The present patient was a 4-year-old boy. His hepatitis C virus genotype was 2a, and his viral load was high (1400,000？U/mL). The pretreatment liver biopsy revealed no fibrosis or malignancy and mild chronic hepatitis; his Knodell's histological activity (HAI) score was 4. Single nucleotide polymorphism of IL28B (rs8099917) was major type. The patient began antiviral treatment with pegylated interferon alpha 2a (90？μg/week). At week 9, serum HCV RNA became undetectable, with a sensitivity of 50？copies/mL. Antiviral treatment was discontinued at week 11 because the ALT level increased to 610？U/L. After discontinuation of therapy, the patient’s serum HCV RNA status became positive again. The serum viral load increased to 100,000？U/mL. During this period, he had been observed without medication. Sixteen months after stopping treatment, serum HCV became undetectable. Over a 4-year period, HCV RNA became negative and his anti-HCV antibody titer gradually decreased. In conclusion, though antiviral therapy resulted in failure or incomplete therapy, a reduced viral load resulted in viral clearance in the present patient. Interleukin 28B genotype might have association with the clearance of hepatitis C virus after discontinuation of antiviral therapy. 1. Introduction About 70% of hepatitis C virus (HCV) infections lead to chronic liver disease, and chronic HCV infection leads to cirrhosis and hepatocellular carcinoma. Recently, antiviral therapy, such as pegylated interferon (PEG-IFN) and ribavirin, has been successful in more than 50% of infected patients, resulting in clearance of HCV RNA from the serum. It has been assumed that patients infrequently or never achieve elimination of chronic HCV infection without receiving antiviral treatment. Recent studies indicate that there is a relationship between rs8099917 TT interleukin (IL) 28B genotype and HCV treatment response in adults [1]. However, the IL28B genotype influences in HCV infection among children have been a little investigated. We report the case of a boy with viral clearance after discontinuation of PEG-IFN α2a monotherapy because of elevated transaminase levels. IL28 genotyping was performed in this patient. 2. Case Presentation A 2-year-old boy was referred to our hospital due to chronic hepatitis C infection. Markers of hepatitis A virus, hepatitis B virus, cytomegalovirus, and human immunodeficiency virus were negative. Tests for hepatitis E, and Epstein-Barr viruses were not performed. Autoantibody titers were not high, and serum IgG was within the normal range. The possibility of autoimmune
References
[1]
Y. Tanaka, N. Nishida, M. Sugiyama et al., “Genome-wide association of IL28B with response to pegylated interferon-α and ribavirin therapy for chronic hepatitis C,” Nature Genetics, vol. 41, no. 6, pp. 1105–1109, 2009.
[2]
H. Watanabe, T. Saito, H. Shinzawa et al., “Spontaneous elimination of serum hepatitis C virus (HCV) RNA in chronic HCV carriers: a population-based cohort study,” Journal of Medical Virology, vol. 71, no. 1, pp. 56–61, 2003.
[3]
H. Uto, K. Hayashi, K. Kusumoto et al., “Spontaneous elimination of hepatitis C virus RNA in individuals with persistent infection in a hyperendemic area of Japan,” Hepatology Research, vol. 34, no. 1, pp. 28–34, 2006.
[4]
J. Denis, P. E. Rautou, B. Lambare, S. Herbert, V. Auray-Cartier, and T. Asselah, “Chronic hepatitis C: viral clearance several months after discontinuation of therapy in two non-responders,” Infection, vol. 35, no. 3, pp. 197–200, 2007.
[5]
K. B. Schwarz, P. Mohan, M. R. Narkewicz et al., “Safety, efficacy and pharmacokinetics of peginterferon α2a (40？kd) in children with chronic hepatitis C,” Journal of Pediatric Gastroenterology and Nutrition, vol. 43, no. 4, pp. 499–505, 2006.
[6]
T. Fujisawa, H. Komatsu, A. Inui et al., “Spontaneous remission of chronic hepatitis C in children,” European Journal of Pediatrics, vol. 156, no. 10, pp. 773–776, 1997.
[7]
Y. Hattori, E. Orito, T. Ohno et al., “Loss of hepatitis C virus RNA after parturition in female patients with chronic HCV infection,” Journal of Medical Virology, vol. 71, no. 2, pp. 205–211, 2003.
[8]
M. Somsouk, G. M. Lauer, D. Casson et al., “Spontaneous resolution of chronic hepatitis C virus disease after withdrawal of immunosuppression,” Gastroenterology, vol. 124, no. 7, pp. 1946–1949, 2003.
[9]
P. Fialaire, C. Payan, D. Vitour et al., “Sustained disappearance of hepatitis C viremia in patients receiving protease inhibitor treatment for human immunodeficiency virus infection,” Journal of Infectious Diseases, vol. 180, no. 2, pp. 574–575, 1999.
[10]
M. Yoshikawa, Y. Morimoto, A. Shiroi, H. Yoshiji, S. Kuriyama, and H. Fukui, “Spontaneous elimination of serum HCV-RNA after total gastrectomy for early gastric cancer in a patient with chronic hepatitis C,” American Journal of Gastroenterology, vol. 96, no. 3, pp. 922–923, 2001.
[11]
K. Shiraki, H. Ohto, N. Inaba et al., “Guidelines for care of pregnant women carrying hepatitis C virus and their infants,” Pediatrics International, vol. 50, no. 1, pp. 138–140, 2008.
[12]
A. Ruiz-Extremera, J. A. Mu？oz-Gámez, M. A. Salmerón-Ruiz, et al., “Genetic variation in interleukin 28B with respect to vertical transmission of hepatitis C virus and spontaneous clearance in HCV-infected children,” Hepatology, vol. 53, no. 6, pp. 1830–1838, 2011.
[13]
G. Indolfi, M. Sambrotta, M. Moriondo, C. Azzari, and M. Resti, “Genetic variation in interleukin-28B locus is associated with spontaneous clearance of HCV in children with non-1 viral genotype infection,” Hepatology, vol. 54, no. 4, pp. 1490–1491, 2011.
[14]
B. Caroleo, L. Gallelli, O. Staltari, G. De Sarro, and V. Guadagnino, “Serum transaminase elevations during pegylated interferon treatment of chronic HCV hepatitis probably induced by polyethylene glycol,” Intervirology, vol. 51, no. 6, pp. 407–409, 2009.
[15]
M. Nagashima, M. Kudo, H. Chung et al., “Elevated serum ALT levels during pegylated interferon monotherapy may be caused by hepatic iron overload,” Intervirology, vol. 51, 1, pp. 76–85, 2008.
