The serological differentiation of acute and chronic Schistosoma japonicum infection by ELISA using keyhole limpet haemocyanin as antigen.
Antibodies (immunoglobulin (Ig) G and IgM) that recognize keyhole limpet haemocyanin (KLH), which shares a well defined carbohydrate epitope with the surface of larval schistosomes, were determined by enzyme-linked immunosorbent assay in patients with acute or chronic schistosomiasis japonica. Marked differences in IgG and IgM responses were evident between acute and chronically infected patients at a serum dilution of up to 1:2000. The acute sera had mean (+/- standard deviation) optical density values at 405 nm for IgG and IgM of 0.64 +/- 0.18 and 0.30 +/- 0.19 respectively; the chronic sera had mean readings for IgG and IgM of 0.14 +/- 0.08 and 0.04 +/- 0.03 respectively. Setting the lowest positive limit at 2 standard deviations above the mean value for chronic sera, 41 (98%) of the 42 patients previously diagnosed as having acute schistosomiasis were correctly identified by anti-KLH IgG and 35 (83%) of the 42 patients were correctly identified by anti-KLH IgM detection. Of 17 patients studied longitudinally, IgG optical density values dropped 45% and those of 5 patients fell below the established cut-off level 6 months after treatment. This study supports the use of KLH for rapidly and easily identifying individuals with acute Schistosoma japonicum infection.
Human Institute of Parasitic Diseases, Yueyang, Human, People's Republic of China.
Y
Y
Li
A L
AL
Rabello
A J
AJ
Simpson
N
N
Katz
D000208:Acute Disease; D000818:Animals; D000909:Antibodies, Helminth / Q000032:analysis; D002908:Chronic Disease; D004797:Enzyme-Linked Immunosorbent Assay; D006433:Hemocyanins; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D012549:Schistosoma japonicum / Q000276:immunology; D012554:Schistosomiasis japonica / Q000175:diagnosis*; D012698:Serologic Tests
D000909:Antibodies, Helminth; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin