33.5. Monitoring CLL with sFLCs

Chapter 33

A preliminary study by Aue et al. [678] highlighted the potential utility of sFLCs for monitoring CLL. Prior to treatment, a total of 8/11 patients with a κ CLL clone had κ sFLC concentrations above the normal range. After 6 months of ibrutinib therapy, there was a 76% reduction in κ sFLCs (p<0.01), and in 7/8 patients sFLC concentrations had normalised. By contrast, λ FLCs were initially low and then increased to normal levels following therapy. Similar findings were reported for 8 of 9 patients with a λ clone. The authors suggested that sFLC monitoring might provide an insight into both the killing of the tumour cells and the recovery of normal B-cell function.


  1. What is the source of sFLCs in CLL?


  1. FLCs may be produced by the tumour clone, polyclonal bystander lymphocytes and plasma cells in the tumour microenvironment (Section 33.2).



    • 1. Aue G, Farooqui M, Jones J, Valdez J, Martyr S, Soto S et al. In patients with chronic lymphocytic leukaemia (CLL) Ibrutinib effectively reduces clonal IgM paraproteins and serum free light chains while increasing normal IgM, IgA serum levels, suggesting a nascent recovery of humoral immunity. Blood 2013;122:4182a