Willcox M, Björkman A, Brohult J
Ann Trop Med Parasitol. 1983 Aug;77(4):335-47. doi: 10.1080/00034983.1983.11811722.
In a study in northern Liberia of the malaria and beta-thalassaemia hypothesis, the frequencies of beta-thalassaemia and HbS traits were 9.1 and 3.4% in the Mano and 9.5 and 1.7% in the Gio tribal samples. HbC and HbN were present at low frequency. G6PD deficiency was found in 16% of males. An observed increase with age of beta-thalassaemia trait frequencies was consistent with the selection hypothesis. However, we could not entirely exclude that associated iron deficiency influenced the results in the six to 11 month age group. Malaria was holoendemic; Plasmodium falciparum predominated, P. malariae and P. ovale were also identified. Plasmodium falciparum prevalence rates were similar in normal and beta-thalassaemia trait children but parasite densities were consistently lower in the latter. Using the criterion of a falciparum parasite density of 1 x 10(9) 1(-1) or greater to indicate a potentially important infection, the relative risk in beta-thalassaemia traits one to four years old from the cross-sectional study was 0.45 (upper 95% confidence interval 0.79) and 0.41 (0.61) in two to nine year trait carriers from a longitudinal study. Plasmodium falciparum gametocyte rates were lower in beta-thalassaemia trait children (P less than 0.005). The geometric mean titre of P. falciparum antibodies was lower in beta-thalassaemia trait children from the one to four year group (P less than 0.05). Otherwise immunological studies showed little difference between the different Hb types. Parasitological findings were consistent with relative resistance of HbS trait carriers towards P. falciparum infection. We found no evidence for relative resistance of beta-thalassaemia traits towards P. malariae infection nor that G6PD deficient males were more resistant to P. falciparum than those with normal activity. We conclude that the results are consistent with relative resistance of beta-thalassaemia trait carriers to P. falciparum malaria.
在利比里亚北部进行的一项关于疟疾与β地中海贫血假说的研究中，马诺部落样本中β地中海贫血和血红蛋白S（HbS）性状的频率分别为9.1%和3.4%，吉奥部落样本中则分别为9.5%和1.7%。血红蛋白C（HbC）和血红蛋白N（HbN）的出现频率较低。16%的男性被发现存在葡萄糖-6-磷酸脱氢酶（G6PD）缺乏症。观察到的β地中海贫血性状频率随年龄增加的现象与选择假说相符。然而，我们不能完全排除相关的缺铁因素对6至11个月龄组结果的影响。疟疾为高度地方性流行；恶性疟原虫占主导，间日疟原虫和卵形疟原虫也被鉴定出来。正常儿童和β地中海贫血性状儿童的恶性疟原虫流行率相似，但后者的寄生虫密度始终较低。使用恶性疟原虫寄生虫密度为1×10⁹个/升或更高作为潜在重要感染的标准，横断面研究中1至4岁β地中海贫血性状儿童的相对风险为0.45（95%置信区间上限为0.79），纵向研究中2至9岁性状携带者的相对风险为0.41（0.61）。β地中海贫血性状儿童的恶性疟原虫配子体率较低（P<0.005）。1至4岁组β地中海贫血性状儿童的恶性疟原虫抗体几何平均滴度较低（P<0.05）。除此之外，免疫学研究表明不同血红蛋白类型之间差异不大。寄生虫学研究结果与HbS性状携带者对恶性疟原虫感染的相对抗性相符。我们没有发现β地中海贫血性状对间日疟原虫感染具有相对抗性的证据，也没有发现G6PD缺乏的男性比活性正常的男性对恶性疟原虫更具抗性的证据。我们得出结论，这些结果与β地中海贫血性状携带者对恶性疟原虫疟疾的相对抗性相符。
