Performance of HLA-B and C alleles/haplotypes as indicators of psoriatic arthritis severity
| Score 1 | Score 2 | Score 3 | Score 4 | |
|---|---|---|---|---|
| (alleles only | (alleles only | (alleles+haplotypes | (alleles+haplotypes | |
| unweighted) | weighted and reduced) | unweighted) | weighted) | |
| Higher risk alleles/haplotypes | 1×B*08:01:01 | 0.70×B*08:01:01 | 1×B*08:01-C*07:01 | 0.57×B*08:01-C*07:01 |
| 1×B*18:01:01 | 0.97×B*18:01:01 | 1×B*27:05-C*02:02 | 0.94×B*27:05-C*02:02 | |
| 1×B*27:05:01 | 1×B*37:01.-C*06:02 | 0.93×B*37:01-C*06:02 | ||
| 1×B*37:01:01 | 1.00×B*37:01:01 | 1×C*05:01 not in B*44 haplotype | 1.34×C*05:01 not in B*44 haplotype | |
| 1×C*02:02:02 | 0.90×C*02:02:02 | |||
| 1×C*07:01:01 | ||||
| Lower risk alleles/haplotypes | −1×B*07:02:01 | |||
| −1×B*44:02:0101 | −0.64×B*44:02:01:01 | −1×B*44:02:01:01 | −0.69×B*44:02:01:01 | |
| −1×B*44:03:01 | ||||
| −1×C*04:01:01:01 | ||||
| −1×C*07:02:01:01 | −0.43×C*07:02:01:01 | −1×C*07:02:01:01 | −0.50×C*07:02:01:01 | |
| −1×C*16:01:01 | ||||
| Median (IQR; range) for score | 0 (−2 to 2; range −4–4) | 0.06 (−0.4–0.7; range −1.3–1.9) | 0 (−1–1; range −2–2) | 0 (−0.5–0.6; range −1.4–1.9) |
| Unadjusted OR (95% CI; p value) for highest severity tertile (per unit increase in risk score) | 1.30 (1.14 to 1.48; <0.001) | 2.36 (1.60 to 3.47; <0.001) | 1.74 (1.34 to 2.27; <0.001) | 2.43 (1.63 to 3.61; <0.001) |
| AUC (95% CI) | 0.656 (0.589 to 0.723) | 0.666 (0.597 to 0.734) | 0.652 (0.585 to 0.718) | 0.658 (0.590 to 0.726) |
| p Value for AUC vs score 1 | Referent | 0.62 | 0.82 | 0.93 |
| Adjusted† OR (95% CI; p value) for highest severity tertile | 1.35 (1.17 to 1.57; <0.001) | 2.59 (1.70 to 3.95; <0.001) | 1.85 (1.39 to 2.45; <0.001) | 2.68 (1.73 to 4.14; <0.001) |
| AUC for fully adjusted model including HLA risk score | 0.750 (0.687 to 0.813) | 0.755 (0.692 to 0.819) | 0.749 (0.686 to 0.812) | 0.750 (0.687 to 0.813) |
| AUC for non-HLA risk factors alone | 0.703 (0.636 to 0.771) | 0.703 (0.636 to 0.771) | 0.703 (0.636 to 0.771) | 0.703 (0.636 to 0.771) |
| p Value for AUC: full model including HLA risk score vs risk factors alonè | 0.038 | 0.032 | 0.044 | 0.041 |
†PsA severity factors adjusted for included age, current smoking, pack-years of smoking, duration of psoriasis and psoriatic arthritis, years between psoriasis and psoriatic arthritis and TNF inhibitor use.
AUC, area under the curve; HLA, human leukocyte antigen.