Cytotoxic T lymphocyte antigen-4 gene polymorphisms do not confer susceptibility to autoimmune hepatitis types 1 and 2 in Brazil.
OBJECTIVE
Susceptibility to autoimmune hepatitis (AIH) has been linked to different HLA-DR antigens in distinct populations. Recently, an A-G polymorphism in exon 1 of the cytotoxic T lymphocyte antigen-4 (CTLA-4) gene was associated with predisposition to AIH type 1 (AIH-1) in white individuals in North America. This polymorphism has been associated with several other autoimmune diseases, presumably because of its effect in the expression of CTLA-4, an adhesion molecule that downregulates peripheral T cell responses. The aims of this study were to assess the frequency of CTLA-4 genotypes in Brazilian patients with AIH-1 and AIH type 2 (AIH-1), as well as to investigate the influence of these genotypes in disease expression.


METHODS
Determination of CTLA-4 genotypes was carried out in 106 patients with AIH-1, 26 subjects with AIH-2, and 67 healthy control subjects by polymerase chain reaction (PCR)-based techniques.


RESULTS
No difference in the distribution of CTLA-4 genotypes was observed in subjects with AIH-1 and AIH-2 as compared to healthy controls. Patients with AIH-1 and AIH-2 with the GG genotype exhibited lower gamma-globulin and ALT levels, respectively.


CONCLUSIONS
Susceptibility to AIH-1 and AIH-2 in Brazilian patients is not influenced by exon 1 CTLA-4 gene polymorphisms at position 49.
Bittencourt
Paulo L
PL
University of São Paulo School of Medicine, São Paulo, Brazil.
Palácios
Selma A
SA
Cançado
Eduardo L R
EL
Porta
Gilda
G
Carrilho
Flair J
FJ
Laudanna
Antonio A
AA
Kalil
Jorge
J
Goldberg
Anna C
AC
D000293:Adolescent; D000328:Adult; D000368:Aged; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000235:genetics*; D001938:Brazil; D060908:CTLA-4 Antigen; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D019693:Hepatitis, Autoimmune / Q000145:classification / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic
D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human