The serum free light immunoglobulin chains (FLC) belong to the well characterized and widely used standard methods in patients with multiple myeloma (MM), monoclonal gammopathy of undetermined significance (MGUS), and other plasma cell dyscrasias, together with serum protein electrophoresis, immunofixation, and bone marrow examination. The serum pairs of heavy/light immunoglobulin chains (HLC) play an increasing role in the diagnosis and monitoring of monoclonal gammopathies.
Data describing biological variation of serum pairs of heavy/light immunoglobulin chains (HLC) IgA, HLC IgG, and free light immunoglobulin chains (FLC) are scarce, and data on variation of HLC IgM are missing. The aim was to acquire data on the variation of HLC IgM κ and λ and to verify the variation of HLC IgA, IgG, and FLC.