title: Incidental finding of monoclonal gammopathy in blood donors: a follow-up study.
abstract: BACKGROUND
  The incidental finding of monoclonal immunoglobulin in the sera of healthy blood donors is a relatively frequent event and in such cases the subjects are commonly deferred permanently from donating blood. However, no follow-up studies of these cases have been published so far.
  
  
  METHODS
  Since 2000, all regular blood donors at Trieste Blood Bank have undergone annual screening by serum protein electrophoresis. Cases presenting with monoclonal gammopathy between January 2000 and December 2008 were registered and follow-up was performed until December 2010.
  
  
  RESULTS
  Out of 8,197 regular blood donors, monoclonal gammopathy was detected in 104 subjects (1.3%). The median age at detection was 53 years, the median monoclonal protein concentration was 0.2 g/dL and the cumulative follow-up of these cases amounted to 763 person/years. In two cases asymptomatic multiple myeloma was diagnosed within 6 months of detection of the gammopathy and in 14 cases, the monoclonal gammopathy was transient. The remaining 88 cases were classified as having monoclonal gammopathy of undetermined significance (MGUS). Out of these, two events related to monoclonal gammopathy were observed during the follow up: one lymphoma and one light chain deposition nephropathy.
  
  
  CONCLUSIONS
  According to current prognostic staging systems, the majority of blood donors with monoclonal gammopathy were classified as having low-risk MGUS and had a very low incidence of lymphoproliferative diseases. Permanent deferral of blood donors with stable MGUS causes about a 1% loss of potential blood donations and it represents a "precautionary measure" that needs to be substantiated and validated.
authors.affiliation: Department of Transfusion Medicine, Trieste University Hospital, Trieste, Italy. massimo.laraja@ulss5.it
authors.forename: Massimo
authors.initials: M
authors.lastname: La Raja
authors.forename: Monica
authors.initials: M
authors.lastname: Barcobello
authors.forename: Nicola
authors.initials: N
authors.lastname: Bet
authors.forename: Paolo
authors.initials: P
authors.lastname: Dolfini
authors.forename: Marina
authors.initials: M
authors.lastname: Florean
authors.forename: Federica
authors.initials: F
authors.lastname: Tomasella
authors.forename: Vincenzo
authors.initials: V
authors.lastname: De Angelis
authors.forename: Luca
authors.initials: L
authors.lastname: Mascaretti
mesh_terms: D000328:Adult; D000368:Aged; D001782:Blood Donors; D001797:Blood Protein Electrophoresis; D046148:Donor Selection; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008232:Lymphoproliferative Disorders / Q000097:blood / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D010265:Paraproteinemias / Q000097:blood* / Q000175:diagnosis*; D012189:Retrospective Studies