Serum HLA-B27

The HLA antigen is an expression product of the major histocompatibility complex (MHC) of human beings. In the immune system, it is mainly responsible for the mutual recognition of cells and the induction of immune responses, and the regulation of immune responses. According to the structure, function and tissue distribution of HLA antigens, they can be divided into three categories: Class I molecules are HLA-A, -B, -C series antigens, which are widely distributed on the surface of nucleated cells in various tissues, including platelets and reticulocytes. Mature red blood cells generally do not contain HLA antigens; Class Ⅱ molecules are HLA-D / DR, -DP, and DQ series antigens, which are mainly expressed on B cells and antigen-presenting cells. Both types of antigens are related to transplantation, of which Ⅱ Antigens are more important; Class III molecules are complement components. Data on the correlation between HLA and disease in recent years show that the incidence of certain diseases is related to the detection rate of some specific types of HLA. Most of these patients are unknown diseases with associated immune dysfunction and genetic predisposition. Therefore, analyzing the expression of HLA antigens not only helps to understand the pathogenesis, but also has important significance for the diagnosis, prevention and prognosis of the disease. HLA-B27 gene belongs to type I MHC gene, which is basically expressed on all nucleated cells in the body, especially the surface of lymphocytes is rich in content. As early as more than two decades ago, it has been found that the expression of HLA-B27 antigen is highly correlated with ankylosing spondylitis. Over 90% of patients with ankylosing spondylitis have positive HLA-B27 antigen expression. Only in the general population 5-10% are positive, and ankylosing spondylitis is difficult to diagnose because the symptoms are similar to many diseases. Therefore, the detection of HLA-B27 is of great significance in the diagnosis of the disease. In addition to ankylosing spondylitis in diseases such as spondyloarthropathy, there are many other diseases that are more or less related to the expression of HLA-B27 antigen. Therefore, the detection of HLA-B27 in these diseases It is a very valuable indicator in diagnosis.