Myeloma

Question 1

what is it?

Answer 1

A cause of paraproteinemia
Monoclonal rise in immunoglobulins
• All derived from clonal expansion of a single B-cell
• Identical antibody structure and specificity (size and change)
• Monoclonal immunoglobulin = paraprotein
• Marker of underlying clonal B-cell or plasma cell disorder

Question 2

steps of myeloma development

Answer 2

• Normal plasma cells – MGUS clone (benign premalignant) – asymptomatic myeloma (malignant but no organ damage) – myeloma (overtly malignant)
most common age 65

Question 3

how are immunoglobins detected?

Answer 3

• Serum electrophoresis – separated serum proteins appear as distinct bands or zones
• Proteins move at differing rates determined by their size and change
• Electrophoresis detects abnormal protein bands

Question 4

how does it present?

Answer 4

•	Direct tumour cell effects 
o	Bone lesions 
o	Increased calcium – hypercalcaemia (Stones, bones, groans and psychiatric undertones) 
o	Bone pain 
o	Replace normal bone marrow – marrow failure 
•	Paraprotein mediated effects 
o	Renal failure 
o	Immune suppression 
o	Hyperviscosity 
o	Amyloid

Question 5

what kidney issues does myeloma cause?

Answer 5

30% of patients have renal impairment at diagnosis
o Tubular cell damage by light chains (Light chain deposition; cast nephropathy)
- Damage may be reversible with prompt treatment
- Hydration, stop nephrotoxic drugs
- Switch off light chain production with steroids/chemo
o Sepsis
o Hypercalcemia and dehydration
o Drugs; NSAIDs
o Hyperuricaemia
o Amyloid

Question 6

how is it treated?

Answer 6

combination chemo - mainstay
o Corticosteroids: dexamethasone
o Alkylating agents:cyclophosphamide, melphalan
o ‘Novel agents’ like thalidomide, bortezomib and lenalidomide
o Monoclonal antibodies: daratumumab
o High dose chemotherapy/autologous stem cell transplant in fit patients
o Use paraprotein level to monitor response

Question 7

how are symptoms controlled?

Answer 7

opiate analgesia (avoid NSAIDs)
local radiotherapy - good for pain relief or spinal cord compression
bisphosphonates - corrects hypercalcaemia and bone pain
vertebroplasty - inject sterile cement into fractured bone to stabilise

Question 8

what is the prognosis?

Answer 8

relapse is inevitable

survival is 5-10 years in younger patients

Question 9

what is MGUS?

Answer 9

monoclonal gammopathy of undetermined significance
paraprotein <30g/l
bone marrow plasma cells <10%

Question 10

what is the difference between myeloma and MGUS?

Answer 10

• No evidence of myeloma end organ damage
o Normal calcium
o Normal renal function
o Normal haemoglobin
o No lytic lesions
o No increase in infections
• Risk of progression to myeloma is 1% per year