Myelomas Flashcards
What is myeloma?
Myeloma is the chief plasma cell dyscrasia which are due to an abnormal proliferation of a single clone of plasma cells. This causes a large secretion of Immunoglobulin or immunoglobulin fragments resulting in dysfunction of organs such as the kidneys.
What are the risk factors for myeloma?
Old Age
Afro Caribbean 2:1 Caucasian
Radiation
Family History
How are myelomas classified?
This is based on the type of immunoglobulin production. 2/3rd are IgG, 1/3 are IgA, very few are IgM, IgE or IgD
What are the clinical features of myeloma?
Susceptibility to infection as all other Ig levels are low (immunoparesis)
Bence jones protein in the urine – these are free Ig light chains of kappa or lambda filtered by the kidneys
Backpain, pathological fractures, and vertebrae collapse due to osteolytic bone lesions
Hypercalcaemia due to increased osteoclast activity
Marrow infiltration and failure – anaemia, thrombocytopenia and leukopenia
Renal impairment
Recurrent bacterial infections
Pathological fracture – myeloma can form a mass in the bone marrow, when one is present this is called a plasmacytoma if more than 1 then multiple myeloma. This can result in pathological fracture
How is suspected myeloma investigated?
FBC Blood film showing Rouleaux Persistently raised ESR Us and Es (raised urea and creatinine and calcium) Bone marrow biopsy and aspiration
Screening test is serum electrophoresis looking for paraprotein (abnormal immunoglobulin)
Prognostic indicator = Beta 2 Microglobulin
Serum free light chain – test for Kappa and Lambda light chains which are produced by plasma cells. If the ratio is skewed in favour of one this indicates Myeloma.
Imaging – X-ray showing lytic punched out regions of bone. CT or MRI may also be useful
What are the diagnostic criteria for a myeloma?
Diagnostic criteria
- Monoclonal protein band in serum or urine electrophoresis
- > 10% plasma cells on marrow biopsy
- Evidence of end organ damage from myeloma e.g. CRAB – Calcium elevation, Renal insufficiency, Anaemia and Lytic bone lesions
What is a paraprotein?
Paraprotein – abnormal immunoglobulin protein fragment produced by the cancerous cells.
How can you manage the symptoms of myeloma?
Analgesia for the bone pain (avoid NSAIDs)
Bisphosphonates to reduce fracture and pain. Targeted radiation therapy may sometimes be used to reduce pain from the lesions.
Transfusion for anaemia if needed
Renal impairment – hydrate very well, dialysis may be required
Infections – treat rapidly, Ig infusions may be required if recurrent
How is myeloma managed?
Treatable but not curable
Combination therapy including steroid, immunomodulator, proteasome inhibitors and monoclonal antibodies (for 12-18months if not suitable for transplant). Treat long term.
Autologous stem cell transplants
This usually allows paraprotein levels to plateau.
Treatment stopped until inevitably paraprotein rises again then repeat treatment but change one of the drugs.
Monitor for neutropenia and thromboembolism (chemo agent used can cause)
What are the poor prognostic factors for Myeloma?
Worse if > 2 osteolytic lesions High B2 Microglobulin Low Hb Low Albumin Death usually due to infection or renal failure
What is MGUS
Pre malignant state that progresses to Malignant disease in 1% of cases. So just having paraprotein present isn’t indicative of disease as many elderly people have paraproteins present – this is referred to as MGUS (monoclonal gammopathy of undetermined significance).
What confers an increased risk of malignant transformation of MGUS?
The risk is increased if high paraprotein level, presence of an abnormal paraprotein and if it is anything except IgG.
