Normal values ​​of three rheumatism items

On rainy days, patients with rheumatism suffer particularly from the humid climate, which causes them to experience painful symptoms in the joints throughout their body, especially in their hands and feet, which cannot be avoided by other means. Such a long-term tormenting disease forces many people to seek medical help. When you go to the hospital for a check-up, you will be asked to take a three-item rheumatism test, and the doctor will prescribe medicine for the patient based on this. So what do the above indices represent? What are the normal values ​​for the three rheumatism tests?

ASO, RF and CRP are the examination items of the "three rheumatism items" commonly found in hospitals. Many patients, even non-rheumatologists, believe that the three rheumatic tests are an important basis for diagnosing and screening "rheumatic diseases". How significant are the three rheumatism items in the diagnosis of "rheumatism"? Let us analyze them one by one.

1C-reactive protein (CRP)

C-reactive protein (CRP) is an acute phase response protein secreted by the liver when the body is invaded by microorganisms or when tissues are damaged or inflamed. Elevated CRP levels can be detected in patients with rheumatic diseases during the active phase of the disease, and can return to normal after the disease is effectively controlled. Therefore, CRP can be used as an indicator of the activity of rheumatic diseases.

Increased CRP is a signal of "inflammation" released in the body. Tissue damage, infection inflammation, immune inflammation and even tumors are all buttons that trigger "inflammation" in the body. Therefore, simply testing CRP is not helpful for the diagnosis of rheumatic disease, but it has certain judgment significance for the assessment of the condition of rheumatic disease that has been clearly diagnosed.

2 Rheumatoid Factor (RF)

Rheumatoid factor (RF) is mainly present in the serum and synovial fluid of patients with rheumatoid arthritis. It is an autoantibody against deformed IgG, and IgM is considered to be the main type of rheumatoid factor.

Popular science articles about "rheumatoid factor and rheumatoid arthritis" can be found everywhere. Although rheumatoid factor is named after rheumatoid arthritis, it can appear in other diseases, such as Sjögren's syndrome, chronic hepatitis B infection, blood diseases, etc. RF can also be detected in 5% of the healthy population.

Although RF is positive, it does not necessarily mean rheumatoid arthritis. However, high titer RF (≥3 times the upper limit of normal value) should still be carefully investigated in combination with the patient's medical history and physical examination to exclude the possibility of rheumatic disease.

3 Antistreptolysin O (ASO) is the antibody produced by the human body to correspond to the hemolysin O produced by group A streptococci after the human body is infected with the streptococcus, that is, "anti-O".

The normal value is generally below 200 units. If it is higher than 200 units, it means that there has been a recent hemolytic streptococcal infection. Streptococcal infection usually indicates rheumatic fever, but the incidence of rheumatic fever is very low nowadays. Clinically, most ASO elevations are caused by streptococcal infection. If there is no clear migratory pain in the large joints (shoulders, knees, ankles, etc.), drug treatment is generally not required.

It is difficult to diagnose a rheumatic disease through the three rheumatic tests, but as mentioned above, high titers of RF and CRP should still alert us to the possibility of rheumatic disease. The correct approach is to take the three rheumatism test reports, make an appointment with the rheumatology and immunology department, listen to the analysis and opinions of the rheumatologist, and further complete the specific examination of rheumatism - the detection of autoantibodies, so as to determine whether you have rheumatism.