The gene complex is subdivided into 2 regions Class 1 The A B and C loci

These proteins are found on most nucleated cells and interact with CD8+ T lymphocytes. Class 2 Comprising of DR, DP, DQ loci present only on B lymphocytes, monocytes, macrophages and activated T lymphocytes. Interact with CD4+ T lymphocytes.

• Class 1 and 2 genes are closely linked so one set of gene loci is usually inherited from each parent though there is a small amount of crossover.

• There is ~1:4 chance of 2 siblings being HLA identical.

• There are other histocompatibility loci apart from the HLA system but these appear less important generally except during HLA matched stem cell transplantation when even differences in these minor systems may cause GvHD.

0 0

Post a comment