Introduction Common variable immunodeficiency (CVID) is a primary immune disorder characterised by impaired B cell differentiation and hypogammaglobulinaemia. It predisposes to encapsulated bacterial infections, commonly affecting the respiratory tract. 8%–20% of CVID patients have a granulomatous form. Granulomatous CVID may share clinical features with sarcoidosis, namely persistent cough, breathlessness, fatigue, fever, and arthralgia. Non caseating granulomata in lymph node biopsies and elevated angiotensin converting enzyme levels occur in both conditions. Differentiation between the two conditions is essential to allow management with immunoglobulin replacement and avoidance of excessive corticosteroids.
Method Patients with a diagnosis of “sarcoidosis” recorded in chest clinic letters between April 2009 and September 2010 were identified. Clinic letters, blood tests, histology and imaging were reviewed.
Results 175 patients with a diagnosis of sarcoidosis were identified. 80% had lymphadenopathy and 62% pulmonary involvement. Dermatological, ocular, rheumatological and other involvement was found in 19%, 17%, 16% and 9% respectively. 24% had potential features of CVID, such as recurrent chest infections, sinusitis, bronchiectasis or inflammatory bowel disease. Total globulin had been measured in 172/175 (98%) patients. 45/172 (26%) had elevated total globulin; 3/172 (2%)had low total globulin levels. Immunoglobulins had been measured in 106/175 (61%). Immunoglobulins had been measured in: 20/28 (71%) of those with recurrent sinusitis or lower respiratory tract infections; 20/25 (80%) of those with bronchiectasis; and8/8 (100%) of those with both recurrent chest infections and bronchiectasis. Four patients had persistently low IgM, two had persistently low IgA and one had persistently low IgG. No single patient had polyclonal hypogammaglobulinaemia, but levels were not measured in 11/42 (26%) with potential features of CVID.
Conclusion Our study identified a cohort of patients with a diagnosis of sarcoidosis and features associated with CVID. We found that immunoglobulins were not being routinely measured during the work-up of patients with sarcoidosis as recommended by the Map of Medicine. Recent review of 28 local CVID patients identified two who were initially misdiagnosed with sarcoidosis. In one case this misdiagnosis persisted for 8 years. Granulomatous CVID is uncommon, but respiratory physicians should ensure that their routine work-up for sarcoidosis excludes this treatable condition.