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Stephen M Korbet

Publications and source records attributed to Stephen M Korbet.

13 recordsLinked to original sources
PubMed2006

Severe lupus nephritis: racial differences in presentation and outcome.

This study assessed whether certain clinicopathologic variables could explain the impact of race on outcome in 86 patients who had severe lupus nephritis and were available for long-term follow-up after participating in a prospective, controlled, clinical trial. Fifty-four (63%) patients were white, 21 (24%) were black, and 11 (13%) were categorized as other. The proportion of patients with anti-Ro, anti-nRNP, and anti-Sm was significantly greater among black patients. Biopsies with segmental active proliferative and necrotizing lesions that involved >or=50% of glomeruli +/- membranous glomerulonephritis (class III >or=50%+/-V) were significantly more common (white 44%, black 76%, other 36%; P < 0.05) and diffuse proliferative glomerulonephritis +/- membranous glomerulonephritis (class IV+/-V) was less common (white 54%, black 24%, other 64%) among black patients. Attainment of a remission was greatest among white patients (white 52%, black 29%, other 27%; P = 0.09). Features that were predictive of a remission were white race, baseline serum creatinine, and class IV+/-V lesions. Patient survival at 10 yr (white 81%, black 59%, other 73%; P = 0.029) and renal survival at 10 yr (white 68%, black 38%, other 61%; P = 0.015) were significantly poorer in black patients. Predictors of ESRD were serum creatinine, the presence of anti-Ro antibodies, class III >or=50%+/-V lesions, and failure to achieve a remission. In conclusion, racial differences were observed in the serologic and histologic features at presentation, response to treatment, and outcome of patients with severe lupus nephritis. In a population of patients with severe lupus nephritis, black patients were significantly more likely to have a serologic profile and renal lesions that were associated with more aggressive renal disease and resulted in worse outcomes than white patients.

Adult↗
PubMed2005

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.

Black or African American↗
PubMed2005

Pulmonary-renal syndrome in a newborn with placental transmission of ANCAs.

Despite clinical and experimental data suggesting a direct relationship between antineutrophil cytoplasmic antibodies (ANCAs) and disease activity in patients with microscopic polyangiitis (MPA), the causal relationship between perinuclear ANCAs specific for myeloperoxidase (MPO-ANCA) and disease manifestations has been controversial. We describe the case of a woman with a history of pulmonary-renal syndrome caused by MPA whose disease became clinically and serologically active during pregnancy. Forty-eight hours after delivery, the newborn developed pulmonary hemorrhage and abnormalities in renal function. The newborn's cord blood showed an immunoglobulin G MPO-ANCA level identical to that of the mother's serum, indicating passive transfer of the antibody to the neonate. Our findings represent the first human model supporting the interpretation that MPO-ANCAs were immunopathogenic.

Adult↗
PubMed2004

Glomerular podocytopathy in patients with systemic lupus erythematosus.

A series of patients with systemic lupus erythematosus (SLE) and proteinuria were studied to determine whether nephrotic-range proteinuria was associated with diffuse epithelial cell foot process effacement in the absence of peripheral glomerular immune aggregate deposition. Biopsies from patients with known or suspected SLE and a histologic diagnosis of (1) normal by light microscopy, (2) mesangial proliferative glomerulonephritis, or (3) focal segmental glomerulosclerosis were studied. Biopsies were excluded when they demonstrated endocapillary proliferation or necrosis by light microscopy or electron-dense glomerular basement membrane deposits by electron microscopy. Patients were required to fulfill four of 11 American Rheumatologic Association criteria for the diagnosis of SLE, and proteinuria could not be associated with nonsteroidal anti-inflammatory drug use. Eighteen biopsies were studied, eight from patients with nephrotic-range proteinuria (>/=3 g/d) and 10 from patients with non-nephrotic proteinuria. The time from diagnosis of SLE to biopsy was shorter for nephrotic patients that for nonnephrotic patients. Seven of eight biopsies from nephrotic patients demonstrated at least 80% foot process effacement, whereas no biopsy from a nonnephrotic patient exhibited >20% effacement. There were no other significant pathologic differences between the nephrotic and nonnephrotic patients. The single common morphologic feature associated with nephrotic proteinuria was diffuse visceral epithelial cell foot process effacement. It is concluded that the development of nephrotic-range proteinuria in patients with SLE without peripheral immune aggregate deposition or endocapillary proliferation on renal biopsy is more likely a manifestation of SLE than the coexistence of idiopathic minimal-change glomerulopathy and SLE.

Adult↗
PubMed2004

Renal biopsy: update.

PURPOSE OF REVIEW: The renal biopsy is an invaluable tool in the diagnosis, prognosis, and management of patients with kidney disease. As the success of the procedure is defined not only by the ability to obtain adequate tissue but also by the safety profile, significant advances which define risk factors and determine the optimal timing of observation after the percutaneous native renal biopsy merit discussion. Alternative methods of obtaining tissue, such as transvenous renal biopsies, have also been described, especially in patients with contraindications to the percutaneous method. RECENT FINDINGS: The percutaneous renal biopsy has been established as a safe and effective method of obtaining renal parenchyma. Complications, although rare, may occur and the majority of these are related to bleeding. The optimal timing of observation after the biopsy should be determined by when most complications occur, and, as over 33% of complications occur after 8 h, an observation period of at least 24 h is recommended. In patients with contraindications to the percutaneous approach, such as failure of adequate radiologic visualization or a bleeding diathesis, alternative methods of obtaining tissue have been attempted. These include open, laparascopic, transurethral, or transvenous renal biopsy. SUMMARY: Without contraindications, the percutaneous renal biopsy remains the standard method of acquiring renal tissue. At least 24 h of observation is recommended after the percutaneous native kidney biopsy for the development of potential complications. When a contraindication to the procedure exists, other methods of renal biopsy by experienced physicians may be attempted.

Biopsy↗
PubMed2004

Timing of complications in percutaneous renal biopsy.

Percutaneous renal biopsy (PRB) is a safe and effective tool in the diagnosis and management of renal disease; however, the optimal timing of observation after biopsy is not clearly established. With the use of real-time ultrasound guidance, PRB of native kidneys was performed in 750 adult patients at an academic institution by an attending nephrologist or fellow between June 1983 and June 2002. All patients were observed for 23 to 24 h after biopsy for the presence, severity, and timing of complications. Biopsy-related complications occurred in 98 (13%) patients; minor complications occurred in 50 (6.6%) patients, and major complications occurred in 48 (6.4%) patients. One (0.1%) patient died as a result of the biopsy. Multivariate analysis using logistic regression found only serum creatinine at baseline predictive of a complication. Patients with a serum creatinine > or = 5.0 mg/dl were 2.3 times as likely to have a complication (odds ratio, 2.3; 95% confidence interval, 1.3 to 4.1; P < 0.005). Complications were identified in 38 (42%) patients by < or = 4 h, in 61 (67%) patients by < or = 8 h, in 77 (85%) patients by < or = 12 h, and in 81 (89%) patients at < or = 24 h. The PRB remains a safe procedure, but the risk of complication is higher in patients with advanced renal insufficiency. After biopsy, an observation time of up to 24 h remains optimal as an observation period of < or = 8 h risks missing > or = 33% of complications.

Adult↗
PubMed2004

Focal segmental glomerulosclerosis in nephrotic adults: presentation, prognosis, and response to therapy of the histologic variants.

The histopathologic diagnosis of primary focal segmental glomerulosclerosis (FSGS) has come to include a number of histologic lesions (variants), but the prognostic significance of these discrete lesions is controversial because published information regarding the presentation, course, and response to treatment is limited. A retrospective analysis was conducted of 87 nephrotic adult patients with biopsy-proven primary FSGS. Patients were categorized on the basis of histologic criteria into those with a classic scar (36 patients), the cellular or collapsing lesion (40 patients), or the tip lesion (11 patients) of FSGS to evaluate differences in presentation, response to therapy, and clinical outcomes. The clinical features at biopsy were similar among the three groups with the exception that patients with the tip lesion were older and patients with the collapsing lesion had more severe proteinuria. Over the course of follow-up, 63% of patients treated attained remission and the response to steroid therapy was similar among the groups (classic scar 53% versus collapsing lesion 64% versus tip lesion 78%; P = 0.45). The overall renal survival was significantly better for patients who entered remission compared with patients who did not enter remission (92% versus 33% at 10 yr; P < 0.0001). The renal survival at 10 yr for patients who entered remission was similar among the three groups (classic scar 100% versus tip lesion 100% versus collapsing lesion 80%; P = 0.61). In patients who did not enter remission, the renal survival at 10 yr was significantly worse for patients with collapsing lesion and tip lesion (classic scar 49% versus tip lesion 25% versus collapsing lesion 21%; P = 0.002). In conclusion, the prognosis for nephrotic FSGS patients who enter remission is excellent regardless of the histologic lesion. Because the remission rate after treatment is similar among patients with the histologic variants, response to therapy cannot be predicted on the basis of histology alone. Thus, nephrotic patients with primary FSGS should receive a trial of therapy irrespective of the histologic lesion when not contraindicated.

Adult↗
PubMed2003

Angiotensin antagonists and steroids in the treatment of focal segmental glomerulosclerosis.

The use of angiotensin converting enzyme inhibitors (ACEIs) along with good blood pressure control have been shown to significantly decrease the level of proteinuria and slow the progression of renal insufficiency in patients with nondiabetic glomerular disease including focal segmental glomerulosclerosis (FSGS). Thus, this should be part of the therapeutic approach for all proteinuric patients with FSGS and should be considered the mainstay of therapy for patients with FSGS secondary to conditions associated with hyperfiltration and/or reduced nephron mass and those patients with nonnephrotic primary FSGS. However, nephrotic patients with primary FSGS may continue to have marked proteinuria and progression of renal disease despite these measures and thus require a more aggressive approach with the use of steroids and immunosuppressive agents. Although primary FSGS was once thought to be a steroid-nonresponsive lesion, recent experience has provided a note of optimism in the use of steroids and immunosuppressive agents in treating this otherwise progressive glomerulopathy. As a result, a course of steroid therapy in primary FSGS is now warranted in nephrotic patients with reasonably well preserved renal function in whom it is not otherwise contraindicated.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2002

Percutaneous renal biopsy.

Percutaneous renal biopsy (PRB) is an integral part of the clinical practice of nephrology. It is essential in the diagnosis of glomerular, vascular, and tubulointerstitial diseases of the kidney, providing information that is invaluable in prognosis and patient management. The use of real-time ultrasound and automated biopsy needles has simplified and improved the success and safety of this procedure. In the recent past, we have seen a shift of the PRB from nephrologists to radiologists and this has raised appropriate concern that loss of this procedure may undermine the nephrologist's status as a subspecialist. We must continue to properly train young nephrologists in the proper technique and value of performing renal biopsy procedures or we stand to lose control of a procedure that was an integral part of the development of our subspecialty.

Biopsy, Needle↗
PubMedDate not supplied

The effect of technique failure on outcome in black patients on continuous ambulatory peritoneal dialysis.

BACKGROUND: We previously reported that, while black patients have a better patient survival than white patients on peritoneal dialysis (PD), they also have a significantly higher technique failure rate (39% vs 8%, p < 0.0001). The purpose of this study was to determine the effect of technique failure/transfer to hemodialysis (HD) on patient survival in black PD patients. METHODS: We retrospectively evaluated 137 incident black patients entering our PD program from January 1987 to December 1997. During the course of follow-up, 82 (60%) patients remained on PD (PD group) while 55 (40%) patients were permanently transferred to HD (PD-HD group). The primary outcome measured was patient survival. RESULTS: Average age was 49 +/- 15 years, 42% were male, and 40% had diabetes mellitus. At baseline, serum creatinine was 10.8 +/- 5.4 mg/dL, serum albumin 3.4 +/- 0.7 g/dL, body mass index 27.3 +/- 6.5 kg/m2, peritoneal transport status was high in 18% and high-average in 61%, and residual glomerular filtration rate was 3.4 +/- 3.5 mL/minute. There were no significant differences in clinical features, nutritional status, peritoneal transport, residual renal function, or dialysis adequacy at baseline between the PD group and PD-HD group. While a greater proportion of patients transferring to HD had cardiac disease (53% vs 32%, p < 0.05), there were no other significant differences in 15 comorbid conditions assessed at baseline. The primary reason for transfer was peritonitis (64%) and the overall peritonitis rate in the PD-HD group was significantly higher than in the PD group (2.21 vs 1.17 episodes/patient-year, p < 0.0001). Overall follow-up was 34 +/- 25 months for PD group and 44 +/- 26 months for PD-HD group (p < 0.01), with a mean time on PD prior to transfer to HD of 22 +/- 18 months. During the course of follow-up, there were no significant differences between the two groups in the number of patients transplanted or deaths. Patient survival at 1, 2, and 5 years was 91%, 80%, and 57% for PD group and 96%, 92%, and 55% for PD-HD group [p = not significant (NS)]. A risk-adjusted time-dependent Cox regression analysis resulted in an adjusted relative risk of death that was not significantly different for those who transferred from PD to HD versus those who remained on PD (relative risk 1.49; 95% confidence interval 0.77-2.89; p = NS). CONCLUSIONS: In black patients on PD, transfer to HD is not associated with any significant difference in patient survival compared to patients remaining on PD. While a high rate of peritonitis predisposes to technique failure, we found no features at baseline predictive of patients at greatest risk to fail PD. Since technique failure does not portend a poorer prognosis, PD remains a viable option for black patients entering an end-stage renal disease program.

Aged↗