Characteristics of established myeloma and lymphoblastoid cell lines derived from an e myeloma patient: A comparative study

Abstract The in vitro characteristics of two types of cell lines established from bone marrow and peripheral blood of an E myeloma patient have been compared. Both types, one with a lymphoblast morphology and the other with plasma cell/plasmablast morphology, secreted monoclonal immunoglobulins in vitro. The former produced IgGK while the latter synthesized the IgEL myeloma protein, which in a previous report was shown to be identical with the myeloma protein in vivo. The myeloma cells were difficult to establish and more stringent in their in vitro requirements than the lymphoblastoid cells. Myeloma cells could only grow in the presence of feeder cells or medium harvested from such cells, while lymphoblasts were capable of independent growth in standard media. The lymphoblastoid line was principally similar to those obtainable from normal lymph nodes (Nilsson et al., 1968; Nilsson, 1971a) and is therefore regarded as being of non‐neoplastic origin. It is thus possible to obtain permanent immunoglobulin‐secreting lines of non‐neoplastic origin as well as myeloma lines of neoplastic origin from patients with myelomatosis. The dynamic and static morphology of the former most closely correspond to the appearance described for lymphoblasts or “immunoblasts”,i.e. lymphocytes stimulated by phyto‐hemagglutinin, while myeloma cells resemble plasma cells of varying maturity. The reasons for the morphologic differences are unknown, but they were sufficiently distinctive to permit unequivocal distinction between the two types of lines.