Relationship between Antibody Levels, IgG Binding toPlasmodium falciparum-Infected Erythrocytes, and Disease Outcome in Hospitalized Urban Malaria Patients from Dakar, Sénégal

Abstract

Background. Management of clinical malaria requires the development of reliable diagnostic methods and efficient biomarkers for follow-up of patients. Protection is partly based on IgG responses to parasite antigens exposed at the surface of infected erythrocytes (iRBCs). These IgG responses appeared low during clinical infection, particularly in severe disease. Methods. We analyzed the IgG binding capacity to the surface of live erythrocytes infected by knob positive FCR3 strain. Sera from 69 cerebral malaria (CM) and 72 mild malaria (MM) cases were analyzed by ELISA for IgG responses to five antigens from iRBC and by flow cytometry for IgG binding as expressed in labeling index ratio (LIR). The relationship between IgG levels, LIR, parasitemia, age, and the clinical outcomes was evaluated. Results. We found a significant decrease of LIR in adult CM fatal cases compared to surviving patients (p = 0.019). In MM, LIRs were correlated to IgG anti-iRBC and anti-PfEMP3/5 levels. In CM, no correlation was found between LIR, IgG levels, and parasitemia. Conclusion. The IgG binding assay was able to discriminate outcome of cerebral malaria cases and it deserves further development as a potential functional-associated assay for symptomatic malaria analysis.

Production and characterization of polyclonal antibody against Bengal tiger (Panthera tigris tigris) immunoglobulin G

“…IgG is the predominant immunoglobulin in humoral immunity and has the longest serum half-life of all immunoglobulin isotypes (Leusen and Nimmerjahn 2013). There may be a relationship between IgG level and severity of diseases or immune responses to vaccines (Kumagai et al 2001;Isa et al 2002;Oliveira et al 2009;de la Torre et al 2016;Mbengue et al 2016). Therefore, IgG plays a critical role in the protection against diseases, and it can be of value in revealing immunological responses (Kinyanjui et al 2004;Stanisic et al 2009).…”

Analysis of antibody responses to selected Plasmodium falciparum merozoite surface antigens in mild and cerebral malaria and associations with clinical outcomes

“…They were defined as having a positive blood smear for P. falciparum with fever and no symptoms of severe malaria, as previously reported [20,22]. They were defined as having a positive blood smear for P. falciparum with fever and no symptoms of severe malaria, as previously reported [20,22].…”

“…A group of 91 MM cases was enrolled as control in the infectious disease unit during the same time-period. They were defined as having a positive blood smear for P. falciparum with fever and no symptoms of severe malaria, as previously reported [20,22].…”

Control of Vector-Borne Human Parasitic Diseases

“…Mbengue et al [10] present the results of an IgG binding assay able to discriminate the outcome of cerebral malaria cases in Senegal, with the prospect of a potential functional-associated assay for symptomatic malaria analysis.…”