Correlation between serum levels of free light chain and phenotype of plasma cells in bone marrow in primary AL amyloidosis.

Abstract

To investigate whether there is a correlation between subtypes of plasma cells in the bone marrow and the production of M-protein, flow cytometry and serum free light chain (FLC) analyses were carried out in 17 patients with primary systemic AL amyloidosis (mean age, 59.9+/-8.8 years) and controls with M-protein (MGUS controls, n=6) and without it (negative controls, n=9). The patients showed a significantly higher value in the serum predominant FLC:serum creatinine ratio (43.8+/-63.2) and CD38++ CD19- CD56+ subpopulation (monoclonal plasma cells) (2.57+/-5.35%) than either the negative (p<0.0005 and p<0.001, respectively) or MGUS controls (p<0.05). With respect to maturation of plasma cells in the bone marrow, the intermediate (MPC-1+ CD45- CD49e-) and mature (MPC-1+ CD45+ CD49e-) subtypes were significantly higher (49.2+/-23.2%, p<0.005) and lower (27.6+/-21.3%, p<0.005) in the patients than in the negative controls, respectively. The serum predominant FLC:serum creatinine ratio was elevated in parallel with an increase in CD38++ CD19- CD56+ and MPC-1+ CD45- CD49e- cells and a decrease in mature subtypes (MPC-1+ CD45+ CD49e- and MPC-1+ CD45+ CD49e+ cells), There was a significantly positive correlation between the serum predominant FLC:serum creatinine ratio and either CD38++ CD19- CD56+ (r=0.510, p<0.05) or MPC-1+ CD45- CD49e- cells (r=0.481, p<0.05). In primary AL amyloidosis M-protein is probably produced by increased monoclonal plasma cells in the bone marrow, particularly by the intermediate subpopulation with a phenotype of MPC-1+ CD45- CD49e-.

• Authors: Yasuhiro Shimojima, Masayuki Matsuda, Takahisa Gono, Wataru Ishii, Tomohisa Fushimi, Yoshinobu Hoshii, Toshiyuki Yamada, Shu-Ichi Ikeda
• Journal: Amyloid : the international journal of experimental and clinical investigation : the official journal of the International Society of Amyloidosis (Amyloid) Vol. 12 Issue 1 Pg. 33-40 (Mar 2005) ISSN: 1350-6129 [Print] England
• PMID: 16076609 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antigens, CD
• Immunoglobulin Light Chains
• Myeloma Proteins
• multiple myeloma M-proteins

Topics

• Adult
• Aged
• Amyloidosis (blood)
• Antigens, CD (analysis)
• Bone Marrow Cells (pathology)
• Female
• Flow Cytometry
• Humans
• Immunoglobulin Light Chains (blood)
• Immunophenotyping
• Male
• Middle Aged
• Myeloma Proteins (analysis)
• Plasma Cells (pathology)