低丙种球蛋白血症的发病率和患病率尚不明确,因为该病可由多种原发性和继发性缺陷引起。与继发性低丙种球蛋白血症相比,原发性低丙种球蛋白血症不太常见[2]Onigbanjo M, Orange J, Perez E, et al. Hypogammaglobulinemia in a pediatric tertiary care setting. Clin Immunol. 2007;125:52-59.http://www.ncbi.nlm.nih.gov/pubmed/17631052?tool=bestpractice.com
有证据表明,在美国人中,原发性免疫缺陷 (PID) 的患病率为 1/1200。[3]Boyle JM, Buckley RH. Population prevalence of diagnosed primary immunodeficiency diseases in the United States. Pharm Policy Law. 2008;10:99-108.但是,并不是所有界定的 PID 疾病 (>150) 都会导致低丙种球蛋白血症。原发性抗体缺乏症是最常见的一种PID,在 PID 登记调查项目中,这种疾病占所有病例的 77%。[4]Kirkpatrick P, Riminton S. Primary immunodeficiency diseases in Australia and New Zealand. J Clin Immunol. 2007;27:517-524.http://www.ncbi.nlm.nih.gov/pubmed/17588141?tool=bestpractice.com在这些缺乏症中,选择性 IgA 缺乏症是最常见的(患病率在 1/700-1/300之间),但该疾病经常无症状。
普通变异型免疫缺陷病 (CVID) 的患病率约为 1/30,000,这是最具临床相关性、需要静脉使用免疫球蛋白的抗体缺乏症。[5]Bonilla FA, Khan DA, Ballas ZK, et al. Practice parameter for the diagnosis and management of primary immunodeficiency. J Allergy Clin Immunol. 2015;136:1186-1205.http://www.jacionline.org/article/S0091-6749%2815%2900883-0/fulltexthttp://www.ncbi.nlm.nih.gov/pubmed/26371839?tool=bestpractice.com[6]Conley ME, Notarangelo LD, Etzioni A. Diagnostic criteria for primary immunodeficiencies: representing PAGID (Pan-American Group for Immunodeficiency) and ESID (European Society for Immunodeficiencies). Clin Immunol. 1999;93:190-197.http://www.ncbi.nlm.nih.gov/pubmed/10600329?tool=bestpractice.com证据表明,大多数患有低丙种球蛋白血症和 PID 的儿童,存在婴儿期暂时性低丙种球蛋白血症或 CVID,有 7% 的患儿存在重症联合免疫缺陷病 (SCID)。[2]Onigbanjo M, Orange J, Perez E, et al. Hypogammaglobulinemia in a pediatric tertiary care setting. Clin Immunol. 2007;125:52-59.http://www.ncbi.nlm.nih.gov/pubmed/17631052?tool=bestpractice.com进一步的证据表明,在澳大利亚的活产婴儿中,SCID 的年发病率为 1.8/100,000。[7]Yee A, De Ravin SS, Elliott E, et al. Severe combined immunodeficiency: a national surveillance study. Pediatr Allergy Immunol. 2008;19:298-302.http://www.ncbi.nlm.nih.gov/pubmed/18221464?tool=bestpractice.com
低丙种球蛋白血症可发生在任何年龄,视基础疾病而定。SCID 出现在婴儿早期,而婴儿期暂时性低丙种球蛋白血症和 X 连锁无丙种球蛋白血症 (XLA) 可能出现在儿童早期(当母源性 IgG 抗体水平下降时)或婴儿晚期。CVID 可在早期或晚期发生。[8]Quinti I, Soresina A, Spadaro G, et al; Italian Primary Immunodeficiency Network. Long-term follow-up and outcome of a large cohort of patients with common variable immunodeficiency. J Clin Immunol. 2007;27:308-316.http://www.ncbi.nlm.nih.gov/pubmed/17510807?tool=bestpractice.com多数导致低丙种球蛋白血症的疾病无性别差异,但存在一些较为罕见的 X 连锁遗传病(例如,XLA)。在东欧和中欧国家(总人口为 145,530,870),XLA 的患病率估计为 1/1,399,000。[9]Tóth B, Volokha A, Mihas A, et al. Genetic and demographic features of X-linked agammaglobulinemia in Eastern and Central Europe: a cohort study. Mol Immunol. 2009;46:2140-2146.http://www.ncbi.nlm.nih.gov/pubmed/19419768?tool=bestpractice.com与骨髓瘤和慢性淋巴细胞白血病 (CLL) 有关的继发性低丙种球蛋白血症多见于年龄较大(年龄 >50 岁)的人群。