Opsonic activity of myeloma immuno‐globulins (mm‐lg)

Publisher Website
Google Scholar
Abstract
Patients with MM are at an increased risk for life‐threatening bacterial infections, primarily by organisms that require opsonization for interaction with granulocytes. In the present study we used a neutrophil chemiluminescence (CL) assay of opsonization to explore the opsonic activity of MM‐lg for zymosan particles. Particles were treated with serum lacking in Ig to explore the contribution of Ig to zymosan opsonization. This serum was found to have 69 ± 2.6% (X̄ ± SEM) of the opsonic activity of normal serum (P < .001). Normal serum concentrations of normal IgG, MM‐IgG, and MM‐IgA all lacked opsonic activity for zymosan. However, when particles were treated with Nl‐IgG, MM‐IgG, or MM‐IgA as well as complement, normal opsonic activity was generated. Increasing the concentration of the Ig to stimulate MM serum did not inhibit this opsonic activity. Thus both MM‐IgG and MM‐IgA can function as normal, nonspecific opsonins.