Gastrointestinal disorders in patients with common variable immunodeficiency

Abstract

Common variable immunodeficiency (CVID) is a group of inherited antibody immune disorders. Patients often suffer from recurrent bacterial infections, autoimmune or dysregulatory complications, and have an increased risk of developing cancer (e. g., lymphoma, gastric cancer). The most common gastrointestinal pathogens include Helicobacter pylori, Campylobacter jejuni, and Giardia lamblia; in more severe cases, norovirus or cytomegalovirus (CMV) may cause significant diarrhoea. Bacterial overgrowth syndrome is also common. CVID is associated with alterations in the microbio­me, which contributes to complications in distant organs such as the lungs and liver. Non-infectious complications can affect the entire gastrointestinal tract. Notable examples include intestinal metaplasia of the gastric mucosa with a risk of carcinoma, enteropathy mimicking celiac dis­ease, inflammatory bowel dis­ease-like colitis, nodular regenerative hyperplasia, and pre-portal hypertension. These complications typically develop slowly and subtly over time. Once malnutrition sets in, irreversible changes to the intestinal mucosa are often present. Managing CVID requires a multidisciplinary approach and regular screening. Endoscopic examinations, including repeated and multiple bio­psies, are essential for accurate dia­gnosis. Elastography is suitable for detecting hepatopathies. Serological blood tests are generally not helpful. Treatment is challenging and should be individualized. Immunoglobulin replacement therapy reduces the frequency of infections only. In cases of non-infectious complications, immunomodulatory therapy is required and, tailored to the patient’s genetic background, if possible.