Impaired chemiluminescence response by neutrophils in patients with multiple myeloma.

Neutrophil chemiluminescence (CL) as a measure of oxygen-dependent killing activity was evaluated in 3 groups of patients: (a) 63 patients with multiple myeloma (MM); (b) 31 subjects with monoclonal gammopathy of undetermined significance (MGUS); (c) 32 healthy controls. Neutrophil CL response was shown to be significant reduced both in patients with MM (p less than 0.001) and in subjects with MGUS (p less than 0.001). A significant difference was also observed between the results obtained in MM and those of MGUS (p less than 0.001). Treated MM patients showed a more severe impairment of neutrophil chemiluminescence response than that observed in untreated patients (p less than 0.001). It is suggested that the impairment of neutrophil CL response, possibly related to decreased killing activity, may play a role, along with other known causes, in the increased susceptibility to infection observed in MM patients.