Thymalfasin for Immune Recovery in Adults With Sepsis

Inclusion Criteria: * Age older than 18 years, of any sex. Sepsis according to Sepsis-3 criteria, defined as documented or suspected infection with an increase in Sequential Organ Failure Assessment (SOFA) score of at least 2 points from baseline. APACHE II score of 15 to 30, inclusive, at ICU admission. An immunosuppressed phenotype, defined by reduced monocyte HLA-DR expression meeting No more than 48 hours from sepsis onset to enrollment. Written informed consent provided by the participant or legally authorized representative. Exclusion Criteria: * Known allergy to thymalfasin or any of its excipients. A history of primary or acquired immunodeficiency, such as HIV infection or post-transplant immunosuppression. Treatment with immunosuppressive agents or immunostimulants within 3 months before enrollment, including systemic corticosteroids at a prednisone-equivalent dose greater than 20 mg/day for at least 7 consecutive days, cyclosporine, tacrolimus, or azathioprine. Active malignancy or ongoing anticancer treatment. Chronic liver disease classified as Child-Pugh class C, or end-stage renal disease requiring maintenance dialysis. Pregnancy or breastfeeding. Expected survival of less than 48 hours at enrollment, such as irreversible brain death after cardiac arrest or terminal multiple organ failure. Concurrent participation in another interventional clinical trial. Any other condition that, in the investigator's judgment, makes participation unsuitable.