The role of major histocompatibility complex class I chain-related  gene A antibodies in organ transplantation.
OBJECTIVE
Major histocompatibility complex class I chain-related gene A (MICA) antigens are expressed on the endothelium, they are polymorphic and have been shown to be recognized by antibodies produced by transplant recipients. Methods for detection of these antibodies have become available. In the 15th International Histocompatibility Workshop, a study for MICA antibody testing and of MICA genotyping was organized.


RESULTS
Antibodies against MICA antigens have been determined either using cells transfected with MICA alleles or recombinant MICA antigens. MICA epitopes were characterized by empirical study of human sera and by correlation with MICA polymorphic amino acids. Sera were absorbed with cells transfected with MICA alleles and site-directed mutagenesis was employed to analyze complex sera. A number of clinical studies have shown associations of antibodies against MICA with decreased survival of kidney transplants and in one investigation with acute rejection in recipients of heart allografts.


CONCLUSIONS
In addition to the HLA antigens, which elicit a strong immune response against allografted organs, the MICA antigens may be recognized as foreign and induce the production of MICA-specific antibodies. Antibodies against MICA have been associated with a decrease in the survival of organ allografts. The results suggest the MICA antigens are transplantation antigens that can induce an immune response associated with graft failure.
Zou
Yizhou
Y
Transplantation Immunology Division, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390-8886, USA.
Stastny
Peter
P
D000906:Antibodies / Q000097:blood*; D018604:Epitope Mapping; D000939:Epitopes; D005838:Genotype; D006084:Graft Rejection / Q000276:immunology / Q000517:prevention & control; D006085:Graft Survival; D006648:Histocompatibility; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D016377:Organ Transplantation / Q000009:adverse effects; D011110:Polymorphism, Genetic; D014019:Tissue Donors; D016896:Treatment Outcome
D000906:Antibodies; D000939:Epitopes; D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A