Abstract:

Objective To establish and verify the rule of M protein recognition by serum protein electrophoresis,and to investigate the role of this rule in screening M protein among healthy subjects. Methods According to related literatures,the rule of M protein recognition was established according to the region of M protein in serum protein electrophoresis. Serum protein electrophoresis was carried out in 312 random clinical serum samples. M protein was screened according to the established rule of M protein recognition,which was verified by immunofixation electrophoresis. Serum samples of 1 170 healthy subjects and 236 clinical samples excluding hematology,nephrology,rheumatology and immunology,bone tumor,hepatology and geriatrics were collected. Serum protein electrophoresis was performed on each sample. M protein was screened according to M protein recognition rule. Immunofixation electrophoresis was used to confirm and type suspicious samples. Results In the 312 random clinical serum samples,28 samples,including M peak or suspicious M peak,were screened by serum protein electrophoresis,among which 16（5.12%） samples were confirmed as M protein positive by immunofixation electrophoresis. One case was missed in serum protein electrophoresis,and the missed rate was 0.32%. The positive rate of M protein was 2.14%（25/1 170） in 1 170 healthy subjects. The positive rates of M protein were 2.64% in males and 1.82% in females. The positive rate of M protein in males was higher than that in females. Among the 25 M protein positive samples,the positive rate of IgG type M protein was the highest（60%）,followed by IgM type（24%）. Among the 236 clinical samples excluding hematology,nephrology,rheumatology and immunology,bone tumor,hepatology and geriatrics,10 cases had M protein,and the positive rate was 4.24%. ConclusionsThe established M protein recognition rule have a value in M protein recognition by serum protein electrophoresis,which is worth to be applied widely.

Key words: M protein, Recognition rule, Serum protein electrophoresis, Monoclonal gammopathy of undetermined significance