Patients with CVID will be offered to participate in this observational trial during the routine annual visit in the outpatient clinic at the Center of chronic Immunodeficiency (CCI) of the University Medical Center Freiburg, Germany. Clinical and laboratory data at the time of presentation will be assessed. Additionally, parameters of abdominal ultrasound, duplex sonography of the liver and spleen, and liver and spleen stiffness at the time of presentation will be evaluated. If applicable, clinical and/or interventional parameters indicating clinically significant portal hypertension (i.e. presence of varices or portal-hypertensive gastropathy in esophago-gastroduodenoscopy, presence of ascites) within 12 months prior and after the index visit will be assessed. During the visit, serum/plasma samples and peripheral blood mononuclear cells (PBMC) are collected and stored in an associated biobank.