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[Relationship between M-Protein of Multiple Myeloma and False Positive Syphilis Serological Results]
Tao-Jun He1, Fan Mo1, Xiao-You Xiao1
1Department of Clinical Laboratorical Examination, The Affiliated Futian Hospital of the Medical College of Guangdong, Shenzhen 518033, Guangdong Province, China.
Background:
The false positive in conventional syphilis serological test was found in patients with multiple myeloma (MM).
Objective:
To investigate the relationship between the M-protein of patients with MM and the false positive in conventional syphilis serologic test.
Methods:
The M-protein of 68 MM cases was typed with immunofixation electrophoresis and 68 cases of MM were screened with non-specific and specific syphilis serologic tests, then the samples with syphilic serological positive were chosen and confirmed with immonobloting test, finally the relationship between M protein of MM and the false positive of syphilis serological test were analysed.
Results:
Four out of 68 cases showed the positive in syphilis serological test and further were confimed to be false positive by immunoblotting test, the false positive rate was nearly 6%. The M-protein of MM patients in our hospital mostly possessed IgG, κ type, followed by IgA, κ type, light chain κ type. In general, κ : λ = 2.4 : 1. Among samples of 4 cases with syphilis serological positive 2 cases were of IgG and κ type, 1 case was of IgG, λ type, another 1 case was IgA, κ type.
Conclusion:
The M-protein of IgG and IgA types in MM patients results in syphilis serological false positive reaction. The clinicians and laboratorial technicians should pay a great attention to screen the MM patients for the false positive syphilis serological test so as to avoid the misdiagnosis and subsequent embarassment.
