Department of Medicine, University of Otago, New Zealand.
Department of Rheumatology, Immunology and Allergy, Christchurch Hospital, Christchurch, New Zealand.
Rheumatology (Oxford). 2018 Dec 1;57(12):2183-2189. doi: 10.1093/rheumatology/key237.
To determine factors that predict inadequate serum urate (SU) lowering response in a randomized controlled trial of allopurinol dose escalation (DE) in gout.
Participants undergoing allopurinol DE were classified as: complete response (CR)-reached target SU at month 9 and 12 of the DE phase or if still dose escalating at month 9 reached target SU by month 12; partial response (PR)-reached target at some stage but not fulfilling criteria for CR; or inadequate response (IR)-did not reach target SU at any time.
IR was uncommon, occurring in 13/150 (8.7%), compared with 82 (54.7%) CR, and 55 (36.6%) PR. Mean (s.e.m.) SU was higher at the end of the 12-month DE in IR compared with both CR and PR groups; 7.6 (0.31) vs 5.01 (0.06) and 5.97 (0.17) mg/dl respectively (P < 0.001). In univariate analysis, compete responders tended to be older, be receiving less allopurinol, have longer gout duration and were more likely to be New Zealand (NZ) European ethnicity, compared with IR+PR. Using multi-variate logistic regression analysis, only longer duration of gout and NZ European ethnicity remained significant independent predictors of CR. Baseline SU ⩾ 8 mg/dl had a sensitivity of 69.2% and specificity of 85.1% in predicting IR. The odds ratio for an IR if baseline SU was ⩾8 mg/dl was 11.7 (95% CI 3.3, 41.2).
A minority of people with gout never reach target SU when allopurinol dose is increased in a treat-to-target manner. Approximately one-third of those with SU ⩾ 8mg/dl despite allopurinol ⩾300mg/d have an IR to DE.
Australian New Zealand Clinical Trails Registry, https://www.anzctr.org.au, ACTRN12611000845932.
在一项别嘌醇剂量递增（DE）治疗痛风的随机对照试验中，确定预测血清尿酸（SU）降低不足的因素。
接受别嘌醇 DE 的参与者分为：完全缓解（CR）-在 DE 阶段的第 9 个月和第 12 个月达到目标 SU，或在第 9 个月仍在剂量递增时在第 12 个月达到目标 SU；部分缓解（PR）-在某个阶段达到目标，但不符合 CR 标准；或缓解不足（IR）-在任何时候都未达到目标 SU。
IR 较为少见，150 例中仅有 13 例（8.7%），而 CR 为 82 例（54.7%），PR 为 55 例（36.6%）。在 DE 的 12 个月结束时，IR 组的 SU 均值（s.e.m.）高于 CR 和 PR 组；分别为 7.6（0.31）、5.01（0.06）和 5.97（0.17）mg/dl（P<0.001）。在单变量分析中，与 IR+PR 相比，完全缓解者往往年龄较大、接受的别嘌醇剂量较少、痛风持续时间较长，且更有可能是新西兰（NZ）欧洲裔。使用多变量逻辑回归分析，只有痛风持续时间较长和 NZ 欧洲裔是 CR 的独立显著预测因素。基线 SU ⩾8mg/dl 对 IR 的预测具有 69.2%的敏感性和 85.1%的特异性。如果基线 SU ⩾8mg/dl，IR 的优势比为 11.7（95%CI 3.3，41.2）。
当以治疗目标的方式增加别嘌醇剂量时，少数痛风患者从未达到目标 SU。尽管别嘌醇 ⩾300mg/d，但仍有大约三分之一的 SU ⩾8mg/dl 的人对 DE 有 IR。
澳大利亚新西兰临床试验注册中心，https://www.anzctr.org.au，ACTRN12611000845932。
