Lerolle D, Dreyer-Dufer C, Allain J P
Nouv Presse Med. 1981 Apr 25;10(18):1483-7.
A 65-year-old man developed severe haemorrhagic diathesis associated with complete and isolated factor V deficiency due to the presence of a circulating antibody inhibiting specifically Factor V. No evidence of autoimmune disease was found, but the patient had received isoniazid, streptomycin and PAS for pulmonary tuberculosis 12 years before the inhibitor was discovered. This low titer (4 micro/ml) was an IgG of the gamma G1, gamma G2, or gamma G4 subclass. It was stable at 56 degrees C but unstable at low pH, had strong affinity for human plasma Factor V and did not cross-react with either porcine or bovine Factor V. Its inhibitory activity was blocked by both normal human plasma or serum, but not be the plasma of a patient with severe, inherited Factor V deficiency. A 4-week immunosuppressive treatment with prednisone and azathioprine resulted in disappearance of the antibody and return of Factor V to a normal level. However, this level rapidly decreased after immunosuppression was discontinued, and could only be maintained at 40 to 60% of normal values by longterm treatment with prednisone and cyclophosphamide.
一名65岁男性因存在特异性抑制因子V的循环抗体而出现严重出血素质，伴有完全性孤立性因子V缺乏。未发现自身免疫性疾病证据，但该患者在发现抑制剂12年前曾接受异烟肼、链霉素和对氨基水杨酸治疗肺结核。这种低滴度（4微克/毫升）抗体是γG1、γG2或γG4亚类的IgG。它在56℃稳定，但在低pH值时不稳定，对人血浆因子V有很强的亲和力，且与猪或牛的因子V无交叉反应。其抑制活性可被正常人血浆或血清阻断，但不能被严重遗传性因子V缺乏患者的血浆阻断。泼尼松和硫唑嘌呤4周的免疫抑制治疗导致抗体消失，因子V水平恢复正常。然而，免疫抑制治疗停止后，该水平迅速下降，只有通过泼尼松和环磷酰胺长期治疗才能维持在正常值的40%至60%。
