A1208 AASLD ABSTRACTS

• L0038

DECREASED ACTIVITY OF GASTRIC CLASS III (Z) ADH CAN EXPLAIN INCREASED BIOAVAILABILITY OF ALCOHOL IN WOMEN, E. Baraona New York, NY; K. Dohmen, New York, NY; G. Pozzato, Trieste, Italy; C. S. Lieber, New York, NY. Section of Liver Disease & Nutrition, Alcohol Research Center, Bronx V.A. & Mount Sinai Medical Centers, NY, USA and University of Trieste, Italy.

Women are more vulnerable than men to alcohol-induced diseases. This could be due to their higher blood levels. No comparable effect was observed after i.v. administration, suggesting an increased bioavailability of the imbibed alcohol. Furthermore, below the age of 50, this effect was associated with a decrease in total gastric ADH activity, rather than with a lesser rate of ethanol elimination, which in fact may be increased in women. To quantify the difference in bioavailability, the amount of alcohol that reaches the systemic blood after i.v. and oral administration of the same dose (0.3 g/kg body wt.) was compared one hour after a standard meal in 20 men and 17 women. This amount (first-pass metabolism; FPM) was estimated by the differences in areas under the i.v. and oral blood alcohol curves and quantified by integration of the Michaelis-Menten equation over the entire curve of blood concentrations. In women, FPM was 10% of the dose, compared to 21% in men (p < 0.01). It correlated with total gastric ADH activity at 500 mM of ethanol, a concentration likely to occur in the stomach. The gastric mucosa expresses the following 3 classes of ADH isozymes in a decreasing order of affinity for ethanol: ~tADH, a Class I isozyme also present in the liver, zADH, a Class IV ADH characteristic of the upper gastro-intestinal tract, and ~ADH, a Class III isozyme found in most tissues. All of them can operate at the high alcohol concentrations prevailing in the stomach after the drinking of alcoholic beverages. To investigate which isozyme was involved in the gender difference, we used endoscopic biopsy tissue obtained from the gastric corpus of 30 men and 19 women, with normal histology and no H. pylori infection. Activity of the ADH isozymes was assesed by using preferred substrates for Class I (acetaldehyde) and Class IV (m-nitrobenzaldehyde) and a specific reaction of Class III, namely glutathione-dependent formaldehyde dehydrogenase. Since we previously observed an increased bioavailability of imbibed alcohol in Japanese subjects (compared to Caucasians) in association with decreased zADH activity, we focused on this Class IV isozyme. Unexpectedly, there was only a trend for a decrease in Class IV activity in women, with no differences in Class I ADH activity, but there was a 58% reduction in Class III ADH, determined by the formaldehyde dehydrogenase activity (p < 0.003). In summary, 1) an increased bioavailability of imbibed alcohol in women compared to men was confirmed and quantified, 2) this was found to be associated with, and probably due to, a reduced gastric Class III (Z) ADH activity of women compared to men. Since )~ADH is present in most tissues, the significance of a possible decrease in its physiological activity with other substrates is now being explored in various tissues, including the liver.

L0039

PROGNOSTIC VALUE OF CAFFEINE PLASMA CLEARANCE IN CIRRHOTIC PATIENTS. JC. Barhare 1; C. Bories 2; JF. Cadranel 3; P. Ltvy 4; JP. Capron 4; P. Sttpani 2; JP. Latrive 1; D. Capron 4. Centres Hospitaliers de 1 : Compi~gne ; 2 : Beauvals ; 3 : Creil ; 4 : Amiens, FRANCE.

Caffeine plasma Clearance (CpC) is a simple and cheap method allowing a quantitative assessment of liver function. In patients with cirrhosis, CpC is correlated with the Child-Pugh score (1) ; however, the prognostic value of CpC had never been assessed prospectively; moreover, studies about prognostic value of hepatic clearances had given conflicting results (2,3). The aim of our study was to compare CpC and Child-Pugh classification for predicting survival in patients with cirrhosis. Seventy-two patients were included in this prospective study [M : 49; F: 23. Age : 56.4 +/- 10.5 years (mean +/- SD)] ; etiology of cirrhosis was alcoholic in 65 patients, related to viral B or C hepatitis in 5 and cryptogenic in 2. Eleven patients belonged to Child-Pugh class A, 34 to class B and 27 to class C. A 300 mg oral dose of caffeine was given at 4 pm ; plasma samples were obtained at 8 pm and the next morning at 8 am. Caffeine plasma concentrations were determined by an automated enzyme-immunoassay and CpC was calculated from plasma disappearance curve assuming first-order kinetics. The prognostic value of the ten following variables was studied : age, sex, Child-Pugh class and score, encephalopathy, ascites, prothrombin time, serum bilirubin, serum albumin and CpC. During follow-up, 37 patients (51%) died [length of follow-up : 9.6 +/- 9.7 months in non-survivors ; 20.2 +/- 14.8 months in survivors ; 15.1 +/- 13.6 months in the whole study (mean +/- SD)]. Univariate analysis showed that the Child-Pugh score (p=0.01), the Child-Pugh class (p=0.04) and CpC (p=0.03) were significant predictors of survival whereas the 7 other variables were not. CpC was significantly correlated with Child-Pugh score and class (p<0.001). A-Logrank test performed with the 3 variables selected in univariate analysis demonstrated that the Child-Pugh score and the Child° Pugh class were the only variables significantly related to survival (p=0.04), whereas CpC had no independent prognostic value. In conclusion, our results suggest that CpC has no role in the prediction of prognosis in patients with cirrhosis since it does not add any information once the Child-Pugh classification has been used.

GASTROENTEROLOGY Vol. 114, No. 4

[1] FN. Lewis et al. J Hepatol 1992 ; 14 : 157-62. [2] JP. Villeneuve et al. Hepatology 1986 ; 6 : 928-31. [3] D. Urbain et al. J Hepatol 1995 ; 22 : 179-83.

L0040

MODULATION OF NON-TRANSFERRIN-BOUND IRON (NTBI) TRANSPORT AND TRANSFERRIN RECEPTORS EXPRESSION BY NITRIC OXIDE (NO) DONORS IN HepG2 CELLS. D. Barisani G. Cairo* and D. Coute. Cattedra di Gastroenterologia IRCCS Ospedale Maggiore, and *Centro Studi Patologia Cellulare, CNR, Milano, Italy.

Background: Nitric oxide regulates several cellular processes, including iron transport. NO donors (S-nitroso-N-acetylpenicillamine, SNAP and sodium nitroprusside, SNP) can modulate iron regulatory protein (IRP) activity and thus transferrin receptor mRNA. However, no data are available on the effect of nitric oxide on NTBI transport. Aim: To evaluate non-transferrin-bound iron transport in HepG2 cells treated with NO donors. Methods: HepG2 cells were incubated with SNP or SNAP (0.5 and 1 mM) for 6-30 hours. 55Fe-NTA (molar ratio 1:4) was employed as a model for NTBI, and both Fe 3÷ and Fe 2÷ uptake were measured at 5 and 15 min. Transferrin receptor mRNA was evaluated by Northern Blot and IRP activity by gel retardation assay. Results: The effect of nitric oxide was time-dependent and reached a plateau between 24-30 hours. Both Fe 3+ and Fe z+ uptake were significantly decreased by treatment with NO donors in a dose-dependent manner, being 52% and 27% of control uptake in cells treated with 1 mM SNP and SNAP, respectively. The reduction in the transport of both forms of iron indicates that NO donors affected the transporter rather than the reductase present on the cell surface. The effect of 1 mM SNP or SNAP was maintained at all iron concentrations tested, and double-reciprocal plot revealed a reduction in Vmax (50, 36 and 14 fmol/~tg protein/min in control, SNP- and SNAP-treated cells, respectively), whereas no Km variation was observed. These data indicate a decreased number of receptors for NTBI on the cell surface, and were not attributable to cell death, since no reduction in viability or DNA fragmentation (sign of apoptosis) could be detected. Both IRP activity and transferrin receptor mRNA were reduced by SNP treatment, whereas SNAP caused a modest increase. Conclusions: Both SNP and SNAP significantly reduce NTBI transport in HepG2 cells, whereas they have a dual effect on IRP activity and transferrin receptor mRNA. These data suggest that nitric oxide acts on non-transferrin-bound iron transport through a IRP independent mechanism, probably chelating free intracellular iron, which seems to regulate this transporter.

• L0041

INCREASED FREQUENCY OF THE HLA-DR1 ALLELE IN AN IRISH ANTI-D POPULATION WITH SELF-LIMITED HEPATITIS C VIRUS INFECTION. S. Barrett, E. Ryan, and J. Crowe. Hepatobiliary Unit, Mater Misericordiae Hospital, Dublin, Ireland.

Genetically determined resistance or susceptibility to chronic hepatitis C virus infection (HCV) may contribute to the course of liver disease and may be linked to the major histocompability complex. The purpose of this study was to examine the role of HLA class II alleles in the outcome of HCV infection in a unique cohort of pationts who were infected with HCV through contaminated Anti-D immunoglobulin in 1977. One hundred and forty anti-HCV positive females were assessed for HLA class II antigens. Of these, 78 patients (Mean age 44.2, SD=7.2) were HCV RNA positive by RT PCR. The remaining 62 (Mean age 43.6, SD=6.8) were persistently HLA RNA negative with normal levels of aminotransferases. HCV-DR typing was performed by PCR and a reverse line blot assay which determines HLA alleles to a specificity beyond the level of the sixteen known serotypes (Amplicor DRB, Roche Diagnostics). The allele frequencies were compared to that for a control group of 5000 bone marrow donors negative for anti-HCV. Statistical analysis was performed using Pearsons ~2 test with continunity correction. P values were corrected for multiple comparisons (Bonferroni-type correction). Analysis of HLA class II antigens did not show a significant difference between the anti-HCV positive group and the control group. When the anti-HCV positive group was assessed separately however according to the presence or absence of HCV RNA the frequency of the HLA- DR1 allele was found to be higher in PCR negative individuals 18/62 (29%) compared to 6/78 (7.7%) PCR positive individuals. The difference was statistically significant (corrected P value=0.0038). There was no significant difference in the frequency of other HLA-DR alleles identified in these groups. Conclusions: 1) The presence of the DR1 allele is associated with HCV RNA negative status. 2) There does not appear to be a general susceptibility allele for chronic HCV infection. Our data suggests that the presence of the HLA-DR1 allele constitutes an important genetic factor for the elimination of the hepatitis C virus in Ireland.