Primary hypogammaglobulinemia with IBD-like features: An ECCO CONFER Multicenter Case Series.

Hypogammaglobulinemia is a disorder characterized by low serum immunoglobulin levels and had high prevalence of gastrointestinal manifestations. In some cases, clinical and endoscopic features are indistinguishable from those of inflammatory bowel disease (IBD). This was a multicenter case series performed as a part of the European Crohn's and Colitis Organisation (ECCO) Collaborative Network of Exceptionally Rare case reports (CONFER) project. This report includes 27 patients with primary hypogammaglobulinemia and IBD-like features [20 males and 7 females, median age 45.6 years (Interquartile range (IQR) 35.2-59]. Crohn's disease-like features were noted in 23 patients, four patients had ulcerative colitis-like features. The diagnosis of hypogammaglobulinemia preceded IBD-like features diagnosis in 20 patients (median of 7 years prior, IQR 2.6-20.6 years), and followed IBD-like features appearance in 7 cases (median of one year after, IQR 0.45-5.6 years).Hypogammaglobulinemia etiologies were common variable immunodeficiency (66.6%), agammaglobulinemia (7.4%), selective IgA-deficiency (11.1%), Goods syndrome (7.4%), IgG subclass deficiency with IgA deficiency (3.7%) and hyper-IgM (3.7%). In addition to antibiotics and intravenous immunoglobulin (IVIG) for hypogammaglobulinemia, 12 patients received IBD-related treatment including 5-ASA (2 patients), corticosteroids (1 patient), thiopurines (3 patients), anti-TNFs (4 patients) and vedolizumab (2 patients). By the end of the follow-up [44.5 months (IQR 18-81)], 21/27 (77%) patients were in clinical remission. This case series describes IBD-like features in patients with hypogammaglobulinemia. The diagnosis of IBD-like features mainly occurred after that of hypogammaglobulinemia, with successful recovery in the majority of cases after appropriate treatment.