Multiple myeloma is a group of diseases characterized by proliferation of a single plasma cell clone that overproduces monoclonal immunoglobulin molecules known as paraprotein. Myeloma cells are located in the bone marrow and blood, while paraprotein is found in the blood and urine. Diagnostic features include more than 10% plasma cells in bone marrow, presence of an M-band on serum electrophoresis, hypercalcemia, and Bence-Jones proteins in urine that precipitate with heating. Clinical manifestations include bone disease, impaired renal function, anemia, hypercalcemia, and infections.

1. Multiple myeloma

2. What is multiple myeloma (MM)?
 MM is a group of diseases
characterized by proliferation of single
plasma cell clone (myeloma cell) to
cause overproduction of monoclonal
immunoglobulin molecules known as
paraprotein (myeloma M-protein)

3. What is the origin of M-protein?
% of patients:
 55% - IgG
 23% - IgA
 20% - Ig light chains
 2 % - IgD, IgM

4. Where are myeloma cells and
paraproteins localized?
Myeloma cells
 Bone marrow
 Blood
Paraprotein
 Blood
 Urine (light chain –
Bence- Jones protein)

5. What is biochemical profile of
multiple myeloma?
 Plasma cell > 10%
 Serum electrophoresis: M- band
(sharp peak in the gamma-globin
fraction)
 Hypercalciemia
 Normal Alkaline phosphatase
 20% of patients with light chain
paraprotein do not detect it in
serum but show presence of
Bence-Jones protein in the urine

7. Cytogenetic analysis of
chromosome

8. What are Bence-Jones proteins?
How are they detected by heating
test?
 The presence of specific
protein in the urine of
patient with MM was first
reported by Bence-Jones
in 1848.
 Bence-Jones protein is
immunoglobulin light
chain.
 Heat test: ppt at 40-50C
but dissolve on further
urine heating to boiling
point
 Henry Bence-Jones
(1813-1873) English
physician and chemist

9. Clinical features
Bone disease
Impaired renal
function
Anemia
Hypercalciemia
Chronic
infections

10. Bone disease – lytic lesions of
bone
 Activation of
osteoclasts
(increase
resorption)
 Inhibition of
osteoblasts
(decrease
formation)
 Pain, deformation

11. Impaired renal function
 Overflow proteinuria
 Multiple myeloma
may cause renal
tubular amyloidosis
 Obstruction of
lumen of nephrons
by paraproteins

12. Anemia
 Bone marrow erythropoietic cell are
replaced by the plasma cells, resulting
in anemia

13. Hypercalcemia