| 1. |
- Giha, Hayder A., et al.
(author)
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Age-dependent association between IgG2 and IgG3 subclasses to Pf332-C231 antigen and protection from malaria, and induction of protective antibodies by sub-patent malaria infections, in Daraweesh
- 2010
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In: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 28:7, s. 1732-1739
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Journal article (peer-reviewed)abstract
- The certainty of the protective role of acquired immunity in malaria is the major drive for malaria vaccine development. In this study, we measured the levels of total IgG and IgG subclasses to four candidate malaria vaccine antigens; MSP2-3D7, MSP2-FC27, AMA-1 and Pf332-C231, in plasma obtained from a cohort of 136 donors from Daraweesh in Sudan. The cohort was followed for malaria infection for 9 years. After an initial analysis, the immune response to Pf332-C231 antigen was the only one found associated with protection, thus taken for further analysis. The number of previous clinical malaria episodes experienced by the donors was used as an index for relative protection. The number of these episodes was found to be negatively correlated with the levels of pre-existing total IgG, IgG2 and IgG3 to Pf332-C231 (correlation coefficient, CC - 0.215, p=0.012; CC - 0.195, p=0.023 and CC - 0.211, p=0.014, respectively), and also with age (CC - 0.311, p<0.001). Unexpectedly, equal levels of Pf332-C231 antibodies were induced by both patent and sub-patent infections regardless of the number of previous malaria episodes (1-7). Combining the correlation analysis with a multi-linear regression, three variable markers for protection were emerged, two age-dependent, the antibody response to Pf332-C231 and an unidentified marker (likely immune response to other antigens), and the third was an age-independent unidentified marker (possibly gene polymorphisms). In conclusion, this report suggests a protective effect for IgG subclasses to Pf332-C231 antigen against malaria.
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| 2. |
- Giha, Hayder A, et al.
(author)
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Association of a single nucleotide polymorphism in the C-reactive protein gene (-286) with susceptibility to Plasmodium falciparum malaria
- 2010
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In: Molecular Medicine. - : Springer Science and Business Media LLC. - 1076-1551 .- 1528-3658. ; 16:1-2, s. 27-33
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Journal article (peer-reviewed)abstract
- The role of inflammation in malaria pathogenesis is not fully understood, although C-reactive protein (CRP) may have a negative influence on host immunity to infections. An upstream polymorphism, -286 (C > T > A), in the CRP gene is known to influence CRP levels. In this study, a cohort of 192 Sudanese donors, followed for malaria infection for 9 years, had their CRP -286 gene locus genotyped by pyrosequencing. The number of malaria episodes experienced by each individual over the study period was used as an index for malaria susceptibility. The prevalence of the CRP alleles A, C and T were 21%, 52% and 27%, respectively. Importantly, the A-allele, unlike the C- and T-alleles or CRP genotypes, was significantly associated with an increased number of malaria episodes, P = 0.007. The proportion of A-allele carriers among donors not known to have had malaria during the study period was 18%, whereas it was 43% and 63% among donors who had experienced 1-4 and > or =5 malaria episodes, respectively, over the same period (P = 0.002). Furthermore, the A-allele was associated with higher parasite counts. In conclusion, the CRP -286 A-allele was associated with an increased susceptibility to uncomplicated Plasmodium falciparum malaria.
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| 3. |
- Giha, Hayder A., et al.
(author)
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Clustering of malaria treatment failure (TF) in Daraweesh : hints for host genetic susceptibility to TF with emphasis on immune-modulating SNPs
- 2010
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In: Infection, Genetics and Evolution. - : Elsevier BV. - 1567-1348 .- 1567-7257. ; 10:4, s. 481-6
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Journal article (peer-reviewed)abstract
- In malaria, drug resistance and treatment failure (TF) are not synonymous, although are escalating together. Over 9 years of surveillances for malaria morbidity and TF in Daraweesh village in eastern Sudan (1991-2004), 136 donors (15-78 years) from 43 households, treated for 278 malaria episodes and had experienced 46 incident of TF, were included in this study. Blood obtained from the donors in 2005, was used for measurement of IgG subclasses against Pf332-C231 antigen and GM/KM allotyping and for genotyping of the donors for; FcgammaRIIA 131 (HH, RH, RR), CRP 286 (C
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