PEG-IFN-α Plus Ribavirin in Elderly Chronic Hepatitis C Kim HI et al. Figure 2. Adverse Events and Laboratory Abnormalities Neutropenia, neutrophil counts ≤ 750 cells/mm3; anemia, hemoglobin level ≤ 10 g/dL; thrombocytopenia platelet counts ≤ 3 5×105 cells/mm . All P values of adverse reactions other than alopecia and anemia were > 0.05 tients and elderly patients (≥ 65 years) according to their hepatitis C virus genotype (41.5 % vs. 40.7 % for genotype 1; P = 0.899, 89.7 % vs. 86.4 % for genotype 2; P = 0.703, respec- tively) (12). They suggested that obtaining an early viro- logical response may be essential to achieve a sustained virological response in elderly patients with a CHC infec- tion. Furthermore, a Korean study by Sinn et al. showed that older patients had a SVR rate that was comparable to the SVR rates of younger patients (80 % , 73 % , and 75 % for the < 50 years, 50-59 years, and ≥ 60 years patient groups, respectively; P = 0.42) (13). However, Sinn et al. de- fined older patients as 60 years or older, which was lower than patients in previous studies from Japan, and the percentage of genotype 1 patients was lower than in the study by Honda et al. (40 % vs. 81 % ) (10, 12). In addition, the APRI was found to be the only independent predictor of SVR, translating to 95 % of the elderly patients with an APRI < 0.80 (13). In our study, the overall SVR was not sig- nificantly different between the elderly (≥ 65 years) and non-elderly patients (< 65 years) (65.8 % vs. 76.2 % , P = 0.15). However, elderly patients with genotype 1 showed significantly lower SVR than non-elderly patients (30.8 % vs. 66.0 % , P = 0.03). In contrast, the SVR rate in patients with HCV genotype 2 or 3 was not significantly different between the elderly and non-elderly groups (84.0 % vs. 81.3 % , P = 0.85). In this study, HCV genotype was the only independent factor associated with SVR in the elderly pa- tients (P = 0.04), while viral load and APRI score were not Hepat Mon. 2012 significantly associated with SVR. The discrepancies in factors associated with SVR may be due to the relatively small sample size of the elderly group and the possibility of bias as better candidates were more likely to be select- ed among the older compared to the younger patients. Consistent with previous studies (10, 11, 13), we found that the rates of treatment discontinuation and dose modifi- cation due to adverse events or laboratory abnormalities were higher for older patients. Interestingly, our study showed that the elderly group had a significantly high- er incidence of anemia (< 10 g/dL) (31.6 % vs. 12.6 % ; P = 0.005) and more frequent dose modification of ribavirin (34.2 % vs. 13.3 % ; P = 0.003). Because a substantial amount of the ribavirin dose is excreted by the kidney, the risk of toxic reactions to this drug may be greater for elderly pa- tients in whom the serum creatinine level might remain normal as the glomerular filtration rate decreases (14). Therefore, ribavirin should be administered cautiously to elderly patients, starting at the lower end of the dos- age range, with renal function monitoring and dosage adjustments made as needed. A common adverse effect of ribavirin is reversible hemolytic anemia, and the risk increases with age (15, 16). Dose reduction is recommend- ed when the hemoglobin level is < 10 g/dL, and therapy cessation is recommended when the hemoglobin con- centration decreases to < 8.5 g/dL (7). CHC is becoming a disease of the elderly and elderly patients with chronic HCV infection often being a severe 435