ULTRASTRUCTURAL AND IMMUNOCYTOCHEMICAL CHARACTERIZATION OF CIRCULATING MONONUCLEAR CELLS IN PATIENTS WITH MYELOMATOSIS

Abstract

The ulstrastructure of blood mononuclear cells from 2 Ig[immunoglobulin]G myeloma patients was studied, and cells reacting with antiidiotypic serum and polyspecific anti-Ig serum were characterized by immunoperoxidase techniques. Abnormal mononuclear cells were present in the blood of both patients, which morphologically were classified as atypical small to medium-sized lymphocytes, polymorphic immature lymphocytes (lymphoblasts), predominantly of the lymphoplasmocytic type and atypical, plasmocytic cells cells or myeloma cells. Immunocytochemical observations showed that most of the abnormal cells, including atypical small to medium-sized lymphocytes, reacted with antiidiotypic and polyspecific anti-Ig serum. Periods of relapse and remission were correlated with an increase and decrease, respectively, of the number of abnormal cells and cells which reacted with antiidiotypic and anti-Ig serum. The observations indicate that circulating lymphoid cells are part of the myeloma clone.