BACKGROUND/AIMS: Mesalazine is an effective drug for treating ulcerative colitis (UC), but causes allergic symptoms in a few cases. Therefore, the objective of this study was to evaluate the usefulness of the drug-induced lymphocyte stimulation test (DLST) for the diagnosis of mesalazine allergy. METHODS: Patients with UC treated with mesalazine with or without a history of associated adverse events (AEs) were enrolled at Kyorin University Hospital from July 2016 to April 2017. RESULTS: The DLST was performed in 104 patients with UC, of which 24 had a history of AEs due to mesalazine treatment. The control value of DLST was 337.4±296.3 counts per minute (cpm) in the AE+ group and 408.0±371.9 cpm in the AE− group. The measured value of DLST was 578.8±424.7 cpm in the AE+ group and 476.5±471.8 cpm in the AE− group. The stimulation index (SI) was 243.9%±291.1% in the AE+ group and 119.8%±53.0% in the AE− group. The SI value and DLST positivity were significantly higher in the AE+ group than in the AE− group (P=0.030 and P=0.029, respectively). The test sensitivity and specificity were 0.240 and 0.805, respectively, and the false-positive and false-negative rate was 0.195 and 0.760, respectively. CONCLUSIONS: The DLST for mesalazine showed low sensitivity and high specificity, suggesting that it may be useful for the definitive diagnosis of allergy to mesalazine.
Colitis, Ulcerative ; Diagnosis ; Humans ; Hypersensitivity* ; Lymphocyte Activation* ; Lymphocytes* ; Mesalamine* ; Sensitivity and Specificity

We report a case of ureteral endometriosis thought to have developed following relapse of pelvic peritoneal endometriosis after laparoscopic surgery. The patient was a woman in her late 40s who had undergone laparoscopic right adnexectomy for an endometrial cyst 5 years earlier. Electrocoagulation was performed for residual endometriosis of adherent cyst wall on the right sacrouterine ligament. The normal left ovary was preserved and she received no postoperative hormonal therapy. She developed right back pain during menstruation 5 years after the surgery. Pyeloureterography revealed stenosis of the ureter to the right of the uterus. Urinary cytology revealed endometrial cells with no atypia. Conservative management was opted for because malignant transformation of endometriosis was considered unlikely and she was expected to reach menopause within a few years. She is now doing well 24 months after initiation of progestin treatment with placement of a ureteral stent. Postoperative hormonal therapy is recommended for patients who are considered to have possible lesions of residual endometriosis and for whom ovarian function is preserved.