Gert De Hertogh © ECCO

The past 2 years, 2020 and 2021, have been challenging for everybody, but with the help of the ever-enthusiastic ECCO Organisation and their co-workers, the H-ECCO Committee was able to organise a well-attended masterclass at the recent virtual congress in July.

We divided the masterclass into four sessions: Basics of IBD, Scoring Schemes and Standards, Neoplasia and New Concepts in IBD.

Pamela Baldin © ECCO

Paediatric-onset Inflammatory Bowel Diseases (IBDs) represent about 25%–30% of all IBDs. As in adult patients, cases are classified as Ulcerative Colitis (UC) or Crohn’s Disease (CD). In addition, a third diagnostic category, unclassified-IBD (U-IBD), can be used when a definite differential diagnosis between UC and CD is not possible.

Paediatric-onset IBDs, by definition, are those IBDs which are diagnosed in children and adolescents under the age of 17 years. They are further categorised as very early onset IBD (VEO-IBD) when the disease is diagnosed before 6 years of age, infantile IBD when the diagnosis is made before 2 years of age and neonatal-onset IBD when the patient is 28 days old or less. 

Francesca Rosini  © ECCO

The histological diagnosis of Inflammatory Bowel Disease (IBD) is not an easy task for a pathologist. In the modern era, personal pathology experience alone is insufficient to make a diagnosis of IBD. The information that a pathologist must know in order to evaluate IBD samples appropriately and to make a diagnosis is diverse, and for the most part should be provided by the gastroenterologists, surgeons or clinicians responsible for the care of patients. Even the most experienced pathologist cannot report a case without knowing the clinical background of the patient. Obviously, this should be the standard for all samples, not only for IBD.

Ann Driessen © ECCO

Pamela Baldin © ECCO

The animal model is a useful tool to unravel different pathogenetic mechanisms, to detect biomarkers for monitoring and to test the efficacy and safety of drugs in the preclinical phase. In Inflammatory Bowel Disease (IBD) research, the mouse is the most widely used animal model. Animal models are classified into four categories, namely chemical models, cell transfer models, genetically engineered models, and congenic models. Based on the mechanism of the animal model, different aspects of the pathogenesis of intestinal inflammation in IBD are examined, such as epithelial integrity and wound healing, and innate and adaptive immunity [1].

Gert De Hertogh  © ECCO

As the new chair of the H-ECCO Committee, it is my pleasure to introduce our two newly elected members for 2020, Ann Driessen and Pamela Baldin, who are both Belgian pathologists. Thus, the current members of the H-ECCO Committee are: Monika Tripathi (Addenbrooke’s Hospital, Cambridge, UK), Francesca Rosini (Imperial College Healthcare NHS Trust, London, UK), Ann Driessen, Pamela Baldin, and myself, Gert De Hertogh (University Hospitals KULeuven, Belgium).

Roger Feakins © ECCO

The Histopathology Committee of ECCO (H-ECCO) is now more than 5 years old, having started as a new working group. It is an enthusiastic group that supports various activities and interacts well with other ECCO Committees. The most identifiable and consistent activity is the H-ECCO IBD Masterclass, a successful event attracting more than 70 delegates annually from Europe and further afield.

Francesca Rosini © ECCO

Crohn’s Disease (CD) and Ulcerative Colitis (UC) are considered multisystemic diseases. They affect the gastrointestinal tract but can also involve other systems and organs. Almost 50% of patients with Inflammatory Bowel Diseases (IBDs) experience at least one extraintestinal manifestation (EIM). The principal organs and structures affected by EIMs are, amongst others, joints and bones, eyes, liver and the hepatobiliary system and skin [1].

Monika Tripathi © ECCO

Elective or emergency surgical interventions in the management of Inflammatory Bowel Disease (IBD) are mainly reserved for patients with medical refractory disease and life-threatening complications. Approximately 20%–30% of Ulcerative Colitis (UC) and 70%–80% of Crohn’s Disease (CD) patients will need surgery within the first to second decade following primary disease diagnosis [1].

Magali Svrcek © ECCO

Immune checkpoints (ICK) are downregulators of T cell immunity. Immune checkpoint inhibitors (ICKi), by blocking the co-inhibitory receptors on T cells to activate their cytotoxic immune function, have become a major therapeutic tool in oncology, notably for the treatment of metastatic melanoma, non-small cell lung carcinoma, renal cell carcinoma, urothelial carcinoma and mismatch repair (MMR) deficient/microsatellite-unstable tumours. In particular, therapeutic monoclonal antibodies have emerged against cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), which primarily inhibits T cell activation, and programmed cell death 1 (PD-1), which limits the effector function of activated T cells in the periphery. Food and Drug Administration-approved ICKi include ipilimumab (CTLA-4 inhibitor), pembrolizumab and nivolumab (anti-PD-1) and atezolizumab (anti-PD-L1).

Gert de Hertogh © ECCO

Histopathologists have traditionally fulfilled three functions in Inflammatory Bowel Disease (IBD) care. First, they play a role in the initial diagnosis, together with gastroenterologists, endoscopists and radiologists. Second, they establish a differential diagnosis at clinical flares of the disease, resolving the question of whether there is reactivation of the IBD, a superinfection or an unrelated pathology. Third, they are involved in the screening of patients for premalignant lesions and cancer.