Amyloidosis and multiple myeloma are distinct conditions that are sometimes related. Understanding this relationship is important.
The Connection Between Amyloidosis and Multiple Myeloma
Amyloidosis is a rare disorder characterized by the accumulation of abnormal protein deposits called amyloid. AL (light chain) amyloidosis, also known as primary amyloidosis, is the most common form of systemic amyloidosis and is directly linked to multiple myeloma. These deposits can lead to organ dysfunction and damage.
Multiple myeloma is a cancer affecting plasma cells, a type of white blood cell found in the bone marrow that produces antibodies. In this condition, cancerous plasma cells multiply uncontrollably. While multiple myeloma involves the growth of abnormal cells in the bone marrow, AL amyloidosis primarily involves the buildup of abnormal light chains produced by these cells.
The abnormal plasma cells in multiple myeloma can produce excessive amounts of abnormal light chain proteins, also known as monoclonal proteins or M-proteins. These light chains can misfold and clump together, forming amyloid fibrils. Around 10% to 15% of individuals with multiple myeloma may also develop AL amyloidosis.
Recognizing Symptoms of AL Amyloidosis and Multiple Myeloma
The symptoms of AL amyloidosis are diverse and often non-specific. Individuals might experience fatigue, swelling in the ankles and legs, shortness of breath, numbness or tingling in the hands or feet, unexplained weight loss, or an enlarged tongue. Kidney involvement is common, affecting 60% to 70% of people.
Multiple myeloma also presents with a range of symptoms, including bone pain, fatigue due to anemia, kidney problems, and frequent infections. When both conditions are present, symptoms can overlap or be primarily driven by the amyloidosis. Symptoms of AL amyloidosis often emerge before a formal diagnosis of multiple myeloma or are diagnosed concurrently.
Diagnosis and Confirmation
The diagnostic process for both conditions involves several tests. Blood and urine tests are performed to detect abnormal proteins, such as serum and urine protein electrophoresis and free light chain assays, which can identify M-proteins. The presence of an abnormal light chain in urine is sometimes referred to as Bence Jones protein.
A bone marrow biopsy is performed to confirm multiple myeloma by checking for abnormal plasma cells. To confirm amyloid deposits, a tissue biopsy, such as a fat pad biopsy or an organ biopsy, is used. Imaging studies, including echocardiograms, MRIs, and PET scans, help assess the extent of organ involvement and damage.
Treatment Strategies
Treatment for multiple myeloma and AL amyloidosis involves a dual approach: targeting the underlying abnormal plasma cells to halt the production of amyloid-forming proteins and providing supportive care for organ damage. The goal is to reduce the light chain burden. Many treatments for multiple myeloma are also beneficial for AL amyloidosis.
These treatments often include chemotherapy, proteasome inhibitors like bortezomib, and immunomodulatory drugs such as lenalidomide. In some cases, autologous stem cell transplantation (ASCT) is utilized, where a patient’s own stem cells are collected and reinfused after high-dose chemotherapy. Supportive care for affected organs may involve diuretics for heart or kidney issues, pain management, and nutritional support.
Prognosis and Outlook
The prognosis for individuals with both amyloidosis and multiple myeloma is influenced by several factors, including the extent of organ involvement, especially the heart and kidneys, and the response to treatment. Advancements in treatment have improved outcomes. Early diagnosis and aggressive treatment are important for preserving organ function and enhancing quality of life. Ongoing monitoring and management are also part of care.