mercaptopurine and Focal-Nodular-Hyperplasia

Nodular regenerative hyperplasia (NRH) is increasingly being recognised in patients with inflammatory bowel disease (IBD). However, the pathogenesis and incidence of NRH in IBD, and the putative roles played by azathioprine (AZA), mercaptopurine (MP), or tioguanine (TG) remain unclear.. To summarise the data on the association between NRH and thiopurine therapy in patients with IBD.. A literature search was performed in PubMed and MEDLINE databases using the keywords 'nodular regenerative hyperplasia AND (inflammatory bowel disease OR Crohn's disease OR ulcerative colitis) AND (azathioprine OR mercaptopurine OR tioguanine OR thioguanine).' No time limit was placed on studies included.. Inflammatory bowel disease patients treated with AZA have a cumulative incidence of NRH of approximately 0.6% and 1.28% at 5 and 10 years, respectively, whereas those treated with high-dose TG (>40 mg/day) have a frequency of NRH of up to 62%, which is higher in patients with elevated liver enzymes and/or thrombocytopaenia than those without these abnormalities (frequency 76% vs. 33%). Conversely, low-dose TG therapy (<20 mg/day) is relatively safe, with no cases of NRH observed. NRH has also been found in 6% of operated thiopurine-naïve IBD patients. Male gender, older age, and stricturing disease/small bowel resection have been consistently identified as high-risk factors for NRH.. The pathogenesis of nodular regenerative hyperplasia in patients with IBD is complex and multifactorial involving disease-specific, genetic and iatrogenic risk factors. Clinicians should maintain a high index of suspicion for diagnosing nodular regenerative hyperplasia, especially in IBD patients with high-risk factors on thiopurine therapy, regardless of the presence of laboratory abnormalities.

Topics: Azathioprine; Colitis, Ulcerative; Crohn Disease; Female; Focal Nodular Hyperplasia; Humans; Immunosuppressive Agents; Incidence; Male; Mercaptopurine; Risk Factors; Thioguanine; Time Factors

Topics: Adult; Allopurinol; Crohn Disease; Drug Therapy, Combination; Enzyme Inhibitors; Focal Nodular Hyperplasia; Humans; Hypertension, Portal; Immunosuppressive Agents; Male; Mercaptopurine

Thiopurine therapy, particularly thioguanine, has been associated with nodular regenerative hyperplasia (NRH) of the liver. Combination therapy of allopurinol and an adapted low-dose thiopurine leads to a pharmacokinetic profile that has similarities to that of thioguanine. Therefore, allopurinol-thiopurine combination therapy may also be associated with NRH of the liver. We assessed the prevalence of NRH in patients with inflammatory bowel disease (IBD) treated with allopurinol-thiopurine combination therapy by liver biopsy specimen examination.. An observational, cross-sectional study was conducted in a Dutch IBD-referral center. Adult patients with IBD, treated for at least 1 year with allopurinol-thiopurine combination therapy were eligible. All patients underwent a liver biopsy, after standard laboratory and thiopurine metabolite concentration assessments. Histopathology was assessed by an experienced liver pathologist.. Twenty-two patients with IBD were included. The mean duration of combination therapy at the time of the liver biopsy was 24.7 months (SD 5.7). NRH was observed in one of the biopsies (4.8%), any grade of nodularity was observed in 3 biopsy specimens (14%). Other findings included phlebosclerosis (24%), perisinusoidal fibrosis (81%), sinusoidal dilatation (43%), perivenular fibrosis (14%), and periportal fibrosis (29%). Around the time of biopsy, the median 6-thioguanine nucleotide and 6-methylmercaptopurine ribonucleotide concentrations were 705 pmol × 10 red blood cells (RBC) (interquartile range 498-915) and 355 pmol × 10 RBC (interquartile range 225-670).. The prevalence of histologically assessed NRH in patients with IBD, who were treated with allopurinol-thiopurine combination therapy, was 5%. This percentage is in line with thiopurine-naive and thioguanine-using patients with IBD. None of the included patients had clinical symptoms or signs suggestive of (noncirrhotic) portal hypertension.

Topics: Adult; Allopurinol; Antimetabolites; Cross-Sectional Studies; Drug Therapy, Combination; Female; Focal Nodular Hyperplasia; Humans; Inflammatory Bowel Diseases; Liver; Male; Mercaptopurine; Middle Aged; Netherlands; Prevalence