02074nas a2200241   4500000000100000008004100001260001300042653002900055653002200084653004000106653001100146653002500157653002500182100001500207700001400222700001600236700001800252245011300270300001000383490000700393520141800400022001401818       1994                            d  c1994 Apr10aAntigen-Antibody Complex10aBlotting, Western10aElectrophoresis, Polyacrylamide Gel10aHumans10aLeprosy, lepromatous10aMyelin Basic Protein1 aCórsico B1 aCroce M V1 aMukherjee R1 aSegal-Eiras A00aIdentification of myelin basic proteins in circulating immune complexes associated with lepromatous leprosy.  a38-430 v713 a<p>Circulating immune complexes (CIC) were first measured in lepromatous patients (LL) by the 125I-C1q binding assay and the polyethylene glycol (PEG) precipitation test. High levels were found by both methods (95 and 90% of positives, respectively). LL-CIC were investigated for the presence of neural antigens. CIC were precipitated in 3.5% PEG, filtered through protein A-Sepharose affinity chromatography, eluted with glycine-HCl, pH 2.8, and washed with PBS; fractions after CIC dissociation were studied by SDS-PAGE and Western blotting. The LL-CIC PEG precipitates and the glycine-HCl eluates were positive in 76 and 71% respectively against anti-myelin basic proteins (MBP) monoclonal antibody, showing a single band at 15-25 kDa similar to the one obtained incubating MBP with anti-MBP. No reaction was detected with CIC-PBS fractions; strips were incubated with other anti-neural antibodies such as anti-glial fibrillary acidic proteins, anti-S-100, and anti-neurofilaments, without any reactivity. Our results demonstrate that LL-CIC contain MBP as an antigen; its significance could be related to the pathogenesis of leprosy since the liberation of MBP after Mycobacterium leprae nerve damage may elicit anti-MBP autoantibodies to myelin breakdown, which reacts with peripheral nerve MBP inducing CIC formation. This mechanism may be important in demyelination and destruction of nerve in leprosy.</p>  a0090-1229