BACKGROUNDS

The aim of the study was to evaluate the serum levels of 18 selected parameters in monoclonal gammopathy of undetermined significance, and the initial, asymptomatic phase of multiple myeloma, also from the point of view of the potential contribution to the differentiation of these two units.

MATERIALS AND METHODS

The analyzed 119-patient group consisted of 59 individuals with monoclonal gammopathy of undetermined significance and 60 patients with multiple myeloma assessed at the time of diagnosis before the start of the treatment. For the evaluation of serum levels we used radioenzyme assay (thymidine kinase), immunoradiometry (IGF-1), enzyme immunoassay (osteocalcin, osteoprotegerin, ICTP), electrochemiluminiscence (PINP), quantitative sandwich enzyme immunoassay (MIP-1 alpha and MIP-1 beta, IL-17, osteopontin, HGF, VEGF, angiogenin, endostatin, syndecan-1/CD138), and for the assessment of serum levels of free light chains kappa and lambda, the Freelite system. Statistical evaluation was done using the Pearson chi-quadrat test and the U-test according to Mann-Whitney (p < 0.05).

RESULTS

Statistically significant differences between monoclonal gammopathy of undetermined significance and multiple myeloma were found in the case of serum levels of thymidine kinase (0.0002), ICTP (0.001), MIP-1 alpha (0.002), osteopontin (<0.0001), HGF (< 0.0001), syndecan-1 (<0.0001), and the kappa/lambda ratio (0.0002), while lower significance was found in the case of angiogenin (0.031) and endostatin (0.011). Statistically non-significant differences between multiple myeloma and monoclonal gammopathy of undetermined significance were within the serum levels of IGF-1, osteocalcin, bALP, PINP, OPG, MIP-1 beta, IL-17, parathormon and VEGF.

CONCLUSION

Statistical analysis revealed significant differences between monoclonal gammopathy of undetermined significance and multiple myeloma in 9 of the 18 evaluated parameters. However, due to the significant overlapping of the measured values, none of the parameters is unambiguously able to distinguish between the units. A certain contribution in the discrimination of multiple myeloma from monoclonal gammopathy of undetermined significance was found in markedly increased serum levels of thymidine kinase, MIP-1 alpha, osteopontin, HGF and significant pathology of the kappa/lambda index.