Hendrickse R G
University of Liverpool, U.K.
Ann Trop Med Parasitol. 1997 Oct;91(7):787-93. doi: 10.1080/00034989760545.
Similarities between the geographical and climatic prevalences of kwashiorkor and of exposure to dietary aflatoxins, and between the biochemical, metabolic and immunological derangements in kwashiorkor and those in animals exposed to aflatoxins, prompted investigation of the associations between kwashiorkor and aflatoxins. Studies in Africa in the 1980s indicated a role for these toxins in the pathogenesis of the disease. Paediatric cases of kwashiorkor are less prone to severe Plasmodium falciparum malaria than normal children. In mice infected with P. berghei, aflatoxin exposure inhibits parasite growth and ameliorates morbidity. Aflatoxins occur in < or = 40% of samples of breast milk from tropical Africa, usually as low concentrations of the relatively non-toxic derivatives of aflatoxin B1 (AFB1) but sometimes as high concentrations of the very toxic AFB1. This could explain kwashiorkor in breast-fed babies. Aflatoxin exposure occurs in > or = 30% of pregnancies in tropical Africa and the toxins are often in cord blood, sometimes at extremely high concentrations. Aflatoxins are now incriminated in neonatal jaundice and there is circumstantial evidence that they cause perinatal death and reduced birthweight. Aflatoxin-induced immunosuppresion may explain the aggressive behaviour of HIV infection in Africa. There are similarities between observations on HIV cases in Africa and those on heroin addicts in Europe, where 'street' heroin is frequently contaminated with aflatoxin. Aflatoxins were found in 20% of random urine samples from heroin addicts in the U.K. and the Netherlands. Aflatoxins have also been incriminated in episodes of food poisoning which have been associated with serious morbidity and mortality, particularly among young children.
夸休可尔症的地理和气候流行情况与膳食黄曲霉毒素暴露情况之间的相似性,以及夸休可尔症与黄曲霉毒素暴露动物在生化、代谢和免疫紊乱方面的相似性,促使人们对夸休可尔症与黄曲霉毒素之间的关联展开调查。20世纪80年代在非洲进行的研究表明这些毒素在该疾病的发病机制中起作用。夸休可尔症的儿科病例比正常儿童更不易感染严重的恶性疟原虫疟疾。在感染伯氏疟原虫的小鼠中,黄曲霉毒素暴露会抑制寄生虫生长并减轻发病率。在热带非洲,≤40%的母乳样本中存在黄曲霉毒素,通常是低浓度的相对无毒的黄曲霉毒素B1(AFB1)衍生物,但有时是高浓度的剧毒AFB1。这可以解释母乳喂养婴儿患夸休可尔症的原因。在热带非洲,≥30%的孕妇会接触黄曲霉毒素,且这些毒素常在脐带血中出现,有时浓度极高。黄曲霉毒素现在被认为与新生儿黄疸有关,有间接证据表明它们会导致围产期死亡和出生体重降低。黄曲霉毒素诱导的免疫抑制可能解释了非洲艾滋病毒感染的侵袭性。非洲艾滋病毒病例的观察结果与欧洲海洛因成瘾者的观察结果存在相似之处,在欧洲,“街头”海洛因经常被黄曲霉毒素污染。在英国和荷兰,20%的海洛因成瘾者随机尿液样本中发现了黄曲霉毒素。黄曲霉毒素还被认为与食物中毒事件有关,这些事件与严重的发病率和死亡率相关,尤其是在幼儿中。