Interferon treatment advantage patients to achieve hepatitis B surface antigen transfer negative Disease: HBeAg negative chronic hepatitis B (hepatitis B minor triplet) Description: male, 49 years old, HBsAg positive found in 1985 during physical examination, although no symptoms, but always worried about the fluctuation of the disease. 2008, liver function fluctuations, liver discomfort. Very nervous, worried about the emergence of cirrhosis, liver cancer, and heavy mental burden. Treatment expectation: I hope to achieve a stable condition without progression, preferably with complete cure and removal of hepatitis B virus. Examination and medication status: Diagnosis: HBeAg negative chronic hepatitis B. History: HBsAg positive for 24 years, recurrent abnormal liver function for more than 1 year, chronic hepatitis B diagnosed in September 2008; no history of antiviral treatment; mother-to-child transmission. Examination: Virology: HBV DNA 113 IU/mL (reference value <12 IU/mL); serology: HBsAg (+), HBsAb (-), HBeAg (-), HBeAb (+); biochemistry: ALT 188 U/L, AST 143 U/L. Treatment course: The patient was a middle-aged male with no previous history of antiviral therapy, high baseline ALT level The HBV DNA level was low, suggesting an active immune response, and the response rate was higher with pegylated interferon-2a treatment at this time. After administration of pegylated interferon-2a, HBVDNA became negative at 2 months and liver function ALT fluctuated around 100 U/L; HBsAg quantification was 117.3 at 4 months of treatment and 71.27 at 7 months; after 1 year of treatment (standard course, i.e. 48 weeks), HBVDNA remained negative and HBsAg continued to decrease to 48.7, but no HBsAg clearance. Considering the patient's advanced age, continued HBVDNA negativity and significant treatment side effects, the course of treatment was not extended. After discontinuation of the drug, the patient was reviewed regularly and HBsAg quantification has remained stable at around 40. The HBsAg quantification continued to decline with the addition of immunomodulatory therapy such as thymidine, and HBsAg cleared by 32 months after stopping interferon, and anti-HBsAb appeared at 34 months. The patient continued to be followed up for 6 months, and all indicators were stable, and HBVDNA negativity and HBsAg serological conversion were always maintained. The patient currently has a normal work life and good mental outlook. During the course of treatment, the patient developed fever, decreased leukocytes and platelets, with the lowest leukocytes down to 2.6×109/L and platelets 45×109/L. He had been treated symptomatically with colony-stimulating factor injection and interferon was not reduced; the blood picture returned to normal soon after stopping interferon. Expert summary: This patient had high baseline ALT, low HBVDNA, and low HBsAg, so treatment with pegylated interferon-2a obtained sustained negative HBVDNA and even a delayed effect of HBsAg clearance 2-3 years after stopping the drug, achieving clinical cure. PEGylated interferon-2a therapy is the right choice. For advantageous patients, that is, patients with high baseline ALT, low HBVDNA and low HBsAg, choosing long-acting interferon therapy can increase the chance of clinical cure and may be preferred when conditions permit. During long-acting interferon therapy, the change in HBsAg quantification helps to judge the efficacy. Patients with a more significant decrease in HBsAg quantification during treatment are expected to have a good outcome and should adhere to treatment more actively. In this case, HBsAg decreased rapidly after treatment, but the course of treatment was not continued to 72 weeks due to adverse reactions. If the course of treatment had been extended, serological conversion of anti-HBsAb might have occurred earlier. In fact, interferon adverse reactions are manageable and recover quickly after discontinuation. Paying attention to communication with patients during treatment and actively managing adverse reactions can help them enhance treatment compliance and ensure a full course of treatment so as not to miss the opportunity.