title: [Detection of immune complex by C1q solid phase enzyme immunoassay].
abstract: We have developed a new and improved method for detecting immune complexes (IC) by C1q solid-phase enzyme immunoassay (CSP-EIA). The sensitivity of this method was between 0.62 micrograms/ml and 1.25 micrograms/ml, and values in normal individuals were 1.8 micrograms/ml and less. The positive rate of IC of sera in which abnormal values were detected by autoimmune disease associated laboratory examinations was 50.0% in RA (2+), 20.4% in ANA (+), 60.0% in CH50 (less than 10), 41.7% in LE latex (+). In sera of RA (2+), the higher the value of CRP detected by a semi-quantitative analysis was, the higher the frequency having abnormal high IC values was. The number of IC positive sera, in which enzyme-linked immunoglobulins were detected, was 18 of 68 (positive rate 26.5%). The number of IC positive samples in asymptomatic carriers of sera, whose titer of anti-HTLV-I antibody was positive by gelatin particle agglutination assay (PA), was 14 of 67 (pos. rate 18.4%). All of these 14 samples were high positivity of anti-HTLV-I antibody (titer greater than or equal to 256 times). In urine of some patients with urogenital diseases, IC-like substances to show positive reaction by our CSP-EIA were detected. However, any positive reaction was not detected either by an anti-C1q- or an anti-C3d method. Studies are in progress to elucidate detailed characterization of the IC-like substances.
authors.affiliation: Department of Research & Development, Japan Medical Laboratories, Onojo.
authors.forename: H
authors.initials: H
authors.lastname: Sakaeda
authors.forename: H
authors.initials: H
authors.lastname: Igata
authors.forename: Y
authors.initials: Y
authors.lastname: Mibuchi
authors.forename: K
authors.initials: K
authors.lastname: Yonemasu
mesh_terms: D000936:Antigen-Antibody Complex / Q000032:analysis* / Q000652:urine; D015481:HTLV-I Antibodies / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D012016:Reference Values; D012680:Sensitivity and Specificity
chemical_list: D000936:Antigen-Antibody Complex; D015481:HTLV-I Antibodies