Monitoring myeloma: light chain isotype suppression. A new parameter

Optimal therapy in patients with multiple myeloma relies on methods which indicate stability or progression of disease. At present, patients are assessed by monitoring the myeloma M-component in the serum and the urinary light chain excretion levels, or by calculating the myeloma cell mass. However, clinical disease activity does not always correlate with changes in these indices. Recent studies suggest that monitoring the expression of light chain isotypes on peripheral blood lymphocytes may provide evidence of progressive disease before clinical deterioration. Stable plateau phase disease has been shown to be associated with suppression of the expression, on peripheral blood lymphocytes, of the light chain isotype concordant with the malignant paraprotein. Loss of this suppression has been associated with active disease.