Sánchez-Arcila Juan Camilo, de França Marcelle Marcolino, Pereira Virginia Araujo, Vasconcelos Mariana Pinheiro Alves, Têva Antonio, Perce-da-Silva Daiana de Souza, Neto Joffre Rezende, Aprígio Cesarino Junior Lima, Lima-Junior Josue da Costa, Rodrigues Mauricio Martins, Soares Irene Silva, Banic Dalma Maria, Oliveira-Ferreira Joseli
Laboratorio de Imunoparasitologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Av. Brasil 4365, Manguinhos, Rio de Janeiro, Brazil.
Instituto de Infectologia Emílio Ribas, São Paulo, Brazil.
Malar J. 2015 Nov 6;14:442. doi: 10.1186/s12936-015-0978-7.
Polyparasitism is a common condition in humans but its impact on the host immune system and clinical diseases is still poorly understood. There are few studies of the prevalence and the effect of malaria-intestinal parasite co-infections in the immune response to malaria vaccine candidates. The present study determines whether the presence of malaria and intestinal parasites co-infection is associated with impaired IgG responses to Plasmodium vivax AMA-1 and MSP-119 in a rural population of the Brazilian Amazon.
A cross-sectional survey was performed in a rural area of Rondonia State and 279 individuals were included in the present study. At recruitment, whole blood was collected and Plasmodium and intestinal parasites were detected by microscopy and molecular tests. Blood cell count and haemoglobin were also tested and antibody response specific to P. vivax AMA-1 and MSP-119 was measured in plasma by ELISA. The participants were grouped according to their infection status: singly infected with Plasmodium (M); co-infected with Plasmodium and intestinal parasites (CI); singly infected with intestinal parasites (IP) and negative (N) for both malaria and intestinal parasites.
The prevalence of intestinal parasites was significantly higher in individuals with malaria and protozoan infections were more prevalent. IgG antibodies to PvAMA-1 and/or PvMSP-119 were detected in 74 % of the population. The prevalence of specific IgG was similar for both proteins in all four groups and among the groups the lowest prevalence was in IP group. The cytophilic sub-classes IgG1 and IgG3 were predominant in all groups for PvAMA-1 and IgG1, IgG3 and IgG4 for PvMSP-119. In the case of non-cytophilic antibodies to PvAMA-1, IgG2 was significantly higher in IP and N group when compared to M and CI while IgG4 was higher in IP group.
The presence of intestinal parasites, mainly protozoans, in malaria co-infected individuals does not seem to alter the antibody immune responses to P. vivax AMA-1 and MSP-119. However, IgG response to both AMA1 and MSP1 were lower in individuals with intestinal parasites.
多重寄生虫感染在人类中很常见，但其对宿主免疫系统和临床疾病的影响仍知之甚少。关于疟疾与肠道寄生虫共感染的患病率及其在对疟疾候选疫苗免疫反应中的作用的研究很少。本研究旨在确定在巴西亚马逊地区的农村人口中，疟疾和肠道寄生虫共感染的存在是否与对间日疟原虫AMA-1和MSP-119的IgG反应受损有关。
在朗多尼亚州的一个农村地区进行了一项横断面调查，本研究纳入了279名个体。招募时，采集全血，通过显微镜检查和分子检测来检测疟原虫和肠道寄生虫。还进行了血细胞计数和血红蛋白检测，并通过ELISA法检测血浆中对间日疟原虫AMA-1和MSP-119的特异性抗体反应。参与者根据其感染状况进行分组：单纯感染疟原虫（M）；同时感染疟原虫和肠道寄生虫（CI）；单纯感染肠道寄生虫（IP）以及疟疾和肠道寄生虫均为阴性（N）。
疟疾患者中肠道寄生虫的患病率显著更高，原生动物感染更为普遍。74%的人群检测到了针对PvAMA-1和/或PvMSP-119的IgG抗体。在所有四组中，两种蛋白的特异性IgG患病率相似，且在各组中患病率最低的是IP组。对于PvAMA-1，嗜细胞亚类IgG1和IgG3在所有组中占主导，对于PvMSP-119，IgG1、IgG3和IgG4占主导。就针对PvAMA-1的非嗜细胞抗体而言，与M组和CI组相比，IP组和N组中的IgG2显著更高，而IP组中的IgG4更高。
疟疾合并感染个体中肠道寄生虫（主要是原生动物）的存在似乎不会改变对间日疟原虫AMA-1和MSP-119的抗体免疫反应。然而，肠道寄生虫感染者对AMA1和MSP1的IgG反应较低。
