Infliximab desensitization in patients with inflammatory bowel diseases: a safe therapeutic alternative.

BACKGROUND: Hypersensitivity reactions (HSR) to the administration of infliximab (IFX) in Inflammatory Bowel Diseases (IBD) patients are not rare and usually lead to drug discontinuation. We report data on safety and effectiveness of desensitization to IFX in patients with previous HSR. METHODS: We conducted a retrospective monocentric observational study. Patients for whom a desensitization protocol to IFX was realized after a previous HSR were included. Anti-drug antibodies (ADA) and IFX trough levels at both inclusion and six months after desensitization were collected. Clinical outcomes, including recurrence of HSR were evaluated. RESULTS: From 2005 to 2020, 27 patients (Crohn's Disease: 26 (96%) were included). Desensitization after HSR was performed after a median time of 10.4 months (2.9-33.1). Nineteen (70%) patients received immunosuppressants at time of desensitization. Eight (30%) patients presented HSR at first (n = 2), second (n = 4) or third (n = 2) IFX perfusion after desensitization. None led to intensive care unit transfer or death. Thirteen (48%) had clinical response at 6 months and 8 (29%) were still under IFX treatment two years after desensitization. IFX trough levels and ADA were available for 14 patients at time of desensitization. Most patients (12 out of 14) had ADA at a high level. At 6 months, among the 7 patients with long term response to IFX, 4 presented a decrease of ADA titers and 2 had a significant trough level of IFX. CONCLUSION: IFX desensitization in patients with IBD is a safe therapeutic alternative and represents a potential option for patients refractory to multiple biologics.What is already known? Hypersensitivity reactions to the administration of infliximab is frequent. Occurrence of hypersensitivity reaction, either immediate or delayed, usually leads to permanent drug discontinuation.What is new here? Infliximab desensitization is well tolerated with no hypersensitivity reaction recurrence in 70% of patients. Clinical success at 6 months was of 48% and around a third of patients remained under infliximab therapy two years after desensitization. Antidrug antibodies decreased and infliximab trough levels increased in these patients showing the impact of desensitization on immunogenicity.How can this study help patient care? Infliximab desensitization represents a potential option for patients refractory to multiple biologics who presented hypersensitivity reaction to the drug.

Pneumocystis jirovecii Pneumonia in Patients with Inflammatory Bowel Disease-a Case Series.

BACKGROUND AND AIM: Pneumocystis jirovecii pneumonia [PJP] is a very rare, potentially life-threatening pulmonary fungal infection that occurs in immunocompromised individuals including patients with inflammatory bowel disease [IBD]. Our aim was to describe immunosuppressive treatment exposure as well as the outcome in IBD patients with PJP. METHODS: PJP cases were retrospectively collected through the COllaborative Network For Exceptionally Rare case reports of the European Crohn's and Colitis Organisation. Clinical data were provided through a case report form. RESULTS: In all, 18 PJP episodes were reported in 17 IBD patients [10 ulcerative colitis and seven Crohn's disease]. The median age at PJP diagnosis was 55 years (interquartile range [IQR], 40-68 years]. Two PJP [11.1%] occurred in patients on triple immunosuppression, 10 patients [55.6%] had double immunosuppressive treatment, four patients [22.2%] had monotherapy and two PJP occurred in absence of immunosuppressive treatment [one in a human immunodeficiency virus patient and one in a patient with a history of autologous stem cell transplantation]. Immunosuppressive therapies included steroids [n = 12], thiopurines [n = 10], infliximab [n = 4], ciclosporin [n = 2], methotrexate [n = 1], and tacrolimus [n = 1]. None of the patients diagnosed with PJP had received prophylaxis. All patients were treated by trimethoprim/sulphamethoxazole or atovaquone and an intensive care unit [ICU] stay was required in seven cases. Two patients [aged 71 and 32 years] died, and one patient had a recurrent episode 16 months after initial treatment. Evolution was favourable for the others. CONCLUSION: This case series reporting potentially fatal PJP highlights the need for adjusted prophylactic therapy in patients with IBD on immunosuppressive therapy.

Autologous organoid co-culture model reveals T cell-driven epithelial cell death in Crohn's Disease.

Lympho-epithelial interactions between intestinal T resident memory cells (Trm) and the epithelium have been associated with inflammatory bowel disease (IBD) activity. We developed ex vivo autologous organoid-mucosal T cell cocultures to functionally assess lymphoepithelial interactions in Crohn's Disease (CD) patients compared to controls. We demonstrate the direct epithelial cell death induced by autologous mucosal T cells in CD patients but not in controls. These findings were positively correlated with T cell infiltration of the organoids. This potential was inhibited by limiting lympho-epithelial interactions through CD103 and NKG2D blocking antibodies. These data directly demonstrate for the first time the direct deleterious effect of mucosal T cells on the epithelium of CD patients. Such ex-vivo models are promising techniques to unravel the pathophysiology of these diseases and the potential mode of action of current and future therapies.