Cancer antigen CA125 has been widely used in the diagnosis of malignant tumors, especially ovarian tumors. Recent studies have shown that CA125 has certain reference value in the diagnosis, treatment and follow-up of tuberculous peritonitis, and the relevant literature is reviewed as follows.1.CA125In 1981, Bast et al. took the lead in applying monoclonal antibody against CA125 to confirm the expression of cancer antigen CA125 in ovarian cancer cells, and Canney et al. further found that 93% of ovarian cancer patients had elevated concentrations of CA125 in their blood, while the concentration of CA125 in the blood of healthy people was less than 65U/ml. Canney et al. further found that 93% of ovarian cancer patients have elevated blood CA125 concentration, while less than 1% of healthy people have blood CA125 concentration >65U/ml. At present, serum CA125 has become one of the auxiliary diagnostic indexes of ovarian cancer, which has a greater guiding role in determining the staging, progression, regression or recurrence of ovarian cancer. Further clinical studies have found that not only the concentration of CA125 in the blood of ovarian cancer patients is elevated, but also the concentration of CA125 in the blood of gynecological primary malignant tumors, such as endometrial, fallopian tube, cervical and myometrial cancers, and the concentration of CA125 in the blood of some patients with some non-gynecological malignant tumors, such as lymphatic carcinoma, breast carcinoma, melanoma, lung carcinoma, gastric carcinoma, hepatocellular carcinoma, cholangiocarcinoma, pancreatic carcinoma, renal cell carcinoma and colorectal carcinoma. Some patients with rectal cancer have elevated blood CA125 concentrations, with a positivity rate of about 22%. In addition, some non-cancer diseases, such as endometriosis, uterine fibrosis, pelvic inflammatory disease, pancreatitis, autoimmune disease, pleurisy, pericardial infection, chronic renal failure and hepatic granulomatous hyperplasia, etc., the concentration of CA125 can be moderately elevated in some patients, with a positivity rate of 3% to 6%. In some normal physiological conditions, such as early pregnancy and menstruation, the blood CA125 concentration will also increase, but the magnitude is not large. It can be seen that elevated blood CA125 concentration is not only seen in patients with ovarian cancer, but also occurs in other gynecological malignant tumors, non-gynecological tumors, chronic inflammation and some physiological conditions.2. Serum or ascites of patients with tuberculous peritonitis and CA125 concentration In 1989, Ronay reported that two cases of patients with tuberculous peritonitis had elevated serum CA125 concentration, and then scholars from abroad reported that CA125 concentration of patients with tuberculous peritonitis had elevated, and then scholars from abroad reported that CA125 concentration of patients with tuberculous peritonitis had elevated. CA125 elevation in patients with tuberculous peritonitis, in recent years, China Chen Weizhong et al also found that the serum CA125 concentration of patients with tuberculous peritonitis was elevated, therefore, the serum CA125 concentration of patients with tuberculous peritonitis can be higher than normal, and the possibility of tuberculous peritonitis should be taken into account when elevated serum CA125 concentration is found.Mas et al found that, before applying the antituberculosis bacteria drug treatment, the serum CA125 concentration of patients with tuberculous Mas et al. found that before the application of anti-tuberculosis drugs, the serum CA125 concentration of patients with tuberculous peritonitis was as high as more than 10 times the normal value, and after 4 months of treatment, the serum CA125 concentration returned to normal, therefore, it is considered that the serum CA125 concentration can be used as an observational index for the efficacy of the treatment of tuberculous peritonitis. There is not much research data on the concentration of CA125 in ascites of tuberculous peritonitis, some people reported that the concentration of CA125 in ascites of patients with tuberculous peritonitis was elevated and higher than the level of serum CA125, and the detection of the level of CA125 in ascites could help in the diagnosis of tuberculous peritonitis; however, some people believed that the analysis of CA125 in ascites did not help in diagnosis, and that confirmation of the diagnosis needed to rely on the dissecting of the abdomen and the pathologic examination.3 The mechanism of elevated serum or ascites CA125 in patients with tuberculous peritonitis Barbieri et al. applied CA125 monoclonal antibody to confirm by immunohistochemistry that CA125 exists in tissues of epithelial origin of the body cavity of the normal embryo, such as mesothelial tissues (including the peritoneum, pleura, and pericardium) and mullerian duct epithelium (including fallopian tubes, endometrium, and cervical endothelium), and when these tissues undergo lesions such as When these tissues become diseased, such as carcinoma, this cell surface antigen is reactivated to express CA125, and the specific mechanism by which CA125 is elevated in the serum or ascites of patients with tuberculous peritonitis is not well understood. It is hypothesized that in tuberculous peritonitis, the mesothelial cells of the peritoneum are stimulated and the CA125 gene is activated, thus expressing and producing a large amount of CA125 to be released into the peritoneal fluid, which is then absorbed through the peritoneal barrier and absorbed into the bloodstream at a certain ratio, thus leading to a significant increase in the level of CA125 in the peritoneal fluid and serum.4. The significance of the determination of CA125 in the diagnosis and treatment of tuberculous peritonitisCurrently, there is no clear clinical diagnosis for The diagnosis of tuberculous peritonitis is mostly based on clinical symptoms, signs, ascites routine and other laboratory results, followed by experimental anti-tuberculosis treatment. Because patients often lack typical clinical manifestations, and routine examination of ascites often has no characteristic changes, it is more difficult to diagnose tuberculous peritonitis. Although peritoneal biopsy can make a clear diagnosis, it is more difficult to accurately obtain biopsy tissue, and the study found that the confirmation rate of caseous necrotizing granuloma was 47.6%, and some patients with tuberculous peritonitis did not find peritoneal tuberculous nodules and other characteristic changes, and the reason for this may be related to the fact that there is less biopsy tissue (routine general 2~3 pieces). Studies have shown that serum and/or ascites CA125 levels are elevated in patients with tuberculous peritonitis, and tuberculous peritonitis should be highly suspected when unexplained abnormally elevated serum and/or ascites CA125 levels are found, after exclusion of diseases of the abdominal cavity or other organs. Serum CA125 concentration can be significantly elevated in patients with ovarian cancer, and data show that serum CA125 concentration can also be significantly elevated in patients with tuberculous peritonitis; therefore, in clinical work, malignant tumors and tuberculous peritonitis should not be identified solely on the basis of the degree of elevated CA125 concentration. For female patients, if there are tumors of uterine appendages, ascites, anemia, weight loss, and elevated CA125 concentration, ovarian cancer must be considered first, but if there are only elevated serum and ascites CA125 concentration, the possibility of tuberculous peritonitis should be considered, and the concentration of CA125 in patients with tuberculous peritonitis can be elevated with the onset and development of tuberculous peritonitis, and return to normal with the cure of the disease, therefore, dynamic Therefore, the dynamic observation and detection of CA125 concentration has certain significance for the diagnosis, treatment and follow-up of tuberculous peritonitis.