Immunogenetics and infectious diseases: special reference to the mayor histocompatibility complex

Abstract

Many studies have tried to identify genetic markers for infectious diseases, some of them have focused on human leukocyte antigens (HLA). The products of HLA genes interact with surfacespecific receptors of T lymphocytes, resulting in activation of the host's immune response. Association of bacterial, viral, parasitic and fungal infections with the host's HLA has been widely investigated. The type and strength of this association differs among distinct populations, as well as among racial and/or ethnic groups. The new molecular methods for the identification of the HLA alleles, and the resulting new nomenclature, have contributed to a better understanding of this system. Unfortunately, this information has not been adequately transmitted to clinicians, which hampers the understanding of the association between the HLA system and diseases. We revised relevant studies on the association of HLA genes with infectious diseases, demonstrating their importance in the pathogenic mechanisms, through increased susceptibility or protection against infections and their complications.

Causes of false-positive HIV rapid diagnostic test results

“…The degree of similarity between a pathogen antigen and host HLA antigens will increase or decrease the level of immune response [57]. HLA polymorphism modifies the immune response to tuberculosis, leprosy, malaria, Klebsiella, Bartonella henselae, Chlamydia, Shigella, Yersinia, schistosomiasis, Chagas disease, dengue fever, HIV, HTLV-1, hepatitis B and hepatitis C, and may act alone or in combination with other genes conferring susceptibility to, or protection against, infectious diseases [57].…”

Role of Humoral and Cell-Mediated Immune Responses against Influenza Infections

“…Human major histocompatibility complex (MHC) polymorphism contributes to the genetic diversity of the species and to the differences in susceptibility to diseases among genetically distinct groups, thus making it difficult for large-scale epidemics to occur [5]. The essential role of the HLA antigens lies in the self-recognition and thus defense against microorganisms [9].…”

“…In recent times, great interest has been generated in genetic markers that interact with other factors for determining host's responses to the infectious diseases [5,6]. Genetic factors are among the main determinants for susceptibility to infectious diseases in human beings [5,7].…”

“…Genetic factors are among the main determinants for susceptibility to infectious diseases in human beings [5,7]. Epidemiological studies have demonstrated that more than 40 diseases are more frequently found in individuals carrying certain types of HLA class I or II alleles in comparison to other general populations [8].…”

“…The magnitude of these effects could be quite large but probably not be absolute [9]. HLA is the most polymorphic genetic system in human beings having numerous alleles and consequently have the combinations with different possibilities [5].…”