A study of possible ill effects from prolonged immunotherapy in treatment of allergic diseases.

It has been claimed that immunotherapy in allergic diseases may result in morbidity from chronic antigenic stimulation by the formation of immune complexes and by contributing to development of arteritis, amyloidosis and paraproteinaemia. We examined 35 older patients who received injections of allergen extracts for between two and 30 years and compared them with an age-matched control group. Treated patients had significantly higher serum IgG and lower total IgE than controls but no increased incidence of paraproteins or evidence of immune complex disease such as urinary abnormalities, increased Clq binding levels, cryoglobulins or rheumatoid fever.