Combination of KIR and HLA gene variants augments the risk of developing birdshot chorioretinopathy
Combination of KIR and HLA gene variants augments the risk of developing birdshot chorioretinopathy in HLA-A*29-positive individuals.
Birdshot chorioretinopathy (BCR), a chronic ocular inflammatory disease with characteristic choroidal lymphocytic infiltrates, has been strongly associated with human leukocyte antigen (HLA)-A29. Although HLA-A29 occurs frequently in all populations, BCR affects only a small percentage of HLA-A29-positive Caucasians, indicating additional susceptibility factors for BCR. Discovery of HLA class I-specific killer cell immunoglobulin-like receptors (KIR) led to a series of epidemiological studies implicating KIR-HLA gene combinations in disease. Here, we characterized KIR-HLA pairs in BCR patients and controls carrying HLA-A*29 as well as controls lacking HLA-A*29. KIR-HLA pairs implicated for weak inhibition (KIR2DL2/3+HLA-C1 and KIR3DL1+HLA-Bw4(T80)) in combination with activating KIR genes associated with autoimmunity (KIR2DS2, 2DS3 and 2DS4) augment the risk of developing BCR in HLA-A*29-positive individuals. The reciprocal association of strong inhibitory pairs (KIR3DL1+HLA-Bw4(I80) and KIR2DL1+HLA-C2) in combination with those implicated in protection from infection (KIR3DS1+HLA-Bw4(I80) and KIR2DS1+HLA-C2) was observed in HLA-A*29-negative controls. These results suggest that a profound effect of KIR2DS2/S3/S4 in the absence of strong inhibition may enhance the activation of natural killer cells and T-cell subsets against intraocular self-antigens, thereby contributing to pathogenesis of BCR.Genes and Immunity advance online publication, 13 March 2008; doi:10.1038/gene.2008.13.
Levinson RD, Du Z, Luo L, Monnet D, Tabary T, Brezin AP, Zhao L, Gjertson DW, Holland GN, Reed EF, Cohen JH, Rajalingam R.
1Ocular Inflammatory Disease Center, Jules Stein Eye Institute, David Geffen School of Medicine at UCLA, University of California at Los Angeles, Los Angeles, CA, USA.