ANALYTICAL STUDY OF SALIVARY IMMUNOGLOBULINS IN MULTIPLE MYELOMA.

An immunochemical characterization of salivary immunoglobulins from ten patients with multiple myeloma was undertaken. Seven of the patients had IgA monoclonal components and their transfer to saliva could be proved immunochemically in five. Three salivas containing monoclonal IgA were fractionated by gel filtration on Sephadex G-200, and secretory component could be detected in the same peaks as the monoclonal IgA. Molecular si/e studies by electrophoresis in sodium dodecyl sulphate-polyacrylamide gel showed that in most salivas oligomeric forms of IgA were exclusively or predominantly detected. These findings suggest that oligomeric IgA of systemic origin might be as effectively transferred to external secretions as oligomeric IgA of regional origin. Of the three remaining patients, two had IgG monoclonal proteins that could be detected in concentrated saliva, while the monoclonal component of the last patient was of light chain type. In this last patient no free light chains were detected in concentrated saliva, but normal IgA as well as an apparently increased amount of polyclonal IgG were evident. [ABSTRACT FROM AUTHOR]