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Background: 6-Thioguanine (6-TG) has been used as an alternative thiopurine for inflammatory bowel disease (IBD) patients not responsive to or intolerant of azathioprine (AZA) and 6-mercaptopurine (6-MP). 6-TG-related hepatotoxicity, including liver biochemistry value elevations, sinusoidal collagen deposition on electron microscopy, and veno-occlusive disease, have been described related to its use as therapy for neoplastic disease., Methods: We studied 38 liver biopsies from patients treated with 6-TG, almost all of whom (n = 125) received 6-TG for 1 to 3 years at the Inflammatory Bowel Disease Center at Cedars-Sinai Medical Center. All biopsies were fixed in 4% buffered formalin and prepared in the usual manner. Hematoxylin and eosin, Masson's trichrome (trichrome), and reticulin silver impregnation (reticulin) stained slides were studied. In 23 cases, tissue was also prospectively fixed in glutaraldehyde and processed for electron microscopy., Results: In 20 of the 37 patients studied (53%), nodular regeneration of varying degree was seen with reticulin. In only 4 of these 20 instances (11% of the total) were the changes seen with hematoxylin and eosin and in 3 of the 4, only in retrospect after studying the reticulin preparation. Minimal fibrosis was seen with trichrome in only 13 biopsies (34%), but sinusoidal collagen deposition was observed in 14 of the 23 cases studied with electron microscopy (60%). The biopsy from the 1 patient with nodular hyperplasia obvious with hematoxylin and eosin also demonstrated changes of venous outflow obstruction., Conclusions: 6-TG-treated IBD patients are at significant risk for nodular hyperplasia, early fibrosis and, less often, venous outflow disease (Budd-Chiari). The natural history of these changes is unknown and follow-up biopsies are needed to determine histologic and clinical sequela. Patients not demonstrating nodular hyperplasia or fibrosis who continue with 6-TG because there are no better therapeutic choices should be periodically rebiopsied.

Context: Nodular hyperplasia (also referred to as nodular regenerative hyperplasia and nodular regenerative hyperplasia of the liver) is a sequel to therapy with thioguanine in patients with hematologic malignancies. Recently, 6-thioguanine has been used to treat patients with inflammatory bowel disease who have been resistant to other forms of therapy., Objective: To study liver biopsies from 3 patients with inflammatory bowel disease who had received thioguanine for more than a year, and who had elevated serum liver enzyme values and underwent percutaneous liver biopsy., Design: Percutaneous liver biopsies and histologic examinations were performed, including staining with the reticulin silver impregnation method., Results: All 3 patients had foci of nodular regenerative hyperplasia, which was best seen with the reticulin silver impregnation method., Conclusions: Thioguanine-treated inflammatory bowel disease patients are at risk for the development of nodular hyperplasia. Reticulin-stained histologic sections are necessary to recognize this change. Further studies are needed to determine the frequency and significance of this change.

Background & Aims: Thioguanine (6-TG) has been studied as an alternative thiopurine in inflammatory bowel disease (IBD). Short-term safety and efficacy data were favorable. Experience with 6-TG in patients with acute lymphoblastic leukemia raised long-term safety concerns when implicated in nodular regenerative hyperplasia (NRH) of the liver and portal hypertension. The aim of this study was to describe the association between 6-TG and NRH in IBD., Methods: Liver chemistries and complete blood counts were monitored, and patients were encouraged to undergo liver biopsy. Clinical data were collected by chart review, and associations were tested by univariate and multivariable analyses. Patients were classified based on the presence (group 1) or absence (group 2) of laboratory abnormalities., Results: Laboratory abnormalities occurred in 29 of 111 patients (26%). Elevations of liver enzymes and a decrease in platelet counts (<200,000) were most commonly observed. Male gender (odds ratio, 2.9; 95% CI, 1.1-7.3; P < 0.03) and preferential 6-methylmercaptopurine production on 6-mercaptopurine/azathioprine (odds ratio, 3.0; 95% CI, 1.2-7.4; P < 0.04) were independently associated with laboratory abnormalities. No association was seen with duration of 6-TG treatment, cumulative dose, or 6-TG nucleotide levels. The median increase in alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase levels was 39, 30, and 75 U/L, respectively, in group 1, and the median decrease in platelet count was 115,000 in group 1 versus 7000 in group 2 (P < 0.001). NRH occurred in 76% of patients undergoing biopsy in group 1 and 33% in group 2., Conclusions: NRH is a common finding in 6-TG-treated patients with IBD. The progression or reversibility of NRH remains unknown. Our findings suggest that 6-TG should not be considered as therapy for patients with IBD.

Tissue carcinoembryonic antigen (CEA) was studied in five groups of patients: eight ulcerative colitis patients with mild or no dysplasia, five ulcerative colitis patients with severe dysplasia, seven Crohn's disease patients with nondiseased colon, nine Crohn's disease patients with diseased colon., and 18 colorectal cancer patients from the noncancerous colon resection margins. CEA levels were significantly lower in the normal colon Crohn's group than all other groups (p < 0.05). CEA levels were significantly higher in the severe dysplasia ulcerative colitis group than all other groups (p < 0.05). The Crohn's disease patients with diseased colon, the ulcerative colitis patients with mild or no dysplasia, and the colorectal cancer group with noncancerous colon all had similar intermediate CEA levels. [ABSTRACT FROM AUTHOR]