From the Guidelines
Paraproteinemia should be diagnosed and managed based on the underlying cause, with a focus on regular monitoring for monoclonal gammopathy of undetermined significance (MGUS) and aggressive treatment for multiple myeloma, including chemotherapy, immunomodulatory drugs, proteasome inhibitors, and possibly stem cell transplantation, as recommended by the most recent guidelines 1.
Diagnosis and Management
The diagnosis of paraproteinemia typically involves serum protein electrophoresis, immunofixation, and free light chain assays to identify and quantify the abnormal proteins. The most common causes of paraproteinemia include multiple myeloma, MGUS, Waldenström macroglobulinemia, and certain lymphomas.
- Serum protein electrophoresis and immunofixation are used to identify and quantify the abnormal proteins in the blood.
- Free light chain assays are used to detect and quantify the light chain proteins in the blood and urine.
- Bone marrow aspiration and biopsy are used to evaluate bone marrow plasma cell infiltration and detect quantitative and/or qualitative abnormalities of bone marrow plasma cells.
- Imaging studies, such as full skeleton radiographic survey or whole-body, low-dose CT, are used to evaluate lytic bone lesions.
Prognosis and Treatment
The prognosis of paraproteinemia varies widely depending on the specific diagnosis, with MGUS having a relatively benign course while multiple myeloma typically requires ongoing treatment.
- MGUS requires regular monitoring, while multiple myeloma may need aggressive treatment with chemotherapy, immunomodulatory drugs like lenalidomide, proteasome inhibitors such as bortezomib, and possibly stem cell transplantation.
- The treatment of multiple myeloma has dramatically changed over the last two decades, with the introduction of new drug classes, including proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies 1.
- Regular follow-up with hematology specialists is essential for all patients with paraproteinemia to monitor disease progression and adjust treatment as needed.
Recent Guidelines
The most recent guidelines for the diagnosis and management of paraproteinemia recommend a comprehensive diagnostic workup, including serum protein electrophoresis, immunofixation, free light chain assays, bone marrow aspiration and biopsy, and imaging studies 1.
- The guidelines also recommend regular monitoring for MGUS and aggressive treatment for multiple myeloma, including chemotherapy, immunomodulatory drugs, proteasome inhibitors, and possibly stem cell transplantation.
- The use of serum free light chain assays has been shown to have prognostic value in plasma cell disorders, including monoclonal gammopathy of undetermined significance, smoldering myeloma, active myeloma, immunoglobulin light chain amyloidosis, and solitary plasmacytoma 1.
From the Research
Definition and Prevalence of Paraproteinemia
- Paraproteinemia is a condition characterized by the presence of monoclonal immunoglobulins or light chains in the blood or urine, produced by a clonal population of mature B cells, most commonly plasma cells 2.
- The incidence of paraproteinemia in individuals aged >50 years is 3.2% 2.
- Paraproteinemia can be associated with a variety of laboratory abnormalities, which may occur as a result of the underlying disease process or interference by the paraproteins with laboratory tests in vitro 3.
Types of Paraproteinemias
- Paraproteinemias can be considered as a spectrum of conditions ranging from monoclonal gammopathy of undetermined significance (MGUS), through asymptomatic, to symptomatic myeloma 2.
- MGUS is defined by a low level of paraprotein <30 g/l, bone marrow plasma cells <10%, and the absence of myeloma-related organ or tissue damage 2.
- Light chain and intact immunoglobulin multiple myeloma are types of paraproteinemias that can be detected using serum free light chain measurements and serum and urine electrophoresis 4.
Diagnosis and Monitoring
- Serum free light chain measurements and serum and urine electrophoresis are used to detect and monitor paraproteinemias 4.
- The serum free light chain test has been shown to provide greater sensitivity than urine electrophoresis for monitoring paraproteinemias 4.
- Diagnostic laboratories should be aware that certain medications, such as daratumumab, can be detected on routine serum protein electrophoresis and should liaise closely with clinicians to ensure accurate interpretation of results 5.
Treatment and Management
- Treatment of paraproteinemias may be aimed specifically at the underlying hematologic disorder or at managing associated neuropathies 6.
- Autologous stem cell transplant and thalidomide in combination with dexamethasone have been shown to be effective in the treatment of myeloma 2.
- Neurologists play an important role in the management of paraproteinemias, particularly when neuropathy is the presenting feature, and can work collaboratively with hematologists to formulate therapeutic plans and goals 6.