Detection of fibrinogen antigens with two latex techniques applied to urine concentrates

Fibrinogen antigens were measured either with an agglutination inhibition method (using latex particles coated with fibrinogen; Diagen test) or with a direct agglutination technique (using latex particles coated with a mixture of anti-D and anti-E antibodies; Thrombo-Wellcotest). Both methods were compared with the tanned red cell haemagglutination inhibition immunoassay (TRCHII) during progressive degradation of fibrinogen with plasmin and using purified fibrinogen fragments or urine concentrates from chronic glomerulonephritis or transplanted patients. Due to the different sensitivity of the two latex techniques to fibrinogen and its plasmin derivatives, their combined use may be helpful to distinguish the nature of the fibrinogen-like material excreted in urine.