Al168 AASLD ABSTRACTS GASTROENTEROLOGY, VOI. 108, NO. 4

• URSODEOXYCHOLIC ACID PREVENTS STEROID RESISTANT REJECTION IN LIVER TRANSPLANT RECIPIENTS. Ala I. Sharara Carlos A. Camargo and Pierre-A Clavien. Liver Transplantation Program, Departments of Medicine and Surgery, Duke University Medical Center, Durham, NC INTRODUCTION: Acute cellular rejection (ACR) is a major problem following orthotopic liver transplantation (OLT) with an incidence of 50%-70%. Steroid resistant rejection occurs in 20%-35% of recipients and necessitates the use of antilymphocyte therapy causing an increased infectious and future neoplastic risk. Ursodeoxycholic acid (UDCA) hag been shown to be beneficial in several cholestatic disorders of the liver and to possess in vivo imlnunomodulatory activity and mild in vitro immunosuppressive properties. In a pilot study, we investigated the role of UDCA given at the time of ACR on the incidence of recurrent and/or steroid resistant rejection. PATIENTS AND METHODS: Consecutive patients undergoing OLT using cyclosporine induction and a conventional triple immunosuppress ion regimen (cyclosporine, prednisone and azathioprine) were enrolled. ACR was diagnosed using clinical, biochemical and histologic parameters, graded histologically according to Demetris et al(Am J Surg Pathol 1990;14 suppl 1:49-63) and treated with a three day course of high dose methylprednisolone (500 mg at day 1,400 mg at days 2 and 3). UDCA (10 mg/kg/d) was given orally at the time of first episode of rejection and was discontinued at 6 months. Steroid resistant rejection was defined as persistent biochemical and histological evidence of rejection after two courses of bolus steroids. All patients were followed up for a minimum of 3 months. RESULTS: Thirty patients underwent OLT over a 7 month period. There were 3 early deaths (cardiac n=2 and ARDS n=l). Fourteen patients (52%) developed acute cellular rejection and were started on ursodeoxycholic acid. All episodes of ACR occured within the'first 4 weeks and were biopsy proven (mean histological grade of rejection = 2) One patient (4%) had a second episode of rejection two months following OLT. No patient developed steroid resistant rejection requiring antilymphocyte therapy. No adverse effects attributable to UDCA were noted. C O N C L U S I O N S : UDCA appears to have a role in preventing recurrent and/or steroid resistant rejection following OLT but the mechanism of action in this setting is not known. The adjuvant role of UDCA in liver transplantation requires further evaluation in randomized controlled trials.

• MARKEDLY INHIBITED 7-DEHYDROCHOLESTEROL-A r- REDUCTASE ACTIVITY IN LIVERMICROSOMES FROM SMITH-LEMLI-OPITZ HOMOZYGOTES. S. Shefer, G. Salen, A.K. Batta, G.S. Tint. UMD-NJ Medical School, Newark, NJ, VA Medical Center, East Orange, NJ.

We investigated the enzyme defect in late cholesterol biosyn- thesis in the Smith-Lemli-Opitz (SLO) syndrome, a recessively in- herited developmental disorder characterized by facial dysmor- phism, mental retardation, and multiple congenital anomalies. Reduced plasma and tissue cholesterol with increased 7- dehydrocholesterol (7-DHC) concentrations are biochemical fea- tures diagnostic of the inherited enzyme defect. Using isotope in- corporation assays, we measured the transformation of the precur- sors, [3~-3H]lathosterol and [1,23H]7-DHC into cholesterol by liver microsomes from 7 control and 4 SLO homozygous subjects. Two important reactions in the pathway were examined: the introduction of the double bond in lathosterol at C-5(6) to form 7-DHC catalyzed by lathosterol-5-dehydrogenase, followed by the reduction of the double bond at C-7(8) in 7-DHC catalyzed by 7-DHC-Ar-reductase yielding cholesterol. Microsomes from all subjects rapidly converted pH]lathosterol to 7-DHC which was transformed efficiently to cho- lesterol only by controls demonstrating a precursor-product rela- tionship between lathosterol, 7-DHC, and cholesterol. Although mi- crosomal lathosterol 5-dehydrogenase activities were similar in con- trol and SLO subjects (120!-_8 versus 100 _+ 7 pmol/mg pro- tein/min, p=NS), liver microsomes from 4 SLO homozygotes syn, thesized only small amounts of cholesterol. When I~H]7-DHC was incubated directly with microsomes, 7-DHC-~r-reductase activity was 10 times greater in controls compared to SLO specimens (440 + 60 pmol/mg/min versus 41 + 4 pmol/mg/min, p < 0.0001). Conclusions: These results demonstrate that the pathway of lathosterol to cholesterol in human liver includes 7-DHC as the key intermediate. In the SLO homozygotes, the transformation of 7-DHC to cholesterol by hepatic microsomes was blocked although 7-DHC was produced abundantly from lathosterol. Thus, lathosterol 5, dehydrogenase is active and indicates that SLO microsomes are vi- able. Accordingly, microsomal 7-DHC-AT-reductase is inherited ab- normally in SLO homozygotes.

• TALC CRYSTALS IN THE LIVER OF PATIENTS WITH CHRONIC HEPATITIS C INFECTION, KE Sherman, S Lewey, R Creager, ZD Goodman. Univ. of Cincinnati Medical Center, Cincinnati, OH, Fitzsimons Army Medical Center, Aurora, CO and the Armed Forces Institute of Pathology, Washington, D.C,

The presence of talc crystals in the liver has been associafed with prior history of intravenous drug abuse (IVDA). Patients with hepatitis C virus (HCV) infection often deny IVDA and many patients have no other identifiable risk factors, To evaluate the possible role of prior surreptitious IVDA in patients with chronic HCV infection the following study was performed. Methods: 109 patients with chronic hepatitis C (ALT abnormal > 6 months, HCV ELISA and RIBA positive) underwent careful evaluation for risk factors potentially associated with HCV infection. All patients underwent liver biopsy. Liver biopsies were )'eviewed by two observers to determine histologic stage and then examined by polarized light microscopy to reveal the presence or absence of typical talc crystals. Patients with discordance between history and histologic findings were re- interviewed, and confronted with the information, Results: Patient interviews revealed the following risk factors; IVDA-17.4%, blood transfusion-24.3%, possible household/occupational exposure-14,2% and tattoos-15.3%, No identifiable risk factors were noted in 28.8% of the cohort. Talc crystals were seen in 9/109 (8.3%) of liver specimens. Of this group, only two patients admitted to prior history of IVDA, Seventeen patient with an IVDA history did not have identifiable talc crystals. Follow-up phone interviews were possible with 5/7 patients with talc who had previously denied IVDA history. Of the 5 patients, 3 admitted to prior IVDA, but only after being confronted with the liver biopsy evidence. Conclusion: The findings of talc crystals in liver biopsy specimens appears to be a specific, but not a sensitive marker for prior IVDA. Identification of talc crystals from liver tissue may contribute to categorization of risk factors in patients with community acquired HCV infection.

A POSSIBLE PROTECTIVE ROLE FOR TH1 CYTOKINES IN LIVER INJURY, Zen~,dun Shi and DC Rocker. Liver Center Laboratory and the Dept, b t Medicine, Univ. Of California, San Francisco.

Mechanisms important in liver injur~¢ and fibrosis, are complex and likely involve interplay between smunle factors and_ the extracellular matrix. Cytoldnes appear to play a critical role during cell activation a nct ~;ene expression during this process. We have previously shown that IFN~,is antiproliferative and antifibrogenic for rat hepatic lipocytes, the primary cellular source of matrix proteins during fibrogenesis. Since IF.N~ is a member of the Thl cytokine family and appears to protect the river against hepatic fibrosis, we investigated whetfier differential cytnkine subset (i.e Thl vs. Th2) expression was related tO the development of liver injury and fibrosis. Methods: ~alb-c and C57 black 6 male mice were gavaged weekly with CC14 for up to 4 wks. Live'r sections were stained with anti-desmin antibody and Masson's Trichrome. Whole liver colla,~en type I mRNA was detected by RNase protection assay. Cytokine mRN'A expression (Thl-IFNT, TNFc~ Th2-IL-4; TGF!3 ant1 ravt~l - a constitutively expressed mRNA) was.analyzed by quantitative PCR. Kesults: Pericentral degeneration and intlammatory infiltration w a s observed 24 his after CC]4 treatment and was more prominent in Balb-c mice than in C57 Black 6 mice. After 4 doses of (ZC14, granulomas consisting of macrophages, lymphocytes, lipocytes and..d-egenerated nepatocytes were prominent in tile liver of Balb-c mice. Lollagen was located in and around granuloma and large bands of fibrosis were identified. In contrast, C57 Black 6 mice developed miniinal injury and only occasional thin fibrotic septa. After 1 and 4doses of CC14, whole liver collagen type I mRNA in Balb-c mice was 5.2 and 1.6-fold that of C57 BlacV 6 mice respective~ ( n=4 p<0.05 for Balb;-c vs, C57 B!ack 6 at each time point ). Results or quantitative PCR on cructe nonparencnymal cells extracts t n=4 ) are shown below:

Relative C'¢tokine mRNA Abundance Balb-c C57 Black 6

TNFo~ 1 2.89 5.76 3.51 3.39 IL-4 1 4.24 2.66

TGF[3 I 3.23 0.96 2.46 HPRT 1 1.28 1.35 1.40

*scannin~ densitometry units were arbitrarily set at "1 ". Conclusion: The ~tata indicate that C57 Black 6 mice' express high intrinsic levels of Thl cytoldnes (IFNy and T N F a ) a n d are l e s s suscept ble to CC14 induced'liver injury and fibrosis than Balb-c mice. This data implies that Thl cytokines including IFN3, may be protective aga nst liver injury and fibrosis. Whether differential cytokine profiles could play a role in human liver diseases or could explain divergent responses to injurious agents is open to speculation.