Spath P
Acta Med Austriaca. 1979;6(5):180-2.
Among the acquired hemolytic anemias, drug-induced immune hemolytic anemias (IHA) play a significant role. Many different drugs are capable of causing IHA, alphamethyldopa and penicillins have been responsible for the greatest number of cases. For the majority of the other drugs single cases of IHA are reported. Drug-induced immune hemolysis may be mediated by different immune mechanisms including the immune cytotoxicity type (penicillins and cephalosporins) with predominantly extravascular hemolysis. Immune hemolysis of most other drugs is due to immune complexes formed by the drug and specific antibodies leading to intravascular hemolysis in the presence of complement activation. So far, the autoimmune type of IHA caused by alphamethyldopa is unexplained, serologically this form cannot be distinguished from warm antibody auto-IHA. The clinical importance of drug-induced IHA depends on the severity of anemia and the problem of diagnosis leading to adequate therapeutic measures. Only a small number of cases showing a positive direct antiglobulin (Coombs') test caused by drugs will develop IHA. Therefore this finding does not require absolutely withdrawal of the drug, but careful observation of the patient. The diagnosis of drug-induced IHA is necessary for its distinction from auto-IHA and other secondary IHA. The study of such IHA has great importance for the understanding of other drug-induced cytopenias and may give explanations of the pathogenetic mechanisms of yet unexplained autoimmune phenomena.
在获得性溶血性贫血中，药物诱导的免疫性溶血性贫血（IHA）起着重要作用。许多不同的药物都能够引起IHA，其中α-甲基多巴和青霉素导致的病例最多。对于大多数其他药物，仅有个别IHA病例的报道。药物诱导的免疫性溶血可能由不同的免疫机制介导，包括免疫细胞毒性型（青霉素和头孢菌素），主要为血管外溶血。大多数其他药物引起的免疫性溶血是由于药物与特异性抗体形成免疫复合物，在补体激活的情况下导致血管内溶血。到目前为止，由α-甲基多巴引起的自身免疫型IHA的病因尚不清楚，在血清学上这种类型无法与温抗体自身免疫性IHA区分开来。药物诱导的IHA的临床重要性取决于贫血的严重程度以及诊断问题，这会导致采取适当的治疗措施。只有少数由药物引起的直接抗球蛋白（库姆斯）试验呈阳性的病例会发展为IHA。因此，这一发现并不绝对需要停用药物，但需要对患者进行仔细观察。药物诱导的IHA的诊断对于将其与自身免疫性IHA和其他继发性IHA区分开来是必要的。对这种IHA的研究对于理解其他药物诱导的血细胞减少症非常重要，并且可能为尚未解释的自身免疫现象的发病机制提供解释。
