Immune Reconstitution of Immunosuppressed Sepsis Patients

Inclusion Criteria: 1. Patients of age ≥ 18 yrs and older but \< 80 yrs 2. Patients with persistent suspected sepsis at 48-120 hrs after admission 3. Two or more criteria for the systemic inflammatory response syndrome (SIRS) (see reference #19 for SIRS criteria) and a clinically or microbiologically suspected infection. 4. At least one organ failure as defined by a SOFA score of ≥2 at any time point during the 48-120 hrs after admission to the ICU 5. Requirement of vasopressor treatment as follows: i) epinephrine or norepinephrine at ≥ 0.05 µg/kg/min ideal body weight; ii) vasopressin, or iii) dopamine at ≥ 4-5 μg/kg/min ideal body weight, continuously for 4 hrs or more, provided that at least 20 ml/kg of ideal body weight of crystalloid or an equivalent volume of colloid was administered during the 24-hour interval surrounding the start of vasopressor treatment, to maintain systolic pressure ≥ 90 mmHg or a mean arterial pressure ≥ 60 mmHg at any time point during their sepsis course preceding enrollment into the IL-7 study. 6. Lymphopenia with an absolute lymphocyte count ≤ 900 cells/mm3 at either the day of consent or the day prior to consent during their ICU stay. 7. Predicted length of stay in the ICU of up to two weeks after starting drug therapy treatment in the trial 8. Ability to obtain a signed informed consent from patient or LAR consent. Exclusion Criteria: 1. Cancer with current chemotherapy or radiotherapy and/or .receipt of chemotherapy or radiotherapy within the last 6 weeks 2. Cardiopulmonary resuscitation within the previous 4 weeks without objective evidence of full neurologic recovery) or patients who have minimal chance of survival and are not expected to live \> 3-5 days as defined by an APACHE II score of ≥ 35 at time of consideration for study eligibility 3. Patients with a history of or who currently have evidence of autoimmune disease including for example: myasthenia gravis, Guillain Barre syndrome, systemic lupus erythematosis, multiple sclerosis, scleroderma, ulcerative colitis, Crohn's disease, autoimmune hepatitis, Wegener's etc. 4. Patients who have received solid organ transplant or bone marrow transplant 5. Patients with active or a history of acute or chronic lymphocytic leukemia 6. AIDS-defining illness (category C) diagnosed within the last 12 months prior to study entry 7. History of splenectomy 8. Any hematologic disease associated with hypersplenism, such as thalassemia, hereditary spherocytosis, Gaucher's Disease, and autoimmune hemolytic anemia 9. Pregnant or lactating women 10. Participation in another investigational interventional study within the last 6 months prior to study entry, with the exception of studies aimed at testing sedation products belonging to standard of care such as Propofol, Dexmedetomidine, Midazolam. 11. Patients receiving immunosuppressive drugs, e.g., TNF-alpha inhibitors, for rheumatoid arthritis, inflammatory bowel disease or any other reason, or systemic corticosteroids other than hydrocortisone at a dose of 300 mg/day 12. Patients receiving concurrent immunotherapy or biologic agents including: growth factors, cytokines and interleukins, (other than the study medication); for example IL-2,growth factors, interferons, HIV vaccines, immunosuppressive drugs, hydroxyurea, immunoglobulins, adoptive cell therapy 13. Prisoners