01847nas a2200301   4500000000100000008004100001260001300042653001000055653000900065653002700074653002900101653001700130653001100147653001200158653001600170653002100186653002600207653002900233100001200262700001500274700001600289700001200305245006700317300001200384490000700396520112800403022001401531       1985                            d  c1985 Jul10aAdult10aAged10aAntibodies, Monoclonal10aAntigen-Antibody Complex10aErythrocytes10aHumans10aleprosy10aMiddle Aged10aRadioimmunoassay10aReceptors, Complement10aReceptors, Complement 3b1 aTausk F1 aHoffmann T1 aSchreiber R1 aGigli I00aLeprosy: altered complement receptors in disseminated disease.  a58s-61s0 v853 a<p>We have studied the expression of the C3b receptor (CR1) on erythrocytes of 55 patients with Hansen's disease. We developed a radioimmunoassay utilizing a monoclonal antibody that recognized an epitope different from the C3b binding site, which therefore enabled us to measure total number of CR1 regardless of receptor occupancy. We observed that patients in the lepromatous pole of the disease had a mean of 310 CR1/erythrocyte, whereas the ones in the tuberculoid pole showed a mean of 577 CR1/erythrocyte; 77 normal controls had a mean of 512 CR1/erythrocyte. The number of C3b receptors on the cells of lepromatous patients was significantly decreased (p less than .001) when compared to the normal population or tuberculoid patients. The presence of receptors for the C3b fragment of complement (CR1) on the surface of human erythrocytes enables these cells to participate in a number of immune functions including the clearance of circulating immune complexes. These findings could bear importance in the ability of the host to clear immune complexes from the circulation in patients with lepromatous leprosy.</p>  a0022-202X