Abstract
Alport syndrome (AS) is in the differential diagnosis of hematuria. Variability in clinical presentation and in the ultrastructural changes of the glomerulus can make the diagnosis of AS a challenge in female patients. The purpose of this report is to present immunostaining for glomerular basement membrane (GBM) expression of α5(IV) as an adjunctive diagnostic method. Renal biopsy specimens from eight female patients with clinical presentation suggestive of AS were studied. The patients were between 7 and 36 years of age; six were between 12 and 15 years. Light microscopy and immunohistochemistry using a monoclonal antibody to α5(IV) were performed. Controls showed a continuous linear pattern along the GBM in normal kidneys and absence in renal biopsy specimens from male X-linked AS patients. To express the variability of the ultrastructural GBM changes among the patients in the series, we developed a semi-quantitative Alport Index, obtained by quantification of severity and extent of ultrastructural GBM changes. With immunohistohemistry, we showed an interrupted, discontinuous linear pattern for α5(IV) in glomeruli from the eight patients in the series, confirming the diagnosis of X-linked AS. The ultrastructutal Alport Index varied between 6 and 47, showing the heterogeneity in the severity of the GBM changes, even among the six patients aged between 12 and 15 years. In three of the eight biopsy specimens, the predominant change was thin GBM, and the Alport Index was below 20. Immunohistochemistry for α5(IV) in renal biopsy specimens can identify female patients heterozygous for X-linked AS. In this series, the method led to the diagnosis of AS in female patients in whom the predominant ultrastructural change was thin basement membrane.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 404-408 |
| Number of pages | 5 |
| Journal | Human pathology |
| Volume | 29 |
| Issue number | 4 |
| DOIs | |
| State | Published - 1998 |
Bibliographical note
Funding Information:From the Department of Pathology, School of Medicine, Tulane University, New Orleans, LA; the Department of Pathology, Children's Mercy Hospital, Kansas City, MO; and the Department of Pediatrics, University of Minnesota, Minneapolis, MN. Accepted for publication August 12, 1997. Supported in part by a National Institutes of Health grant to Clifford E. Kashtan. Presented in part at the International Academy of Pathology, Budapest, Hungary, October 1996. Address correspondence and reprint requests to Suzanne Meleg-Smith, MD, Tulane University School of Medicine, Department of Pathology, 1430 Tulane Ave SL-79, New Orleans, LA 70112-2699. Copyright © 1998 by W.B. Saunders Company 0046-8177/98/2904-001658.00/0 from the eight patients in the series, confirming the diagnosis of X-linked AS. The ultrastructutal Alport Index varied between 6 and 47, showing the heterogeneity in the severity of the GBM changes, even among the six patients aged between 12 and 15 years. In three of the eight biopsy specimens, the predominant change was thin GBM, and the Alport Index was below 20. Immunohistochemlstry for c~5(IV) in renal biopsy specimens can identify female patients hetero-zygons for X-linked AS. In this series, the method led to the diagnosis of AS in female patients in whom the predominant ultrastructural change was thin basement membrane. HUM PATI-IOL 29:404-408. Copyright © 1998 by W.B. Saunders Company Key words: Alport syndrome, thin basement membrane disease, immunohistochemistry for collagen 1V ct5, renal biopsy, GBM ultrastructure.
Keywords
- Alport syndrome
- GBM ultrastructure
- Immunohistochemistry for collagen IV α5
- Renal biopsy
- Thin basement membrane disease