[The role of the human histocompatibility antigens in the pathogenesis of neurological disorders].
BACKGROUND
Several studies have been trying to define genetic markers of neurological disorders. Among them, antigens and alleles of the HLA (human leukocyte antigens) system are distinguished. The HLA exerts genetic influence on the susceptibility, clinical aspects and severity of many diseases. The discovery of new molecular methods to typify HLA alleles and the recent nomenclature updates have been contributing to a better understanding of this system. Unfortunately, this information has not been adequately published in the clinical literature.


OBJECTIVE
To review the structure, function, nomenclature and methods of detection of the HLA polymorphism and its associations with common neurological disorders.


METHODS
Articles that were published between 1990 and 2004 were searched in the MEDLINE and LILACS databases. This review demonstrated that although the HLA association is well established for some neurological disorders (e.g., HLA-DQB1*0602 with multiple sclerosis and narcolepsy; HLA-B7 e HLA-A2 with Alzheimer's disease; HLA-DR3-DR8 with Lamber-Eaton syndrome; and HLA class II Parkinson's disease and amyotrophic lateral sclerosis), these associations are not consistent and vary in different ethnic groups.


CONCLUSIONS
It is necessary to study populations from different ethnic backgrounds to identify new associations or to strength the ones already identified. This knowledge will contribute in the evaluation of the risk that a person carrying a particular allele or haplotype has to develop a neurological disease and therefore contribute towards a better understanding of its pathogenesis.
Alves
C
C
Universidade Federal da Bahia (UFBA), Hospital São Rafael, Salvador, Bahía, Brasil. cresio.alves@uol.com.br
Veiga
S
S
Souza
T
T
Toralles
M B
MB
da Silva-Bacellar
A L
AL
D000483:Alleles; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006649:Histocompatibility Antigens / Q000276:immunology*; D006801:Humans; D009422:Nervous System Diseases / Q000276:immunology / Q000503:physiopathology; D011110:Polymorphism, Genetic; D012189:Retrospective Studies
D005819:Genetic Markers; D006649:Histocompatibility Antigens