IgG subclasses pattern and high-avidity antibody to the C-terminal region of merozoite surface protein 1 of Plasmodium vivax in an unstable hypoendemic region in Iran

• Published in: Acta tropica Vol. 112; no. 1; pp. 1 - 7
• Main Authors: Mehrizi, Akram Abouie, Zakeri, Sedigheh, Salmanian, Ali-Hatef, Sanati, Mohammad Hossein, Djadid, Navid Dinparast
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01.10.2009; Elsevier
• Subjects: Adolescent; Adult; Aged; Animals; Antibodies, Protozoan; Antibodies, Protozoan - blood; Antibodies, Protozoan - classification; Antibody; Antibody Affinity; Avidity; Biological and medical sciences; C-terminal region of MSP-1; Child; Child, Preschool; Endemic Diseases; Female; General aspects; Genetics; Human protozoal diseases; Humans; Immune response; Immunoglobulin G; Immunoglobulin G - blood; Immunoglobulin G - classification; Infant; Infectious diseases; Iran; Iran - epidemiology; Life Sciences; Malaria; Malaria, Vivax; Malaria, Vivax - epidemiology; Malaria, Vivax - immunology; Male; Medical sciences; Merozoite Surface Protein 1; Merozoite Surface Protein 1 - immunology; Middle Aged; Parasitic diseases; Plasmodium vivax; Plasmodium vivax - immunology; Protozoal diseases; Young Adult; Iran; Asia; Plasmodium vivax; Avidity; Immune response; Malaria; C-terminal region of MSP-1; Antibody; Protozoa; Apicomplexa; Protozoal disease; IgG; Parasitosis; Infection; Tropical medicine; Merozoite surface protein-1
• ISSN: 0001-706X; 1873-6254; 1873-6254
• DOI: 10.1016/j.actatropica.2009.05.016

The C-terminal region of Plasmodium vivax merozoite surface protein 1 (PvMSP-1 19) is a leading vaccine candidate for inclusion in a polyvalent malaria vaccine. In the present study, the IgG subclasses profile and the avidity of IgG to PvMSP-1 19 were evaluated in individuals ( n = 94) naturally exposed to P. vivax parasite in malaria endemic areas in Chabahar districts, Iran. In individuals with patent P. vivax malaria, 86.1% was sero-positive to PvMSP-1 19 and IgG1 (81.9%) was the predominant subclass. In addition, to determine the persistence of specific IgG, IgG1 and IgG3 antibodies to PvMSP-1 19, the frequency of antibodies was determined in the infected subjects ( n = 74) after treatment with standard chloroquine and it was detected that the frequency of responders was significantly reduced to 51.3%, 51% and 16.2%, respectively. The antigen-binding avidity of IgG antibodies to PvMSP-1 19 was measured in sero-positive sera and the high-avidity of IgG, IgG1 and IgG3 was found in 66.6%, 61% and 47% of the infected subjects with P. vivax, respectively. The present result shows that individuals who exposed to vivax malaria in the endemic region in Iran develop antibodies with high-avidity to PvMSP-1 19. These results could help to understand the interactions between the host and P. vivax parasite in development of MSP-1 19-based vaccine.