Myeloma and other plasma cell disorders Flashcards
What is MGUS and how is it diagnosed ?
Sometimes, small clones of plasma cells develop and produce a low amount of paraprotein but you have no other features of myeloma. This is called monoclonal gammopathy of unknown significance (MGUS).
Diagnosed by exlusion
What are the test results you need to diagnose MGUS by exlcusion ?
Paraprotein <30g/l
Bone marrow faulty plasma cells <10% (would be greater than 10% in the bone marrow in myeloma)
No evidence of myeloma end organ damage;
- Normal calcium
- Normal renal function
- Normal Hb
- No lytic lesions
- No increase in infections
What is Amyloid light chain amyloidosis ?
- AL amyloidosis is caused by an abnormality in certain cells found in the bone marrow, called plasma cells.
- The abnormal plasma cells produce abnormal forms of light chain proteins, which enter the bloodstream and can form amyloid deposits.
What do the amyloid deposits result in ?
Depends on the organs affected
- Kidney - Nephrotic syndrome
- Heart - Cardiomyopathy
- Liver - Organomegaly deranged LFT’s
- Neuropathy - Autonomic, Peripheral
- GI tract - Malabsorption
What are the main symptoms which can present in amyloidosis?
Nephrotic symptoms:
- Severe swelling (edema), particularly around your eyes and in your ankles and feet
- Foamy urine, which may be caused by excess protein in your urine
- Weight gain due to excess fluid retention
- Fatigue
- Loss of appetite
Cardiomyopathy:
- shortness of breath
- oedema
- an abnormal heartbeat (arrhythmia)
How is AL amyloidosis diagnosed ?
Organ biopsy confirming AL amyloid deposition - Use Congo red stain which shows “Apple-green” birefringence under polarised light
How is the extent of AL amyloidosis staged ?
- SAP scan
- Echocardiogram
- Heavy proteinuria
What is Waldenstrom’s Macroglobulinaemia (IgM paraprotein)?
- It is an uncommon condition seen in older men.
- It is a lymphoplasmacytoid malignancy characterised by the secretion of a monoclonal IgM paraprotein
What are the clinical features of Waldenstrom’s Macroglobulinaemia (IgM paraprotein)?
- Monoclonal IgM paraproteinaemia
- B symptoms - weight loss, lethargy, night sweats
- Hyperviscosity syndrome e.g. visual disturbance, confusion, coma, cardiac failure
- Hepatosplenomegaly
- Lymphadenopathy
- Cryoglobulinaemia e.g. Raynaud’s
What is the treatment of WM?
- Chemotherapy and
- Plasmapheresis (removes paraprotein from the circulation)
Why is hyperviscocity such a problem in WM?
Because there is lots of circulating IgM and it is a pentamer so a big molecule so hence hyperviscocity is more of a problem in this condition