Abstract: | The ultrastructure of blood mononuclear cells from two IgG myeloma patients was studied, and cells reacting with anti-idiotypic 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 or myeloma cells. Immunocytochemical observations showed that most of the abnormal cells, including atypical small to medium-sized lymphocytes, reacted with anti-idiotypic 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 anti-idiotype and anti-Ig serum. The observations indicate that circulating lymphoid cells are part of the myeloma clone. |