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Increase in platelet count based on inosine triphosphatase genotype during interferon beta plus ribavirin combination therapy
Author(s) -
Nomura Hideyuki,
Miyagi Yugo,
Tanimoto Hironori,
Yamashita Nobuyuki,
Ito Kiyoaki,
Masaki Naohiko,
Mizokami Masashi
Publication year - 2012
Publication title -
journal of gastroenterology and hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.214
H-Index - 130
eISSN - 1440-1746
pISSN - 0815-9319
DOI - 10.1111/j.1440-1746.2012.07171.x
Subject(s) - ribavirin , itpa , medicine , platelet , gastroenterology , pegylated interferon , immunology , combination therapy , pharmacology , hepatitis c virus , virus
Background and Aim: The inosine triphosphatase ( ITPA ) genotype is associated with ribavirin‐induced anemia and pegylated interferon α (PEG IFN‐α)‐induced platelet reduction during PEG IFN‐α plus ribavirin combination therapy. Natural IFN‐β plus ribavirin therapy is associated with increases in platelet counts during treatment. We investigated decreases in platelet counts according to ITPA genotype during natural IFN‐β/ribavirin therapy to determine if patients with low platelet counts were eligible for this combination therapy. Methods: A total of 187 patients with chronic hepatitis C received PEG IFN‐α/ribavirin or natural IFN‐β/ribavirin therapy. Decreases in platelet counts based on ITPA genotype were investigated during treatment through 24 weeks. Results: Platelet counts decreased during week 1 of PEG IFN‐α/ribavirin therapy, but increased during week 2, after which platelet counts decreased gradually. Platelet counts decreased until week 4 of natural IFN‐β/ribavirin therapy, after which platelet counts increased. Platelet counts after week 8 were higher relative to pretreatment platelet counts. Patients with the ITPA ‐CC genotype showed a smaller decrease in platelet counts during natural IFN‐β/ribavirin therapy than those with the ITPA ‐CA/AA genotype; platelet counts after week 8 of this therapy were higher than pretreatment platelet counts, regardless of pretreatment platelet counts. Multivariate logistic regression analyses showed that natural INF‐β/ribavirin therapy was the only significant independent predictor for an increase in platelets through week 8. Conclusion: Natural IFN‐β/ribavirin therapy is safe for patients with the ITPA ‐CC genotype, even if their pretreatment platelet counts are low.