Multiple Myeloma and Lymphoid Leukemias Flashcards
B-lymphocyte general
Recognize epitopes of antigens by way of antibody molecues on their surface
First produce IgM
Isotype switching (IgG later)
Immunoglobulin structure
2 heavy chains - greater molecular weight, have Fc that is recognized
2 light chains - lighter
Define monoclonal gammopathy
Pathological clonal expansion of a single B or plasma cell leading to the excessive production of a homogeneous monoclonal immunoglobulin or a polypeptide subunit of the immunoglobulin
Define paraproteinemia
Implies that there is a structural abnormality in the immunoglobulin (ie incomplete Ig)
M-protein
Monoclonal protein
Does not imply anything structurally about the molecule other than its homogeneous nature
Cryoglobulins
Abnormal proteins that precipitate at temperatures below body temperature
Define multiple myeloma
Clonal origin: malignancy of B lymphocyte plasma cell lineage
Arises in bone marrow
Systemic disease
Production of immunoglobulin
Incidence and Signalment of Multiple myeloma
Rare in cats, not found in bone; usually liver and spleen
More common in dogs, tends to cause bone lesions and is found in marrow
Pathology and natural behavior of multiple myeloma
Immunoglobulin production - M component - Paraprotein - Usually complete Ig . Just light chains Bence Jones . Just heavy chains heavy chain disease - Cryoglobulins insoluble <37 degrees Celsius
Sequelae of M component
Infection - Decreased production of normal Ig - Immunologic cripples Hypersensitivity syndrome - Increased total protein - Hypervolemia Organ or bone infiltration with neoplastic cells
Hyperviscosity syndrome
Heart failure - Increased perfusion pressure and hypervolemia lead to cardiomyopathy - Myocardial hypoxia Neuro signs - Poor perfusion - Seizure, lethargy, abnormal mentation
Renal failure
High protein content in filtrate Tubular obstruction - Bence Jones proteinuria Amyloidosis Ascending pyelonephritis Tumor infiltration Decreased perfusion
Ophthalmic abnormalities
Dilated and tortuous retinal vessels
Retinal hemorrhage
- Acute hemorrhage
Hemorrhagic diathesis
Decreased platelet adhesion
Interference with coagulation cascade and fibrin polymerization
Consumption of coagulation factors
Myelophthisis and thrombocytopenia
Other signs of multiple myeloma
Severe skeletal pain Pathologic fracture Spinal cord compression Myeloma induced osteolysis - Osteoclast activation
