Lab Testing for Gout

Gouty arthritis is more commonly just called gout. This condition is a result of the deposition of uric acid, or monosodium urate, crystals kind of like needles. These crystals build up in tissues and joint fluid, resulting in serious pain, swelling, and inflammation. The most impacted joint is typically the big toe of either foot, but gout can also strike the entire foot, ankles, knees, wrists, elbows, and hands. 

Gout attacks might happen sporadically, and they can last multiple days. In an attack, uric acid deposits might accumulate in soft tissues, tendons, and cartilage. They might even form lumps underneath the skin known as tophi. Crystals that accumulate inside the kidneys can result in kidney stones as well as kidney damage. Most gout episodes turn out to be acute, only lasting a few days. However, the frequency and severity of attacks can increase, and some individuals wind up developing chronic forms of gout. 

Uric acid itself is a product from purines being broken down. Purines are compounds found not only in all tissues of the human body, but also in many foods, including anchovies, mushrooms, asparagus, dried beans, and liver. Uric acid is typically carried throughout the bloodstream before elimination through a person’s urine. If uric acid production goes up, an individual consumes high volumes of foods known for robust purine levels; or if a person’s kidneys can’t sufficiently eliminate the present uric acid, then concentrations of it can go up in the blood. This is known as hyperuricemia. If crystals build up in the joints, then they can trigger the pain related to gout. 

Gout is something that happens more often with men than it does with women. It happens more also in adults, typically happening in women after they get to menopause and men past the age of 30. Those with a family history of gout, those who are obese, and anyone with kidney disease, cardiovascular disease, hyperlipidemia, type 2 diabetes, and hypertension have a higher risk than normal of developing gout. Gout is also known to be associated specifically with metabolic syndrome, which is a term frequently used for describing a set of these symptoms. Drugs, such as aspirin/salicylates, cyclosporine, and thiazide diuretics useful for treating hypertension, can all interfere with the excretion of uric acid. So too, can excessively use of alcohol. 

Gout must be distinguished from other conditions known to result in similar symptoms. These include rheumatoid arthritis, autoimmune arthritis; septic arthritis, which results from some joint infections; and CPPD, which was once known as pseudogout but is now calcium pyrophosphate deposition, a condition resulting from deposits of calcium pyrophosphate crystals. Treating any of those conditions differs greatly from the treatments applied for gout management. 

Laboratory Testing

Testing goals include the identification of gout, distinguishing it from any other conditions (like kinds of arthritis which might have very similar symptoms), and the investigation of what is causing higher levels of uric acid in a person’s blood at the time. 

Synovial Fluid Analysis: Used to see symptoms or signals of joint infection, also used for the detection of any needle-like crystals, which are derivatives of uric acid. 

Uric Acid: Used to find heightened concentrations in the blood; when a gout diagnosis is made, then uric acid testing might happen for routine monitoring. 

Basic Metabolic Panel: A BMP is a set of tests useful in monitoring and analysis of kidney function. 

Complete Blood Count: A CBC can determine leukocytosis, where there are abnormally high volumes of white blood cells present and help distinguish between gout and septic arthritis. 

There are other tests, such as ANA, or antinuclear antibody, and RF, or rheumatoid factor, that can be done to rule out various other potential sources for arthritis symptoms. A synovial fluid or blood culture might be necessary if there is suspicion of septic arthritis.