HLA stands for human leukocyte antigen and determines the rate of success of organ transplants, e.g., host vs. graft disease. A private antigen is an HLA found on an HLA molecule coded for by only a single allele. HLA-B27 is private. HLA-typing is the next step after blood grouping evidence if blood group data is incompatible. The classes of HLA's are tabulated below.
Data regarding each class is summarized, as well.
Figure 1 illustrates the genetic layout of the three classes of MHC's on 6p. The centromere is on the left and the telomeric end is to the right. The structure of MHC-I proteins is shown in Figure 2 . The H chain is a glycoprotein of molecular weight 44,000. It consists of 3 a chains.