Hepatitis C infection in Alaska Natives with persistently normal, persistently elevated or fluctuating alanine aminotransferase levels.
OBJECTIVE
An estimated one-third of patients with chronic hepatitis C virus (HCV) infection have persistently normal alanine transaminase (PNALT); however, in many previous studies alanine aminotransferase (ALT) levels were followed for < or = 12 months.


METHODS
We analyzed data from a population-based cohort of 935 Alaska Natives with HCV, recruited from 1994 to 2005, to determine the proportion of persons with PNALT, persistently elevated ALT (PEALT), and fluctuating ALT (FLUXALT) to determine factors for each ALT state. We selected persons with two positive HCV RNA results > or = 1 year apart and > or = 6 ALT levels measured over the subsequent 3 years with at least 1 month between ALT measurements (n = 265). We defined a person as having PNALT, PEALT, or FLUXALT when all six ALT levels were normal, elevated, or did not fit either of the above two categories, respectively, during the 3-year follow-up period.


RESULTS
Among 208 persistently HCV RNA-positive persons, 13 had PNALT, 121 PEALT, 74 FLUXALT. Among 77 persons who underwent liver biopsy, those with PEALT were more likely to have Ishak fibrosis scores > 2 compared with persons with FLUXALT (44% vs. 10%, OR 7.0, 95% CI: 1.5-33.2). No statistically significant differences were found in ALT classification by age, gender, infection duration, median body mass index, alcohol consumption, residence, risk behavior, RNA level, or genotype.


CONCLUSIONS
Only 6% of persons with chronic HCV had PNALT. Persons with PEALT were significantly more likely to have higher fibrosis scores on liver biopsy than those with FLUXALT. Previous studies with short follow-up periods may have overestimated the proportion of persons with normal ALT levels.
Bruce
Michael G
MG
Arctic Investigations Program, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, Alaska. zwa8@cdc.gov
Bruden
Dana
D
McMahon
Brian J
BJ
Christensen
Carol
C
Homan
Chriss
C
Sullivan
Dan
D
Deubner
Heike
H
Hennessy
Thomas
T
Williams
Jim
J
Livingston
Stephen
S
Gretch
David
D
D000328:Adult; D000410:Alanine Transaminase / Q000097:blood*; D000413:Alaska; D015331:Cohort Studies; D005260:Female; D016174:Hepacivirus / Q000235:genetics / Q000302:isolation & purification; D019698:Hepatitis C, Chronic / Q000201:enzymology* / Q000473:pathology / Q000821:virology; D006801:Humans; D007198:Indians, North American; D008137:Longitudinal Studies; D008297:Male; D012367:RNA, Viral / Q000097:blood
D012367:RNA, Viral; D000410:Alanine Transaminase