Proximal interleukin-10 gene polymorphisms in Italian patients with systemic sclerosis.

Interleukin-10 (IL-10) can favour the development of fibrosis by promoting a relative shift towards T helper 2 responses. Three single base pair substitutions in the 5' flanking region of the IL-10 gene (G/A -1082, C/T -819 and C/A -592) influence the amount of IL-10 secreted in cell cultures: the GCC haplotype is associated with an increased production, while the ACC and the ATA haplotypes are associated with intermediate and decreased production. Accordingly, three phenotypes have been individuated: high producers (GCC+/GCC+), medium producers (GCC+/GCC-) and low producers (GCC-/GCC-). We hypothesised that IL-10 haplotypes and genotypes are differently expressed in patients with systemic sclerosis (SSc) with the limited cutaneous SSc (lcSSc) subset or the diffuse cutaneous SSc (dcSSc) subset. One hundred and sixty-one unrelated Italian patients with SSc and 94 controls have been included. Their DNA was extracted and stored before being analysed by polymerase chain reaction with sequence-specific primers. The GCC haplotype is overrepresented in patients with SSc; subjects with dcSSc were the primary contributors to these results (dcSSc: 52.2% vs controls: 37.2%; chi2= 8.519, 2 d.f., corrected P= 0.04). In Scl70-positive patients, the GCC haplotype increased the likelihood of presenting the dcSSc subset [chi2= 12.56, P < 0.0005; odds ratio (OR) = 3.89, 95% confidence interval (CI(95)) = 1.69-9.08]; these results were confirmed at the phenotypic level (chi2= 11.67, 2 d.f., P= 0.003). In Scl70-positive patients, the high-producing phenotype was associated with poor survival, independently from disease subset and gender (hazard ratio = 9.9, CI(95)= 1.6-61.27, P < 0.05). The IL-10 haplotype and genotype associated with high IL-10 production may alter the susceptibility to SSc and/or its expression, increasing the prognostic value of other well-known markers of disease severity.

Anti-thyroid antibodies in Italian scleroderma patients: association of anti-thyroid peroxidase (anti-TPO) antibodies with HLA-DR15.

OBJECTIVE: To evaluate the frequency of anti-thyroid antibodies in a group of patients with scleroderma (SSc) and to analyze their genetic association with the HLA class II antigens. METHODS: Anti-thyroglobulin (anti-TG) and anti-thyroid peroxidase (anti-TPO) antibodies were measured by hemagglutination techniques. Thyroid function was evaluated by determining the levels of FT3, FT4 and TSH. HLA-DR typing was carried out using a standard complement-dependent microlymphocytotoxicity test. RESULTS: The proportions of patients with anti-TG and anti-TPO antibodies were 12% (10/85) and 19% (16/85) respectively. Two patients with anti-thyroid antibodies had overt hypothyroidism and shared the HLA-DR3 allele. The SSc subjects with anti-TPO antibodies showed a higher frequency of the HLA-DR15 allele than the patients without these antibodies. CONCLUSION: A considerable number of patients with scleroderma have antibodies to thyroid antigens without exhibiting any alterations of their thyroid function. HLA-DR15 is an immunogenic marker for the formation of antibodies against microsomal thyroid peroxidase.