Factors Associated With Chronic Intestinal Inflammation Resembling Inflammatory Bowel Disease in Pediatric Intestinal Failure: A Matched Case-Control Study.

BACKGROUND AND AIMS: There is a subset of intestinal failure patients with associated chronic intestinal inflammation resembling inflammatory bowel disease. This study aimed to evaluate factors associated with chronic intestinal inflammation in pediatric intestinal failure. METHODS: This was a single-center retrospective case-control study of children <18 years old with intestinal failure. Cases were defined by abnormal amounts of chronic intestinal inflammation on biopsies. Children with diversion colitis, eosinophilic colitis, or isolated anastomotic ulceration were excluded. Cases were matched 1:2 to intestinal failure controls based on sex, etiology of intestinal failure, and duration of intestinal failure. Multivariable conditional logistic regression was used to compare clinical factors between cases and controls, accounting for clustering within matched sets. A subgroup analysis was performed assessing factors associated with escalation of anti-inflammatory therapy. RESULTS: Thirty cases were identified and matched to 60 controls. On univariate analysis, longer parenteral nutrition (PN) duration (1677 vs 834 days, P = 0.03), current PN use (33.3% vs 20.0%, P = 0.037), and culture-proven bacterial overgrowth (53.3% vs 31.7%, P = 0.05) were associated with chronic intestinal inflammation. On multivariable analysis, no variable reached statistical significance. On subgroup analysis, duration of intestinal failure, location of inflammation, and worst degree of inflammation on histology were associated with escalation of therapy. CONCLUSIONS: PN dependence and intestinal dysbiosis are associated with chronic intestinal inflammation in children with intestinal failure. Severity of inflammation is associated with escalation of therapy. Further analysis is needed to assess these associations and the efficacy of treatments in this population.

Breaking Down Barriers: Epithelial Contributors to Monogenic IBD Pathogenesis.

Monogenic causes of inflammatory bowel diseases (IBD) are increasingly being discovered. To date, much attention has been placed in those resulting from inborn errors of immunity. Therapeutic efforts have been largely focused on offering personalized immune modulation or curative bone marrow transplant for patients with IBD and underlying immune disorders. To date, less emphasis has been placed on monogenic causes of IBD that pertain to impairment of the intestinal epithelial barrier. Here, we provide a comprehensive review of monogenic causes of IBD that result in impaired intestinal epithelial barrier that are categorized into 6 important functions: (1) epithelial cell organization, (2) epithelial cell intrinsic functions, (3) epithelial cell apoptosis and necroptosis, (4) complement activation, (5) epithelial cell signaling, and (6) control of RNA degradation products. We illustrate how impairment of any of these categories can result in IBD. This work reviews the current understanding of the genes involved in maintaining the intestinal barrier, the inheritance patterns that result in dysfunction, features of IBD resulting from these disorders, and pertinent translational work in this field.

A comprehensive review of monogenic causes of IBD that result in impaired intestinal epithelial barrier is detailed, including genes involved in maintaining the intestinal barrier, features of IBD resulting from these disorders, and pertinent translational work in this field.

Cryptogenic organizing pneumonia after rituximab therapy for presumed post-kidney transplant lymphoproliferative disease.

Cryptogenic organizing pneumonia (COP, formerly bronchiolitis obliterans organizing pneumonia) is rare in children. We describe an 11-year-old girl with Epstein-Barr virus (EBV) reactivation/presumed post-transplant lymphoproliferative disease (PTLD) 15 months after undergoing a deceased donor kidney transplantation. Treatment with reduced immunosuppression, ganciclovir, and cytomegalovirus immunoglobulin was complicated by severe graft rejection, prompting therapy with methylprednisolone, anti-thymocyte globulin and four weekly doses of rituximab (total 1500 mg/m(2)). Tacrolimus- and prednisone-based anti-rejection prophylaxis was complemented with low-dose sirolimus. When the lactate dehydrogenase and uric acid levels rose 10 weeks after the first rituximab infusion and bilateral pulmonary nodules were detected by computerized tomography, recurrence of PTLD was suspected. Open lung biopsy of the clinically asymptomatic patient identified the nodules as COP, characterized by abundant CD3(+) T-cells, few B-cells, and the absence of EBV, cytomegalovirus, or adenovirus antigens. With normalization of the peripheral B-cell count, EB viremia reappeared and persisted, despite minimal immunosuppression. Four years later, the patient was diagnosed with classical Hodgkin lymphoma-type PTLD with multiple pulmonary and abdominal nodes. This first report of rituximab-associated, pediatric COP highlights the risk of pulmonary complications after treatment with B-cell depleting agents in solid organ transplant recipients, and the importance of a histopathologic diagnosis and vigilant follow-up of such lesions.

Rituximab treatment of collapsing C1q glomerulopathy: clinical and histopathological evolution.

A 13-year-old girl with obesity and hyperinsulinism developed steroid-resistant nephrotic syndrome due to collapsing glomerulopathy with dominant C1q-containing mesangial immune deposits (CG/C1qN). She became overtly diabetic while receiving alternate-day prednisone and tacrolimus, requiring insulin injections. Despite the addition of mycophenolate mofetil to the treatment regimen, renal function subsequently declined. Rituximab (four weekly doses of 375 mg/m2) was tried 6 months after initial presentation and 3 months after weaning all glucocorticoids. Glomerular filtration rate (GFR) and proteinuria improved. Unexpectedly, blood sugar control normalized 6 weeks after antibody infusion. Rituximab was readministered 20 months after the first course because of deteriorating renal function, but the effect on GFR and proteinuria was modest. A retrospective analysis revealed that tubulointerstitial infiltrates present in the biopsies prior to treatment with rituximab contained numerous CD20+ and CD3+ (CD4 > CD8) lymphocyte aggregates. Rebiopsy 10 weeks after repeat rituximab therapy demonstrated the elimination of B-cell infiltrates and the apparent decrease of interstitial T-cell infiltrates, yet persistent, advanced global glomerulosclerosis, interstitial fibrosis and tubular atrophy. In conclusion, CG/C1qN was associated with B- and T-cell-rich tubulointerstitial infiltrates. B-cell-directed therapy delayed clinical progression during early disease but failed to prevent or ameliorate chronic changes, despite effective tissue B-cell clearance. The incidental resolution of diabetes was noted after rituximab treatment.