C1 inhibitor deficiency in a patient with rheumatoid arthritis--increased risk of adverse effects of penicillamine?

We report the coincidence of hereditary angioedema and rheumatoid arthritis in a male patient and in his father. During treatment with D-penicillamine the patient developed a transient lupus-like disorder with glomerulonephritis that resolved when D-penicillamine was discontinued. He later was diagnosed with malignant lymphoma. Impaired classical complement pathway function could have contributed to development of the drug reaction.