Incidence of gammopathies in long-term plasmapheresis donors at Canadian Blood Services.

Abstract

To investigate the long-term consequences of repeated plasmapheresis on donor health, their donation histories and demographic data were reviewed to determine the frequency of development of monoclonal (Mc) gammopathies or other gamma globulin abnormalities (OGGAs). Samples from apheresis plasma donors collected at Canadian Blood Services were tested initially and every 4 months for total protein (TP) followed by serum protein electrophoresis (SPE). Out-of-range samples or those showing abnormal band patterns were forwarded to a hospital laboratory for additional investigation. Of 52,972 donors who donated 471,446 apheresis plasmas over 9 years, 89,490 samples were sent for TP and SPE testing. Of 3005 samples forwarded for further investigation, abnormal immunofixation electrophoresis (IFE) results were found in 209 (0.4%) donors, 85 from first-time (FT) and 124 from repeat (RPT) plasma donors during participation in the program. There were 167 donors with Mc gammopathies (73 FT, 94 RPT) and 42 with OGGAs (12 FT, 30 RPT). FT or RPT donors with Mc gammopathies or OGGAs were significantly older than those with normal SPEs. RPT donors with Mc gammopathies or OGGAs also had a longer donation period than donors with normal SPEs. The incidence of Mc gammopathies (2.41 per 1000 donors) did not significantly increase from 2004 to 2012. Older donors had a higher incidence of Mc gammopathies and longer donation periods than their healthy counterparts. Overall, gammopathy rates were below those reported over the same age range in the general population.