As a systemic autoimmune disease of dry syndrome, its laboratory examination also has a lot of its own characteristics. Routine blood examination Mild anemia (about 25%), mostly anemia of orthocytic orthopigmentation; different degrees of leukopenia (30%); eosinophilia or lymphocytosis (25%); mild platelet reduction (8-13%). Biochemical examination 1. Increased ESR (90% or more). 2, increased albumin and globulin (50%), mainly gamma protein; a few have macroglobulin or cryoglobulinemia. 3.Mild impairment of glomerular filtration function. Renal tubular function examination 1, urine cannot be acidified, urine pH ≥ 6. 2, urinary potassium, urinary calcium excretion increased, combined with Fanconi syndrome patients may appear glucosuria, amino acid urine, hypokalemia and RTA. 3, part of the hyperchloremic acidosis, suspected RTA to perform ammonium chloride loading test. 4.Lower urine specific gravity. Hematuria can be seen microscopically or visually. 5.Blood and urine β2-m increase. Immunological examination IgM, IgA and secretory IgA are elevated, and individual patients with desiccation syndrome can be found with macroglobulin and cold agglutinin. Due to the presence of IgG and its complexes in the blood, the blood viscosity sometimes increases. Anti-SSA antibodies (50-70%) and/or anti-SSB antibodies (30-60%) are positive in patients with dry syndrome. 60-70% or more of patients are positive for rheumatoid factor. About 33% of patients are positive for anti-thyroid and anti-smooth muscle antibodies. All patients with positive antithyroid antibodies have positive anti-gastric lining cell antibodies. Anti-salivary gland duct antibodies are present in about half of the patients. About 10% of patients are positive for lupus cells. In recent years, precipitating antibodies against soluble nucleic acid antigens of lymph-like cell exudates have been found. Tuberculin and dinitrochlorobenzene skin tests and lymphocyte transformation tests are suggestive of low cellular immunity.