Background. Serum free light chains (sFLC), the most commonly detected paraprotein in CLL, were recently proposed as useful tools for the prognostication of CLL patients. Objective. To investigate the prognostic implication of sFLC and the summated FLC-kappa plus FLC-lambda in a CLL patients’ series. Patients and Methods. We studied 143 CLL patients of which 18 were symptomatic and needed treatment, while 37 became symptomatic during follow-up. Seventy-two percent, 18%, and 10% were in Binet stage A, B and C, respectively. Median patients’ followup was 32 months (range 4–228). Results. Increased involved (restricted) sFLC (iFLC) was found in 42% of patients, while the summated FLC-kappa plus FLC-lambda was above 60？mg/dL in 14%. Increased sFLC values as well as those of summated FLC above 60 were related to shorter time to treatment ( and , resp.) and overall survival ( and , resp.). They also correlated with β2-microglobulin ( and , resp.), serum albumin ( for summated sFLC), hemoglobin ( ), abnormal LDH ( and , resp.), Binet stage ( ) and with the presence of beta symptoms ( for summated sFLC). Conclusion. We confirmed the prognostic significance of sFLC in CLL regarding both time to treatment and survival and showed their relationship with other parameters. 1. Introduction Chronic lymphocytic leukemia is the most common type of leukemia in the Western world accounting for 40% of all leukemias. It affects mainly elderly patients as the median age of diagnosis is about 72 years and the male to female ratio is 2？:？1. So far, Rai and Binet staging systems are used for predicting CLL patients’ outcome. Other prognostic markers, which have been established but mainly concern symptomatic CLL patients, are lymphocyte CD38 expression, presence of ZAP-70, immunoglobulin (Ig) heavy gene mutation status, and cytogenetic profile [1–6]. In symptomatic patients the presence of unmutated Ig heavy chain variable region, the presence of ZAP-70, and CD-38 expression predict worse clinical outcome. Chromosomal abnormalities with importance for disease prognosis are deletion of long arm of chromosome 13, deletion of petit arm of chromosome 17 (del p17), and deletion of the long arm of chromosome 11 (del q11) with the first indicating a better prognosis than the last ones. Nevertheless the presence of these factors in patients does not signify that they should start treatment in the absence of symptomatic disease. Immunoglobulins (Igs) are produced by terminally differentiated B cells (either plasma cells or long lived memory cells), with the capacity to produce
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