mean serum levels of C4, IgA and IgM were increased by 30%, 25% and 23%, respectively in children with FSGS-TB compared with FSGS-nonTB. Initial estimated creatinine clearance was similar in the two groups, but after a mean follow-up of 2.4 years, the mean estimated creatinine clearance of children with FSGS-TB was significantly reduced by 46% from the initial value, but remained stable in the FSGS-nonTB group. FSGS-TB children also had significantly increased requirements for renal replacement therapy compared with children with FSGS-nonTB. We conclude that TB infection is commonly associated with FSGS in black South African children; this may have deleterious effects on renal function.

Racial differences in the incidence and renal outcome of idiopathic focal segmental glomerulosclerosis in children

The North American Pediatric Registry reports that from 1987 to 1989 blacks and Hispanic children accounted for 23% of all renal transplants performed but 38% of those performed for focal segmental glomerulosclerosis (FSGS). From these data, we infer that blacks and Hispanics form a disproportionate number of FSGS patients who progress to end-stage renal disease (ESRD) compared with white children. To explore this hypothesis we assessed our single-center experience of FSGS comparing black and Hispanic with white children. Of 177 black and Hispanic children followed in our clinic for idiopathic nephrotic syndrome (NS) between 1974 and 1989, 57 were diagnosed as having FSGS (group I). The mean age at onset of NS of these group I patients was 7.3 +/- 4.6 years and the mean duration of follow-up was 8.25 +/- 4.3 years. During the same period, 13 of 65 white patients (group II) with idiopathic NS were found to have FSGS. Their mean age (7.8 +/- 4.8 years) and duration of follow-up (8.8 +/- 4.8 years) were similar. Therapeutic modalities in the two groups were also similar. Of group I patients, 78% (42/54) reached ESRD compared with 33% (4/12) of group II patients (P less than 0.01). Life table analysis showed that 50% of black and Hispanic children will reach ESRD within 3 years of FSGS.(ABSTRACT TRUNCATED AT 250 WORDS)

Possible genetic predisposition to idiopathic focal segmental glomerulosclerosis

HLA-A, B, and DR antigen frequencies were studied in a group of 57 patients to determine possible inborn susceptibility to idiopathic focal segmental glomerulosclerosis (FSGS). There were 34 white patients and 23 black patients, most of whom had nephrotic syndrome and later developed renal failure. HLA-DR4 was significantly increased in both patient groups when compared with their respective control groups. This association has not been previously reported. Of note, the association with DR4 was most striking in patients with adult onset disease (in blacks, relative risk equals 5.2; in whites, relative risk equals 5.8). No other antigen was increased in both patient groups but HLA-A28 was increased in blacks. These data support the notion of genetic predisposition to focal segmental glomerulosclerosis in two different ethnic groups.