Crohn's-like Enteritis in X-Linked Agammaglobulinemia: A Case Series and Systematic Review

Cellular and molecular basis of proximal small intestine disorders

The proximal part of the small intestine, including duodenum and jejunum, is not only dedicated to nutrient digestion and absorption but is also a highly regulated immune site exposed to environmental factors. Host-protective responses against pathogens and tolerance to food antigens are essential functions in the small intestine. The cellular ecology and molecular pathways to maintain those functions are complex. Maladaptation is highlighted by common immune-mediated diseases such as coeliac disease, environmental enteric dysfunction or duodenal Crohn's disease. An expanding spectrum of more than 100 rare monogenic disorders inform on causative molecular mechanisms of nutrient absorption, epithelial homeostasis and barrier function, as well as inflammatory immune responses and immune regulation. Here, after summarizing the architectural and cellular traits that underlie the functions of the proximal intestine, we discuss how the integration of tissue immunopathology and molecular mechanisms can contribute towards our understanding of disease and guide diagnosis. We propose an integrated mechanism-based taxonomy and discuss the latest experimental approaches to gain new mechanistic insight into these disorders with large disease burden worldwide as well as implications for therapeutic interventions.

In vivo staging of colitis, adenoma and carcinoma in CRC progression by combination of H4R/DRD4-targeted fluorescent probes

Colorectal cancer (CRC) is the third most prevalent malignancy and the second leading cause of cancer-related mortality worldwide. Currently, CRC staging heavily relies on invasive surgical procedures for in vitro pathological analysis, which entails long detection cycles and increases the risk of metastasis. There is an urgent need for specific biomarkers to classify adenomas and cancers, while early in vivo staging detection could potentially reduce mortality and morbidity rates. This study focused on Type IV histamine receptor (H4R), which is highly expressed only in the inflammatory stage, and Dopamine receptor D4 (DRD4), which is highly expressed in colorectal adenoma and carcinoma stages. Fluorescent targeted molecular probes H4R-Cy5 and DRD4-M were constructed respectively. The in vitro cell level proves that H4R-Cy5 only has high specificity for RAW264.7 cells, and DRD4-M only has good affinity for HT29 cells. In inflammation-HT29 subcutaneous tumors, H4R-Cy5 and DRD4-M can target inflammation and tumor lesions respectively. In addition, this study is the first to combine the two probes to explore the feasibility of in vivo non-invasive staging on CRC mouse models. The results show that H4R-Cy5 can distinguish and identify the stages of inflammation in vivo, and the DRD4-M probe can accurately identify the stages of colorectal adenoma and carcinoma in vivo. The combination of these two probes can achieve precise non-invasive staging of colitis, adenoma and carcinoma, which is a major advance in the development of accurate diagnostic methods for colorectal precancerous lesions and has important implications for the selection of treatment strategies.

Ustekinumab in pediatric patients with Crohn's disease: safety, and efficacy results from a multicenter retrospective study in China

Background

Ustekinumab (UST) is approved as an effective therapy for Crohn's disease (CD) in adults. Off-label use is increasing in the pediatric population, more data on safety and efficacy in pediatric patients with CD is urgently needed.

Aims

This study aimed to evaluate the clinical efficacy and safety of UST in children and adolescents with Crohn's disease.

Methods

This multicenter retrospective study carried out at three tertiary care centers, and identified children who received their first dose of UST at 18 years old or younger and followed up for a minimum of 24 weeks. Data on demographics, disease behavior, location and activity, treatment history were collected. The primary outcomes were clinical remission at weeks 24-32 and weeks 48-56 of UST therapy. Secondary outcomes were clinical response at the same time points, endoscopic remission, changes in C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), albumin and fecal calprotectin, improvement in growth parameters, and rate of adverse events.

Results

Sixteen patients were included, and 11/13 (84.6%) continued to receive UST after 1 year. Our data demonstrate that the clinical remission rates were 41.7% at weeks 24∼32 with the Weighted pediatric CD activity index (wPCDAI) was lower than baseline (43.8, IQR: 31.3-51.9 vs.15, IQR: 5.6-25, p < 0.001) and 75% at weeks 48-56 with wPCDAI was lower than baseline (42.5, IQR: 23.8-50 vs. 7.5, IQR: 0-13.8, p = 0.004). Five of eleven children achieved endoscopic remission. No serious adverse events were recorded during the study period.

Conclusions

UST is efficacious and safe in pediatric patients with CD. Pediatric patients could benefit from UST as either a primary or secondary biologic therapy for the induction, or maintenance of remission of CD.