TCRBV20S1 and TCRBV3S1 gene segment polymorphisms in systemic sclerosis.
OBJECTIVE
To compare the frequencies of variants of TCRBV20S1 and TCRBV3S1 gene segments in patients with systemic sclerosis (SSc) and in controls. The null allele (allele 2) of TCRBV20S1 is associated with reduced levels of Vbeta20+ T-cells in the peripheral blood, while allele 1 of TCRBV3S1 is related to a low frequency of Vbeta3.1+ T-cells.


METHODS
One hundred thirty patients with SSc and 118 healthy volunteer controls were genotyped for TCRBV20S1, and 117 patients and 85 controls were genotyped for TCRBV3S1 variants by PCR-RFLP. Patients underwent clinical evaluation, serology, pulmonary function tests, high resolution computed tomography, and Doppler echocardiography.


RESULTS
The genotypic frequencies of TCRBV20S1 were 0.46 (allele 1/allele 1), 0.43 (allele 1/allele 2), and 0.11 (allele 2/allele 2) in SSc patients; in controls the frequencies were 0.70, 0.26, and 0.04, respectively (p < 0.001). The Mantel-Haenszel odds ratio (stratified by race and sex) of the allele 2 carrier state was 3.88 (95% CI 1.94 to 7.75). The allelic and genotypic frequencies of the TCRBV3S1 gene segment did not differ significantly in patients and controls. However, among patients, allele 1 (TCRBV3S1) carriers had a higher prevalence of interstitial lung disease (adjusted p = 0.032).


CONCLUSIONS
The null allele of the TCRBV20S1 and the allele 1 of TCRBV3S1 gene segments may be considered risk factors for the development of SSc and interstitial lung disease, respectively, suggesting a protective role of Vbeta20+ and Vbeta3.1+ cells in the pathogenic immune responses in SSc.
Bredemeier
Markus
M
Division of Rheumatology, Radiology, and Cardiology of the Hospital de Clínicas de Porto Alegre, RS, Brazil.
Chies
José Artur Bogo
JA
Wieck
Andréa
A
Capobianco
Karina Gatz
KG
Pitrez
Eduardo Hennemann
EH
Rohde
Luis Eduardo Paim
LE
Pinotti
Antônio Fernando Furlan
AF
Brenol
João Carlos Tavares
JC
Xavier
Ricardo Machado
RM
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D019674:Genes, T-Cell Receptor beta / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000150:complications / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D045743:Scleroderma, Diffuse / Q000150:complications / Q000235:genetics*; D045745:Scleroderma, Limited / Q000150:complications / Q000235:genetics*