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

Abstract

Background: Anti-Merozoite surface proteins (MSP) IgG response are really associeted with lower malaria morbidity and mortality. However, only few studies have looked at the implications of their variations on the course of clinical and biological forms of severe malaria. Methods: This cross-sectional, prospective, and analytical study evaluates the IgG responses 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 WHO-forms of severity. The mean hemoglobin level was 11.2 ± 3 g/dL The parasitemia was lower (< 0.5%) in 80% of cases. In the evolution, 10 patients deceased making the lathality rate of 11.6%. The presence of associated diagnoses and comorbidities 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.