title: Fc gamma receptor IIa (CD32) polymorphism and antibody responses to asexual blood-stage antigens of Plasmodium falciparum malaria in Sudanese patients.
abstract: In a prospective clinical study in New Halfa Teaching Hospital, the possible association between FcgammaRIIa-R/H131 polymorphism and anti-malarial antibody responses with clinical outcome of Plasmodium falciparum malaria among Sudanese patients was investigated. A total of 256 individuals were consecutively enrolled, comprising 115 patients with severe malaria, 85 with mild malaria and 56 malaria-free controls. Genotyping of FcgammaRIIa-R/H131 dimorphism was performed using gene-specific polymerase chain reaction (PCR) amplification with allele-specific restriction enzyme digestion of the PCR product. The antibody responses to asexual blood-stage antigens were assessed by an enzyme-linked immunosorbent assay. The frequency of the FcgammaRIIa-R/R131 genotype was significantly higher in those with severe malaria when compared with patients with mild malaria, while the FcgammaRIIa-H/H131 genotype showed a significant association with mild malaria. A reduced risk of severe malaria with IgG3 antibodies in combination with the H/H131 genotype was observed. Furthermore, low levels of IgG2 antibodies reactive with the Pf332-C231 antigen were also associated with lower risk of severe malaria in individuals carrying the H131 allele. The levels of IgG1 and IgG3 antibodies were statistically significantly higher in the mild malaria patients when compared with the severe malaria patients. Taken together, our study revealed that the FcgammaRIIa-R/R131 genotype is associated with the development of severe malaria, while the H/H131 genotype is more likely to be associated with mild malaria. Our results also revealed that the natural acquisition of immunity against clinical malaria appeared to be more associated with IgG1 and IgG3 antibodies, signifying their roles in parasite-neutralizing immune mechanisms.
authors.affiliation: Department of Immunology, Wenner-Gren Institute, Stockholm University, Stockholm, SwedenDepartment of Biochemistry, Faculty of Medicine, University of Khartoum, Khartoum, SudanTropical Diseases Research Laboratory, Department of Medical Microbiology & Parasitology, College of Medicine of the University of Lagos, Idi-araba, Lagos, NigeriaDepartment of Zoology, Faculty of Sciences, University of Khartoum, Khartoum, SudanClinical Epidemiology Unit, Department of Medicine, Karolinska Hospital, Karolinska Institute, Stockholm, SwedenClinical Research Centre, Örebro University Hospital, Örebro, SwedenDepartment of Microbiology and Immunology, Faculty of Medicine, Khartoum University, Khartoum, Sudan;Department of Immunology, Faculty of Medicine, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: A
authors.initials: A
authors.lastname: Nasr
authors.affiliation: Department of Immunology, Wenner-Gren Institute, Stockholm University, Stockholm, SwedenDepartment of Biochemistry, Faculty of Medicine, University of Khartoum, Khartoum, SudanTropical Diseases Research Laboratory, Department of Medical Microbiology & Parasitology, College of Medicine of the University of Lagos, Idi-araba, Lagos, NigeriaDepartment of Zoology, Faculty of Sciences, University of Khartoum, Khartoum, SudanClinical Epidemiology Unit, Department of Medicine, Karolinska Hospital, Karolinska Institute, Stockholm, SwedenClinical Research Centre, Örebro University Hospital, Örebro, SwedenDepartment of Microbiology and Immunology, Faculty of Medicine, Khartoum University, Khartoum, Sudan;Department of Immunology, Faculty of Medicine, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: N C
authors.initials: NC
authors.lastname: Iriemenam
authors.affiliation: Department of Immunology, Wenner-Gren Institute, Stockholm University, Stockholm, SwedenDepartment of Biochemistry, Faculty of Medicine, University of Khartoum, Khartoum, SudanTropical Diseases Research Laboratory, Department of Medical Microbiology & Parasitology, College of Medicine of the University of Lagos, Idi-araba, Lagos, NigeriaDepartment of Zoology, Faculty of Sciences, University of Khartoum, Khartoum, SudanClinical Epidemiology Unit, Department of Medicine, Karolinska Hospital, Karolinska Institute, Stockholm, SwedenClinical Research Centre, Örebro University Hospital, Örebro, SwedenDepartment of Microbiology and Immunology, Faculty of Medicine, Khartoum University, Khartoum, Sudan;Department of Immunology, Faculty of Medicine, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: M
authors.initials: M
authors.lastname: Troye-Blomberg
authors.affiliation: Department of Immunology, Wenner-Gren Institute, Stockholm University, Stockholm, SwedenDepartment of Biochemistry, Faculty of Medicine, University of Khartoum, Khartoum, SudanTropical Diseases Research Laboratory, Department of Medical Microbiology & Parasitology, College of Medicine of the University of Lagos, Idi-araba, Lagos, NigeriaDepartment of Zoology, Faculty of Sciences, University of Khartoum, Khartoum, SudanClinical Epidemiology Unit, Department of Medicine, Karolinska Hospital, Karolinska Institute, Stockholm, SwedenClinical Research Centre, Örebro University Hospital, Örebro, SwedenDepartment of Microbiology and Immunology, Faculty of Medicine, Khartoum University, Khartoum, Sudan;Department of Immunology, Faculty of Medicine, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: H A
authors.initials: HA
authors.lastname: Giha
authors.affiliation: Department of Immunology, Wenner-Gren Institute, Stockholm University, Stockholm, SwedenDepartment of Biochemistry, Faculty of Medicine, University of Khartoum, Khartoum, SudanTropical Diseases Research Laboratory, Department of Medical Microbiology & Parasitology, College of Medicine of the University of Lagos, Idi-araba, Lagos, NigeriaDepartment of Zoology, Faculty of Sciences, University of Khartoum, Khartoum, SudanClinical Epidemiology Unit, Department of Medicine, Karolinska Hospital, Karolinska Institute, Stockholm, SwedenClinical Research Centre, Örebro University Hospital, Örebro, SwedenDepartment of Microbiology and Immunology, Faculty of Medicine, Khartoum University, Khartoum, Sudan;Department of Immunology, Faculty of Medicine, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: H A
authors.initials: HA
authors.lastname: Balogun
authors.affiliation: Department of Immunology, Wenner-Gren Institute, Stockholm University, Stockholm, SwedenDepartment of Biochemistry, Faculty of Medicine, University of Khartoum, Khartoum, SudanTropical Diseases Research Laboratory, Department of Medical Microbiology & Parasitology, College of Medicine of the University of Lagos, Idi-araba, Lagos, NigeriaDepartment of Zoology, Faculty of Sciences, University of Khartoum, Khartoum, SudanClinical Epidemiology Unit, Department of Medicine, Karolinska Hospital, Karolinska Institute, Stockholm, SwedenClinical Research Centre, Örebro University Hospital, Örebro, SwedenDepartment of Microbiology and Immunology, Faculty of Medicine, Khartoum University, Khartoum, Sudan;Department of Immunology, Faculty of Medicine, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: O F
authors.initials: OF
authors.lastname: Osman
authors.affiliation: Department of Immunology, Wenner-Gren Institute, Stockholm University, Stockholm, SwedenDepartment of Biochemistry, Faculty of Medicine, University of Khartoum, Khartoum, SudanTropical Diseases Research Laboratory, Department of Medical Microbiology & Parasitology, College of Medicine of the University of Lagos, Idi-araba, Lagos, NigeriaDepartment of Zoology, Faculty of Sciences, University of Khartoum, Khartoum, SudanClinical Epidemiology Unit, Department of Medicine, Karolinska Hospital, Karolinska Institute, Stockholm, SwedenClinical Research Centre, Örebro University Hospital, Örebro, SwedenDepartment of Microbiology and Immunology, Faculty of Medicine, Khartoum University, Khartoum, Sudan;Department of Immunology, Faculty of Medicine, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: S M
authors.initials: SM
authors.lastname: Montgomery
authors.affiliation: Department of Immunology, Wenner-Gren Institute, Stockholm University, Stockholm, SwedenDepartment of Biochemistry, Faculty of Medicine, University of Khartoum, Khartoum, SudanTropical Diseases Research Laboratory, Department of Medical Microbiology & Parasitology, College of Medicine of the University of Lagos, Idi-araba, Lagos, NigeriaDepartment of Zoology, Faculty of Sciences, University of Khartoum, Khartoum, SudanClinical Epidemiology Unit, Department of Medicine, Karolinska Hospital, Karolinska Institute, Stockholm, SwedenClinical Research Centre, Örebro University Hospital, Örebro, SwedenDepartment of Microbiology and Immunology, Faculty of Medicine, Khartoum University, Khartoum, Sudan;Department of Immunology, Faculty of Medicine, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: G
authors.initials: G
authors.lastname: ElGhazali
authors.affiliation: Department of Immunology, Wenner-Gren Institute, Stockholm University, Stockholm, SwedenDepartment of Biochemistry, Faculty of Medicine, University of Khartoum, Khartoum, SudanTropical Diseases Research Laboratory, Department of Medical Microbiology & Parasitology, College of Medicine of the University of Lagos, Idi-araba, Lagos, NigeriaDepartment of Zoology, Faculty of Sciences, University of Khartoum, Khartoum, SudanClinical Epidemiology Unit, Department of Medicine, Karolinska Hospital, Karolinska Institute, Stockholm, SwedenClinical Research Centre, Örebro University Hospital, Örebro, SwedenDepartment of Microbiology and Immunology, Faculty of Medicine, Khartoum University, Khartoum, Sudan;Department of Immunology, Faculty of Medicine, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: K
authors.initials: K
authors.lastname: Berzins
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood* / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D016778:Malaria, Falciparum / Q000097:blood / Q000235:genetics* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000276:immunology*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D017452:Receptors, IgG / Q000235:genetics*; D013397:Sudan
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G; D017452:Receptors, IgG