title: Proposal and validation of prognostic scoring systems for IgG and IgA monoclonal gammopathies of undetermined significance.
abstract: OBJECTIVE
  The presenting clinico-hematologic features of 1,283 patients with IgG and IgA monoclonal gammopathies of undetermined significance (MGUS) were correlated with the frequency of evolution into multiple myeloma (MM).
  
  
  METHODS
  Two IgG MGUS populations were evaluated: a training sample (553 patients) and a test sample (378 patients); the IgA MGUS population consisted of 352 patients.
  
  
  RESULTS
  Forty-seven of the 553 training group patients and 22 of 378 test group IgG patients developed MM after a median follow-up of 6.7 and 3.6 years, respectively. Multivariate analysis showed that serum monoclonal component (MC) levels of < or =1.5 g/dL, the absence of light-chain proteinuria and normal serum polyclonal immunoglobulin levels defined a prognostically favorable subset of patients, and could be used to stratify the patients into three groups at different 10-year risk of evolution (hazard ratio, 1.0, 5.04, 11.2; P < 0.001). This scoring system was validated in the test sample. Thirty of the 352 IgA patients developed MM after a median follow-up of 4.8 years, and multivariate analysis showed that hemoglobin levels of <12.5 g/dL and reduced serum polyclonal immunoglobulin correlated with progression. A pooled statistical analysis of all of the patients confirmed the validity of Mayo Clinic risk model showing that IgA class, serum MC levels, and light-chain proteinuria are the most important variables correlated with disease progression.
  
  
  CONCLUSIONS
  Using simple variables, we validated a prognostic model for IgG MGUS. Among the IgA cases, the possible prognostic role of hemoglobin emerged in addition to a decrease in normal immunoglobulin levels.
authors.affiliation: UO Ematologia 1/CTMO, Fondazione Ospedale Maggiore PoMaRe, Istituto di Ricovero e Cura a Carattere Scientifico, Università degli Studi, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Rossi
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Petrucci
authors.forename: Andrea
authors.initials: A
authors.lastname: Guffanti
authors.forename: Luigi
authors.initials: L
authors.lastname: Marcheselli
authors.forename: Davide
authors.initials: D
authors.lastname: Rossi
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Callea
authors.forename: Federico
authors.initials: F
authors.lastname: Vincenzo
authors.forename: Marianna
authors.initials: M
authors.lastname: De Muro
authors.forename: Alessandra
authors.initials: A
authors.lastname: Baraldi
authors.forename: Oreste
authors.initials: O
authors.lastname: Villani
authors.forename: Pellegrino
authors.initials: P
authors.lastname: Musto
authors.forename: Andrea
authors.initials: A
authors.lastname: Bacigalupo
authors.forename: Gianluca
authors.initials: G
authors.lastname: Gaidano
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Avvisati
authors.forename: Maria
authors.initials: M
authors.lastname: Goldaniga
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Depaoli
authors.forename: Luca
authors.initials: L
authors.lastname: Baldini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017098:IgA Deficiency / Q000150:complications / Q000175:diagnosis*; D017099:IgG Deficiency / Q000150:complications / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis* / Q000209:etiology / Q000276:immunology / Q000401:mortality; D010265:Paraproteinemias / Q000150:complications / Q000175:diagnosis* / Q000401:mortality; D011379:Prognosis; D012107:Research Design; D016019:Survival Analysis; D055815:Young Adult