Clinical relevance of hypogammaglobulinemia, clinical and biologic variables on the infection risk and outcome of patients with stage A chronic lymphocytic leukemia

The prognostic effect of hypogammaglobulinemia (HGG), clinical and biologic characteristics on the infection risk and outcome has been retrospectively analyzed in 899 patients with stage A chronic lymphocytic leukemia (CLL). Low levels of IgG were recorded in 19.9% of patients at presentation, low levels of IgM and/or IgA in 10.4% and an additional 20% of patients developed HGG during the course of the disease. Before the start of any treatment, 160 (12.9%) patients experienced at least one grade ≥3 infection requiring a systemic anti-infective treatment and/or hospitalization. While IgG levels at diagnosis were not associated with an increased risk of grade ≥3 infection or with an adverse outcome, a significantly increased rate of grade ≥3 infections was recorded in patients with unmutated IGHV (p=0.011) and unfavorable FISH aberrations (p=0.009). Late onset HGG, more frequently recorded in patients with Rai stage I-II (p=0.001) and unmutated IGHV (p=0.001), was also associated with a higher rate of severe infections (p=0.002). These data indicate that, stage A patients with clinical and biologic characteristics of a more aggressive disease develop more frequently late onset HGG, grade ≥3 infections and require a closer clinical monitoring