Profile of Immune-Endothelial Markers and Molecular Monitoring of Plasmodium Falciparum Resistance to Antimalaria Medicines among Patients with Malaria in Lagos, Nigeria

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Date
2017-12
Authors
Igbasi, U.T
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Abstract
The interplay of parasite intrinsic resistance and human immune responses play important roles in clinical malaria presentations, in vivo efficacy of antimalarial drug, emergence and spread of resistance. Antimalarial drug resistance in Plasmodium falciparum is one of the major obstacles in the global malaria elimination target. This study evaluated the profile of immune-endothelial biomarkers and anti-malarial drug resistant genes among malaria cases in Lagos, Nigeria. A cross sectional study was conducted in 20 communities (between October 2010 and September 2011) and 7 health facilities (between March 2013 and February, 2014) across Lagos State. Enzyme-linked immune sorbent assay was performed to determine the plasma profile of TNF-α, IFN- γ, IL-10, IgG, IgE, VCAM-1 and ICAM-1. Genomic DNA was extracted from malaria positive dried blood spots (DBS) using QIAamp® DNA Mini kit (Qiagen, Germany). Nested PCR, sequencing, sequence alignment and analysis were done for K13, crt, mdr-1, dhfr and dhps genes. Ethical best practices were complied with in the study process. Significant increase in mean plasma levels of IL-10 (9365.1±.5 pg/ml, p=0.046), IgE (34760.63±2954.5 pg/ml, p=0.005), ICAM-1 (1.03x106±20689.2 pg/ml, p<<0.001) and median level of VCAM-1 (1.11x106 pg/ml, range 3,725-6-273,725 pg/ml, p<0.001) were reported in malaria infected individuals compared to the malaria negative control group (p<0.01). In contrast the median levels of IFN-γ (17585 pg/ml, range 381-240366 pg/ml, p=0.619); TNF-α (527 pg/ml range 148-3704 pg/ml, p= 0.128) and mean level of IgG (4936.53±211.4 pg/ml, p= 0.842) were similar in both malaria positive and negative samples tested (p>0.005). IL-10 correlated with parasite density (r= 0.191; p= 0.033). Polymorphism in K13-propeller gene was observed with point mutations at codons A578S=1 (0.5%), D464N =1(0.5%) and Q613H= 3 (1.5%), while 96.9% were wild K13 genotype. Profile of crt wild haplotype was CVMNK= 64 (30.8%) while mutant crt haplotypes were: CVIET= 129 (62.0%); CVIDT= 4 (1.9%); CVMDT = 3(1.4%); CVIKT= 2(1.0%); CVINT= 1(0.5%); CVMET= 1(0.5%); CVMEK= 1(0.5%); CVMKT = 1 (0.5%) and CVMNT = 2 (1.0%). Profile of mdr-1 wild genotype included- 178 (82.4%) while mutant mdr-1 genotypes were: N86Y= 25 (11.6%); E130K= 5 (2.3%); D1246Y= 7 (3.2%); S149P= 1 (0.5%) and T28S= 1 (0.5%). The prevalence of wild dhfr genotype was 8 (3.3%) while 227 (94%) mutant dhfr triply genotypes (N51I+C59R+S108N) were reported; mutation at codons 16 and 164 in dhfr genes was not observed in this study. The frequency of mutation at multiple sites in dhps genes include; 437 (95.2%); 540 (0.8%), 581 (23.1%) 431 (16.7%), 436 (28.5%) and 613 (30.9%). Polymorphism in K13 gene in Lagos was established, and confirmed that artemisinin is still efficacious in Lagos State. New mutant haplotypes and high frequency of chloroquine and sulphadoxine-pyrimethamine resistant marker genes are still in circulation and could threaten their efficacy as partner drugs for ACT. Biomarkers could be used to predict malaria outcome and classification.
Description
A Thesis Submitted to the School of Postgraduate Studies, University of Lagos
Keywords
Drug-resistant , Immune-endothelial , Anti-malaria , Plasmodium falciparum
Citation
Igbasi, U.T (2017). Profile of Immune-Endothelial Markers and Molecular Monitoring of Plasmodium Falciparum Resistance to Antimalaria Medicines among Patients with Malaria in Lagos, Nigeria. A Thesis Submitted to University of Lagos School of Postgraduate Studies Phd Thesis, 216p.