Abstract

Yao SS, Offianan AT, Tiacoh NL, Ako AAB, Koffi D, Kouame E, Tuo K, Beourou S and Djaman J

Successful antimalarial drugs treatment might be due to intrinsic susceptibility of P. falciparum and host’s factors. In this study we assessed relationship between host IgG antibody responses and treatment outcome with Artesunate+Amodiaquine (AS+AQ) and Artemether+Lumefantrine (AL) in high transmission setting of Cote d’Ivoire. The study was done as part of a clinical drug-efficacy trial of AS+AQ and AL conducted at Man in western Côte d’Ivoire. Serum samples from the time of malaria diagnosis and 7 days later were analyzed for total IgG against schizonte extract (07/03) and 5 specific-P. falciparum Ags using a quantitative indirect ELISA. IgG antibody responses were related to treatment outcome. A total of 56 and 55 serum samples in AL and AS + AQ group respectively were available for antibody analysis, on day 0 and day 7. The levels IgG to CSP, GLURP and SALSA increased significantly with age (p<0.05). Antibody responses against all antigens decreased significantly, except SALSA and sch07/03 in day 7 after treatment, with the greatest decreasing seen in IgG response to GLURP (p= 0.0013). Adequate Clinical and Parasitological Response PCR corrected (ACPR) was of 98.3% (AS +AQ) and 100% (AL). Prevalence and levels of anti-Glutamate-rich Protein (GLURP) and anticircumsporozoite (CSP)-specific IgG antibodies were significantly higher (P < 0.001) in Patients with ACPR in AS+AQ and AL group respectively. GLURP and CSP IgG antibody responses in Man region may contribute to malaria treatment success and support hypothesis that acquired immunity enhances clinical efficacy of antimalarial dugs.