Severity of malaria in relation to a complement receptor 1 polymorphism: a case-control study
Insights
The McCoy (McC) blood group genotype McCa/b increases susceptibility to severe malaria, while McCb/b significantly reduces the risk. These CR1 polymorphisms warrant further investigation in malaria-endemic regions.
Area of Science:
- Genetics
- Immunology
- Infectious Diseases
Background:
- Inconsistent findings exist regarding the association between CR1 polymorphisms (Knops blood group antigens: Swain-Langley (Sl) and McCoy (McC)) and clinical malaria outcomes.
- Complement receptor 1 (CR1) plays a role in immune responses, and its variations may influence malaria susceptibility.
Purpose of the Study:
- To investigate the association between CR1 polymorphisms in exon 29 (Sl and McC antigens) and the clinical outcomes of malaria in Ghanaian children.
- To clarify the role of specific Knops blood group alleles in malaria severity.
Main Methods:
- Genotyping of Sl and McC blood group alleles using PCR and RFLP in 150 Ghanaian children with malaria.
- Logistic regression analysis to evaluate the effect of Sl and McC genotypes on malaria clinical outcomes.
Main Results:
- The McCa/b genotype showed a significant two-fold increase in susceptibility to severe malaria (OR = 2.31, P = 0.043).
- The McCb/b genotype was associated with an 88% reduced risk of severe malaria (OR = 0.12, P = 0.013).
- No significant associations were found between Sl genotypes (Sl1/1, Sl1/2, Sl2/2) or the McCa/a genotype and severe malaria. A trend towards reduced susceptibility to cerebral malaria and severe malarial anemia was observed for McCb/b.
Conclusions:
- The McCa/b genotype is linked to increased severe malaria susceptibility, whereas the McCb/b genotype is associated with a reduced risk.
- Further large-scale studies in African malaria-endemic regions are recommended to validate these findings on CR1 polymorphisms and malaria outcomes.
Background:
Studies on the relationship between complement receptor 1 (CR1) polymorphisms in exon 29 encoding the Knops blood group antigens (Swain-Langley (Sl) and McCoy (McC)) and outcome of clinical malaria have produced inconsistent results.
Methods:
Blood samples from Ghanaian children (n = 150) aged 1-12 years with complicated and uncomplicated malaria were genotyped for the Sl and McC blood group alleles by polymerase chain reaction and restriction fragment length polymorphism. Effect of Sl and McC genotypes on the clinical outcome of malaria was evaluated using logistic regression.
Results:
McCa/b genotype was significantly associated with more than two-fold increased susceptibility for severe malaria (OR = 2.31; 95% CI: 1.03-5.20, P = 0.043). However, McCb/b was associated with an 88% reduced risk of severe malaria (OR = 0.12; 95% CI: 0.02-0.64, P = 0.013). In contrast, there was no significant association between severe malaria and Sl1/1, Sl1/2, Sl2/and McCa/a genotypes. There was a trend towards decreased susceptibility to both cerebral malaria (CM) (OR = 0.13; 95% CI: 0.02-1.15, P = 0.07) and severe malarial anaemia (SA) (OR = 0.14; 95% CI: 0.02-1.19, P = 0.07) for McCb/b genotype when compared with the McCa/a genotype. There were no significant associations between Sl1/2 or Sl2/2 genotype and CM or SA when compared with Sl1/1 genotype.
Conclusions:
McCa/b was associated with increased susceptibility to severe malaria and McCb/b associated with reduced risk of severe malaria. Further studies with large sample size in other malaria endemic regions in Africa are warranted to confirm these findings.
More Related Videos
10:22Methods to Investigate the Regulatory Role of Small RNAs and Ribosomal Occupancy of Plasmodium falciparum
Published on: December 4, 2015
10:27Methods to Increase the Sensitivity of High Resolution Melting Single Nucleotide Polymorphism Genotyping in Malaria
Published on: November 10, 2015
