TY - JOUR
T1 - Naturally acquired antibody responses to plasmodium vivax and plasmodium falciparum Merozoite Surface Protein 1 (MSP1) C-Terminal 19 kDa domains in an area of unstable malaria transmission in Southeast Asia
AU - Wang, Qinghui
AU - Zhao, Zhenjun
AU - Zhang, Xuexing
AU - Li, Xuelian
AU - Zhu, Min
AU - Li, Peipei
AU - Yang, Zhaoqing
AU - Wang, Ying
AU - Yan, Guiyun
AU - Shang, Hong
AU - Cao, Yaming
AU - Fan, Qi
AU - Cui, Liwang
N1 - Publisher Copyright:
© 2016 Wang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in anymedium, provided the original author and source are credited.
PY - 2016/3
Y1 - 2016/3
N2 - Understanding naturally acquired immunity to infections caused by Plasmodia in different malaria endemicity settings is needed for better vaccine designs and for exploring antibody responses as a proxy marker of malaria transmission intensity. This study investigated the sero-epidemiology of malaria along the international border between China and Myanmar, where malaria elimination action plans are in place. This study recruited 233 P. vivax and 156 P. falciparum infected subjects with acute malaria at the malaria clinics and hospitals. In addition, 93 and 67 healthy individuals from the same endemic region or from nonendemic region, respectively, were used as controls. Acute malaria infections were identified by microscopy. Anti-recombinant PfMSP119 and PvMSP119 antibody levels were measured by ELISA. Antibody responses to respective MSP119 were detected in 50.9% and 78.2% patients with acute P. vivax and P. falciparum infections, respectively. There were cross-reacting antibodies in Plasmodium patients against these two recombinant proteins, though we could not exclude the possibility of submicroscopic mixed-species infections. IgG1, IgG3 and IgG4 were the major subclasses. Interestingly, 43.2% of the healthy endemic population also had antibodies against PfMSP119, whereas only 3.9% of this population had antibodies against PvMSP119. Higher antibody levels were correlated with age and parasite density, but not with season, gender or malaria history. Both total IgG and individual IgG subclasses underwent substantial declines during the convalescent period in three months. This study demonstrated that individuals in a hypoendemic area with coexistence of P. vivax and P. falciparum can mount rapid antibody responses against both PfMSP119 and PvMSP119. The significantly higher proportion of responders to PfMSP119 in the healthy endemic population indicates higher prevalence of P. falciparum in the recent past. Specific antibodies against PvMSP119 could serve as a marker of recent exposure to P. vivax in epidemiological studies.
AB - Understanding naturally acquired immunity to infections caused by Plasmodia in different malaria endemicity settings is needed for better vaccine designs and for exploring antibody responses as a proxy marker of malaria transmission intensity. This study investigated the sero-epidemiology of malaria along the international border between China and Myanmar, where malaria elimination action plans are in place. This study recruited 233 P. vivax and 156 P. falciparum infected subjects with acute malaria at the malaria clinics and hospitals. In addition, 93 and 67 healthy individuals from the same endemic region or from nonendemic region, respectively, were used as controls. Acute malaria infections were identified by microscopy. Anti-recombinant PfMSP119 and PvMSP119 antibody levels were measured by ELISA. Antibody responses to respective MSP119 were detected in 50.9% and 78.2% patients with acute P. vivax and P. falciparum infections, respectively. There were cross-reacting antibodies in Plasmodium patients against these two recombinant proteins, though we could not exclude the possibility of submicroscopic mixed-species infections. IgG1, IgG3 and IgG4 were the major subclasses. Interestingly, 43.2% of the healthy endemic population also had antibodies against PfMSP119, whereas only 3.9% of this population had antibodies against PvMSP119. Higher antibody levels were correlated with age and parasite density, but not with season, gender or malaria history. Both total IgG and individual IgG subclasses underwent substantial declines during the convalescent period in three months. This study demonstrated that individuals in a hypoendemic area with coexistence of P. vivax and P. falciparum can mount rapid antibody responses against both PfMSP119 and PvMSP119. The significantly higher proportion of responders to PfMSP119 in the healthy endemic population indicates higher prevalence of P. falciparum in the recent past. Specific antibodies against PvMSP119 could serve as a marker of recent exposure to P. vivax in epidemiological studies.
UR - http://www.scopus.com/inward/record.url?scp=84962193491&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84962193491&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0151900
DO - 10.1371/journal.pone.0151900
M3 - Article
C2 - 26999435
AN - SCOPUS:84962193491
SN - 1932-6203
VL - 11
JO - PloS one
JF - PloS one
IS - 3
M1 - e0151900
ER -