Rie Osaki

A new isoform of interleukin-32 suppresses IL-8 mrna expression in the intestinal epithelial cell line ht-29

Interleukin (IL)-32 plays a role in the pathophysiology of inflammatory bowel disease (IBD). We isolated a new isoform of the IL-32 transcript in the process of cloning the full-length IL-32 gene from human colonic subepithelial myofibroblasts (SEMFs). The expression of mRNA in the samples was assessed by RT-PCR and real-time PCR analyses. The PCR products from the IL-32 genes were ligated into the expression vector pIRESneo2. The new isoform of the IL-32 transcript (336 nucleotides) completely lacked exon 4 of the IL-32γ gene, and was 60 bp shorter than IL-32α. TNF-α induced the mRNA expression of the new IL-32 isoform in a dose- and time-dependent manner. Stable transfection of this new isoform significantly decreased TNF-α-induced IL-8 mRNA expression in HT-29 cells, but the expression of the IL-32α gene had no effect. The mRNA expression of this new isoform was significantly elevated in the inflamed mucosa of IBD patients. A new isoform of the IL-32 transcript may play an anti-inflammatory role in the inflamed mucosa of IBD.

Polymorphism of the inosine triphosphate pyrophosphatase gene predicts ribavirin-induced anemia in chronic hepatitis C patients.

Ribavirin (RBV)-induced anemia is a serious side effect of pegylated interferon (PEG-IFN) plus RBV therapy which is the standard care most effective for hepatitis C virus (HCV) infection. In the present study, we investigated the association of inosine triphosphate pyrophosphatase (ITPA) genotypes with RBV-induced hemoglobin (Hb) reduction in HCV patients treated with PEG-IFN/RBV therapy. The genotypes of the ITPA rs1127354 single nucleotide polymorphism were determined in 179 patients with HCV infection. Among them, 52 patients were treated with PEG-IFN/RBV. The frequency of the ITPA major allele (CC) was 76.3% and that of the minor allele (CA and AA) was 23.7%. A rapid decrease in Hb levels during the initial 4 weeks was observed in patients with the ITPA major allele (CC), but not in patients with the ITPA minor allele (C/A and AA). Hb levels at 4 weeks were significantly lower in patients with the ITPA major allele than the levels in patients with the minor allele. Out of the 41 patients, 6 (14.6%) with ITPA major allele had Hb levels <10 g/dl and 11 patients (26.8%) had a decline in Hb of >3 g/dl. None of the patients with the ITPA minor allele had such data. There were no significant differences in virological responses of HCV-RNA between patients with the ITPA major allele and those with the minor allele. In conclusion, the ITPA genotypes may be a useful marker for prediction of RBV-induced anemia.

Interleukin-28B genotypes determine response to pegylated-interferon plus ribavirin therapy in patients with hepatitis C virus infection

We recently reported that the interleukin (IL)-28B major genotype is a predictor of early suppression of the hepatitis C virus (HCV) at 12 weeks in response to pegylated interferon (PEG-IFN) plus ribavirin (RBV) therapy. The present study investigated the relationship between IL-28 genotypes and the virological response to PEG-IFN/RBV therapy at 24 and 48 weeks. Genotypes of the IL-28B rs8099917 T>G single nucleotide polymorphism were determined in 177 patients with HCV infection. Among them, 56 patients with HCV1 infection were treated with PEG-IFN/RBV. The frequency of the IL-28B major allele (TT) was 73.8% in patients with HCV serotype 1 and 86.3% in patients with HCV serotype 2. The rate of HCV-RNA positivity was significantly lower at 48 weeks in patients with the IL-28B major allele compared to patients with the IL-28B minor allele (TG or GG). The rate of HCV-RNA positivity at 24 weeks tended to be lower in patients with the IL-28B major allele, but there was no statistical significance (P=0.059). The sustained virological response (SVR) rate was 45.9% in patients with the IL-28B major allele, but 13.3% in patients with the IL-28B minor allele. The SVR correlated with the IL-28B major allele (OR=7.13, P=0.010), early virological response (OR=33.3, P=0.008), HCV-RNA ≤ 6.3 log IU/ml (OR=81.2, P=0.009) and γ-GTP ≤ 47 IU/l (OR=49.4, P=0.027). The IL-28B genotype is a significant pre-treatment predictor of the response to PEG-IFN/RBV therapy at 48 weeks in patients with HCV infection.