Monoclonal gammopathy of undetermined significance and smouldering multiple myeloma: emphasis on risk factors for progression

Abstract

SummaryMonoclonal gammopathy of undetermined significance (MGUS) is characterized by a serum monoclonal protein <30 g/l, <10% plasma cells in the bone marrow, and absence of end-organ damage (CRAB-hypercalcaemia, renal insufficiency, anaemia, or bone lesions). MGUS is present in 3% of persons >50 years and in 5% >70 years of age. The risk of progression to multiple myeloma (MM) or a related disorder is 1% per year. Patients with risk factors consisting of an abnormal serum free light chain ratio, non-immunoglobulin G (IgG) MGUS, and an elevated serum M protein ‡15 g/l had a risk of progression at 20 years of 58%, compared with 37% with two risk factors present, 21% with one risk factor present, and 5% when none of the risk factors were present. Smouldering (asymptomatic) multiple myeloma is characterized by having a serum IgG or IgA monoclonal protein of 30 g/l or higher and/or 10% or more plasma cells in the bone marrow but no evidence of end-organ damage. The cumulative probability of progression to active MM or amyloidosis was 51% at 5 years, 66% at 10 years and 73% at 15 years; the median time to progression was 4AE8 years.

Dense Deposit Disease

“…The above data suggest that DDD occurring in patients with MGUS is associated with a poor prognosis (which would have been predicted by our study on the basis of age alone) and does not represent a form of renal involvement by dysproteinemia. Taking into account the high prevalence of MGUS in the elderly (3% in persons Ͼ50 of age and 5% in persons Ͼ70 yr of age) (19), the concurrence of DDD and MGUS may be coincidental. On the other hand, it is likely that the detection of M-spike provided a compelling indication for workup of the underlying renal disease, which proved to be DDD.…”

Beta‐2‐microglobulin is an independent predictor of progression in asymptomatic multiple myeloma

“…To date, none of the previous studies on asymptomatic MM focused on B2M, [3][4][5][6][7][8][9][10][11][12][13][14][15] and only 2 reports included B2M among baseline variables. 7,10 In the study by Moulopoulos et al, 7 patients with asymptomatic MM who presented with B2M >2.5 mg/L had a short time to progression to symptomatic disease.…”

“…[3][4][5][6][7][8][9][10][11][12][13][14][15] Therefore, in the current study, we investigated a cohort of patients who had asymptomatic MM to verify 1) whether B2M levels predict progression to symptomatic MM and 2) how B2M interacts with currently known predictors of progression to symptomatic MM.…”

Clinical Course of Monoclonal and Oligoclonal Gammopathies in Patients Infected with Orientia tsutsugamushi

“…1,2 Furthermore, certain pathogens, such as human immunodeficiency virus (HIV) or hepatitis C virus, show not only a transient pattern but also a persistent pattern of MG or OG and are associated with B cell malignancies. [9][10][11][12][13][14][15][16] In this context, a finding of MG or OG in certain infectious diseases requires more invasive tests to identify the underlying progress.…”

“…Clinical findings of BGs are similar to those of MGs. 1 Triclonal gammopathies (TGs) are much rarer than BGs and their incidence is unknown. 3 All three gammopathies frequently require further invasive or cost-intensive diagnostic procedures, such as bone marrow examination, for proper diagnosis of the underlying disorder.…”