CLINICAL ASPECTS OF SERUM-FREE IMMUNOGLOBULIN LIGHT CHAINS DETECTION IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA

Presence of Serum-Free Immunoglobulin Light Chains (sFLC) was analyzed for 15 patients with newly diagnosed Chronic Lymphocytic Leukemia (CLL). All patients were also characterized by peripheral blood lymphocytes’ immunotype (including κ/λ), presence of absolute lymphocytosis and clinical data. Of the 15 patients 11 had elevated concentrations of monoclonal sFLC: 7 patients had elevated κ sFLC (κ/λ ratio > 1,65); 4 patients had elevated λ sFLC (κ/λ ratio < 0,26). The type of elevated clone for sFLC was the same as the isotype of clonal lymphocytosis. The remaining 4 of 15 patients did not have elevated concentrations of sFLC whereas clonal lymphocytosis (λ type for all 4 patients) and absolute lymphocytosis were observed. 10 of 15 patients received 6 courses of RFC-therapy. For those patients sFLC concentration was measured before and after the therapy. In 6 of 10 patients tumor clone of sFLC was detected. After RFCtherapy, 4 of those patients demonstrated a reduction in concentrations of elevated sFLC on average for 63,1% and a normal κ/λ ratio that corresponded with the absence of clonal and absolute lymphosytosis. The remaining 2 patients did not have a decrease in sFLC concentrations and had abnormal κ/λ ratio, however, tumor clone lymphocytes and absolute lymphocytosis were not detected, that was presented with better overall clinical outcome. In 4 out of 10 patients that demonstrated no initial elevation in clonal sFLC, measured sFLC concentrations varied within the normal range. Conclusions: 73,7% of CLL patients in our study showed elevated concentrations of clonal sFLC. Serum-Free Light Chains concentration could serve as an integral criterion for evaluation of tumor mass and therapy effectiveness.

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