Three monoclonal IgG components, an IgG4(Λ), an IgG2(κ) and an IgG1/IgG3 (κ) Gm(f,b) hybrid, in a single myeloma patient

Clinical significance of serum triple monoclonal components: a report of 6 cases and a review of the literature

A serum multiple monoclonal component (MC) is very rare. We here report 6 patients with 3 MCs. The triple MC was detected in all of them by immunofixation. 2/6 patients did not present hematological or oncological associated disease, while in the remaining 4, Waldenström macroglobulinaemia (2 cases), Polycythemia Vera and non-Hodgkin lymphoma were diagnosed. Of the 49 global patients reported in the literature (6+43), 64.6% had a lymphoproliferative disorder and only in 3 cases there was no associated disease. Therefore, the detection of such laboratory evidence should propel physicians to a deeper investigation.

Immunoglobulin G paraprotein cross-reactivity with immunoglobulin M measurement

We report a case of IgG paraprotein cross-reactivity with IgM measurement in a patient with IgGkappa multiple myeloma and associated IgA and IgM immune paresis. IgM measurements using a Beckman-Coulter Synchron LX IgM reagent initially gave unmeasurably low IgM concentrations (<0.3 g/L) but IgM quantitation using later batches of reagent gave IgM concentrations of 13-42 g/L. Immunofixation confirmed the continued presence of the IgGkappa paraprotein band with suppression of IgA and IgM and analysis on the Behring BN2 and Beckman-Coulter Immage instruments showed IgM concentrations of <0.2 g/L. Immunofixation using the Synchron LX IgM reagent as antiserum confirmed binding of the Synchron LX IgM antiserum to the IgGkappa paraprotein. This case highlights the importance of checking all unexpected immunoglobulin measurements with previous results and immunofixation findings to avoid mistakes.

Multiple M components in two patients with splenic lymphoma with villous lymphocytes

Splenic lymphoma with villous lymphocytes (SLVL) is a rare lymphoproliferative disorder characterized by the presence of typical lymphoid cells with villous projections and monoclonal immunoglobulin (M-Ig) in about 30% of patients. The simultaneous presence of more than one M-Ig in SLVL has not been reported. We present two patients with SLVL, each with three serum M components associated with the presence of rheumatoid factor (RF) and antiphospholipid antibodies (APLA) together with fatal thromboembolic events. Both patients presented with splenomegaly and typical bone marrow cytology with 30-50% infiltration of lymphoid cells that had the characteristics of villous lymphocytes. Immunohistochemistry of bone marrow histology showed CD20++, CD43-/+, CD5-, IgM+, lambda+ and kappa-. In serum, two M-IgM lambda components were combined with M-IgG lambda in case 1 and with M-IgA lambda in case 2. In both cases, M-IgM displayed RF as well as lupus anticoagulant activity and free monoclonal lambda (lambda) light chains were present. In addition to M-IgM, in case 1 M-IgG also behaved like an APLA. One patient was splenectomized. Both patients suffered thromboembolic complications and died 3 and 8 months after presentation with signs of massive pulmonary thromboembolism.