Analysis of IgG Responses to P. falciparum Antigens MSP1, MSP4-20 and MSP4-40 during Severe Malaria in Dakar, Senegal

Abstract

Background: Antibodies to merozoite surface antigens (MSPs), the primary targets of malaria vaccine research, are associated with low malaria morbidity. However, few studies have looked at the implications of their variations on the evolution of clinical-biological forms of severe malaria.Methods: This cross-sectional, prospective, and analytical study evaluates by ELISA the IgG responses directed against the antigens MSP1, MSP4-20 and MSP4-40 of P. falciparum during severe malaria in patients hospitalized in the infectious diseases department of Fann university hospital from October 1, 2017, to November 30, 2019.Results: A total of 86 patients were selected. The average age of patients was 34 ± 17 years. Renal (74.4%), neurological (63.9%) and hepatic (55.8%) impairment were the main forms of severity. The mean hemoglobin level was 11.2 ± 3 g/dL with low parasitaemia (< 0.5%) in 80% of cases. In the evolution, 10 patients deceased achieving a lethality of 11.6%. The presence of associated diagnosis and comorbidity was linked to low levels of anti-MSP4-40 IgG (p = 0.032) and anti-MSP1 (p = 0.037), respectively. The number of failures per patient increased with the fall in the levels of anti-MSP1 IgG (p = 0.017) and MSP4-20 (p = 0.04). Only high levels of anti-MSP4-40 IgG were statistically associated with low lethality (p = 0.037). Conclusion:Anti-MSP1, MSP4-20, and MSP4 antibodies are involved in the anti-plasmodial humoral response in severe malaria. Their blood levels can serve as prognostic biomarkers for an optimal management.