Currently, treatment options for Epstein-Barr virus (EBV) infection are limited, with unsatisfactory efficacy and no established standard therapy. Therefore, our center is conducting a prospective, multicenter, single-arm clinical trial to evaluate the efficacy and safety of PD-1 inhibitor in combination with tenofovir, chidamide, and lenalidomide in patients with EBV infectious diseases, aiming to provide a more effective and safer therapeutic option for EBV infectious diseases.

Inclusion Criteria:

1. Diagnosed with EBV infectious diseases, including infectious mononucleosis, chronic active EBV infection, or other EBV infectious diseases;
2. EBV DNA ≥ 10⁴ copies/mL in whole blood or plasma;
3. Age ≤ 75 years with ECOG performance status ≤ 2;
4. Estimated life expectancy over 3 months;
5. Patients must be able to undergo follow-up. They should understand the nature of their disease and voluntarily agree to participate in this study for treatment and follow-up.

Exclusion Criteria:

1. Patients with impaired liver or kidney function, specifically defined as serum direct bilirubin, indirect bilirubin, and/or ALT, AST, or serum creatinine >2 times the upper limit of normal (ULN), unless such abnormalities are attributed to lymphoma;
2. Patients with bone marrow failure, defined as absolute neutrophil count (ANC) <1.5×10⁹/L or platelets <75×10⁹/L;
3. Patients who have experienced grade III or higher neurotoxicity within the past 2 weeks;
4. Patients with chronic heart failure classified as NYHA class III or IV, or left ventricular ejection fraction (LVEF) <50%, or those with a history of the following cardiac events within the past 6 months: acute coronary syndrome, acute heart failure (NYHA class III or IV), or significant ventricular arrhythmias (sustained ventricular tachycardia, ventricular fibrillation, or resuscitated sudden cardiac arrest);
5. Patients with AIDS, syphilis, or active hepatitis B (HBV DNA >1×10⁴ copies/mL) or hepatitis C infection;
6. Patients with coexisting hematologic disorders (e.g., hemophilia, myelofibrosis) deemed unsuitable for inclusion by the investigator;
7. Patients with severe concurrent infections;
8. Patients who have undergone grade II or higher surgery within 3 weeks prior to treatment;
9. Patients with substance abuse, medical, psychological, or social conditions that may interfere with study participation or the evaluation of study outcomes;
10. Patients deemed unsuitable for enrollment by the investigator;
11. Patients with known hypersensitivity to components of the investigational drug.