Selective Immunoglobulin A Deficiency and Chronic Obstructive Lung Disease

A 43-year-old woman with far-advanced chronic obstructive lung disease had selective IgA deficiency. Twenty-eight members of her large family were studied; IgA deficiency was found in 6, and 7 others had borderline levels. Serum immunoglobulins G, M, and E were normal, as were alpha-1 antitrypsin levels. Clinical emphysema was found in the proband's mother and two brothers. Intermediate inheritance of IgA deficiency in this family is suggested by a history of consanguinity and intermediate levels of IgA in numerous family members; however, several obligate heterozygous individuals have normal levels. A relation between immunoglobulin deficiency and chronic obstructive lung disease would fit the hypothesis of a proteolytic cause for this disease.