title: Circulating immune complexes in leprosy sera: demonstration of antibodies against mycobacterial glycolipidic antigens in isolated immune complexes.
abstract: Circulating immune complexes (CIC) were assayed in sera of leprosy patients. Using an immunoassay for two mycobacterial antigens--phenolic glycolipid-I (PGL-I) and glycolipid IV (SL-IV)--sera from 65 patients with leprosy (38 lepromatous, 18 borderline, and 9 tuberculoid) were studied. The CIC were isolated by polyethylene glycol (PEG) precipitation, washed, treated with an acid buffer, neutralized, and tested using an enzyme-linked immunosorbent assay (ELISA). We demonstrated that CIC could contain IgG and IgM antibodies reacting against PGL-I and SL-IV. The high levels of antibodies in the precipitable CIC showed concordance with high levels in the original sera, although some patients presented high levels of precipitable CIC in the absence of high titers of antibodies in their sera. It was concluded that some of the CIC observed in patients with leprosy were composed of IgG and IgM immunoglobulins against specific mycobacterial antigens.
authors.affiliation: Departamento de Dermatologia, Escola Paulista de Médicina, São Paulo, Brazil.
authors.forename: J T
authors.initials: JT
authors.lastname: Yamashita
authors.forename: P
authors.initials: P
authors.lastname: Cruaud
authors.forename: F
authors.initials: F
authors.lastname: Papa
authors.forename: O
authors.initials: O
authors.lastname: Rotta
authors.forename: H L
authors.initials: HL
authors.lastname: David
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood*; D000936:Antigen-Antibody Complex / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology*; D011232:Chemical Precipitation; D004797:Enzyme-Linked Immunosorbent Assay; D006017:Glycolipids / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007918:Leprosy / Q000276:immunology*; D008875:Middle Aged; D009166:Mycobacterium leprae / Q000276:immunology*; D009169:Mycobacterium tuberculosis / Q000276:immunology; D011092:Polyethylene Glycols
chemical_list: D000907:Antibodies, Bacterial; D000936:Antigen-Antibody Complex; D000942:Antigens, Bacterial; D006017:Glycolipids; D007074:Immunoglobulin G; D007075:Immunoglobulin M; C082079:glycolipid IV, Mycobacterium tuberculosis; C045169:phenolic glycolipid I, Mycobacterium leprae; D011092:Polyethylene Glycols