Chronic lymphocytic leukemia with associated lambda-light-chain and IgG lambda paraproteins simulating a biclonal gammopathy.

Background: Monoclonal components (MCs) are frequently detected in the sera of patients with B-cell malignancies, by techniques that are getting more and more sensitive. Only few chronic lymphocytic leukemia (CLL) patients with multiple serum paraproteins are reported in the literature.
Methods: In this case report we present a 71-year-old woman with CLL and serum MCs. Immunofixation was performed on agarose film using anti-sera monospecific for the heavy and light chains of human immunoglobulins (anti-gamma, -alpha, -mu, -delta, -epsilon, -kappa, -lambda). Serum free light chains (FLCs) were quantified nephelometrically. Immunofluorescence analysis was performed using fluorochrome-conjugated goat antibodies specific for human mu, gamma or alpha immunoglobulin heavy chains and K or lamda light chains.
Results: Immunofixation revealed two different MCs (IgGlambda + lambda light-chains) in the serum and only one MC (lambda light chains) in concentrated urine. Serum lamda FLCs were 206 mg/L. The bone marrow aspiration and biopsy revealed a 38 % interstitial and nodular infiltration of mature small lymphocytes expressing IgG lambda surface immunoglobulins CD 19, CD20, CD5, and CD23, with negative BCL-1, t(11, 14) and cyclin D1. The plasma cells were less than 1%. Final diagnosis was CLL (Rai stage I) with IgG lamda plus lamda serum paraproteins. Three years later, the patient died because of myocardial infarction after a follow-up period with no need for CLL therapy.
Conclusions: Our hypothesis is that the double MC may be the result of an unbalanced immunoglobulin chain synthesis by the leukemic B-cell clone, resulting in IgGlamda and excess of lambda FLCs.