Association of -318 C/T and +49 A/G cytotoxic T lymphocyte antigen-4 (CTLA-4) gene polymorphisms with a clinical subset of Italian patients with systemic sclerosis.
Systemic sclerosis (SSc) is a complex and heterogeneous autoimmune disorder with a multi-factorial pathogenesis. Like other autoimmune disorders, the possible role of specific cytotoxic T lymphocyte antigen-4 (CTLA-4) gene polymorphisms in predisposing to SSc has been hypothesized, but it remains controversial. CTLA-4 promoter (-318C/T) and exon 1 (+49 A/G) polymorphisms have been analysed in 43 Italian females with SSc and in 93 unrelated matched healthy controls by a newly designed tetra-primer amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) method. No significant association has been found with either polymorphisms.Nevertheless, SSc patients without concomitant Hashimoto's thyroiditis (HT) were carrying both the -318T allele (P = 0.031) and the +49 G allele (P = 0.076) more frequently than SSc patients with HT [defined by positivity for anti-thyroperoxidase (TPO) and anti-thyroglobulin (TGA) autoantibodies] than controls. Haplotype analysis confirms this association (P = 0.028), and suggests the predominant role of the -318T, whereas that of the +49 G, if any, seems weak. Thus, in Italian SSc patients the CTLA-4 -318C/T promoter polymorphism appears to be associated with the susceptibility to develop SSc without thyroid involvement. Larger studies are needed to confirm these findings and to clarify whether the -318C/T polymorphism is the functional responsible or whether it reflects the presence of another linked genetic element in the same chromosomal region.
Balbi
G
G
Department of Oncology, Biology and Genetics, University of Genoa, Genoa, Italy.
Ferrera
F
F
Rizzi
M
M
Piccioli
P
P
Morabito
A
A
Cardamone
L
L
Ghio
M
M
Palmisano
G L
GL
Carrara
P
P
Pedemonte
S
S
Sessarego
M
M
De Angioletti
M
M
Notaro
R
R
Indiveri
F
F
Pistillo
M P
MP
D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000235:genetics*; D000943:Antigens, Differentiation / Q000235:genetics*; D001327:Autoimmune Diseases / Q000235:genetics* / Q000276:immunology; D060908:CTLA-4 Antigen; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D012595:Scleroderma, Systemic / Q000235:genetics* / Q000276:immunology
D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human