Association of HLA-DR7 with rheumatic fever in the Brazilian population.
OBJECTIVE
Rheumatic fever (RF) is a multisystem inflammatory disease that develops as a sequel of untreated throat infection by the group A beta-hemolytic streptococcus. As HLA antigens are known to be important in controlling immunological responsiveness, studies have investigated HLA antigen association with RF. Studies with Caucasians, Black Americans, and Indians showed associations with HLA-DR4, DR2, and DR3, respectively. One study on a Brazilian population suggested an association with HLA-DR7 and HLA-DR53. We investigated the association between RF and antigens HLA-DR7 and DR53 in the white Brazilian population.


METHODS
Thirty-five patients and 209 healthy individuals living in the northern region of the state of Parana, Brazil, were used as test and control groups, respectively. Classical statistical methods were used to compare HLA frequencies between these groups. Results. Data confirmed positive association with HLA-DR7 (46.7 vs. 25.7%; p = 0.015), but not with HLA-DR53 (54.3 vs. 44.5%; p = 0.28). The relative risk and etiologic fractions were 2.4 and 0.27%, respectively.


CONCLUSIONS
Positive association between HLA-DR7 specificity and RF was observed in the white Brazilian population by 2 independent studies, supporting the hypothesis of the involvement of genetic factors in susceptibility of rheumatic fever.
Visentainer
J E
JE
Department of Clinical Analysis, Maringá State University, PR, Brazil.
Pereira
F C
FC
Dalalio
M M
MM
Tsuneto
L T
LT
Donadio
P R
PR
Moliterno
R A
RA
D001938:Brazil; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006683:HLA-DQ Antigens / Q000235:genetics; D006684:HLA-DR Antigens / Q000235:genetics; D015809:HLA-DR7 Antigen / Q000235:genetics*; D059845:HLA-DRB4 Chains; D006801:Humans; D012213:Rheumatic Fever / Q000235:genetics* / Q000276:immunology*; D044465:White People / Q000235:genetics
D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens; C050610:HLA-DR53; D015809:HLA-DR7 Antigen; D059845:HLA-DRB4 Chains