Background and Aim: Tacrolimus is highly effective in intractable ulcerative colitis, but maintenance may be problematic. This study examined 52-week maintenance and adverse events. Methods: This retrospective study of patients who used tacrolimus from April 2009 to December 2021 (N = 136) examined remission induction rates and background factors in the remission (n = 108) and non-remission groups (n = 28); 52-week maintenance; drug-specific maintenance (azathioprine [n = 58] vs tacrolimus [n = 12] and vs biological product [Bio, n = 8]); and adverse events. Results: The mean observation period was 1230175 days. Remission occurred in 72.7%. Significant differences were observed in sex and endoscopic score (before treatment and 2 weeks after tacrolimus trough levels). Maintenance rate at 52 weeks was 61.6%; significant differences were observed in sex, hospitalization duration, and prednisolone during hospitalization (P < 0.05). Drug-specific 52-week maintenance was 67% with azathioprine, 54% with tacrolimus, and 37% with Bio. No tacrolimus-related serious adverse events occurred that led to discontinuation. Discussion: Remission was more common in women with improved endoscopic scores after tacrolimus trough levels and patients with improved endoscopic scores after tacrolimus therapy. Remission maintenance was more common in women with a long hospitalization at remission and high total steroid dose. Results suggest that treatment with adequate prednisolone use during the period with more inflammation may improve subsequent maintenance. Conclusions: In intractable ulcerative colitis, tacrolimus can induce remission even in patients who cannot use azathioprine for maintenance. Remission can be maintained with azathioprine, tacrolimus, or a Bio.

Pediatric onset multiple sclerosis (POMS), characterized by the onset of multiple sclerosis before the age of 18, is gaining increased recognition. Approximately 5 percent of MS cases manifest before the age of 18, with less than 1 percent occurring before the age of 10. Despite its rarity, pediatric MS exhibits distinct characteristics, with an association between younger age at onset and a comparatively slower disease progression. Despite this slower progression, individuals with POMS historically reach disability milestones at earlier ages than those with adult-onset multiple sclerosis. While various immunomodulatory agents demonstrate significant benefits in MS treatment, such as reduced relapse rates and slower accumulation of brain lesions on magnetic resonance imaging (MRI), the majority of disease-modifying therapies (DMTs) commonly used in adult MS lack evaluation through pediatric clinical trials. Current evidence is predominantly derived from observational studies. This comprehensive review aims to consolidate existing knowledge on the mechanisms of action, efficacy, safety profiles, and recommended dosages of available DMTs specifically in the context of pediatric MS. Furthermore, the review outlines recent advancements and explores potential medications still in developmental stages, providing a thorough overview of the current landscape and future prospects for treating POMS.