Initial management of intraabdominal abscesses and preventive strategies for abscess recurrence in penetrating Crohn's disease: a national multicenter study based on ENEIDA registry.

INTRODUCTION: Intra-abdominal abscesses complicating Crohn's disease (CD) are a challenging situation. Their management, during the hospitalization and after resolution, is still unclear. METHODS: Adult patients with CD complicated with intraabdominal abscess who required hospitalization were included from the prospectively maintained ENEIDA registry from GETECCU. Initial strategy effectiveness and safety to resolve abscess was assessed. Survival analysis was performed to evaluate recurrence risk. Predictive factors associated with resolution were evaluated by multivariate regression and predictive factors associated with recurrence were assessed by Cox regression. RESULTS: 520 patients from 37 Spanish hospitals were included; 322 (63%) were initially treated with antibiotics alone, 128 (26%) with percutaneous drainage, and 54 (17%) with surgical drainage. The size of the abscess was critical to the effectiveness of each treatment. In abscesses < 30mm, the antibiotic was as effective as percutaneous or surgical drainage. However, in larger abscesses, percutaneous or surgical drainage was superior. In abscesses > 50mm, surgery was superior to percutaneous drainage, although it was associated with a higher complication rate. After abscess resolution, luminal resection was associated with a lower 1-year abscess recurrence risk (HR 0.43, 95% CI 0.24-0.76). However, those patients who initiated anti-TNF therapy had a similar recurrence risk whether luminal resection had been performed. CONCLUSIONS: Small abscesses (<30mm) can be managed with antibiotics alone, while larger ones require drainage. Percutaneous drainage will be effective and safer than surgery in many cases. After discharge, anti-TNF therapy reduces abscess recurrence risk in a similar way to bowel resection.

Recreation of an antigen-driven germinal center in vitro by providing B cells with phagocytic antigen.

Successful vaccines rely on activating a functional humoral immune response through the generation of class-switched high affinity immunoglobulins (Igs). The germinal center (GC) reaction is crucial for this process, in which B cells are selected in their search for antigen and T cell help. A major hurdle to understand the mechanisms of B cell:T cell cooperation has been the lack of an antigen-specific in vitro GC system. Here we report the generation of antigen-specific, high-affinity, class-switched Igs in simple 2-cell type cultures of naive B and T cells. B cell antigen uptake by phagocytosis is key to generate these Igs. We have used the method to interrogate if T cells confer directional help to cognate B cells that present antigen and to bystander B cells. We find that bystander B cells do not generate class-switched antibodies due to a defective formation of T-B conjugates and an early conversion into memory B cells.

Serological response to vaccines against SARS-CoV-2 in patients with inflammatory bowel disease. / Respuesta serológica a las vacunas frente a SARS-CoV-2 en pacientes con enfermedad inflamatoria intestinal.

OBJECTIVE: To study the serological response (SR) and tolerability of COVID-19 vaccine in patients with inflammatory bowel disease (IBD) and its relation with IBD treatment and type of vaccine. METHODS: Observational, cross-sectional study in patients with IBD vaccinated against COVID-19 without known previous infection. SR was analyzed by the determination of IgG antibodies against the S1 subunit. Safety was studied using a questionnaire to identify adverse effects (AE). RESULTS: 280 patients with IBD were included. Type of vaccines: Comirnaty® 68.8%; Spikevax® 10.8%, Vaxzevria® 18.3%, Ad26.COV2-S® 2.2%. 51.3% had AE, being 100% mild. 65% developed IgG antibodies after vaccination. The SR was higher for vaccines with mRNA technology (100% Spikevax®, 68.5% Comirnaty®) compared to those based on adenovirus vector (38.0% Vaxzevria®, 33.3% Ad26.COV2-S®) (P<.001). In the multivariate analysis, SR was related to age (<60 years; OR: 3.8, 95% CI 1.9-7.0; P<.001). The SR in patients with aminosalicylates was 65.4%, 61.4% with immunosuppressants, 65.8% with anti-TNF, and 68.7% with non-anti-TNF biologicals (P=.9). CONCLUSIONS: One third of patients with IBD did not develop antibodies with the initial vaccination against SARS-CoV-2. The SR to vaccines based on mRNA technology was higher, and it was related to age (higher in younger patients). Immunosuppressants and biologicals did not decrease SR. More than half of the patients presented AD, being mild in all cases.