107 Multiple Myeloma Flashcards
A 69M complains of bone pain and easy fatigability. Labs: creatinine 2.5 mg/dl, hemoglobin 8 mg/dl, serum calcium 12 mg/dl, serum M component and bone marrow plasmacytosis. What is the cause of the bone lesions of this patient?
A. Apoptosis of tumor cells
B. Activation of osteoclasts
C. Activation of osteoblast that form new bone
D. Hypercalcemia
B. Activation of osteoclasts
Monoclonal neoplasm a related to each other by virtue of their development from common progenitors in the late B lymphocytes lineage
Plasma cell disorder
What composes plasma cell disorders?
Multiple myeloma
Waldenstroms macroglobulinemia
Primary amyloidosis
Paraproteinemias/monoclonal gammopathies
What are the heavy chain isotypes and light chain isotopes?
Heavy chain isotopes: M, G, A, D, E
Light chain isotopes: kappa, lambda
What are the 3 structural variation of immuboglobulins?
Isotopeas
Allotypes
Idiotypes
Distinguish between main classes of antibodies of a given species
Isotypes
Reflect differences between individuals of the same species of otherwise similar immunoglobulins
Allotypes
Formed by unique structure of the antigen binding protein portion of the molecule
Idiotypes
Forms the antigen recognition site of the antibody molecule
Variable region
VDJ: heavy chain
VJ: light chain
Which antibody molecule is produced in excess and excreted in the kidneys?
Light chains
Sharp spike in this region during electrophoresis in association with plasma cell disorders and an excellent tumor maker to manage therapy
M component
Two rare skin disorders associated with monoclonal gammopathy
Lichen myxedematosus
Necrobiotic xanthogranuloma
Most common serum concentration in the heavy chain class
IgG are more common than IgA and IgD myelomas
Malignant proliferation of plasma cells derived from a single clone
Multiple myeloma
What is the error found in multiple myeloma?
Errors in switch recombination, genetic mechanism to change antibody heavy chain isotypes in the early transformation process
Common mutations in multiple myeloma
N Ras
K Ras
B raf
Interluekin that play a role in driving myeloma cell proliferation?
Interluekin 6 (IL6)
Mean age of diagnosis of MM
Mean age of diagnosis is 69 years old and uncommon under age 40
Most common symptom of myeloma
Bone pain
What causes the pain in myeloma
- Proliferation of tumor cells
- Activation of osteoclasts that destroy bone
- Suppression of osteoblast that form new bone
Second common clinical problem in patient with myeloma
Susceptibility to bacterial infection
Common infections in multiple myeloma
Pneumonias
Pyelonephritis
Most frequent pathogens in myeloma
Strep pneumoniae
Staph aureus
Kleb pneumoniae
Most common cause of renal failure in multiple myeloma
Hypercalcemia
Earliest manifestation of tubular damage in multiple myeloma
Adult fanconi syndrome: type 2 proximal renal tubular acidosis; loss of Glucose and amino acids as well as defects in the ability to acidify and concentrate urine
True or false. In multiple myeloma, very little albumin is in the urine because glomerular function is usually normal
True
Multiple myeloma is result with what type of anion gap and why?
Patients with multiple myeloma have decreased an anion gap because M component is cationic, resulting in retention of Chloride
Why type of electrolyte imbalance accompany multiple myeloma?
Pseudo Hyponatremia because each volume of serum has less water as a result of increased protein
True or false. Light chain cast nephropathy and amyloidosis is partially reversible with effective therapy
True
True or false. Patients with multiple myeloma are susceptible to developing AKI when dehydrated
True
Type of anemia in multiple myeloma. What’s is the cause of this anemia?
Normocytic normochromic anemia
Due to replacement of normal marrow by expanding tumor cells
Pathophysiology of Clotting abnormalities in multiple myeloma
Failure of the antibody-coated platelets to function properly
What Clotting factors are affected in multiple myeloma?
Clotting factors I, II, V, VII, or VII 2,3 2+3=5 5+2=7 5+3=8
Normal relative serum viscosity
1.8
What is hyperviscosity?
Relative viscosity of serum as compared to water
When does symptoms of hyperviscosity occur?
4.0 centipoise (cP)
When is hyperviscosity reached in patients with multiple myeloma?
IgM: 40 g/dl or 4 g/L
IgG3: 50 g/dl
IgA: 70 g/dl
What type of neuropathy is associated with multiple myeloma?
More sensory than motor and is associated with IgM
IgM targets myelin-associated Globulin
Defines the diagnosis of multiple myeloma
Marrow plasma cytosis of more than 10%
Serum/urine M protein
*least one of the myeloma defining events
What is the character of bone marrow plasma cell in multiple myeloma?
CD138+ and either
Kappa and lambda light chain positive
Important differential diagnosis of patients with multiple myeloma
MGUS
smoldering multiple myeloma (SMM)
True or false. All cases of MGUS transform to multiple myeloma
False. Only 1% transform to multiple myeloma
True or false. All multiple myeloma preceded by MGUS
True
Associated with higher incidence of progression of MGUS to multiple myeloma
Non IgG subtype
Abnormal kappa/lambda ratio
Serum M protein more than. 15 g/dl (1.5 g/L)
Associated with higher incidence of progression of MGUS to multiple myeloma
Non IgG subtype
Abnormal kappa/lambda ratio
Serum M protein more than. 15 g/dl (1.5 g/L)
Features responsible for higher incidence of progression from SMM to MM
Bone marrow plasmacytosis more than 10%
Abnormal kappa/lambda free light chain rario
Serum M protein more than 30 g/L (3.0 g/dl)
Two important variants of multiple myeloma
Solitary bone plasmacytoma
Solitary extramedullary plasmacytoma