Immunofluorescence study of type IV collagen alpha chains in epidermal basement membrane: application in diagnosis of X-linked Alport syndrome.
OBJECTIVE
To detect the distribution of alpha 5 (IV) chain of collagen on the glomerular basement membrane (GBM) and epidermal basement membrane (EBM) in the Chinese Alport syndrome (AS) kindreds and to develop a simple diagnostic alternative method to electronic microscopy for diagnosis of AS.


METHODS
Four male patients from 4 unrelated families manifested with hematuria, sensorineural hearing loss and had distinct family history. All patients had the characteristic AS pathologic changes by electron microscopy on their renal biopsy tissues. Three normal skin samples and 2 normal kidney samples were used as normal controls. Monoclonal antibody-based IF test was performed to examine the alpha 5 (IV) NC1 domain in EBM of normal controls, X-linked AS patients and their parents, and in GBM of normal controls and AS patients.


RESULTS
In normal controls as well as the patients' fathers, all the monoclonal antibodies used in EBM and GBM staining showed positive reactions along basement membranes in a linear pattern. Characteristically, in AS patients there were negative reactions to monoclonal antibodies anti-alpha 5 (IV) NC1 domain in EBM and anti-alpha 3-5 (IV) NC1 domains in GBM. In patients' mothers, alpha 5 (IV) chain was distributed segmentally in EBM.


CONCLUSIONS
The staining of alpha 5 (IV) NC1 domain in EBM by IF can be used to diagnose patients and screen defect-gene carriers of X-linked AS.
Ding
J
J
Department of Pediatrics, First Teaching Hospital, Beijing Medical University, China.
Yang
J
J
Liu
J
J
Yu
L
L
D000328:Adult; D000818:Animals; D001485:Basement Membrane / Q000473:pathology; D001706:Biopsy; D002648:Child; D003094:Collagen / Q000235:genetics / Q000276:immunology*; D006224:Cricetinae; D004817:Epidermis / Q000473:pathology; D019084:Fluorescent Antibody Technique, Indirect; D008040:Genetic Linkage; D006801:Humans; D007137:Immunoglobulin alpha-Chains / Q000276:immunology*; D008297:Male; D009394:Nephritis, Hereditary / Q000175:diagnosis* / Q000235:genetics; D012867:Skin / Q000473:pathology*; D014960:X Chromosome
D007137:Immunoglobulin alpha-Chains; D003094:Collagen