GOUT physiology
Are there other diseases associated with Pseudogout?
hyperparathyroidism, hypothyroidism, hemochromatosis, and Wilson's Disease.
Where are the most common places for these deposits?
in the knees after trauma and after surgical removal of the meniscus
Classification of Gout
Secondary Gout: Related to another disease such as malignant hematopoietic diseases (leukemia), chronic hemolysis, obesity or alcoholism, that causes hyperproduction of uric acids or its undersecretion. decreased clearance of the uric acid by the kidneys.
How can Gout be classified
1. Primary Gout: is either classified as metabolic, caused by hyperproduction of uric acid or renal, caused by underexcretion of uric acid. Most affected patients are overproducers
What are some general characteristics of Gout?
15-35 persons/1000. no known cause ... genetics/env family history of Gout. Almost 95% of all patients with Gout are males.
What is Hyperuricemia?
> 7 mg/dl. 5-15% of normal population have this level have Gout.
What is Pseudogout and where do you find it?
Calcium Pyrophosphate Dihydrate (CPPD) deposition disease refers to the accumulation of this compound in synovial membranes
What is the general pathology of Gout
Hyperuricemia leads to deposits Most deposits are insoluble Monosodium Urate form The disease typically develops after many years of asymptomatic hyperuricemia, usually 15-30 years.
How can the clinical features of gout be classified What else is characteristic of gout pathologically?
In acute Gout, the joint is swollen, hyperemic and warm, and the patient cannot walk because of the excruciating pain. Systemic symptoms include fever, leukocytosis, tachycardia, and general exhaustion. The attacks may last 2-3 days or longer and usually subsides spontaneously. The asymptomatic periods tend to become shorter and shorter as the disease progresses Chronic Gout is marked by less inflammation but more pronounced bone deformities In addition to joint involvement, Gout often presents with subcutaneous deposits of uric acid known as Tophi, most common on the ears, the extensor sites of the arms, over the olecranon, and over the patella.
What are characteristics of Pseudogout?
Principally a condition of old age, preexisting joint damage, it is believed that trauma and the aging process in cartilage promote the CPPD crystals. The major abnormality is an excessive level of inorganic pyrophosphate in the synovial fluid.
What are the clinical features of Pseudogout
Refers to self-limited attacks of acute arthritis lasting from 1 day to 4 weeks and involves one or two joints. About 25% of patients have an acute onset of Gout-like symptoms, presenting as inflammation and swelling of the knees, ankles, wrists, elbows, hips and shoulders. Metatarsophalangeal joints, which are affected in Gout, are usually spared.
What are the renal complications of Gout?
Renal failure is seen in 25% of patients with gout Hypersaturation of urine with uric acids Approx. 20% of all patients have uric acid stones. This may cause obstructive nephropathy or predispose these individuals to chronic pyelonephritis.
Where are the most common sites of deposition?
The most common sites of uric acid deposition are the joints and periarticular connective tissue
What else does the crystallization of the uric acid cause in the joint?
The presence of crystals also activates Complement and Kallikrein, which promotes inflammation and pain,
Are the Tophi painful? Do the crystals polarize
Tophi are usually not painful, and histo-logically they are encapsulated, contain urate crystals and are surrounded by macrophages, lymphocytes, and giant cells. The crystals of uric acid are birefringent that can be seen with polarized microscopy. Deposits of urates can be found in many internal organs, the most significant are the deposits in the kidneys.
What is the name for this deposit in the joint cartilage, ligaments and tendons?
When CPPD deposits in the joint cartilage, it is called Chondrocalcinosis. It can also deposit in ligaments and tendons. The disease can be idiopathic, associated with trauma, or linked to a number of metabolic disorders
What are the gross and microscopic findings?
calcium pyrophosphate deposits appear as chalky white areas on the cartilaginous surfaces. crystals of pseudogout are stubby, short, and rhomboid (coffin-shaped). They are weakly birefringent under polarized light. Only a few mononuclear cells and macrophages surround the foci of crystals.
What is Gout and where is it found
diseases characterized by hyperuricemia and the deposition of uric acid crystals in various tissues
What happens next after the uric acid enters into the joint cavity?
feet are usually colder than the rest of the body and low temperatures reduces uric acid solubility, it promotes crystallization Uric acid crystals are chemotactic/inflammatory
How is Gout diagnosed?
laboratory proof of hyperuricemia. Monoarthritic joint pain involving the great toe is highly characteristic of Gout. X-ray studies may be useful in demonstrating bone erosion with Tophi.
Pathophysiology of Gout What is the overwhelming first symptom of gout? What is a common cause of uric acid release from the joint capsule?
the first symptom that occurs joint of the big toe. (known as Podagra-foot seizure) Uric acid is probably released from the deposits in the joint capsule by minor trauma. It enters the joint cavity and oversaturates the fluid.
