Hr. Rosen et al., Molecular epidemiology of hepatitis C infection in US veteran liver transplant recipients: Evidence for decreasing relative prevalence of genotype 1B, AM J GASTRO, 94(10), 1999, pp. 3015-3019
OBJECTIVE: The U.S. Veteran population represents a unique patient group to
study different HCV genotypes because of geographically diverse exposures.
The aim of this study was to characterize the distribution of HCV genotype
s in U.S. veterans undergoing liver transplantation (OLT), trace genotypes
to modes of acquisition (risk behavior and location), and evaluate the rela
tive prevalence of HCV genotypes according to the time of acquisition.
METHODS: Between 10/88 and 12/95, 110 primary OLTs were performed in U.S. V
eterans at our center. Forty-nine (45%) patients had detectable HCV-RNA by
PCR at the time of OLT. Determination of HCV genotypes was performed by res
triction fragment length polymorphism of the 5' noncoding region and classi
fied according to Simmonds et al.
RESULTS: Twenty-three of 49 (47%) veterans had la, 17 (35%) Ib, two (4%) 2a
, three (6%) 2b, two (4%) 3a, two (4%) mixed (1a/2a, 1b/2a). This distribut
ion of HCV genotypes was comparable to the genotypic distribution of a cont
emporary cohort of nonveteran OLT recipients at the University of Washingto
n. There was a statistically significant association between illicit inject
ion drug use (IDU) and la, with 63% of la patients having IDU whereas only
14% of Ib patients admitted to IDU (p = 0.03). All patients in whom the mod
e of acquisition was unknown had genotype Ib (p = 0.04). Intranasal cocaine
use was strongly correlated with IDU (p = 0.002). Patients who had tattoos
but no history of blood transfusion (BT) or recreational drug use had geno
type 1 (2 had la, 2 had Ib; p = NS). Twenty two (45%) patients had serologi
cal evidence of prior hepatitis B (HBV) infection. Patients who had genotyp
e :2a, 2b, 3a, or mixed were much more likely to have had HBV (seven of nin
e, 78%) than patients with genotype la or Ib (15 of 40, 37.5%) (p = 0.03).
There was no significant correlation between BT, dates, or military branch
of service, high risk behavior in Southeast Asia, level of education, ethni
city, and particular genotype(s). Whereas the proportion of 1b accounting f
or HCV infection in patients with a first exposure before 1968 was 50%, all
patients with a first exposure post-1975 were non-lb (p = 0.04), suggestin
g a change in the epidemiology of HCV in our cohort.
CONCLUSIONS: In U.S. Veterans undergoing OLT: 1) 45% had PCR-confirmed HCV
infection, 2) la was the predominant genotype and was associated with IDU,
and 3) a significant decrease in the prevalence of genotype Ib from the pre
-Vietnam era to post-1975 suggests a changing epidemiology of HCV genotypes
. (C) 1999 by Am. Coll. of Gastroenterology.