1. Methemoglobin has many important physiological functions, including transport function, bidirectional regulation as a growth regulator, immunosuppression, and induction of apoptosis by T lymphocytes. Methemoglobin is closely related to the development of hepatocellular carcinoma and many tumors, and can show high concentrations in many tumors and can be used as a positive test for many tumors.
2. In childhood, serum AFP levels are increased in hepatocellular carcinoma, hepatoblastoma, gonadal teratoblastoma, hepatitis, etc. In adults, serum AFP levels are increased in 60% to 70% of patients with primary liver cancer, testicular cancer, ovarian tumors, malignant teratoma, pancreatic cancer, gastric cancer, intestinal cancer, lung cancer, etc.; in patients with acute and chronic hepatitis, cirrhosis, and other benign liver diseases, AFP levels are also increased. The increase of AFP level in patients with benign liver diseases such as acute and chronic hepatitis and cirrhosis has different degrees of increase, but most of them are less than 1000ug/L. The increase is related to the degree of hepatocyte necrosis and regeneration; generally, the increase of AFP level in benign liver diseases is transient and usually lasts for 2-3 weeks. In contrast, malignant tumors are persistently elevated. Therefore, dynamic observation of serum AFP levels can identify both benign and malignant liver disease and allow early diagnosis of hepatocellular carcinoma. Under physiological conditions, AFP is secreted by newborn infantile hepatocytes. Fetal hepatocytes are not fully developed (differentiated) and secrete a large amount of AFP, which can enter the maternal blood through the umbilical cord blood, so pregnant women will be positive for AFP during pregnancy.