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Infections are a major cause of morbidity and mortality in Chronic Lymphocytic Leukemia (CLL), related to humoral and cellular immune deregulations due to the disease itself and enhanced by immunosuppression associated to treatments. Hypogammaglobulinemia is the most common chronic immune defect in CLL, related to duration and stage of the disease, and correlates with the frequency and severity of infections observed in these patients.

Analyze and compare the frequency and type of infectious episodes requiring hospital admission in a population of patients diagnosed with CLL, with and without hypogammaglobulinemia.

Retrospective analyses of the clinical files of patients with CLL diagnosed between January 2004 and August 2014.

Between January 2004 and August 2014, 151 patients were diagnosed with CLL. Twenty-five patients (16.6%) developed hypogammaglobulinemia, 6 at the time of diagnosis. The mean time from diagnosis of CLL to the development of hypogammaglobulinemia in the remaining patients was 38.2 months (min=4; max=97). Patients with a serum IGg<5g/L and recurrent or severe infections received IVIg replacement therapy.

In the group with hypogammaglobulinemia (n=25), the median age at diagnosis was 71 years (min=50; max=88); 14 men (56%) and 11 women (44%). The initial staging (Rai) was 0 in 11 patients (44%), I in 8 patients (32%), III in 3 patients (12%) and IV in 3 patients (12%). The initial approach was watchful waiting in 16 patients (64%), with 9 patients (36%) requiring treatment. Sixteen patients (64%) required hospital admission related to infectious intercurrences, with 25.6 days as mean time of hospitalization (min=1; max=133). The total number of documented infections was 47 (mean of 3 episodes/patient; min=1; max=9): upper and lower respiratory tract infection in 14 patients (87.5%), urinary tract infection in 6 patients (37.5%); gastroenteritis, lower and upper limb cellulitis, oral candidiasis and febrile neutropenia in 2 patients each (12.5%). One patient developed cryptococcal meningitis and one patient developed septicemia.

In the group without hypogammaglobulinemia (n=126), the median age at diagnosis was 70 years (min=37; max=93); 73 men (58%) and 53 women (42%). The initial staging was 0 in 90 patients (71.4%), I in 24 patients (19%), III in 6 patients (4.8%) and IV in 7 patients (5.6%). The initial approach was watchful waiting in 113 patients (89.7%) and treatment in 13 patients (10.3%). Twenty-two patients (17.4%) required hospital admission due to infectious events, with a mean time of 15.55 days (min=1; max=69) and a total number of 37 infections (mean of 1.7 episodes; min=1; max=5): upper and lower respiratory tract infection in 12 patients (54.5%), urinary tract infection in 6 patients (27.3%); gastroenteritis, septicemia and cellulitis in 3 patients each (13.6%); febrile neutropenia in 2 patients (9.1%). One patient developed a rickettsia infection.

The two groups were similar in terms of age and sex distribution. The proportion of patients staged III and IV was higher in the group with hypogammaglobulinemia. The percentage of patients with infectious events requiring hospital admission was significantly higher in the group with hypogammaglobulinemia (64% vs 17.4%). Fungal infections were only present in the group with hypogammaglobulinemia. A higher number of infectious events in this group required a longer time of hospital admission, reflecting their severity. Therefore, it is important to monitor immunoglobulin levels and to administer immunoglobulin replacement therapy in these patients.