Contributions
Abstract: PB1958
Type: Publication Only
Background
IgM multiple myeloma (MM) and Waldenström’s macroglobulinemia (WM) are two hematologic malignancies with the common finding of IgM monoclonal gammopathy. IgM MM is a rare and poorly characterized disease.
Aims
The paper presents clinical and laboratory results of long term observations of 15 IgM MM patients selected from a group of 889 MM patients (1.6%) diagnosed and treated for several years at the Institute of Hematology and Transfusion Medicine in Warsaw as well as 15 WM patients investigated and treated at the same period of time at our hospital.
Methods
For analysis of serum proteins new Hevylite and Freelite tests (Binding Site Ltd Birmingham, UK) were applied as well as immunofixation using Sebia (Lisses, France) reagents. Fresh and archived frozen serum samples were used for the study.
Results
The clinical presentation of IgM MM patients is heterogenic starting with typical form for non IgM MM through predominant form with characteristic hyperviscosity syndrome and severe disease course to slow and latent form with survival time up to dozens of years. In 2 patients diagnosis of IgM MM was preceded by a 3-year period of monoclonal gammopathy of undetermined significance (MGUS) while in 4 patients (27%) diagnosis of WM was preceded by a 108, 84, 78, 9 months period of IgM MGUS. Median real overall survival of IgM MM patients was 50 months, 5 patients (33%) survived above 7 years and 2 patients (13%) survived above 12 years. Median overall survival of WM patients was 108 months, 7 patients (47%) survived above 10 years, 3 patients (20%) survived above 15 years. Lytic bone lesions were found in 11 (73%) IgM MM patients and in 3 (20%) WM patients. Urine monoclonal free light chains (FLC) detected by immunofixation was present in 60% of IgM MM patients and increased concentrations of involved monoclonal FLC and abnormal FLC κ/λ ratio in serum (by Freelite) in 75 % of IgM MM patients. It was shown that IgM clonality in IgM MM and WM patients can be determined by using immunoglobulin heavy chain /light chain (HLC) immunoassays- Hevylite. Immunofixation and HLC ratios were concordant in all assessed IgM MM and WM patients. In IgM MM patients the suppression of uninvolved polyclonal IgM- detectable by using IgM HLC test - has prognostic significance. The evaluation of IgM HLC in 13 patients with IgM MM at diagnosis revealed a decreased concentration of uninvolved IgM (HLC IgMκ < 0.33 g/L, HLC IgMλ < 0.20 g/L) in 5 patients and normal values in 8 patients. Median overall survival in patients with a decreased uninvolved IgM was 15 months and in patients with normal polyclonal IgM 55 months (p< 0.01).
Conclusion
Session topic: 14. Myeloma and other monoclonal gammopathies - Clinical
Keyword(s): Multiple Myeloma
Abstract: PB1958
Type: Publication Only
Background
IgM multiple myeloma (MM) and Waldenström’s macroglobulinemia (WM) are two hematologic malignancies with the common finding of IgM monoclonal gammopathy. IgM MM is a rare and poorly characterized disease.
Aims
The paper presents clinical and laboratory results of long term observations of 15 IgM MM patients selected from a group of 889 MM patients (1.6%) diagnosed and treated for several years at the Institute of Hematology and Transfusion Medicine in Warsaw as well as 15 WM patients investigated and treated at the same period of time at our hospital.
Methods
For analysis of serum proteins new Hevylite and Freelite tests (Binding Site Ltd Birmingham, UK) were applied as well as immunofixation using Sebia (Lisses, France) reagents. Fresh and archived frozen serum samples were used for the study.
Results
The clinical presentation of IgM MM patients is heterogenic starting with typical form for non IgM MM through predominant form with characteristic hyperviscosity syndrome and severe disease course to slow and latent form with survival time up to dozens of years. In 2 patients diagnosis of IgM MM was preceded by a 3-year period of monoclonal gammopathy of undetermined significance (MGUS) while in 4 patients (27%) diagnosis of WM was preceded by a 108, 84, 78, 9 months period of IgM MGUS. Median real overall survival of IgM MM patients was 50 months, 5 patients (33%) survived above 7 years and 2 patients (13%) survived above 12 years. Median overall survival of WM patients was 108 months, 7 patients (47%) survived above 10 years, 3 patients (20%) survived above 15 years. Lytic bone lesions were found in 11 (73%) IgM MM patients and in 3 (20%) WM patients. Urine monoclonal free light chains (FLC) detected by immunofixation was present in 60% of IgM MM patients and increased concentrations of involved monoclonal FLC and abnormal FLC κ/λ ratio in serum (by Freelite) in 75 % of IgM MM patients. It was shown that IgM clonality in IgM MM and WM patients can be determined by using immunoglobulin heavy chain /light chain (HLC) immunoassays- Hevylite. Immunofixation and HLC ratios were concordant in all assessed IgM MM and WM patients. In IgM MM patients the suppression of uninvolved polyclonal IgM- detectable by using IgM HLC test - has prognostic significance. The evaluation of IgM HLC in 13 patients with IgM MM at diagnosis revealed a decreased concentration of uninvolved IgM (HLC IgMκ < 0.33 g/L, HLC IgMλ < 0.20 g/L) in 5 patients and normal values in 8 patients. Median overall survival in patients with a decreased uninvolved IgM was 15 months and in patients with normal polyclonal IgM 55 months (p< 0.01).
Conclusion
Session topic: 14. Myeloma and other monoclonal gammopathies - Clinical
Keyword(s): Multiple Myeloma