Myeloma

Question 1

What is myeloma?

Answer 1

Plasma cell proliferation malignancy
Mutations which occur as B-lymphocytes differentiate into mature plasma cells
Leads to secretion of immunoglobulin causing organ dysfucntion

Question 2

How is myeloma classified?

Answer 2

Based of Ig product:
2/3 = IgG
1/3 = IgA

Other Ig levels are low causing increased susceptiibility to infection

Question 3

What are clinical features of myeloma

Answer 3

70 years old median age

CRABBI

Calcium - hypercalcaemia due to increased osteoclast activity - constiaption, nausea, anorexia, confusion

Renal - monoclonal production of Ig results in light chain deposition in renal tubules. These cause inflammation and damage resulting in dehydration and increasing thirst

Anaemia: bone marrow crowding from plasma cell infiltration suppresses erythropoiesis leading to anaemia - fatigue and pallor

Bleeding - bone marrow crowding results in thrombocytopenia - bleeding and bruising

Bones - lytic bone lesions due to bone marrow infiltration by plasma cells and cytokine mediated osteoclast overactivity - pain and fragility fractures

Infection - reduction in production of normal Ig results in increased susceptibility

Question 4

What do bloods show in meyloma?

Answer 4

FBC - normocytic, normochromic anaemia
Thrombocyopania
U&E - raised urea and creatiniine
Raised calcium
Raised ESR

Question 5

What Ix in myeloma?

Answer 5

FBC
U&E
Ca
ALP

Serum/urine protein electrophoresis - raised monoclonal IgA/IgG proteins (Paraprotein) - Bence Jones proteins in urine
Paraprotein monoclonal band on electrophoresis

Bone marrow aspiration and trephine biopsy:
Plasema cells raised with abnormal forms

Whole body MRI for lytic bone lesions -rain drop skull

Question 6

How is myeloma diagnosed?

Answer 6

Bone pain/back pain other symptoms and

Monoclonal plasma cells in the bone marrow > 10%
Monoclonal protein band in serum or urine electrophoresis
Evidece of end-organ damage: Hypercalcaemia, renal insufficeincy - raised urea/creatinine, anaemia, lytic bone lesions, fractures

Question 7

What is supportive Mx of myeloma?

Answer 7

Analgesia for bone pain - Avoid NSAIDs due to nephrotoxicity
Bisphosphonates - clodronate, zolendronate, pamidronate - reduce fracture rates and bone pain
Local radiotherapy
Correct anaemia with transfusion and EpO
Renal failure - rehydrate, ensure adequate fluid intake fo 3L/day
Dialysis in AKI
Treat infections with broad spectrum abx until culture results known

Question 8

What is Mx of mueloma

Answer 8

For patients who are suitable for autologous stem cell transplantation induction therapy consists of Bortezomib + Dexamethasone

For patients who are unsuitable for autologous stem cell transplantation, induction therapy consists of Thalidomide + an Alkylating agent + Dexamethasone

Treatment held until paraprotein levels start to rise again at which point further chemo or stem cell transplantation may be considered

Question 9

Describe autologous stem cell transplant

Answer 9

An autologous stem cell transplant is used after high dose chemotherapy administration which targets stem cells. It involves the removal of a patient’s own stem cells prior to chemotherapy, which are then replaced after chemotherapy. This is different from Allogenic stem cell transplantation where stem cells are sourced from HLA matching donors.

Question 10

What are complications of myeloma?

Answer 10

Pain - analgesia
Pathological fracture - zoledronic acid
Infection - annual influenza vaccination, Ig replacmeent therapy
VTE - prophylaxis
Fatigue - Epo analogue
Hyperviscosity - plasmapheresis to remove light chains
Spinal cord compression - dexamethasone
Hypercalcaemia - Rehydrate vigorously with IV saline