Risk factors for the development of bacterial infections in patients with multiple myeloma treated with two different vincristine-adriamycin-dexamethasone schedules

Background and Objectives. We evaluated bacterial infections (BIs) in patients with multiple myeloma (MM) treated with two different schedules of vincristine-adriamycin-dexamethasone (VAD). Design and Methods. Ninety-seven patients were studied during 340 VAD cycles. VAD was given by either continuous intravenous infusion (CII) to hospitalized patients or rapid intravenous infusion (RII) to outpatients. The characteristics of patients and VAD schedules were retrospectively analyzed to detect correlations with the incidence of BI. Results. By analyzing each VAD cycle, we found that profound hypogammaglobulinemia (p=0.06) and posttreatment neutropenia (p=0.08) were associated with a trend for a higher risk of infection, while renal function impairment was significantly correlated with BI risk at both univariate (p<0.02) and multivariate (p<0.002) analyses. Evaluating only the first 4 months of therapy, characterized by a significantly higher incidence of BI than the later period (p<0.0001), previously untreated disease was significantly correlated with BI risk (p<0.04), while male sex (p=0.06), CII schedule (p=0.07), and profound hypogammaglobulinemia (p=0.1) were associated with a tendency to a higher risk of infection; however, at multivariate analysis the latter two parameters independently predicted BI probability (p<0.015 and p<0.03, respectively) as did previously untreated disease (p<0.025). The high probability of CII-related infection was demonstrated to depend on the frequent development of nosocomial infections. Interpretation and Conclusions. Patients with profound hypogammaglobulinemia who receive VAD as first line treatment are at a major risk of BI up to the completion of the fourth month of therapy. In this setting hospitalization should be avoided and, if patients require admission, antibacterial prophylaxis with intravenous immunoglobulins could be appropriate and effective.