Pathologica. 2021 Dec 2. doi: 10.32074/1591-951X-336. Online ahead of print.

Paola Parente ¹, Mario Pastore ², Federica Grillo ³, Matteo Fassan ⁴, Paola Francalanci ⁵, Angelica Dirodi ², Chiara Rossi ⁶, Giovanni Arpa ⁶, Paola De Angelis ⁷, Irene Gullo ⁸, Luca Mastracci ³, Rita Alaggio ⁵, Alessandro Vanoli ⁶

Author information

• ¹Pathology Unit, Fondazione IRCCS Ospedale Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy.
• ²Department of Pediatrics, Fondazione IRCCS Ospedale Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy.
• ³Anatomic Pathology, Ospedale Policlinico San Martino IRCCS, Genova, Italy; Anatomic Pathology, Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genova, Genova, Italy.
• ⁴Departement of Medicine (DIMED), Surgical Pathology Unit, University of Padova, Padova, Italy; Veneto Institute of Oncology, IOV-IRCCS, Padova, Italy.
• ⁵Pathology Unit, Department of Diagnostic and Laboratory Medicine, IRCCS Bambino Gesù Children's Hospital, Roma, Italy.
• ⁶Unit of Anatomic Pathology, Department of Molecular Medicine, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Pavia, Italy.
• ⁷Digestive Endoscopy and Surgery Unit, IRCCS Bambino Gesù Children's Hospital, Roma, Italy.
• ⁸Department of Pathology, Centro Hospitalar Universitário de São João (CHUSJ); Department of Pathology, Faculty of Medicine of the University of Porto (FMUP) and i3S - Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Portugal.

Abstract

Very early onset inflammatory bowel disease (VEO-IBD) represents approximately 25% of cases of IBD-like colitis occurring during childhood and, by definition, it is characterized by an onset prior to 6 years of age. This subgroup of patients presents significant differences from IBD occurring in older children and in adults, including a more severe clinical course, a reduced responsiveness to conventional IBD therapy, and a greater proportion of cases featuring an underlying monogenic disorder. Histological findings from gastro-intestinal (GI) biopsies are characterized by an IBD-like, apoptotic or enterocolitis-like pattern, complicating the differential diagnosis with other pediatric diseases involving GI tract. Moreover, individuals with monogenic disorders may develop significant comorbidities, such as primary immunodeficiency (PID), impacting treatment options. Without an appropriate diagnosis, the clinical course of VEO-IBD has greater potential for escalated treatment regimens involving extensive surgery, more intensive medical therapies and, even more important, inadequate recognition of underlying monogenic defect that may lead to inappropriate (sometimes fatal) therapy. For these reasons, an adequate context leading to an appropriate diagnosis is imperative, calling for a close collaboration between pediatricians, pathologists, geneticists, and immunologists.