An automated micromethod for detection of lytic antimycobacterial antibodies by immune lysis of liposomes sensitized to tuberculin.
Calcein was concentrated inside multilamellar liposomes (MLV) by encapsulation through an osmotic gradient in order to increase its quenching. Immune lysis of these MLV sensitized to PPD by direct encapsulation or by exposure to preformed vesicles was studied in the presence of rabbit anti-BCG serum and of a non-immune rabbit serum as a source of complement, successively added in the wells of a microplate to a final volume of 0.1 ml. A 40 to 50% release of encapsulated calcein was observed after 5 min using a Titertek Fluoroskan II. Preformed liposomes exposed to PPD were more sensitive to anti-BCG serum than liposomes formed in PPD. Trials with human sera revealed a significantly higher level of specific lytic immunoglobulins in tuberculous patients than in non-tuberculous subjects. Key words: Liposome immune lysis assay; lytic antimycobacterial antibodies; tuberculosis, human; test automation.
Legros
F
F
Laboratory of Physiopathology, Université Libre de Bruxelles, Belgium.
Schietecat
P
P
Leroy
C P
CP
Van Vooren
J P
JP
D000907:Antibodies, Bacterial / Q000032:analysis*; D005452:Fluoresceins; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008081:Liposomes; D009161:Mycobacterium / Q000276:immunology*; D014373:Tuberculin / Q000276:immunology; D014376:Tuberculosis / Q000276:immunology
D000907:Antibodies, Bacterial; D005452:Fluoresceins; D008081:Liposomes; D014373:Tuberculin; C007740:fluorexon