Secondary Immunodeficiency Frequency in Patients with Chronic Lymphocytic Leukemia: The Relationship with Stage and Treatment.

Background: Chronic lymphocytic leukemia (CLL) is one of the most common hematological malignancies. In patients with CLL, serum immunoglobulin levels decrease over time due to both the disease itself and the chemo-immunotherapeutic agents used. It was aimed to reveal the relationship between hypogammaglobulinemia and disease stage, and chemo-immunotherapies. Materials and Methods: Data were obtained by retrospectively examining 74 patients who were followed-up between 2008-2019. The relationship between all parameters (demographic characteristics, RAI stages or therapy subtypes) and serum IgG levels was analyzed. Results: Thirty-two of 74 patients received a therapy. Twenty-two patients were on combined therapy with rituximab or only rituximab and 10 were treated with chemotherapeutic agents only. The frequency of hypogammaglobulinemia was 5.4% at the diagnosis, this rate was 55% in patients receiving a therapy. Hypogammaglobulinemia was higher in advanced stages. In patients with rituximab, higher levels of IgG decrease were observed. Conclusion: Serum IgG level was significantly lower in patients with advanced-stage, received chemotherapy, especially rituximab. In addition to basal IgG, immunoglobulin levels should be checked during treatment, and follow-up period. Early replacement intravenous immunoglobulins will be important to reduce severe infection attacks due to secondary immunodeficiency.