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multiple myeloma - mike90 - Printable Version +- USMLE Forum - Largest USMLE Community (https://www.usmleforum.com) +-- Forum: USMLE Forum (https://www.usmleforum.com/forumdisplay.php?fid=1) +--- Forum: Step 1 (https://www.usmleforum.com/forumdisplay.php?fid=2) +--- Thread: multiple myeloma - mike90 (/showthread.php?tid=64482) |
multiple myeloma - mike90 - ArchivalUser - 12-05-2005 Which one of the following substances is secreted by malignant plasma cells in individuals with multiple myeloma and is the osteoclast-activating factor (OAF) that produces the characteristic lytic bone lesions? A. Interleukin 1 B. Interleukin 6 C. Tumor necrosis factor D. Transforming growth factor E. Platelet-derived growth factor 0 - ArchivalUser - 12-05-2005 A. 0 - ArchivalUser - 12-05-2005 IL-1 beta is a major osteoclast activating factor (OAF) produced by myeloma cells 0 - ArchivalUser - 12-05-2005 Is B. IL-6 the right anser? 0 - ArchivalUser - 12-05-2005 I think I was wrong. should be IL-1 0 - ArchivalUser - 12-05-2005 IL-6 is the right choice. Multiple myeloma is characterized by a triad of marrow plasmacytosis, serum or urine M (monoclonal) protein, and lytic bone lesions. Myeloma is a monoclonal malignancy of the B lymphocyte system, with bone pain the most common symptom. Osteolytic, punched-out bone lesions are characteristic, especially in the skull. Since the process is lytic, alkaline phosphatase is usually not elevated. These osteolytic lesions result from the production of osteoclast-activating factor (OAF) by the myeloma cells. This results in increased serum calcium levels (hypercalcemia). OAF is in fact IL-6, and increased amounts of IL-6 are associated with a worse prognosis because the survival of the myeloma cells is dependent upon IL-6. Myeloma is not associated with lymphadenopathy, but recurrent infections are frequent because of the severe suppression of normal immunoglobulins. In fact, infection is the most common cause of death in these patients and is usually due to encapsulated bacteria. There is no increase in viral infections in these patients because their cell-mediated immunity is normal. 0 - ArchivalUser - 12-05-2005 what was the factor that was secreted by osteoblasts and activated osteoclasts,or the otherway round? 0 - ArchivalUser - 12-05-2005 factors secrted by osteoclasts are |