所谓免疫缺陷是指因缺乏免疫活性因子的量与质而使机体缺少免疫防御。从其成因上分为原发性和继发性两种,前者系自身免疫系统异常,多由遗传因素所致。后者因免疫系统以外的疾病或药物等外因引起的继发性免疫缺陷,相同的原因有易产生免疫缺陷的,也有不产生免疫缺陷的。单纯因解剖或生理缺陷所致并,如留置导尿引起尿道感染不属于免疫缺陷症。原发性免疫缺陷症是人类重要的疾病,从免疫机理方面已取得很多资料,但发病率低,日本约为十万分之2或3。引起继发性免疫功能缺陷的疾病,包括 The so-called immune deficiency refers to the lack of immunocompetent factors and the quality and lack of immune defenses. From its causes are divided into primary and secondary two, the former Department of autoimmune disorders, mostly caused by genetic factors. The latter due to immune system diseases or drugs and other external causes of secondary immune deficiency, the same reasons are prone to immunodeficiency, but also does not produce immune defects. Simply because of anatomical or physiological defects and caused, such as indwelling catheterization caused by urinary tract infection is not immune deficiency. Primary immunodeficiency disease is an important human disease and much information has been obtained on the immunological mechanism. However, the incidence rate is low, about two or three hundred thousandths in Japan. Diseases that cause secondary immune deficiencies, including