P53 rs1042522 and CD95 rs1800682 genetic variations in HCV-4a response to antiviral therapy

Abstract

Current estimates indicate that the hepatitis C (HCV) is the leading cause of mortality around the world, with infection rates steadily increasing in Egypt. The dual therapy for this silent epidemic with pegylated-interferon-α2b/ribavirin has markedly improved the success rates in genotype-4 patients. It was reported that apoptosis plays a vital mechanistic role in limiting viral replication. P53, a key regulator of apoptosis, induces CD95 gene expression and subsequently initiates apoptotic cascade to be activated. The current study examined the impact of P53 rs1042522 and CD95 rs1800682 polymorphisms on the treatment response. Three groups of 240 volunteers were enrolled in this study; 86 in sustained virological responders group, 74 in non-responders group, and 80 in control group. All patients had HCV genotype-4a and were interferon treatment naïve. Quantizations of HCV-RNA by qRT-PCR and histological scores were performed for all patients. In addition, genotyping of HCV-RNA, P53 rs1042522 Arg/Pro and CD95 rs1800682 A/G polymorphisms were investigated in all subjects. It was resulted that P53 Pro/Pro homozygous genotype has high significant increase, while CD95 A/A homozygous genotype has high significant decrease when comparing non-responders with responders. Finally, it was concluded that Pro variant of P53 rs1042522 may be used as a genetic predictor for non-responsiveness, while A/A variant of CD95 rs1800682 may be used as a sensitive biomarker for responsiveness to antiviral therapy of HCV genotype-4a infection. In addition, low prolactin, high total testosterone, and high GH levels may provide promising biomarkers for early prediction of the response when associated with these genetic polymorphisms.

Keywords: CD95 rs1800682; HCV gentotype-4a; P53 rs1042522; Response; SNPs.

Figure 1

Detection of the P53 polymorphism by PCR-BstUI digestion. BstUI restriction enzyme cuts the PCR products of the homozygous Arg72Arg and the heterozygous Arg72Pro but does not cut the homozygous Pro72Pro PCR fragment. Lane M represents DNA Marker (100 bp), lane 1 and 2 represent the homozygous Pro72Pro (+72 C/C) genotype at (199 bp), lane 3 and 5 represent the heterozygous Arg72Pro (+72 G/C) genotype at (199 bp +113 bp + 86 bp), and lane 4 represents the homozygous Arg72Arg (+72 G/G) genotype at (113 bp +86 bp).

Figure 2

Detection of the CD95 polymorphism by PCR-MvaI digestion. MvaI restriction enzyme cuts the PCR products of the homozygous −670 G/G and the heterozygous −670 A/G but does not cut the homozygous −670 A/A PCR fragment. Lane M represents DNA Marker (100 bp), lane 1 and 3 represent the homozygous −670 G/G genotype at (189 bp+99 bp+44 bp), lane 2 and 5 represent the heterozygous −670 A/G genotype at (233 bp+189 bp+99 bp+44 bp), and lane 4 represent the homozygous −670 A/A genotype at (233 bp+99 bp).

Figure 3

Response rates of IL28B rs12979860 versus P53 rs1042522, CD95 rs1800682, and BCL-2 rs1800477 polymorphisms according to sustained virological response (SVR) in HCV genotype-4 patients. (A/A, A/B, B/B); represent C/C, C/T, T/T genotypes of IL28B & G/G, G/C, CC genotypes of P53 & A/A, A/G, G/G genotypes of CD95 & G/G, G/A, A/A genotypes of BCL-2, respectively. a; represents high significant difference (p < 0.01), b; represents significant difference (p < 0.05), and c; represents no significant difference (p > 0.05).

Figure 4

ROC curve of P53 rs1042522, CD95 rs1800682, and P53 rs 1042522 plus CD95 rs 1800682 polymorphisms.

Figure 5

Comparative sensitivity and specificity of IL28B (rs12979860), IP-10<150 pg/mL, IL28B (rs12979860) plus IP-10<150 pg/mL, IRRDR (HCV-4a), P53 rs1042522, CD95 rs1800682, and P53 rs1042522 plus CD95 rs 1800682 in order to discriminate between the responders and non-responders among the chronic HCV genotype-4a patients.