Alterations in immunoglobulin synthesis by peripheral blood mononuclear cells from splenectomized patients with and without splenic regrowth.

Unstimulated and pokeweed mitogen (PWM)-stimulated immunoglobulin (Ig) synthesis by peripheral blood mononuclear cells (PBMC) in vitro, serum Ig concentrations, and the degree of splenic regrowth was studied in 33 patients who had been splenectomized following trauma. The concentration of IgG and IgA was significantly raised in the supernatants of unstimulated cultures of PBMC from the patients. The stimulation of Ig synthesis by PWM, measured as a stimulation index (SI), was significantly less in the culture of PBMC from the patients, compared with the controls. The SI was reduced both in those patients whose unstimulated PBMC secreted normal concentrations of IgG and IgA in culture, as well as in those whose cells secreted elevated concentrations of Ig. The concentration of IgM in the serum of the patients was significantly reduced compared with the controls, the serum IgG was raised, and the serum IgA was not altered. The degree of splenic regrowth (splenosis) was measured in the patients by splenic scanning, by using heat-damaged, radiolabeled autologous erythrocytes. The patients were allocated into four groups, depending on whether they had no (11 patients), minimal (11), moderate (seven), or large (four) splenosis. There was no difference between any of the groups with respect to the synthesis of IgG or IgA in culture or the serum Ig concentrations. These results indicate that Ig synthesis by PBMC in vitro, and serum Ig concentrations in vivo, are abnormal in patients who have been splenectomized for trauma, and that the generation of splenosis tissue does not correct these changes.