PROPHYLAXIS AGAINST INFECTIONS WITH LOW-DOSE INTRAVENOUS IMMUNOGLOBULINS (IVIG) IN CHRONIC LYMPHOCYTIC-LEUKEMIA - RESULTS OF A CROSSOVER STUDY

Background. In a recently reported study, low doses of intravenous imm unoglobulins (IVIG) were shown to be as effective as high doses in pro tecting chronic lymphocytic leukemia (CLL) patients against infections , although a control group was not included. With this background we s tarted a crossover study of low-dose IVIG prophylaxis aimed at investi gating its superiority over empirical treatment of infections. Materia ls and Methods. Forty-two CLL patients with hypogammaglobulinemia (IgG < 600 mg/dL) and/or a history of at least one episode of severe infec tion in the 6 months preceding inclusion in the study were randomly al located to receive either an infusion of 300 mg/kg MG every 4 weeks fo r 6 months or no treatment. Then they were switched to observation or IVIG for another 12 months; finally, they received IVIG or no therapy for 6 more months. Results. A significantly lower incidence of infecti ous episodes was observed during IVIG prophylaxis in 30 patients who c ompleted the 6-month period of either observation or MG therapy. The s ame applied to the 17 patients who completed 12 months of either obser vation or IVIG prophylaxis. Interestingly, the restoration of serum Ig G levels obtained in 17 out of 25 patients (mean percent value of IgG increase, 41.8%) did not parallel a decrease in the number of infectio us episodes. Conclusions. A protective effect against infections is de monstrated for low-dose IVIG in the present study. A benefit was shown in patients who completed either 12 or 6 months of MG prophylaxis; ho wever, even this low-dose treatment is not a cost effective way to pre vent infection in CLL patients.