A Proteogenomic Analysis of Haptoglobin in Malaria

Proteomics Clin Appl. 2018 Jul;12(4):e1700077. doi: 10.1002/prca.201700077. Epub 2017 Nov 23.

Abstract

Scope: Haptoglobin (Hp), an acute phase inflammatory protein is associated with malaria pathogenesis in several proteomics and genomics studies. The Hp gene has two co-dominant alleles: Hp1 and Hp2 that produce three genotypes: Hp1/Hp1, Hp1/Hp2 and Hp2/Hp2.

Experimental design: In this study, validation of the proteomics data with Multiple Reaction Monitoring Mass Spectroscopy (MRM-MS) is performed and the association of the Hp gene variants with severe, non-severe malaria and community (healthy) controls using genotyping PCRs and DNA sequencing is analysed.

Results: Highly significant values of Hp is observed in the MRM assay that show a correlation with severity of malaria and is clearly distinguished from another febrile disease, dengue. Moreover, the Hp2/Hp2 genotype is seen in high percentages in non-severe malaria patients (74%) and community controls (72%) whereas patients diagnosed with severe malaria show only (31%) of this genotype. Sequencing of the Hp promoter region reveals three SNPs along with 10 unique haplotypes, out of which five are associated with non-severe and three with severe malaria populations (χ2 = 130; df = 18; p < 0.0001).

Conclusion and clinical relevance: This proteo-genomic study focuses on the correlation of the Hp protein and gene with malaria, thus highlighting the pivotal role of this acute phase immune gene in malaria pathogenesis.

Keywords: MRM; alleles; genotypes; haptoglobin; malaria.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Biomarkers / blood*
  • Case-Control Studies
  • Female
  • Genotype
  • Haptoglobins / genetics
  • Haptoglobins / metabolism*
  • Humans
  • India / epidemiology
  • Malaria / blood*
  • Malaria / epidemiology
  • Malaria / parasitology
  • Male
  • Middle Aged
  • Plasmodium falciparum / isolation & purification
  • Polymorphism, Single Nucleotide*
  • Proteogenomics / methods*
  • Severity of Illness Index*
  • Young Adult

Substances

  • Biomarkers
  • Haptoglobins