Premium
Generation and analysis of an IgG anti‐platelet autoantibody reveals unusual molecular features
Author(s) -
OLEE TSAIWEI,
EN JULIE,
LAI CHUNGJENG,
MO LIAN,
SOO CHO CHUL,
WEI XIN,
WANG XIAOFEN,
L. WOODS, JR VIRGIL,
CHEN POJEN
Publication year - 1997
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1046/j.1365-2141.1997.d01-2112.x
Subject(s) - autoantibody , immunology , platelet , monoclonal antibody , monoclonal , population , antibody , autoimmunity , medicine , environmental health
Although serum transfer studies implicate IgG anti‐platelet autoantibodies in the premature platelet destruction of idiopathic thrombocytopenic purpura (ITP), many characteristics of these putative pathogenic autoantibodies remain unclear. The inability to obtain relevant monoclonal autoantibodies from patients has prevented their molecular, genetic and functional studies as a homogenous population. We have generated a monoclonal IgG anti‐platelet α IIb β 3 autoantibody (termed G1) from an ITP patient. G1 binds human platelets (both resting and activated) and purified α IIb β 3 with a K d of 1.57 × 10 −8 M . G1 utilizes VH4 and Vλ2 genes. The G1 VH region apparently has a 30 nucleotide insertion in its second complementarity determining region (CDR). Notably, somatic CDR insertion in the VH region has been observed only in one IgG rheumatoid factor, and not in any characterized polyreactive human autoantibodies reported in the literature. Combined, these data suggest G1 may be a disease‐relevant autoantibody. Further generation and study of monoclonal IgG anti‐platelet antibodies are warranted to determine the significance of such unusual autoantibodies in the immunopathogenesis of chronic ITP.