Characterization of CD177‐reactive iso‐ and auto‐antibodies

Background CD177 is a surface protein on neutrophils and main mediator for the expression of proteinase 3 (PR3). Its functions are largely unknown. At least three types antibodies have been described to target CD177: isoantibodies, which formed in CD177-null individuals as result an immune reaction following transfusion or pregnancy; autoantibodies present sera from patients with autoimmune neutropenia; antineutrophil cytoplasmic glomerulonephritis polyangiitis. In this study, we aimed compare binding characteristics auto- iso-antibodies optimize their detectability neutrophil serology laboratory. Study design methods The reactivity iso- auto-antibodies against was studied using granulocytes, native CD177/PR3 complex, recombinant PR3. Results All were reactive when immobilized monoclonal antibody (moab) 7D8. Seventy-five percent autoantibodies, but none did not react moab MEM166. majority CD177, whereas most isoantibodies tested positive. Discussion Our results suggest that different epitopes. Isoantibodies mainly alone, while epitope surface, absent lacks Moab MEM166 binds hinders autoantibodies. may help diagnostic strategies, especially identification