[Compromised immune function in multiple myeloma].

Patients with multiple myeloma are at risk for bacterial infections such as Streptococcus pneumoniae, Haemophilus influenzae, and Escherichia coli. Administering oral sulfamethoxazole -trimethoprim for the first 2 months of initial chemotherapy was effective prophylaxis for bacterial infection. Specific antibody titers for S. pneumoniae were significantly reduced in patients compared with normal controls. Pneumococcal vaccination was effective around 30-40% of patients. The response rate of influenza vaccination was also limited. Intravenous immunoglobulin was useful for prophylaxis of severe bacterial infection during plateau-phase of multiple myeloma. The patients who benefit most could be identified by measuring IgG antibody responses to pneumococcal vaccination.