[Study of the clonal characteristics of autoantibodies in chronic idiopathic thrombocytopenic purpura].
OBJECTIVE
To define the clonality characteristics of autoantibodies in chronic idiopathic thrombocytopenic purpura (ITP).


METHODS
The heavy-chain and light-chain phenotype composition of the glycoprotein (GP)-specific IgG antibodies were analysed with a modified monoclonal antibody specific immobilization of platelet antigens (MAIPA) technique. The immunoglobulin heavy-chain gene rearrangement was analysed by PCR amplification.


RESULTS
16 out of the 43 patient sera reacted with least one of the following five GPs, namely GPIIb/IIIa, GPIb, GPIa, GPIV and GPV. Eight of 11 (73%) GP-specific antibodies displayed a restricted heavy-chain phenotypes. 80% (16/20) of the GP-specific antibodies showed a restricted kappa or lambda light-chain phenotype. Moreover, in 6 patients the GP-specific antibodies were found to be both light-chain and heavy-chain restricte. Using PCR amplification of immunoglobulin heavy-chain genes, 3 patients displayed heavy-chain genes rearrangement.


CONCLUSIONS
The GP-specific autoantibodies are derived from a restricted number of B-cell clones in proportion of ITP patients.
Hou
Ming
M
Shandong University Qilu Hospital, Shandong 250012, China. houming2@hatmail.com
Shi
Yan
Y
Peng
Jun
J
Li
Wei
W
Ma
Dao-xin
DX
Zhang
Mao-hong
MH
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood*; D005260:Female; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000145:classification; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D008297:Male; D008875:Middle Aged; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000276:immunology; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000276:immunology; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000276:immunology*
D001323:Autoantibodies; D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D019038:Platelet Glycoprotein GPIb-IX Complex