Biomedical subjects
Publications and source records attributed to Melvin M Schwartz.
BACKGROUND: A 42-year-old man presenting with flank pain was found to have renal failure with severe hypocomplementemia and eosinophilia. INVESTIGATIONS: Physical examination, laboratory testing, renal ultrasonography, and renal biopsies. DIAGNOSIS: Acute immune-complex-mediated tubulointerstitial nephritis. MANAGEMENT: Immunosuppressive therapy with 1 mg/kg/day prednisone.
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.
We describe a case of lipoprotein glomerulopathy, the second ever reported from the United States, in a Mexican man with a hitherto undescribed mutation in the apolipoprotein E gene (substitution of proline for arginine at position 147 [Arg147Pro]). In this patient, glomerular basement membranes showed double contours and circumferential mesangial extensions, suggesting that deposition of lipids could be injurious to endothelial cells. Immunofluorescence staining of thrombi was positive for apolipoprotein E and B. To study the reason for lipid deposition in glomeruli, we incubated normal human kidney sections with serum from the patient and a healthy control. Apolipoprotein E from the patient's serum showed binding to the glomerular capillary wall, but the control did not, suggesting enhanced binding of the mutated apolipoprotein E to glomerular capillaries. Apolipoprotein E genotyping by means of restriction endonuclease digestion of polymerase chain reaction-amplified genomic DNA showed it to be of the wild-type E3/E3.
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.
Explore the source record for details and available documents.
The molecular mechanisms of heparan sulfate proteoglycan downregulation in the glomerular basement membrane (GBM) of the kidneys with diabetic nephropathy remain controversial. In the present study, we showed that the expression of heparanase-1 (HPR1), a heparan sulfate-degrading endoglycosidase, was upregulated in the renal epithelial cells in the kidney with diabetic nephropathy. Urinary HPR1 levels were elevated in patients with diabetic nephropathy. In vitro cell culture studies revealed that HPR1 promoter-driven luciferase reporter gene expression, HPR1 mRNA, and protein were upregulated in renal epithelial cells under high glucose conditions. Induction of HPR1 expression by high glucose led to decreased cell surface heparan sulfate expression. HPR1 inhibitors were able to restore cell surface heparan sulfate expression. Functional analysis revealed that renal epithelial cells grown under high glucose conditions resulted in an increase of basement membrane permeability to albumin. Our studies suggest that loss of heparan sulfate in the GBM with diabetic nephropathy is attributable to accelerated heparan sulfate degradation by increased HPR1 expression.
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.
The currently used classification reflects our understanding of the pathogenesis of the various forms of lupus nephritis, but clinicopathologic studies have revealed the need for improved categorization and terminology. Based on the 1982 classification published under the auspices of the World Health Organization (WHO) and subsequent clinicopathologic data, we propose that class I and II be used for purely mesangial involvement (I, mesangial immune deposits without mesangial hypercellularity; II, mesangial immune deposits with mesangial hypercellularity); class III for focal glomerulonephritis (involving <50% of total number of glomeruli) with subdivisions for active and sclerotic lesions; class IV for diffuse glomerulonephritis (involving > or = 50% of total number of glomeruli) either with segmental (class IV-S) or global (class IV-G) involvement, and also with subdivisions for active and sclerotic lesions; class V for membranous lupus nephritis; and class VI for advanced sclerosing lesions]. Combinations of membranous and proliferative glomerulonephritis (i.e., class III and V or class IV and V) should be reported individually in the diagnostic line. The diagnosis should also include entries for any concomitant vascular or tubulointerstitial lesions. One of the main advantages of the current revised classification is that it provides a clear and unequivocal description of the various lesions and classes of lupus nephritis, allowing a better standardization and lending a basis for further clinicopathologic studies. We hope that this revision, which evolved under the auspices of the International Society of Nephrology and the Renal Pathology Society, will contribute to further advancement of the WHO classification.
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.
The currently used classification reflects our understanding of the pathogenesis of the various forms of lupus nephritis, but clinicopathologic studies have revealed the need for improved categorization and terminology. Based on the 1982 classification published under the auspices of the World Health Organization (WHO) and subsequent clinicopathologic data, we propose that class I and II be used for purely mesangial involvement (I, mesangial immune deposits without mesangial hypercellularity; II, mesangial immune deposits with mesangial hypercellularity); class III for focal glomerulonephritis (involving <50% of total number of glomeruli) with subdivisions for active and sclerotic lesions; class IV for diffuse glomerulonephritis (involving > or =50% of total number of glomeruli) either with segmental (class IV-S) or global (class IV-G) involvement, and also with subdivisions for active and sclerotic lesions; class V for membranous lupus nephritis; and class VI for advanced sclerosing lesions. Combinations of membranous and proliferative glomerulonephritis (i.e., class III and V or class IV and V) should be reported individually in the diagnostic line. The diagnosis should also include entries for any concomitant vascular or tubulointerstitial lesions. One of the main advantages of the current revised classification is that it provides a clear and unequivocal description of the various lesions and classes of lupus nephritis, allowing a better standardization and lending a basis for further clinicopathologic studies. We hope that this revision, which evolved under the auspices of the International Society of Nephrology and the Renal Pathology Society, will contribute to further advancement of the WHO classification.
OBJECTIVE: To characterize the frequency of thrombotic thrombocytopenic purpura (TTP) among patients with systemic lupus erythematosus (SLE) undergoing kidney biopsy. METHODS: A retrospective review of all renal biopsies of patients with SLE at Rush-Presbyterian-St. Luke's Medical Center was performed for the years 1989 to 2001. RESULTS: Four cases of clinical and histopathological TTP were identified among the 257 patients with SLE who underwent renal biopsy during the 12 year study period. CONCLUSION: TTP appears to occur at higher than expected frequency among SLE patients undergoing biopsy for unexplained renal failure.
Explore the source record for details and available documents.
The World Health Organization (WHO) classification of lupus (SLE) nephritis was published almost 20 years ago, and there is world-wide recognition of its utility in the diagnosis and treatment of SLE glomerulonephritis (GN). However, a number of problems have been recognized: The classification of severe segmental (WHO class III > or = 50%) and membranous glomerulonephritis (MGN) complicated by the lesions of severe segmental or diffuse GN (WHO classes Vc > or = 50% or Vd) is ambiguous; The implications of non-immune complex pathogenic mechanisms are not acknowledged and SLE interstitial nephritis and vasculitis are not included in the current classification. We propose a revision that retains the classes of the current WHO classification. Informed by investigations utilizing the WHO classification, it places severe segmental GN in class III (segmental GN) and mixed MGN and segmental and diffuse GN in class V (MGN). It optimizes the use of electron and fluorescence microscopy in defining controversial and ambiguous lesions. It develops subclasses based upon pathogenic insights gained since the advent of the WHO classification. Finally, it recognizes the need to include the disease specific lesions of SLE tubulointerstial nephritis and vasculitis.