A simple adherence test for detection of IgM antibodies in typhoid.
A simple adherence test to detect IgM antibodies in patients with typhoid is described. The test utilises the IgM-"capture" approach, in which the test serum is applied to microtitration plate wells previously coated with anti-human IgM, followed by application of a stained Salmonella typhi antigen suspension which shows adherence in positive cases. By this test, 58 (95%) of 61 sera from confirmed cases of typhoid possessed IgM antibodies to the H or O or both antigens of S. typhi. In patients for whom a diagnosis of typhoid was based only on a significant Widal-test titre, 31 (41%) of 76 sera had IgM antibodies to the H or O or both antigens of S. typhi. Some cross-reactivity of the IgM antibodies was detected, especially with the O antigens of S. paratyphi A and B. A total of 82 sera from non-typhoidal fevers (leptospirosis, typhus, dengue fever) showed no reactivity in this test. In normal sera there was no detectable IgM to the O antigen of S. typhi and only a small number (3.9%) had low levels of IgM to the H antigen. The significance and potential importance of this simple, sensitive, specific and economical test is discussed.
Ong
L Y
LY
Department of Genetics and Cellular Biology, University of Malaya, Kuala Lumpur.
Pang
T
T
Lim
S H
SH
Tan
E L
EL
Puthucheary
S D
SD
D000907:Antibodies, Bacterial / Q000032:analysis; D000942:Antigens, Bacterial / Q000276:immunology*; D003429:Cross Reactions; D006801:Humans; D007118:Immunoassay; D007075:Immunoglobulin M / Q000032:analysis*; D019081:O Antigens; D012485:Salmonella typhi / Q000276:immunology*; D014435:Typhoid Fever / Q000276:immunology*
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; C022863:H antigen; D007075:Immunoglobulin M; D019081:O Antigens