Two myeloma globulins IgG1-kappa and IgG1-lambda, from a single patient (Im). II. Their common cellular origin as revealed by immunofluorescence studies.

Abstract

The patient's (Im) serum contained two myeloma proteins possessing the same heavy chains (γl) and different light chains (κ or λ). The presence of identical antigenic determinants in the variable region of the heavy chains of both proteins raises the problem of their cellular origin. The immunofluorescence technique on bone marrow smears was used to identify the cells producing these proteins. Rabbit antisera monospecific to human κ and λ types of light chains, labelled with fluorescein or rhodamine, were applied onto the smears. These studies always revealed the presence of both κ and λ chains in the same plasma cells, thus suggesting that single cells of this patient are capable of synthesizing both IgG1(κ) and IgG1(λ) proteins.