When compared to the 154 individuals with Rai 0 CLL, the 123 individuals with MBL had a lower percentage of bone marrow lymphocytes (median 20% vs. 40%, P<0.001), a lower prevalence of diffuse bone marrow involvement (2.4% vs. 10.2%, P=0.034), and lower beta-2-microglobulin (median 1.9 mg/l vs. 2.2 mg/l, P=0.002).(27) MBL cases were also found to have more preserved immune function than those with Rai 0 CLL. For example, MBL cases had higher immunoglobulin (Ig) levels: IgG (median 10.60 g/l vs. 9.74 g/l, P=0.012), IgA (median 1.55 g/l vs. 1.40 g/l, P=0.038), and IgM (median 0.74 g/l vs. 0.58 g/l, P=0.003) than those with Rai 0 CLL cases. Clinically, a lower infection risk was observed in individuals with MBL compared to those with Rai 0 CLL.(27) Prior to initial chemotherapy treatment, the incidence of infection was 10.9 vs. 15.1 per 100 patient-years (p=0.030), for those with MBL and CLL respectively.(27)
