Faculty Bibliography

BACKGROUND: 6-Mercaptopurine (6-MP) and azathioprine (AZA) are effective for induction and maintenance therapy of Crohn's disease (CD) and ulcerative colitis (UC). There is an increased risk of lymphoma in patients with inflammatory bowel disease (IBD) treated with 6-MP/AZA. Little, however, is known about the prognosis of IBD patients treated with 6-MP/AZA who develop lymphoma. METHODS: We conducted a retrospective review of 8780 records from three tertiary IBD centers and the records of 600 lymphoma patients from an academic Hematology and Oncology Center. The primary endpoint variable was survival of IBD patients with a lymphoma diagnosis treated or not treated with 6-MP/AZA. A secondary endpoint was the relative survival rate (by gender, race, and ethnicity) extrapolated from the Surveillance Epidemiology and End Results (SEER) database, computed for each subject. RESULTS: Fourteen IBD patients were diagnosed with lymphoma. Twelve had CD and two had UC. Seven patients had treatment with 6-MP/AZA and seven had not. Two patients who received 6-MP/AZA died (both 1 year after diagnosis) and two patients who had not received 6-MP/AZA died (one after 2 years, another 3 years after diagnosis), all from lymphoma. Survival at last follow-up was similar to expected survival based on extrapolated SEER data for both 6-MP/AZA treated and untreated patients. CONCLUSIONS: We found no differences of survival with lymphoma between IBD patients and expected survival for the general population. Also, the prognosis for those IBD patients treated with 6-MP/AZA was not worse than lymphoma patients not treated with 6-MP/AZA. Statistical analysis, however, was limited by the small sample size and heterogeneity of the patients studied.

BACKGROUND: Crohn's disease (CD) has the highest prevalence among individuals of Ashkenazi Jewish (AJ) descent compared to non-Jewish Caucasian populations (NJ). We evaluated a set of well-established CD-susceptibility variants to determine if they can explain the increased CD risk in the AJ population. METHODS: We recruited 369 AJ CD patients and 503 AJ controls, genotyped 22 single nucleotide polymorphisms (SNPs) at or near 10 CD-associated genes, NOD2, IL23R, IRGM, ATG16L1, PTGER4, NKX2-3, IL12B, PTPN2, TNFSF15 and STAT3, and assessed their association with CD status. We generated genetic scores based on the risk allele count alone and the risk allele count weighed by the effect size, and evaluated their predictive value. RESULTS: Three NOD2 SNPs, two IL23R SNPs, and one SNP each at IRGM and PTGER4 were independently associated with CD risk. Carriage of 7 or more copies of these risk alleles or the weighted genetic risk score of 7 or greater correctly classified 92% (allelic count score) and 83% (weighted score) of the controls; however, only 29% and 47% of the cases were identified as having the disease, respectively. This cutoff was associated with a >4-fold increased disease risk (p < 10e-16). CONCLUSIONS: CD-associated genetic risks were similar to those reported in NJ population and are unlikely to explain the excess prevalence of the disease in AJ individuals. These results support the existence of novel, yet unidentified, genetic variants unique to this population. Understanding of ethnic and racial differences in disease susceptibility may help unravel the pathogenesis of CD leading to new personalized diagnostic and therapeutic approaches

Crohn's disease and ulcerative colitis are chronic, immune-mediated inflammatory bowel diseases (IBDs) of unknown etiology with high morbidity in patients who are not receiving adequate medical treatment. A variety of medical therapies are currently available, and much progress has been made to alleviate symptoms and restore quality of life. The mainstay of treatment in those with moderate to severe disease consists of medications that alter or suppress the body's immunologic attack on its own gastrointestinal tract. The medications currently in use are highly effective when given in the appropriate clinical context, but side effects are not uncommon and must be treated expeditiously when they occur. One class of immunosuppressive medication, 6-mercaptopurine and its prodrug azathioprine, is effective at inducing remission and improving the lives of patients with IBD. The most common side effects of these drugs are allergic reactions and rarely can they be severe and life threatening. These reactions can sometimes be overcome by desensitizing the immune system to the drug. This review emphasizes allergy to 6-mercaptopurine and azathioprine and the process of desensitization when these allergic reactions occur in order to continue use of this important class of medication in the total treatment of IBD

Although the risk of developing dysplasia and carcinomas in the colon is known to increase over time in patients with ulcerative colitis, data are scarce on the need for surveillance colonoscopies in patients with long-standing Crohn's colitis. This article discusses the results of a study by Friedman et al. conducted in 259 patients with chronic Crohn's colitis who received a median of four follow-up colonoscopies over 25 years after an initial negative examination result for dysplasia or carcinomas. The cumulative risk for developing dysplasia or carcinomas has only increased from 22% to 25% in the 10 years since the previous report from this study's authors, and the prevalence of extensive colitis was higher in study participants than that expected in a random population of patients with Crohn's colitis. However, Friedman et al. provide convincing evidence that long-term surveillance for the development of colonic dysplasia and cancers is advantageous in this population