BACKGROUND High Immunoglobulin G (IgG) response to Plasmodium falciparum antigens is associated with partial malaria protection in sickle hemoglobin (HbS) children. However, this response has been more studied in children with heterozygous sickle cell trait (HbAS) but little explored in those with homozygous sickle cell trait (HbSS). The current study was conducted to determine the IgG responses against specific Plasmodium falciparum antigens in children with homozygous sickle cell trait (HbSS) by comparing to those with normal hemoglobin (HbAA). METHODS A cross sectional study was conducted between April and July 2018 in Dar es Salaam tertiary hospitals. Parents were consented for their child to give about 5 ml of venous blood. IgG concentration from the blood plasma of 220 children (110 HbAA vs. 110 HbSS) were determined using indirect Enzyme Linked Immunosorbent Assay (ELISA). Then IgG medians were compared between the groups with prism 5 software (GraphPad) using Mann Whitney U test. Where the differences in age, hemoglobin levels and body weight between the groups was analyzed using independent sample t test. Multiple linear regressions were used to control cofounding variables such as body weight, age and hemoglobin level using statistical package for social sciences software (SPSS version 23). P value <0.05 was considered statistically significant. RESULTS The median IgG concentration to PfEBA-175, Pfg27, yPfs28C antigens were HbSS; 20.7 ng/ml (IQR; 18.1-25.6) vs. HbAA; 2.3 ng/ml (IQR; 1.21-3.04), HbSS; 2.76 ng/ml (IQR: 2.08-5.69) vs. HbAA; 1.36 ng/ml (IQR: 1.28-1.76), and HbSS; 26,592 ng/ml (IQR: 10817-41,462) vs. HbAA; 14,164 ng/ml (IQR; 3069-24,302) respectively (p < 0.0001 for all IgG). In both groups; age, body weight and hemoglobin level had no impact on the levels of IgG responses to Plasmodium falciparum antigens except for HbAA group which showed a significant increase in IgG against Pfg27 by 0.004 ng/ml with 1 g/dl increase in Hb level (p = 0.028). CONCLUSIONS This study found significant higher levels of specific Plasmodium falciparum IgG responses in children with homozygous sickle cell trait than those with normal hemoglobin.

中文翻译：

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具有纯合镰状细胞特征的儿童对恶性疟疾特定抗原的免疫球蛋白G应答高于血红蛋白正常的儿童。

背景技术镰状血红蛋白（HbS）儿童对恶性疟原虫抗原的高免疫球蛋白G（IgG）应答与部分疟疾保护相关。但是，这种反应已在具有杂合镰刀细胞性状（HbAS）的儿童中进行了更多的研究，但在具有纯合镰刀细胞性状（HbSS）的儿童中进行了很少的探索。通过与具有正常血红蛋白（HbAA）的儿童进行比较，目前的研究旨在确定针对具有纯合镰刀细胞性状（HbSS）的儿童针对特定恶性疟原虫抗原的IgG反应。方法于2018年4月至7月之间在达累斯萨拉姆三级医院进行了横断面研究。父母被允许为孩子提供约5毫升的静脉血。220名儿童血浆中的IgG浓度（110 HbAA vs. 使用间接酶联免疫吸附测定（ELISA）确定110 HbSS）。然后使用Mann Whitney U检验，使用棱镜5软件（GraphPad）比较各组之间的IgG中值。使用独立样本t检验分析两组之间的年龄，血红蛋白水平和体重差异。使用用于社会科学软件的统计软件包（SPSS 23版），使用多元线性回归来控制诸如体重，年龄和血红蛋白水平之类的共同建立变量。P值<0.05被认为具有统计学意义。结果PfEBA-175，Pfg27，yPfs28C抗原的IgG浓度中值为HbSS。20.7 ng / ml（IQR; 18.1-25.6）vs.HbAA; 2.3 ng / ml（IQR; 1.21-3.04），HbSS; 2.76 ng / ml（IQR：2.08-5.69）vs. HbAA; 1.36 ng / ml（IQR：1.28-1.76）和HbSS；26.592 ng / ml（IQR：10817-41,462）vs. HbAA; 14 分别为164 ng / ml（IQR; 3069-24,302）（对于所有IgG，p <0.0001）。两组；年龄，体重和血红蛋白水平对恶性疟原虫抗原的IgG反应水平没有影响，除HbAA组外，针对Pfg27的IgG显着增加0.004 ng / ml，Hb水平增加1 g / dl（p = 0.028）。结论该研究发现，纯合镰刀细胞性状患儿的恶性疟原虫IgG特异性反应水平明显高于正常血红蛋白患儿。004 ng / ml，血红蛋白水平增加1 g / dl（p = 0.028）。结论本研究发现，镰状细胞纯合子性患儿的恶性疟原虫IgG特异性应答水平明显高于正常血红蛋白患儿。004 ng / ml，血红蛋白水平增加1 g / dl（p = 0.028）。结论该研究发现，纯合镰刀细胞性状患儿的恶性疟原虫IgG特异性反应水平明显高于正常血红蛋白患儿。