Plasmodium falciparum parasites causing cerebral malaria share variant surface antigens, but are they specific?

• Published in: Malaria Journal
• Main Authors: Rogier Christophe, Moukoko Else, Tuikue-Ndam Nicaise, Lalya Francis, Viwami Firmine, Kheliouen Nabila, Deloron Philippe, Aubouy Agnès
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2010
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/1475-2875-9-220; https://doaj.org/article/f7401cec6617495da0c67a41f1f6c74e

Abstract Background Variant surface antigens (VSA) expressed on the surface of Plasmodium falciparum -infected red blood cells constitute a key for parasite sequestration and immune evasion. In distinct malaria pathologies, such as placental malaria, specific antibody response against VSA provides protection. This study investigated the antibody response specifically directed against VSA expressed by parasites isolated from individuals presenting a given type of clinical presentation. Methods Plasma and isolates were obtained from four groups of Beninese subjects: healthy adults, patients presenting uncomplicated malaria (UM), cerebral malaria (CM), or pregnancy-associated malaria (PAM). The reactivity of plasma samples from each clinical group was measured by flow cytometry against parasites isolated from individuals from each clinical group. Results Antibody responses against VSA UM were predominant in CM, UM and HA plasmas. When analysed according to age in all plasma groups, anti-VSA CM and -VSA UM antibody levels were similar until six years of age. In older groups (6-18 and >19 years of age), VSA UM antibody levels were higher than VSA CM antibody levels ( P = .01, P = .0008, respectively). Mean MFI values, measured in all plasmas groups except the PAM plasmas, remained low for anti-VSA PAM antibodies and did not vary with age. One month after infection the level of anti-VSA antibodies able to recognize heterologous VSA CM variants was increased in CM patients. In UM patients, antibody levels directed against heterologous VSA UM were similar, both during the infection and one month later. Conclusions In conclusion, this study suggests the existence of serologically distinct VSA CM and VSA UM . CM isolates were shown to share common epitopes. Specific antibody response to VSA UM was predominant, suggesting a relative low diversity of VSA UM in the study area.