Which of the following is the most likely cause of this patient’s hyper-calcemia?
A 54 y/o woman comes to the physician because of a 5-day history of severe mid-back pain Physical examination shows point tenderness over the T6 vertebra. Serum studies show a
calcium concentration of 13.4 mg/dl; urinalysis shows Bence Jones proteins.
A. Excessive parathyroid hormone production
B. Excessive parathyroid hormone-related protein production
C. Increased fractional calcium gastrointestinal absorption
D. Local interleukin-1 (IL-1) and tumor necrosis factor effect
E. Unregulated 1,25-dihydroxycholecalciferol production
Serum shows a calcium concentration of 13.4 mg urinalysis shows Bence Jones proteins. Hypercalcemia is a condition in which you have too much calcium stored in the body, which can harm your bones and interfere with the processes of the heart and the brain.
Bence Jones proteins are considered to be the first tumor marker used to diagnose and monitor multiple myeloma, which is a type of cancer. Total calcium levels are maintained between 8.8 and 10.2 mg/dL. Parathyroid hormones and vitamin D regulate normal plasma calcium levels by their actions on kidney, intestine, and bone on transport.
Local interleukin-1 (il-1) and tumor necrosis factor effect-the underlying disease is multiple myloma: hypercalcemia in multiple myeloma, where there is bone marrow infiltration by tumor has been ascribed to the release of osteoclast activating factors by the tumor cells. osteoclast-induced bone resorption may occur in discrete focal areas (lytic lesions) or throughout the skeleton. the high rate of bone resorption is associated with an absence of osteoblast-mediated bone formation, resulting in diffuse bone loss. the uncoupling of bone resorption and formation results from paracrine factors, which enhance osteoclast formation and activity and inhibit the capacity for marrow stromal cells to differentiate into osteoblasts. in multiple myeloma, various studies have implicated interleukin (il)-6, rankl (from tnf family), macrophage inflammatory protein 1a, osteoclast activating factor [aka il-1], osteoprotegerin, and il-3 as factors contributing to the development of lytic bone disease and hypercalcemia.