Table 4.
Frequencies of haplotypes and diplotypes of cytotoxic T lymphocyte antigen-4 (CTLA-4) −318 C/T and +49 A/G polymorphisms in systemic sclerosis (SSc) patients according to anti-thyroperoxidase (TPO) and anti-thyroglobulin (TGA) status.
| n (frequency) | ||||
|---|---|---|---|---|
| HT− (2n = 40) | HT+ (2n = 40) | Controls (2n = 186) | P | |
| Haplotypes | ||||
| –318C +49 A: CA | 16 (0·40) | 26 (0·65) | 116 (0·62) | 0·0431 |
| –318C +49 G: CG | 15 (0·37) | 12 (0·30) | 45 (0·24) | |
| –318T +49 A: TA | 9 (0·23) | 2 (0·05) | 25 (0·14) | |
| n (%) | ||||
|---|---|---|---|---|
| Diplotype combinations | HT−2 (n = 20) | HT+3 (n = 20) | Controls (n = 93) | P |
| T+G+ | 4 (20) | 1 (5) | 5 (5·4) | 0·0281 |
| CG/TA | 4 (20) | 1 (5) | 5 (5·4) | |
| T+/G− | 5 (25) | 1 (5) | 17 (18·3) | |
| CA/TA | 5 (25) | 1 (5) | 14 (15·1) | |
| TA/TA | 0 (0) | 0 (0) | 3 (3·2) | |
| T−/G+ | 10 (50) | 10 (50) | 35 (37·7) | |
| CA/CG | 9 (45) | 9 (45) | 30 (32·3) | |
| CG/CG | 1 (5) | 1 (5) | 5 (5·4) | |
| T−/− | 1 (5) | 8 (40) | 36 (38·6) | |
| CA/CA | 1 (5) | 8 (40) | 36 (38·6) | |
| HWE | HWE | HWE | ||
| P = 0·11 | P = 0·81 | P = 0·67 | ||
HWE: Hardy–Weinberg equilibrium tested by Pearson's χ2 test (P < 0·05 indicates a lack of HWE). HT −: SSc patients negative for anti-TPO/TGA. HT+: SSc patients positive for anti-TPO/TGA. In plain text are indicated diplotypes. Bold type indicates the combinations of diplotypes according the presence of both the mutant alleles (−318T and +49 G: T+/G+), only the −318T (T+/G−), only the +49 G (T −/G+) and none of them (T −/G–).
χ2 test
χ2 test: HT −versus HT+, P = 0·019 and HT −versus controls, P = 0·011.
χ2 test: HT+versus controls–, P = 0·48.