|
KMID : 1100820110010030158
|
|
Laboratory Medicine Online
2011 Volume.1 No. 3 p.158 ~ p.162
|
|
|
Immunoglobulin Isotype Switching in a Plasma Cell Myeloma Patient Treated with High-dose Chemotherapy and Hematopoietic Stem Cell Transplantation
|
|
Ham Ji-Yeon
Lee Kyung-Min
Song Kyung-Eun
|
|
|
Abstract
|
|
|
|
A malignant plasma cell clone usually produces a single abnormal monoclonal protein with a constant isotype. However, switching of paraprotein isotype has been reported to be a transient phenomenon associated with the recovery of B-cell function, and, in some cases, the switching might be misinterpreted as relapse. In August 2008, we encountered a case of a 59-year-old man with proteinuria and high IgG level (5.6 g/dL), κ free light chain level of 2,660 mg/L, reversed A/G ratio (0.51), and multiple osteolytic lesions. Plasma cells, which accounted for 57% of all the nucleated cells, in bone marrow aspirates were positive for κ immunostaining. Serum protein electrophoresis showed one M-spike, concentration of 4.87 g/dL in the β region. Immunofixation electrophoresis revealed the peak as an IgG-κ monoclonal protein; therefore, a diagnosis of plasma cell myeloma was made. Complete remission was achieved after chemotherapy, and autologous peripheral stem cell collection was performed. In March 2009, the patient underwent high-dose chemotherapy and autologous peripheral stem cell transplantation support. After 2 months, serum protein electrophoresis showed 2 M-spikes in the γ region with positive IgM-λ, IgG-λ, and IgG-κ, and these bands persisted. The electrophoretic mobility of the IgG-κ protein was different from that of the original disease protein, and bone marrow results were the same as the previous ones. Although immunoglobulin isotype switch is known to have a benign course, it always requires careful monitoring because, in rare cases, true clonal switching may occur.
|
|
|
KEYWORD
|
|
|
Plasma cell myeloma, Immunoglobulin isotype switching, Hematopoietic stem cell transplantation
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|