Cellular immune reactivity in patients with multiple myeloma

: The ConA-, PHA- and PWM-induced lymphocyte transformation rates were significantly decreased in 19 patients with multiple myeloma. Lymphocyte-inherent defects rather than serum factors seem to account for this decreased lymphocyte reactivity. In 58% of the patients a pathologically increased ConA-induced suppressor cell activity, which was negatively correlated with the non-paraprotein IgM-concentration, was found.