Donaldson V H, Bissler J J, Welch T R, Burton M F, Davis A E
Children's Hospital Research Foundation and the Department of Pediatrics, University of Cincinnati College of Medicine, Ohio 45229-3039, USA.
J Lab Clin Med. 1996 Oct;128(4):438-43. doi: 10.1016/s0022-2143(96)80017-5.
Patients with hereditary C4 deficiency are likely to have severe lupus erythematosus. A patient with hereditary angioneurotic edema (HANE) and systemic lupus erythematosus (SLE) had a chronic deficiency in C4 because the hereditary deficiency in C1-inhibitor allowed the C1 in her serum to become activated and then inactivate C4. An attempt was made to repair the C4 deficiency as well as the deficiency in C1-inhibitor by giving infusions of human C1-inhibitor in the hope of inducing remissions of both HANE and SLE. During treatment, antibody to C1-inhibitor developed in the patient; this cleared when the infusions were stopped. During subsequent treatment with danazol alone, measurable C1-inhibitor developed in the patient's serum, but levels of C4 were never significantly increased. Antibody to normal C1-inhibitor was not expected to develop in the patient because she is heterozygous for this autosomal dominant trait. A normal allotype (VAL or MET 458), which would have been in the preparation used but which the patient does not synthesize because she can produce only one allotype (MET 458), appears to have been immunogenic. The antibody isolated from the patient's serum reacted with C1-inhibitor from a normal individual known to be homozygous for 458-VAL but not with one from a homozygote for MET-458.
遗传性C4缺乏的患者很可能患有严重的红斑狼疮。一名患有遗传性血管性水肿（HANE）和系统性红斑狼疮（SLE）的患者存在慢性C4缺乏，因为遗传性C1抑制因子缺乏使得她血清中的C1被激活，进而使C4失活。人们尝试通过输注人C1抑制因子来修复C4缺乏以及C1抑制因子缺乏，以期诱导HANE和SLE缓解。治疗期间，患者体内产生了针对C1抑制因子的抗体；停止输注后该抗体消失。在随后单独使用达那唑治疗期间，患者血清中产生了可检测到的C1抑制因子，但C4水平从未显著升高。预计该患者不会产生针对正常C1抑制因子的抗体，因为她是这种常染色体显性性状的杂合子。制备物中原本会含有一种正常的同种异型（VAL或MET 458），但该患者无法合成，因为她只能产生一种同种异型（MET 458），这种同种异型似乎具有免疫原性。从患者血清中分离出的抗体与一名已知为458-VAL纯合子的正常个体的C1抑制因子发生反应，但不与一名MET-458纯合子的C1抑制因子发生反应。
