Splenic lesions in a patient with Crohn's disease

A bidirectional Mendelian randomization study of spleen volume and Crohn disease

In observational studies, there has been an association found between spleen volume and Crohn disease. We conducted a two-way, two-sample Mendelian randomization analysis to determine whether these associations have a causal relationship. Single nucleotide polymorphisms (P < 5 × 10-8) were used as instrumental variables for spleen volume and Crohn disease. Estimates of the genetic associations between spleen volume and Crohn disease were obtained from the Integrative Epidemiology Unit, European Bioinformatics Institute, UK Biobank, and FinnGen databases. Analysis was performed using MR-Egger regression, weighted median estimator, inverse variance weighted, simple model, and weighted model. Genetically predicted spleen volume was found to be associated with Crohn disease. In the IEU database, the odds ratios (ORs) for Crohn disease caused by spleen volume were 1.237 (95% CI, 1.056-1.417, P = .021), and the ORs for spleen volume caused by Crohn disease were 1.015 (95% CI, 0.985-1.044; P = .049). In the EBI database, the ORs for Crohn disease caused by spleen volume were 1.292 (95% CI, 1.120-1.463, P = .003), and the ORs for spleen volume caused by Crohn disease were 1.026 (95% CI, 1.005-1.046; P = .013). Results from the UKB and FinnGen databases showed no causal relationship between the two. The summary results showed that Crohn disease caused an increase in spleen volume, with ORs of 1.009 (95% CI, 1.000-1.018; P = .047). This study provides evidence for a mutual causal relationship between spleen volume and an increased risk of Crohn disease.

Aseptic Abscess Syndrome: Clinical Characteristics, Associated Diseases, and up to 30 Years’ Evolution Data on a 71-Patient Series

Aseptic abscess (AA) syndrome is a rare type of inflammatory disorder involving polymorphonuclear neutrophils (PMNs), often associated with inflammatory bowel disease (IBD). This study sought to describe the clinical characteristics and evolution of this syndrome in a large cohort. We included all patients included in the French AA syndrome register from 1999 to 2020. All patients fulfilled the criteria outlined by André et al. in 2007. Seventy-one patients were included, 37 of which were men (52.1%), of a mean age of 34.5 ± 17 years. The abscesses were located in the spleen (71.8%), lymph nodes (50.7%), skin (29.5%), liver (28.1%), lung (22.5), and rarer locations (brain, genitals, kidneys, ENT, muscles, or breasts). Of all the patients, 59% presented with an associated disease, primarily IBD (42%). They were treated with colchicine (28.1%), corticosteroids (85.9%), immunosuppressants (61.9%), and biologics (32.3%). A relapse was observed in 62% of cases, mostly in the same organ. Upon multivariate analysis, factors associated with the risk of relapse were: prescription of colchicine (HR 0.52; 95% CI [0.28–0.97]; p = 0.042), associated IBD (HR 0.57; 95% CI [0.32–0.99]; p = 0.047), and hepatic or skin abscesses at diagnosis (HR 2.14; 95% CI [1.35–3.40]; p = 0.001 and HR 1.78; 95% CI [1.07–2.93]; p = 0.024, respectively). No deaths occurred related to this disease. This large retrospective cohort study with long follow up showed that AA syndrome is a relapsing systemic disease that can evolve on its own or be the precursor of an underlying disease, such as IBD. Of all the available treatments, colchicine appeared to be protective against relapse.