Incidence of paraproteinaemia in blood donors.

Paraproteinemia was detected by agarose gel electrophoresis in 13 out of 3,800 apparently healthy blood donors of an Italian district. None of the subjects with a serum M component developed overt B cell malignancy over a prolonged period of observation. The incidence of paraproteinaemia was higher than that reported from previous surveys of similar populations of blood donors in other European countries, possibly due to the sensitivity of the technique adopted for the screening investigation. The main implications of the detection of monoclonal immunoglobulin abnormalities are briefly discussed with particular reference to the possible indications for routine screening of blood donors for the presence of paraproteins.