Temporal Arteritis + Osteoporosis (32) Flashcards
What is GCA?
Inflammatory disease of blood vessels (large and medium) of the head, mainly branches of ECA.
Which part of the the vessel is affected most for GCA?
Tunica medium
What are the pathological changes in microscopic picture of GCA?
- Involved arterial segments develop intimal thickening (with occasional thromboses) that reduces the luminal diameter.
- Classic lesions exhibit medial granulomatous inflammation centered on the internal elastic lamina that produce elastic lamina fragmentation.
- There is an infiltrate of T cells (CD4+ > CD8+) and macrophages.
- Although multinucleated giant cells are seen in approximately 75% of adequately biopsied specimens, granulomas and giant cells can be rare or absent.
- Inflammatory lesions are only focally distributed along the vessel and long segments of relatively normal artery may be interposed.
What is one simple blood test to prove GCA?
ESR (elevated)
Why does blindness occur in GCA?
Ophthalmic artery involvement
What is the most confirmatory test for GCA?
Temporal artery biopsy
Why did the patient develop osteoporosis?
Steroid therapy and post-menopausal status.
What is the treatment for GCA?
Corticosteroids. Start prednisolone 60mg/d PO immediately or IV methylprednisolone if evolving visual loss or history of amaurosis fugax. Typically a 2-year course.
What are the pathological changes in osteoporosis?
- Histologically normal bone that is decreased in quantity.
- Postmenopausal osteoporosis, the increase in osteoclast activity affects mainly bones or portions of bones that have increased surface area, such as the cancellous compartment of vertebral bodies.
- The trabecular plates become perforated, thinned, and lose their interconnections, leading to progressive micro fractures and eventual vertebral collapse.
What is osteoporosis and what is its pathogenesis?
- Metabolic bone disease characterized by low bone mass, micro architectural deterioration of bone tissue, increase bone fragility, and loss of bone matrix.
- Three main mechanisms: inadequate peak bone mass, excessive bone resorption, and inadequate formation of new bone during bone turnover.
- Mechanisms by which corticosteroids cause osteoporosis: direct inhibition of osteoblast formation, direct stimulation of bone resorption, inhibition of GIT calcium absorption, stimulation of renal calcium losses, and inhibition of sex steroids.
How can multiple myeloma be diagnosed?
Punched-out lytic skull lesions on x-ray, M spike on protein electrophoresis, Ig light chains in urine (Bence Jones proteins), and CRAB (hypercalcemia, renal insufficiency attributable to myeloma, anemia, and bone lesions).
What are the causes of osteoporosis?
- Primary: idiopathic, postmenopausal, and senile.
- Secondary: endocrine disorders (Addison disease, diabetes type 1, hyperparathyroidism, hyperthyroidism, hypothyroidism, pituitary tumors, neoplasia, carcinomatosis, and multiple myeloma), gastrointestinal (hepatic insufficiency, malabsorption, malnutrition, and vitamin C and D deficiencies), drugs (alcohol, anticoagulants, anticonvulsants, chemotherapy, and corticosteroids), and miscellaneous (anemia, homocystinuria, immobilization, osteogenesis imperfecta, and pulmonary disease).
What are the other causes of pathological fracture?
Skeletal metastasis, Paget’s disease, multiple myeloma, rickets, osteomalacia, osteogenesis imperfecta, and radiotherapy.
What is multiple myeloma?
- t’s a plasma cell neoplasm commonly associated with lytic bone lesions, hypercalcemia, renal failure, and acquired immune abnormalities.
- It produces large amounts of IgG 55% or IgA 25%.
- It is the most common primary bone tumor in elderly.
What are Bence Jones proteins?
- They are monoclonal globulin proteins or immunoglobulin light chain found in the urine.
- The proteins are produced by neoplastic plasma cells.
- Bence Jones proteins are present in 2/3 of multiple myeloma cases.
