RNA protein kinase SNP at −226 C<T is a biomarker for the clearance of HCV among Egyptian patients

ABSTRACT

Background: RNA-dependant protein kinase R (PKR) is a primary mediator in the defence mechanism of interferon against viral replication and pathogenesis during Hepatitis C virus (HCV) infection. In the present study, we have examined the role of Single Nucleotide Polymorphisms (SNPs) in the promoter region of PKR and the serum level of the same protein on the outcome of HCV-infected Egyptian patients.

Patients and Methods: Genomic DNA was extracted from a total of 135 subjects, including 15 healthy controls, 40 HCV spontaneous resolvers (SRs), and 80 patients with chronic HCV infection. PKR genotyping was assessed using DNA sequencing. Finally, serum levels of PKR, TNF-α, INF-γ, and IL-10 were measured using ELISA technique.

Results: Serum levels of PKR, TNF-α, and INF-γ showed a significant increase in SRs as compared to chronic HCV patients. On the other hand, serum levels of IL-10 were significantly higher in chronic HCV patients compared to SRs. The present study demonstrated two novel SNPs in the PKR promoter region: at −226 C/T and −141 C/G. The PKR SNP at −226 C < T correlated with HCV-infected patients (genotype 4a) outcome among Egyptians. Our data showed the unique presence of the TT genotype in SRs group (three patients: 7.5%) in PKR −226 C/T. Interestingly, subjects with the TT genotype were more likely to clear their HCV infection than those with the CC genotype.

Conclusion: Our work provides more detail about PKR gene polymorphism in HCV genotype 4a as a new clinical tool for anticipating HCV-4a infection outcome.

KEYWORDS:

• Egypt
• genotype 4
• HCV
• PKR promoter region
• single nucleotide polymorphism
• spontaneous resolvers
• viral hepatitis

Abbreviations

SR	=	Spontaneous resolvers
ALT	=	alanine amino transferase
AST	=	aspartate amino transferase
DNA	=	Deoxyribonucleic acid
dsRNA	=	double strand RNA
eIF-2	=	eukaryotic protein synthesis initiation factor 2
HBV	=	Hepatitis B virus
HCV	=	Hepatitis C Virus
IFN-γ	=	Human interferon-gamma
IL-10	=	Human interleukin-10
NCBI	=	National Center for Biotechnology Information
PCR	=	poymerase chain reaction
PKR	=	RNA-dependent protein kinase
PKRBD	=	PKR binding domain
RNA	=	ribonucleic acid
SEM	=	standard error of the mean
SNP	=	single nucleotid polymorphism
SRs	=	Spontaneous resolvers
TNF-α	=	tumor necrosis factor-alpha.

Acknowledgments

The authors express their gratitude to Dr Mohamed A. Mahmoud and Mrs. Howayda Ahmed — the National Liver Institute, Menofia University — for their assistance during the collection of the study’s samples as well as the demographic and clinical data of patients.

Competing interests

All authors declare that they have no competing interests.

Authors’ contributions

Mustafa A. Hamzawy: performed the experiments, data collection and resources; Ahmed Wahid and Amany Abdel Rehim: idea of the work, data analysis, experimental design, and manuscript writing; Gamal Fadl and Mohmmed M.Khalifa: data analysis and general supervision; Sayed F.Abdelwahab: sample collection, data analysis, editing the manuscript, and general supervision.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Governmental funding (Minia University — Faculty of Pharmacy — Biochemistry Department). The study design was approved by Faculty of Pharmacy, Minia University Ethics Committee;