SEARCH RESULTS FOR: Multiple-Myeloma

Multiple Myeloma

Multiple-Myeloma

Multiple Myeloma: Pathogenesis and clinical findings Plasma cell populations in the body normally produce non-clonal (a diverse array of) immunoglobulins Normal SPEP: no spike in the gamma (γ) region Notes: • MGUSismuchmorecommon than MM! • “Plasmacell”:Blymphocytes that produce antibodies/ immunoglobulins Stimulation by specific antigens Genetic changes/mutations accumulate over time in one type of plasma cell Abbreviations/Definitions: • SPEP - Serum Protein Electrophoresis • Ig – Immunoglobulin • Monoclonal – “of one specific genetic strain or subtype” One type of plasma cell starts to proliferate abnormally Monoclonal Gammopathy of Undetermined Significance (MGUS) (Premalignant, mild monoclonal plasma cell proliferation; asymptomatic) In 1-2% of cases, further cytogenetic changes over time stimulate further proliferation of this plasma cell line Multiple Myeloma (MM) (extensive monoclonal B lymphocyte proliferation, causing end organ damage) Slightly more monoclonal plasma cells will produce slightly more monoclonal Immunoglobulins Small spike in the gamma (γ) region of the SPEP (less prominent compared to the spike in MM) More monoclonal plasma cells result in far greater amounts of monoclonal immunoglobulins being secreted Large spike in gamma (γ) region of the SPEP Ig light chains accumulate in the tubules of kidney nephrons Light chain casts obstruct tubules Renal Insufficiency (↓GFR) Osteoblasts ↑ expression of RANK-ligand (RANKL, an apoptosis regulator), and ↓ expression of Osteoprotegerin (OPG, a decoy receptor for RANKL) ↑ osteoclast activity vs osteoblast activityàbone loss Clonal plasma cells overrun normal bone marrow, crowding out production of red blood cells, ↓ red blood cell counts Anemia Authors: Tristan Jones, Tyler Anker, Yan Yu Reviewers: Jennifer Au, Crystal Liu, Man- Chiu Poon*, Lynn Savoie* * MD at time of publication Damaged bones hurt, & become more brittle Bony pain, pathologic fractures Osteolytic bone lesions Osteoclasts release calcium from bone and into blood Hypercalcemia Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published January 12, 2020 on www.thecalgaryguide.com