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

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.

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.

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.

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.