Roberton D M, Colgan T, Ferrante A, Jones C, Mermelstein N, Sennhauser F
Department of Paediatrics, Royal Children's Hospital, Melbourne, Victoria, Australia.
Pediatr Infect Dis J. 1990 Aug;9(8 Suppl):S41-5.
Sixty-seven children with symptomatic IgA deficiency were studied on two separate occasions. Eighteen had aIgAd at presentation, and 49 had pIgAd. IgA concentrations had risen to the normal range for age in 22.2% of children presenting with aIgAd and 77.6% presenting with pIgAd when restudied at a median interval of 3.2 and 3.0 years, respectively. IgG subclass concentrations were measured by enzyme immunoassay in serum samples collected at enrollment from 12 children with aIgAd and 22 children with pIgAd. IgG2 and IgG4 concentrations for these 34 children were below the 5th centile for age and sex more frequently than expected (IgG2: chi square 5.8, P less than 0.025; IgG 4: chi square 18.4, P less than 0.0005). The prevalence of IgG2 deficiency or IgG4 deficiency did not differ significantly between those with aIgAd and those with pIgAd. IgG2 concentrations remained below the 5th centile more frequently than expected when retested in 31 children whose pIgAd had resolved (chi square 4.6, P less than 0.05). Children with aIgAd at presentation had IgG1 and IgG2 concentrations above the 95th centile more frequently than expected (IgG1: chi square 19.7, P less than 0.0005; IgG2: chi square 13.5, P less than 0.001) but this was not seen for IgG3 and IgG4 concentrations. Children with pIgAd did not have elevated IgG1 or IgG2 concentrations at presentation. High IgG1 and IgG2 concentrations in aIgAd may be a compensatory mechanism to afford protection from infection or could be part of a selective secondary response to repeated episodes of infection.
对67名有症状的IgA缺乏症儿童进行了两次独立研究。18名儿童初诊时为非分泌型IgA缺乏（aIgAd），49名儿童初诊时为分泌型IgA缺乏（pIgAd）。分别在中位间隔3.2年和3.0年再次研究时，22.2%初诊为aIgAd的儿童以及77.6%初诊为pIgAd的儿童的IgA浓度已升至该年龄的正常范围。通过酶免疫测定法对12名aIgAd儿童和22名pIgAd儿童入组时采集的血清样本中的IgG亚类浓度进行了检测。这34名儿童的IgG2和IgG4浓度低于年龄和性别的第5百分位数的频率高于预期（IgG2：卡方值5.8，P<0.025；IgG4：卡方值18.4，P<0.0005）。aIgAd儿童和pIgAd儿童中IgG2缺乏或IgG4缺乏的患病率无显著差异。在31名pIgAd已缓解的儿童再次检测时，IgG2浓度低于第5百分位数的频率高于预期（卡方值4.6，P<0.05）。初诊时为aIgAd的儿童的IgG1和IgG2浓度高于第95百分位数的频率高于预期（IgG1：卡方值19.7，P<0.0005；IgG2：卡方值13.5，P<0.001），但IgG3和IgG4浓度未见此情况。初诊时pIgAd儿童的IgG1或IgG2浓度未升高。aIgAd中高IgG1和IgG2浓度可能是一种提供抗感染保护的代偿机制，或者可能是对反复感染发作的选择性二次反应的一部分。
