Dados do Trabalho

Título

THE ROLE OF IgG ANTIBODY IN THE RECURRENCE OF MALARIA CAUSED BY P. VIVAX

Introdução

Malaria is the most significant parasitic disease causing morbidity, anemia and mortality worldwide and vivax malaria recurrence remains a serious challenge against its elimination or eradication. Therefore, any effort toward its control will be of a great importance.

Objetivo (s)

To determine the role of IgG antibody response against P. vivax antigens (AMA-1, MSP1-19 and CSP vk210) in recurrent vivax malaria.

Material e Métodos

This was a case-control study. The cases were the malaria patients that had recurrences while the controls were the patients without recurrence within 180 days of follow-up. The plasma samples from the two groups were subjected to Direct ELISA test to evaluate IgG antibody response against P. vivax antigens (AMA-1, MSP1-19 and CSP vk210) according to the protocol.

Resultados e Conclusão

Forty-two recurrent patients with samples covering the following days: D0 (42), D42 (41), D63 (23), D90 (7), D≥120 (10) and DR (33) were selected as cases and 29 non-recurrent patients with samples covering D0 (29) and D150/D180 (29) were selected as controls. At day of inclusion (D0), the controls demonstrated significantly higher level of IgG antibody response against the two antigens (AMA-1, p = 0.0239 and MSP1-19, p = 0.0006). Conversely, the cases showed higher antibody level at day of recurrence (DR) compared to D150/180 of the controls (when the patient had recovered) with significant differences (AMA-1, p < 0.0001 and MSP1-19, p = 0.0005). Comparing D0 and D150/180 of the controls, the level of the antibody response on D0 were significantly higher than on D150/180 for the two antigens (AMA-1, p= 0.0001 and MSP1-19, p = 0.0001). The patients with an IgG antibody response ≤ median of the reactivity indices (IR) were more among the cases than the controls with relative risk ratio greater than 1 for the 3 antigens. Conclusion: The study showed that, high level of IgG antibody at the onset of vivax malaria symptoms has the potential to prevent recurrence and that the infection by P. vivax induces the rise of IgG antibodies in the body.

Palavras-chave

Recurrence, Antibodies, Antigens, P. vivax

Agradecimentos

Source of Funding: O Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).
My sincere appreciation to CNPq for the funding, UEA, Manaus, PPGMT-FMT, Manaus, our collaborators and all the research team members.