HBsAg in urine: a new approach for the detection of urinary antigens.
In order to define the optimal conditions for detection of microbial antigens in urine, urinary HBsAg excreted during hepatitis B was chosen as a model. Using commercial kits, which mainly involve anti-discontinuous epitopes, we found urinary HBsAg in only 50% of patients with HBsAg in their sera. In contrast, with an inhibition method involving a monoclonal antibody recognizing a continuous epitope, urinary HBsAg was found in 100% of these patients. Structural analysis of HBsAg showed that urinary HBsAg is denatured; it can escape detection by commercial kits well fitted for detection of native serum HBsAg. General implications for the revelation of urinary microbial antigens are discussed.
Service de Microbiologie et d'Immunologie, Hôpital Antoine Béclère, Clamart, France.
S
S
Badur
L
L
Grangeot-Keros
J
J
Pillot
D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D000939:Epitopes; D006509:Hepatitis B / Q000175:diagnosis*; D006510:Hepatitis B Antibodies / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000097:blood / Q000737:chemistry / Q000652:urine*; D006513:Hepatitis B e Antigens / Q000097:blood; D006801:Humans; D007124:Immunoenzyme Techniques; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology / Q000652:urine; D011489:Protein Denaturation
D000911:Antibodies, Monoclonal; D000939:Epitopes; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens; D010446:Peptide Fragments