Disease progression in chronic hepatitis C patients with normal alanine aminotransferase levels

AIM:To investigate whether the disease progression of chronic hepatitis C patients with normal alanine aminotransferase(ALT) levels differs by ALT levels.METHODS:A total of 232 chronic hepatitis C patients with normal ALT(< 40 IU/L) were analyzed.The patients were divided into "high-normal" and "low-normal" ALT groups after determining the best predictive cutoff level associated with disease progression for each gender.The incidence of disease progression,as defined by the occurrence of an increase of ≥ 2 points in the Child-Pugh score,spontaneous bacterial peritonitis,bleeding gastric or esophageal varices,hepatic encephalopathy,the development of hepatocellular carcinoma,or death related to liver disease,were compared between the two groups.RESULTS:Baseline serum ALT levels were associatedwith disease progression for both genders.The best predictive cutoff baseline serum ALT level for disease progression was 26 IU/L in males and 23 IU/L in females.The mean annual disease progression rate was 1.2% and 3.9% for male patients with baseline ALT levels ≤ 25 IU/L(low-normal) and > 26 IU/L(highnormal),respectively(P = 0.043),and it was 1.4% and 4.8% for female patients with baseline ALT levels ≤ 22 IU/L(low-normal) and > 23 IU/L(high-normal),respectively(P = 0.023).ALT levels fluctuated during the follow-up period.During the follow-up,more patients with "high-normal" ALT levels at baseline experienced ALT elevation(> 41 IU/L) than did patients with "lownormal" ALT levels at baseline(47.7% vs 27.9%,P = 0.002).The 5 year cumulative incidence of disease progression was significantly lower in patients with persistently "low-normal" ALT levels than "high-normal" ALT levels or those who exhibited an ALT elevation > 41 U/L during the follow-up period(0%,8.3% and 34.3%,P < 0.001).CONCLUSION:A "high normal" ALT level in chronic hepatitis C patients was associated with disease progression,suggesting that the currently accepted normal threshold of serum ALT should be lowered.