A case of IgE myeloma transformed into IgE-producing plasma cell leukaemia

This is a case report of a challenging diagnosis of IgE monoclonal gammopathy of undetermined significance, which transformed into myeloma, then transformed into IgE-producing plasma cell leukaemia in a 71-year-old male who was followed in Brest, France, from 2015 to 2019. The IgEproducing variant is the rarest sub-type of multiple myeloma, and plasma cell leukaemia is considered to be the rarest and the most aggressive of human monoclonal gammopathies. In November 2015, hypogammaglobulinemia was detected during a systematic check-up. A kappa light chain monoclonal gammopathy was first diagnosed due to an increase of the free kappa/lambda light chains ratio. No monoclonal immunoglobulin was detected by either serum protein electrophoresis (Capillarys 2, Sebia, Issy-les-Moulineaux, France) or immunofixation (Hydrasys 2, Sebia, Issy-les- Moulineaux, France). In June 2018, a blood smear led to the diagnosis of plasma cell leukaemia. A monoclonal peak was detected and identified as IgE-kappa. Analysis of an archival sample taken three years earlier, revealed the presence of a monoclonal IgE, which had been missed at diagnosis. Chemotherapy with bortezomib and dexamethasone was introduced. The patient survived 10 months after the diagnosis of leukaemia. This case shows that an abnormal free light chain ratio should be considered as a possible marker of IgE monoclonal gammopathy even in the absence of a solitary light chain revealed by immunofixation. In addition, the use of an undiluted serum may increase the sensitivity of the immunofixation for the detection of IgE monoclonal gammopathies compared to the 1:3 dilution recommended by the manufacturer.

A New Case of IgE Myeloma

We report a case of IgE myeloma in a 78-year-old woman who presented with bone pain in the shoulder and hip and progressive weakness. Except for hypercalcemia, routine chemistry values were within normal limits. Hemoglobin was decreased and the leukocyte count slightly increased. Plasma cells were not observed in the peripheral blood. Serum protein electrophoresis showed a monoclonal protein in the beta-globulin fraction. Immunofixation confirmed the presence of an IgE kappa monoclonal protein. A bone marrow biopsy revealed an interstitial and nodular infiltration of abnormal plasma cells comprising 60% of nucleated cells present. Skeletal roentgenograms and bone scans of this patient showed osteolytic lesions and osteopenia of the thoracic and lumbar spine and osteolytic destruction of the right half of the sacrum. Flow-cytometric analysis of mononuclear cells isolated from peripheral blood showed that 15% of the lymphocytes bound IgE. Using cell-surface markers, we identified 45% of the IgE-positive cells as natural killer cells. Similar results have been found in other diseases marked by increased IgE. The clinical, radiological, and laboratory findings for this patient are compared with previously reported cases of IgE and other types of myeloma.

Demonstration of monoclonal IgE by isoelectric focusing: first reported case of IgE myeloma in Australia.

A 56-year-old man who presented with back pain was diagnosed with multiple myeloma. Serum protein analysis by isoelectric focusing identified a monoclonal IgE lambda of unique spectrotype compared with other monoclonal immunoglobulins. The similarity of the spectrotype of this monoclonal IgE to that of two purified monoclonal IgEs suggests that these proteins have a characteristic spectrotype, sufficiently different from those of other immunoglobulin classes to allow its recognition.