Common variable immunodeficiency syndrome with chronic diarrhoea.

Common variable immunodeficiency syndrome (CVID) is a heterogeneous disorder characterised by diminished levels of IgG, IgA and/or IgM, and recurrent bacterial infections. Sinopulmonary infections are most commonly reported followed by gastrointestinal (GI) infections. GI tract represents the largest immune organ with abundance of lymphoid cells, its involvement can manifest variably ranging from asymptomatic involvement to florid symptoms and signs. Diffuse nodular lymphoid hyperplasia (DNLH) of the GI tract is characterised by numerous small polypoid nodules of variable size in the small intestine, large intestine or both. It is commonly seen in association to immunodeficiency states such as CVID, IgA deficiency and chronic infections due to Giardia lamblia and Helicobacter pylori and cryptosporidiosis. Repetitive antigenic stimulation leads to lymphoid hyperplasia. We herein describe a case of DNLH of the intestine and another case of duodenal cytomegalovirus (CMV) infection associated with CVID. © BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.