When patients with suspected or confirmed rheumatic diseases come to the rheumatology department, they will often undergo physical examination and various laboratory tests.
I. Some common laboratory tests
1.Routine blood and urine tests, liver function tests: to check whether there are abnormal indicators, to help confirm the diagnosis of the disease and monitor the adverse effects of drugs.
2, erythrocyte sedimentation rate: referred to as blood sedimentation, normal reference value: adult male 0-15mm/h, female 0-20mm/h. High blood sedimentation, indicating that the disease is still in the active period, the higher the more serious. When the blood sedimentation decreases, it means that the drugs are working and the disease is under control. In rheumatic diseases, the blood sedimentation is higher than 25 to be meaningful.
3.C-reactive protein (CRP): normal value ≤10mg/L. High CRP indicates the presence of infection, trauma and inflammation in the body, and the disease is still in the active stage.
4.Anti-streptococcal hemolysin “O”: normal value is less than 1:500, positive shows that may suffer from rheumatic fever.
5, rheumatoid factor: rheumatoid factor is commonly found in a variety of rheumatic diseases and acute and chronic inflammatory diseases. Therefore, you can’t think you have rheumatoid arthritis based on rheumatoid factor alone. However, if the rheumatoid factor titer is high, multiple positive determinations, and positive determinations by multiple methods, then the likelihood of having rheumatoid arthritis is higher.
6.Anti-keratin antibody, anti-perinuclear factor, anti-RA-33/66, anti-Sa antibody: commonly found in patients with rheumatoid arthritis, especially important for the diagnosis of patients with early rheumatoid arthritis.
7, anti-CCP antibodies: have greater significance for the diagnosis of early rheumatoid arthritis.
8.Anti-nuclear antibody: Positive is common in many diseases. Those who also have signs of SLE should be highly suspected of lupus. Negative can almost certainly exclude the diagnosis of lupus.
9. Anti-ds-DNA antibodies: seen almost exclusively in patients with SLE. The higher the titer, the higher the disease activity is indicated.
10. Anti-Sm antibody: seen almost exclusively in patients with SLE. However, not all lupus patients show positivity.
11.Anti-SSA antibody and anti-SSB antibody: they are more significant for the diagnosis of dry syndrome.
12.HLA-B27: It has greater significance for the diagnosis of ankylosing spondylitis.
13.Anti-neutrophil cytoplasmic antibody (ANCA): positive significance for the diagnosis of systemic vasculitis.
Note that each hospital may have different standard values due to the different reagents, instruments and tests used, and the standard values on the test sheets should be used as the final reference.
Second, the commonly used imaging tests
1.X-ray examination: generally choose the most serious part of the symptoms. If the local symptoms are atypical, the doctor will select the common attack site of the disease for X-ray according to the identified direction of consideration. For example, in rheumatoid arthritis, the hands and wrists are often selected; in ankylosing spondylitis, the bilateral sacroiliac joints and hip joints are often selected. Regular X-ray examinations can be performed before and after to determine whether the disease is under control after treatment to judge the efficacy.
2, CT examination: higher resolution, conducive to early detection of the disease, and a more comprehensive and specific reflection of the lesion.
3, magnetic resonance imaging and ultrasound examination: can clearly show the internal pathology of the joint such as cartilage, synovial membrane, joint effusion, etc. It can be used for the examination of ankylosing spondylitis and osteoarthritis.
In addition, joint cavity aspiration and synovial fluid examination, as well as arthroscopy and synovial examination, are considered in patients with severe or undiagnosed fluid accumulation in the joint cavity. It is recommended to choose a large hospital for these tests because of the high requirements for the environment, medical equipment conditions and the technical ability of the doctor.