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Sinha S, Mishra SK, Sharma S, Patibandla PK, Mallick PK, Sharma SK, Mohanty S, Pati SS, Mishra SK, Ramteke BK, Bhatt RM, Joshi H, Dash AP, Ahuja RC, Awasthi S, Venkatesh V, Habib S. Polymorphisms of TNF-enhancer and gene for FcgammaRIIa correlate with the severity of falciparum malaria in the ethnically diverse Indian population. Malar J 2008; 7:13. [PMID: 18194515 PMCID: PMC2245971 DOI: 10.1186/1475-2875-7-13] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2007] [Accepted: 01/14/2008] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Susceptibility/resistance to Plasmodium falciparum malaria has been correlated with polymorphisms in more than 30 human genes with most association analyses having been carried out on patients from Africa and south-east Asia. The aim of this study was to examine the possible contribution of genetic variants in the TNF and FCGR2A genes in determining severity/resistance to P. falciparum malaria in Indian subjects. METHODS Allelic frequency distribution in populations across India was first determined by typing genetic variants of the TNF enhancer and the FCGR2A G/A SNP in 1871 individuals from 55 populations. Genotyping was carried out by DNA sequencing, single base extension (SNaPshot), and DNA mass array (Sequenom). Plasma TNF was determined by ELISA. Comparison of datasets was carried out by Kruskal-Wallis and Mann-Whitney tests. Haplotypes and LD plots were generated by PHASE and Haploview, respectively. Odds ratio (OR) for risk assessment was calculated using EpiInfotrade mark version 3.4. RESULTS A novel single nucleotide polymorphism (SNP) at position -76 was identified in the TNF enhancer along with other reported variants. Five TNF enhancer SNPs and the FCGR2A R131H (G/A) SNP were analyzed for association with severity of P. falciparum malaria in a malaria-endemic and a non-endemic region of India in a case-control study with ethnically-matched controls enrolled from both regions. TNF -1031C and -863A alleles as well as homozygotes for the TNF enhancer haplotype CACGG (-1031T>C, -863C>A, -857C>T, -308G>A, -238G>A) correlated with enhanced plasma TNF levels in both patients and controls. Significantly higher TNF levels were observed in patients with severe malaria. Minor alleles of -1031 and -863 SNPs were associated with increased susceptibility to severe malaria. The high-affinity IgG2 binding FcgammaRIIa AA (131H) genotype was significantly associated with protection from disease manifestation, with stronger association observed in the malaria non-endemic region. These results represent the first genetic analysis of the two immune regulatory molecules in the context of P. falciparum severity/resistance in the Indian population. CONCLUSION Association of specific TNF and FCGR2A SNPs with cytokine levels and disease severity/resistance was indicated in patients from areas with differential disease endemicity. The data emphasizes the need for addressing the contribution of human genetic factors in malaria in the context of disease epidemiology and population genetic substructure within India.
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Affiliation(s)
- Swapnil Sinha
- Division of Molecular and Structural Biology, Central Drug Research Institute, Post box 173, Chattar Manzil, Mahatma Gandhi Marg, Lucknow-226001, India
| | - Shrawan K Mishra
- Division of Molecular and Structural Biology, Central Drug Research Institute, Post box 173, Chattar Manzil, Mahatma Gandhi Marg, Lucknow-226001, India
| | - Shweta Sharma
- Division of Molecular and Structural Biology, Central Drug Research Institute, Post box 173, Chattar Manzil, Mahatma Gandhi Marg, Lucknow-226001, India
| | - Phani K Patibandla
- Department of Microbiology, King George Medical University (KGMU), Lucknow, India
| | | | | | - Sanjib Mohanty
- Department of Internal Medicine, Ispat General Hospital, Rourkela, India
| | - Sudhanshu S Pati
- Department of Biochemistry, Ispat General Hospital, Rourkela, India
| | - Saroj K Mishra
- Department of Internal Medicine, Ispat General Hospital, Rourkela, India
| | | | - RM Bhatt
- NIMR Field Station, Raipur, India
| | - Hema Joshi
- National Institute of Malaria Research (NIMR), New Delhi, India
| | - Aditya P Dash
- National Institute of Malaria Research (NIMR), New Delhi, India
| | | | | | | | - Vimala Venkatesh
- Department of Microbiology, King George Medical University (KGMU), Lucknow, India
| | - Saman Habib
- Division of Molecular and Structural Biology, Central Drug Research Institute, Post box 173, Chattar Manzil, Mahatma Gandhi Marg, Lucknow-226001, India
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