Young R C, Headings V E, Henderson A L, Bose S, Hackney R L
J Natl Med Assoc. 1978 Nov;70(11):849-56.
An epidemiologic study of protease inhibitor (alpha(1)-antitrypsin) was undertaken among 599 ambulatory and hospitalized black American patients with chronic cardiopulmonary disease referred for pulmonary function testing, and 115 ethnically matched, healthy control subjects. Clinical evaluation consisted of respiratory questionnaire completion, physical examination, chest radiograph, and spirography. Protease inhibitor evaluation consisted of measurement of serum trypsin inhibitory capacity in all subjects corrected by comparison with control sera, while 200 of these subjects were phenotyped for alpha(1)-antitrypsin electrophoretic variants.Results showed mean serum trypsin inhibitory capacity for all subjects was 1.56, SD ± 0.47 mg/ml, while corrected values were 111.2, SD ± 30.5 percent of control. Acute phase reactivity was present for patients with heart disease, pulmonary malignancy, p<0.01 for both, and pulmonary fibrosis, p<0.05, when compared with controls. Prevalence of protease inhibitor variants in 29 controls was two heterozygotes for the Z variant (seven percent), and one homozygote for the S variant. Among 94 patients with chronic obstructive pulmonary disease, prevalence was 1.1 percent each for ZZ and SZ phenotypes, and 2.1 percent for MZ. Suprprisingly, the sole ZZ patient had asthmatic bronchitis rather than emphysema.Computed allele frequencies for Pi M and Z were comparable to those for a random sample of black Americans in St. Louis, but differed from a sample of black infants in Brooklyn, NY.These results indicate that protease inhibitor deficiency variants are not as uncommon among black Americans as the literature suggests. Furthermore, the heterozygous state is not necessarily a risk factor in development of chronic obstructive pulmonary disease. Protease inhibitor deficiency states therefore appear to play less important a role in etiology of chronic cardiopulmonary disease in black Americans than among their Caucasian counterparts.Preliminary work was published in abstract form.(1)
对599名前来进行肺功能测试的患有慢性心肺疾病的美国黑人门诊患者和住院患者，以及115名种族匹配的健康对照者进行了蛋白酶抑制剂（α1-抗胰蛋白酶）的流行病学研究。临床评估包括完成呼吸问卷、体格检查、胸部X光片和肺功能测试。蛋白酶抑制剂评估包括测量所有受试者血清中的胰蛋白酶抑制能力，并与对照血清比较进行校正，同时对其中200名受试者进行α1-抗胰蛋白酶电泳变体的表型分析。结果显示，所有受试者的血清胰蛋白酶抑制能力平均值为1.56，标准差±0.47毫克/毫升，校正后的值为对照值的111.2，标准差±30.5%。与对照组相比，心脏病、肺恶性肿瘤患者（两者p<0.01）以及肺纤维化患者（p<0.05）存在急性期反应。29名对照者中蛋白酶抑制剂变体的患病率为两名Z变体杂合子（7%）和一名S变体纯合子。在94名慢性阻塞性肺疾病患者中，ZZ和SZ表型的患病率均为1.1%，MZ为2.1%。令人惊讶的是，唯一的ZZ患者患有哮喘性支气管炎而非肺气肿。计算得出的Pi M和Z等位基因频率与圣路易斯的美国黑人随机样本相当，但与纽约布鲁克林的黑人婴儿样本不同。这些结果表明，蛋白酶抑制剂缺乏变体在美国黑人中并不像文献所表明的那样罕见。此外，杂合状态不一定是慢性阻塞性肺疾病发展的危险因素。因此，蛋白酶抑制剂缺乏状态在美国黑人慢性心肺疾病病因中所起的作用似乎比在白人中要小。初步研究结果已以摘要形式发表。(1)
