Monoclonal Gammopathy of Unknown Significance and Malignant Paraproteinemia in Hong Kong

Abstract

The incidence of multiple myeloma is lower in Southeast Asia than in the West. However, there are few reports on the overall incidence of paraproteinemia and its disease-associations in the Chinese. Therefore, the authors have correlated the laboratory features with the eventual clinical diagnosis in patients with paraproteinemia in a Hong Kong general/teaching hospital. Over 18 months, 1,600 patients were investigated for the presence of paraproteinemia. Paraproteinemia was detected in 157 (10%) patients. In 11 patients, investigations could not be completed. The remaining 146 patients were subjected to detailed clinical, radiologic, and laboratory investigations. Eighty-seven (59.6%) had monoclonal gammopathy of unknown significance (MGUS), 44 (30.1%) myeloma and 15 (10.3%) other lymphoproliferative disorder (LPD). There was no significant difference in the paraprotein concentration, frequency of hypogammaglobulinemia or Bence Jones proteinuria (BJP) or concentration of nonparaprotein immunoglobulin (Ig) between the myeloma and LPD groups. The overall kappa:lambda light chains ratios were 2.9,1.6 and 3.3 in the MGUS, MM and LPD groups, Paraproteinemia occurs both more frequently with increasing age and in association with a variety of diseases, and is thus a relatively common finding in hospital patients. The differential diagnosis in these patients will be between either myeloma, other lymphoproliferative disorder (LPD), or monoclonal gammopathy of uncertain significance (MGUS). The incidence of multiple myeloma is said to be lower in countries in Southeast Asia, including Hong Kong, compared to those in the West. 1 However, with the exception of a recent study from Taiwan, 2 there are no reports on the overall incidence of paraproteinemia and the frequency of associated diseases in this population. It was our clinical impression that the finding of a paraprotein in the Hong Kong hos- respectively. Polyclonal Ig elevation was rare with myeloma (4.5%) but was detected in 33% of patients with LPD (P <.02) and 40% of those with MGUS (P <.0001). Biclonal (and one triclonal) gammopathy was detected in 11.5% of patients with MGUS, 11% with LPD and 4.5% with myeloma. In the MGUS group, infection was the commonest associated clinical disorder (29.3%). Moreover, 70% of patients with biclonal gammopathy and MGUS had an infection. Five of 15 patients with LPD had a T-cell malignancy, including 3 lymphomas and 2 large granular cell leukemias. Only one patient had primary systemic amyloidosis.It is concluded that the high frequency of biclonality and its association with infection, of paraproteinemia in association with T-cell malignancy and of kappa light chains in the MGUS and LPD groups are at variance with reports from the West and probably reflect local differences.

Monoclonal gammopathy of undetermined significance in atomic bomb survivors: incidence and transformation to multiple myeloma

“…As for the transformation from MGUS to MM, a quarter of MGUS patients developed lymphoid malignancies, 66% of which were MM, within 20-35 years of onset (Gregersen et al, 2001;Kyle et al, 2002). In our study, no lymphoid neoplasms other than MM developed among MGUS patients, although other studies have reported a variety of lymphoid malignancies besides MM, including IgM lymphoma, macroglobulinaemia and chronic lymphocytic leukaemia (Kanoh et al, 1990;Blade et al, 1992;van de Poel et al, 1995;Lolin et al, 1996;Ong et al, 1997;Vuckovic et al, 1997;Colls, 1999;Gregersen et al, 2001;Kyle et al, 2002;Ogmundsdottir et al, 2002). The transformation rate in the present study, 21% at 16 years, is quite similar to that of others, for example 12% at 10 years and 25% at 20 years (Kyle et al, 2002), 8AE5% at 5 years and 19AE2% at 10 years (Blade et al, 1992), and 11% at 14 years (van de Poel et al, 1995).…”

“…Within 20-35 years of onset, a quarter of MGUS patients develop lymphoid malignancies such as MM, immunoglobulin (Ig)M lymphoma, primary amyloidosis, macroglobulinaemia and chronic lymphocytic leukaemia (Kyle et al, 2002). The transformation of MGUS to B-cell malignancies has been studied in many countries, including the USA (Kyle et al, 2002), Iceland (Ogmundsdottir et al, 2002, the Netherlands (van de Poel et al, 1995;Ong et al, 1997), Denmark (Gregersen et al, 2001), Spain (Blade et al, 1992), Hong Kong (Lolin et al, 1996), Croatia (Vuckovic et al, 1997), New Zealand (Colls, 1999) and Japan (Kanoh et al, 1990). Here we report on the epidemiology of MGUS and its transformation to MM in the A-bomb survivor study population.…”

Triclonal gammopathy in an extranodal non‐Hodgkin lymphoma patient

“…Most retrospective studies show that the incidence of biclonal gammopathies ranges between 1% and 2.5% of all gammopathies [1,2]. A higher frequency of biclonality has been detected in Southeast Asia [3]. Triclonal gammopathies are much rarer, and their incidence is unknown.…”

Protein electrophoresis, immunoelectrophoresis and immunofixation electrophoresis as predictors for high‐risk phenotype in familial Waldenström macroglobulinemia

“…Reasons for nonparticipation in the follow-up phase included death (n 5 1), terminal illness (nonhematolymphoid malignancy, n 5 1), patient refusal (n 5 7), loss to follow-up (n 5 4), and logistical obstacles (n 5 4). The median interval between initial evaluation and follow-up IFE was 17 years (range, [13][14][15][16][17][18][19][20][21][22][23][24][25].…”