Dry syndrome (hereinafter referred to as SS) is a chronic, even lifelong disease, and various laboratory indicators need to be reviewed regularly during the treatment process after diagnosis. Many patients are very concerned about these indicators, and when they communicate with each other, they get nervous when they see the titer of certain antibodies increase or happy when they see the titer of certain antibodies decrease, but in fact, they are all the reasons for not knowing much about its clinical significance. Laboratory tests for rheumatic diseases are of great value in guiding the diagnosis and treatment of SS diseases, but one should not “chase” or “look at” a single test item unilaterally, but should be closely combined with the overall clinical performance and individual differences to determine the severity of the disease The following are some of the commonly used chemistries for SS. The following are some common laboratory tests for SS: 1. Anti-nuclear antibodies (ANA): A group of autoantibodies, about 70% of SS patients have positive ANA antibodies, among which anti-SSA (Ro) antibodies and anti-SSB (La) antibodies have the highest positive rate, 75% and 52% respectively. In particular, anti-SSB antibodies are highly specific for the diagnosis of SS, and if both anti-SSA and anti-SSB antibodies are positive, SS should be considered first in the diagnosis. It should be noted that ANA, anti-SSA and anti-SSB antibodies are marker antibodies, and their titers are not related to disease activity and degree of disease, i.e., an increase in the titers of these antibodies does not indicate disease activity or aggravation, and a decrease in titers does not indicate disease stability or aggravation. A decrease in the titers of these antibodies does not indicate that the disease is stable or effective in treatment. Therefore, once the positive results of ANA, SSA and SSB antibodies are confirmed, the diagnosis is clear and there is no need to repeat the test in the future. Many patients and even non-professional doctors have misconceptions about this and often dwell on it, repeatedly rechecking ANA antibody, anti-SSA antibody and anti-SSB antibody in the hope that they will turn negative, and even adding or increasing the dosage of hormones and immunosuppressants once they see that the titers of ANA antibody, anti-SSA antibody and anti-SSB antibody are higher than before, which not only wastes money but also causes excessive medical treatment. 2. Immunoglobulins: hyperimmunoglobulinemia is one of the characteristics of SS. The three main immunoglobulins IgG, IgA and IgM can be increased, while IgG is the most common. High levels of IgGemia are closely associated with salivary gland enlargement, lung lesions, and skin purpura, so plasma IgG levels can be considered as an indicator of SS activity. 3, rheumatoid factor (RF): its essence is the antibody against IgG-Fc fragment. RF is positive in rheumatoid arthritis (RA) up to 80%, so it is an important serological marker for the diagnosis of RA, but not the only one. About 3/4 of SS patients can be positive for RF, even a higher percentage than RA. I often see people misdiagnose joint pain plus positive RF as rheumatoid arthritis, but it is actually SS. If RA is secondary to SS, high titer RF often indicates disease activity. About 30-40% of patients with SS have a combination of orthochromic anemia and leukopenia. About 14% of patients have thrombocytopenia. The degree of anemia is generally mild and can be caused by concomitant paranoia, chronic gastritis, bleeding from the gastrointestinal tract or hemorrhoids, and excessive menstruation in women, in addition to immune abnormalities associated with SS. Leukopenia in SS is caused by hyperimmunity and excessive destruction of white blood cells, and there is no effective cure. Generally speaking, leukocytes around 3.00×109/L and other tests are stable and can be observed and reviewed regularly without special treatment. However, those who repeatedly fall below 2.00×109/L should consider intervention therapy. Thrombocytopenia needs attention and treatment, which can easily cause bleeding tendency, especially visceral bleeding. For those with platelets below 50,000, it is best to test every 1 to 2 weeks during treatment. 5.Blood sedimentation (ESR): It is not specific for the diagnosis of rheumatic diseases, and the increase in speed can reflect the presence of inflammation or tissue damage, which can be seen in dozens of diseases. 90% of SS patients can have an increased ESR, which is related to hyperimmunoglobulinemia. 90 % of SS patients who do not have high Ig and have a significantly increased ESR should consider other causes. ESR increases with age and is higher in women than in men, so another way to derive the normal value is male: age M2; female (age + 10) M2. 6. Liver and kidney function: It is possible to understand whether SS patients have liver or kidney involvement. If SS is combined with liver damage, autoimmune hepatitis or biliary cirrhosis, liver function needs to be checked every 1 to 3 months. For long-term use of certain immunosuppressants such as regimen polysaccharide tablets, leflunomide, methotrexate, etc., they should also be monitored regularly due to their side effects on the liver and kidneys. 7. Urinary routine: In SS combined with renal tubular acidosis, due to the weakened renal tubular acidification function, urinary pH >6.5 or even 7 in several laboratory tests, if there are no repeated episodes of hypokalemia, it is generally called subclinical renal tubular acidosis. Proteinuria and microscopic hematuria may also occur in patients with interstitial kidney damage and glomerulonephritis.