The Nestin Expression in Monoclonal Gammopathies

Abstract Abstract 5111 Background. Monoclonal gammopathies (MG) are the most common plasma cell disorders characteristic by a presence of clonal plasma cells (PCs). The nestin is considered to be a marker of multipotent proliferative precursors, but recently its expression was found in PCs of multiple myeloma (MM) as well. Consequences of the nestin expression still remain unclear. Aim. Phenotypic analysis of the nestin expression in the most frequent MGs and its correlation with other markers. Patients and Methods. Total of 45 samples was analyzed [31 newly diagnosed untreated MM patients, 14 untreated monoclonal gammopathy of undetermined significance (MGUS) subjects and 5 non-MG samples]. Whole bone marrow CD38+CD138+ PCs were studied for intracellular expression of nestin and surface expression of CD19, CD20, CD27, CD28, CD33, CD56, and CD117 by flow cytometry. Results. Flow cytometric analysis shown the nestin expression in 21.4 % (3/14) of MGUS and 45.2 % (14/31) of MM patients, on the other hand no expression of nestin was found in non-MG controls. Expression of the nestin was relatively homogeneous, but not highly intensive. The nestin positive PCs did not express CD19 and/or CD20, but expression of CD27 was found in 29.4 % (5/17) cases, CD28 in 11.8 % (2/17), CD33 in 5.9 % (1/17), CD44 in 35.3 % (6/17), CD56 in 88.2 % (15/17), and CD117 in 29.4 % (5/17) cases. Statistical analysis did not found any significant correlation and/or difference in phenotype when compared the nestin positive and negative samples, although the nestin negative samples expressed CD56 less frequently then the nestin positive samples [46.4 % (13/28) vs. 88.2 % (15/17)], respectively. Summary/Conclusion. Our result showed difference in the nestin expression when compared bone marrow of MGUS subjects with MM patients. Although there was no correlation between the nestin positivity and phenotype of PCs, we suppose that the nestin could associate with unfavorable prognosis but further studies are needed to elucidate its clinical implication in MGs. Disclosures: No relevant conflicts of interest to declare.