Low IgE monoclonal gammopathy level in serum highlights 20-yr survival in a case of IgE multiple myeloma

Non-secretory immunoglobulin E myeloma associated with immunoglobulin G monoclonal gammopathy of undetermined significance

A 68-year old woman came to our hospital with a severe case of anemia. Serum immunoelectropheresis identified a monoclonal immunoglobulin (Ig) G and κ protein. The serum IgE level was within the nomal range and the amounts of remaining immunogloblins were low. On bone marrow aspirate, plasma cells made up 55.5% of nucleated cells and the plasma cells showed positive readings for IgE κ and IgG by immunohistochemistry. Serum immunofixation did not reveal the IgE monoclonal band. She was diagnosed as having non-secretory IgE myeloma with IgG monoclonal gammopathy of undetermined significance. The nature of this rare myeloma will be discussed.

Efficacy and outcome of autologous transplantation in rare myelomas

BACKGROUND

As rare myelomas, i.e. the IgD, IgE, IgM and non-secretory forms, constitute only a small proportion of any study, relatively little is known about their prognosis in the era of peripheral stem cell transplantation.

DESIGN AND METHODS

We used the European Group for Blood and Marrow Transplantation Myeloma Database to compare the outcome following autologous transplantation of over 20,000 patients with common myelomas (IgG, IgA and light chain myeloma) with the outcome of patients with rare myelomas: 379 IgD, 13 IgE, 72 IgM and 976 non-secretory cases.

RESULTS

The study confirms the multiple adverse prognostic factors seen in IgD myeloma. Somewhat surprisingly, patients with IgD and non-secretory myeloma both had higher complete remission rates before and after transplantation than patients with common myelomas. However, while the overall survival of patients with non-secretory myeloma was similar to that of the patients with common myelomas, the survival of patients with IgD myeloma was significantly worse (although better than survival rates reported for non-transplanted patients); this was due to higher transplant-related mortality and relapse/progression rates. The post-transplantation survival of patients with IgE or IgM myeloma appears to be very poor.

CONCLUSIONS

This study provides data on the biological features of rare myelomas. The overall survival of patients with IgD, IgE or IgM myeloma is poor following autologous transplantation but substantially better than that reported for patients who were not transplanted.

Prozone effect of serum IgE levels in a case of plasma cell leukemia

We describe a case of multiple myeloma (MM) and secondary plasma cell leukemia (PCL) secreting IgE-kappa immunoglobulin. To our knowledge, only 2 cases of IgE-producing secondary PCL have been reported in the medical literature. In our patient, the only tumor marker available for monitoring the therapeutic response to chemotherapy and allogeneic stem cell transplantation was the quantitative M component at serum protein electrophoresis (SPEP), because serum free light chains were in the normal range, Bence-Jones proteinuria was absent, and quantitative serum IgE levels provided inaccurate and erratic results, due to the prozone effect. This is a laboratory phenomenon that occurs when antigen excess interferes with antibody-based methods requiring immune complex formation for detection. It is important to recognize the presence of a prozone effect, because it can produce falsely normal results, and therefore it could lead clinicians to incorrect assessment of the response to therapy.