Safety and Durability of Accelerated Infliximab Dosing Strategies in Pediatric IBD: A Single Center, Retrospective Study.

OBJECTIVES: Infliximab (IFX) is commonly used to treat children with inflammatory bowel disease (IBD). We previously reported that patients with extensive disease started on IFX at a dose of 10 mg/kg had greater treatment durability at year one. The aim of this follow-up study is to assess the long-term safety and durability of this dosing strategy in pediatric IBD. METHODS: We performed a retrospective single-center study of pediatric IBD patients started on IFX over a 10-year period. RESULTS: Two hundred ninety-one patients were included (mean age = 12.61, 38% female) with a follow-up range of 0.1-9.7 years from IFX induction. One hundred fifty-five (53%) were started at a dose of 10 mg/kg. Only 35 patients (12%) discontinued IFX. The median duration of treatment was 2.9 years. Patients with ulcerative colitis ( P ≤ 0.01) and patients with extensive disease ( P = 0.01) had lower durability, despite a higher starting dose of IFX ( P = 0.03). Adverse events (AEs) were observed to occur at a rate of 234 per 1000 patient-years. Patients with a higher serum IFX trough level (≥20 µg/mL) had a higher rate of AEs ( P = 0.01). Use of combination therapy had no impact on risk of AEs ( P = 0.78). CONCLUSIONS: We observed an excellent IFX treatment durability, with only 12% of patients discontinuing therapy over the observed timeframe. The overall rate of AEs was low, the majority being infusion reactions and dermatologic conditions. Higher IFX dose and serum trough level> 20 µg/mL were associated with higher risk of AEs, the majority being mild and not resulting in cessation of therapy.

Lymphoma in Pediatric-Onset Inflammatory Bowel Disease Treated with Infliximab Monotherapy: A Case Series.

BACKGROUND: Inflammatory bowel diseases (IBD) are often treated with anti-tumor necrosis factor alpha (anti-TNFα) medications. Concomitant treatment of IBD with anti-TNFα agents and immunomodulators appears to be associated with an increased risk for lymphoma. METHODS: Patients who developed lymphoma while on monotherapy with an anti-TNFα agent were identified at three centers. Institutional Review Board approval was obtained. RESULTS: Five adolescents and young adult patients with pediatric-onset IBD who were treated with infliximab (IFX) without exposure to thiopurines were subsequently diagnosed with lymphoma. Three of the five patients had bone involvement at presentation. Epstein-Barr virus was positive in 2 cases. Median time from diagnosis of IBD and exposure to IFX prior to diagnosis of lymphoma was 5 and 4.3 years, respectively. CONCLUSIONS: This case series reports long-term follow-up for young patients with IBD who were treated with IFX monotherapy and developed lymphoma. Three of the five patients had bone involvement. In general, the risk of lymphoma following exposure to anti-TNFα medications alone remains low, but the incidence of primary bone lymphomas in IBD has not been reported. Studies examining longer exposure times may be needed to determine the true lymphoma risk in patients treated with IFX monotherapy.

Vedolizumab Experience in Children and Adolescents With Inflammatory Bowel Disease: A Multicenter Observational Study.

Background: Vedolizumab is increasingly used off-label to treat children and adolescents with inflammatory bowel disease (IBD). In the absence of rigorous clinical trial experience, multicenter observational data are important to establish expectations for efficacy and safety. We examined 1-year outcomes following vedolizumab therapy in a large multicenter pediatric IBD cohort. Methods: We performed a retrospective study of 159 pediatric patients (4-17 years old) with IBD [78, Crohn disease (CD); 81, ulcerative colitis/IBD-unspecified (UC/IBD-U)] treated with vedolizumab for 1 year at 8 pediatric medical centers in the United States. Demographics, clinical outcomes, laboratory data, and vedolizumab dosing were recorded. The primary outcome was corticosteroid (CS)-free clinical remission at 1 year. Other measured outcomes were clinical remission at 12 and/or 24 weeks, laboratory outcomes at 1 year, and endoscopy/histology results at 1 year. Results: Among the 159 patients (mean age, 14.5 ± 2.4 years; 86% anti-TNF experienced), 68/159 (43%) achieved CS-free clinical remission at 1 year (CD, 35/78, 45%; UC/IBD-U, 33/81, 40%). Vedolizumab therapy failed and was discontinued in 33/159 (21%) patients prior to 1 year (CD, 18/78, 23%; UC/IBD-U, 15/81, 19%). While week 12 clinical remission was not predictive of 1-year clinical remission in either CD or UC/IBD-U, week 24 clinical remission was predictive of 1-year clinical remission only in CD patients. No infusion reactions or serious side effects were noted. Conclusions: Vedolizumab was safe and effective in this pediatric population with approximately 43% achieving CS-free clinical remission at 1 year. Similar efficacy was noted in both CD and UC.

Similar Long-Term Outcomes in Children Presenting With Abscess vs Phlegmon at Diagnosis of Crohn Disease.

Background: Limited data are available for long-term outcomes of pediatric patients with abdominal abscess or phlegmon at diagnosis of Crohn disease. Methods: We performed a retrospective chart review of such children over a recent 6-year period at 5 pediatric inflammatory bowel diseases. Results: Fifty-two patients (mean age 15.9 ± 1.8 years) were reviewed. Thirty-six had an abscess and 27 (75%) required resectional therapy compared to 16 with phlegmon which 10 (63%) requiring surgery. Overall (37/52) 71% had surgery which was performed within 6 months in 32 (86%). Conclusions: A similar high surgical rate exists whether pediatric patients with Crohn disease present with abscess or phlegmon.

Lithium-Induced Chronic Kidney Disease in a Pediatric Patient.

Lithium-induced nephropathy usually manifests in adulthood as it develops slowly after many years of cumulative exposure. There is very limited information available in pediatric patients. Renal function monitoring and timely intervention is the key in preventing lithium-induced chronic kidney disease in these patients. We report a case of a 14-year-old boy who was on lithium for almost 9 years for his complex psychiatric illness. He presented with increased urinary frequency and nocturia. His serum creatinine increased to 1.15 mg/dL (estimated glomerular filtration rate or eGFR 53 ml/min/1.73 m2) from a baseline of 0.78 mg/dL (eGFR 86 ml/min/1.73 m2) a year prior to this presentation. Results of the imaging study were consistent with lithium-induced nephropathy. He was managed conservatively. His serum creatinine returned to baseline of 0.78 mg/dL after a year of discontinuation of lithium, consistent with mild chronic kidney disease. This case highlights the fact that lithium-induced chronic kidney disease can present in pediatric age group when lithium is initiated at a young age in children and that timely intervention may prevent further progression of renal damage. In addition to drug levels, routine monitoring of renal function during lithium therapy is essential.

Role of large thermal fluctuations and magnesium ions in t-RNA selectivity of the ribosome.

The fidelity of translation selection begins with the base pairing of codon-anticodon complex between the m-RNA and tRNAs. Binding of cognate and near-cognate tRNAs induces 30S subunit of the ribosome to wrap around the ternary complex, EF-Tu(GTP)aa-tRNA. We have proposed that large thermal fluctuations play a crucial role in the selection process. To test this conjecture, we have developed a theoretical technique to determine the probability that the ternary complex, as a result of large thermal fluctuations, forms contacts leading to stabilization of the GTPase activated state. We argue that the configurational searches for such processes are in the tail end of the probability distribution and show that the probability for this event is localized around the most likely configuration. Small variations in the repositioning of cognate relative to near-cognate complexes lead to rate enhancement of the cognate complex. The binding energies of over a dozen unique site-bound magnesium structural motifs are investigated and provide insights into the nature of interaction of divalent metal ions with the ribosome.