title: "Idiopathic Bence-Jones proteinuria": a new characterization of an old entity.
abstract: Idiopathic Bence-Jones proteinuria (BJP) is a rare plasma cell dyscrasia, of which the clinical and biological characteristics are yet unclear. Historical data suggested that they are at higher risk of progression to multiple myeloma or other related neoplasms, while recent findings are contradictory. To address these open questions, we evaluated a series of both BJP and monoclonal gammopathy of undetermined significance (MGUS) with production of an intact immunoglobulin plus Bence-Jones proteinuria (MGUS+BJP) with long-term follow-up, regarding their clinical characteristics and progression to multiple myeloma, amyloidosis or other related B cell lymphoproliferative disorders. Two hundred and twenty-nine persons fulfilling the 2004 criteria of MGUS were included in the final analyses: 31 had BJP and 198 had MGUS+BJP. At the time of diagnosis, significantly more persons in the BJP group had renal impairment, anaemia and polyneuropathy. A more detailed analysis revealed discrepancies between the serum and urine light chain type in nine cases, reflecting clonal heterogeneity. The number of disease progressions was higher in MGUS+BJP (n = 30) when compared to BJP (n = 1), with a rate of 1.6 and 0.4 progressions per 100 person-years, respectively. In conclusion, BJP has distinct clinical characteristics and a lower risk of progression when compared to MGUS+BJP. Our data suggest that MGUS+BJP being closer to malignant transformation may be due to the higher portion of genetically heterogeneous, pre-malignant plasma cell subclones.
authors.affiliation: Department of Hematology and Oncology, Medical University of Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria. m.mian@webmaxxi.eu
authors.forename: Michael
authors.initials: M
authors.lastname: Mian
authors.forename: Irene
authors.initials: I
authors.lastname: Franz
authors.forename: Ines
authors.initials: I
authors.lastname: Wasle
authors.forename: Manfred
authors.initials: M
authors.lastname: Herold
authors.forename: Andrea
authors.initials: A
authors.lastname: Griesmacher
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Prokop
authors.forename: Sergio
authors.initials: S
authors.lastname: Cortelazzo
authors.forename: Günther
authors.initials: G
authors.lastname: Gastl
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Willenbacher
authors.forename: Eberhard
authors.initials: E
authors.lastname: Gunsilius
authors.forename: Michael
authors.initials: M
authors.lastname: Fiegl
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000686:Amyloidosis / Q000175:diagnosis / Q000652:urine*; D001536:Bence Jones Protein / Q000652:urine*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis / Q000652:urine*; D011507:Proteinuria / Q000175:diagnosis / Q000652:urine*; D015996:Survival Rate / Q000639:trends
chemical_list: D001536:Bence Jones Protein