BACKGROUND. A defining pathophysiologic feature of sepsis is profound apoptosis-induced death and depletion of CD4+ and CD8+ T cells. Interleukin-7 (IL-7) is an antiapoptotic common γ-chain cytokine that is essential for lymphocyte proliferation and survival. Clinical trials of IL-7 in over 390 oncologic and lymphopenic patients showed that IL-7 was safe, invariably increased CD4+ and CD8+ lymphocyte counts, and improved immunity. METHODS. We conducted a prospective, randomized, double-blind, placebo-controlled trial of recombinant human IL-7 (CYT107) in patients with septic shock and severe lymphopenia. Twenty-seven patients at academic sites in France and the United States received CYT107 or placebo for 4 weeks. Primary aims were to determine the safety of CYT107 in sepsis and its ability to reverse lymphopenia. RESULTS. CYT107 was well tolerated without evidence of inducing cytokine storm or worsening inflammation or organ dysfunction. CYT107 caused a 3- to 4-fold increase in absolute lymphocyte counts and in circulating CD4+ and CD8+ T cells that persisted for weeks after drug administration. CYT107 also increased T cell proliferation and activation. CONCLUSIONS. This is the first trial of an immunoadjuvant therapy targeting defects in adaptive immunity in patients with sepsis. CYT107 reversed the marked loss of CD4+ and CD8+ immune effector cells, a hallmark of sepsis and a likely key mechanism in its morbidity and mortality. CYT107 represents a potential new way forward in the treatment of patients with sepsis by restoring adaptive immunity. Such immune-based therapy should be broadly protective against diverse pathogens including multidrug resistant bacteria that preferentially target patients with impaired immunity. TRIAL REGISTRATION. Trials registered at clinicaltrials.gov: NCT02640807 and NCT02797431. FUNDING. Revimmune, NIH National Institute of General Medical Sciences GM44118.
Bruno Francois, Robin Jeannet, Thomas Daix, Andrew H. Walton, Matthew S. Shotwell, Jacqueline Unsinger, Guillaume Monneret, Thomas Rimmelé, Teresa Blood, Michel Morre, Anne Gregoire, Gail A. Mayo, Jane Blood, Scott K. Durum, Edward R. Sherwood, Richard S. Hotchkiss
Guidelines: The Editorial Board will only consider letters that we deem relevant and of interest to our readers. We will not post data that have not been subjected to peer review, nor will we post letters that are essentially a reiteration of another letter. All accepted letters will be posted on our website within one week of acceptance. We reserve the right to edit any letter for length, content, and clarity. Authors of all accepted letters will be asked to preview any changes. Authors will be notified by e-mail if their letters were not accepted. As this is a final decision, no appeals will be considered.
Specific requirements: All letters must be 400 words or fewer. You may enter the letter as plain text or HTML. The author's name and e-mail address are required, and will be posted with the letter. All possible conflicts of interest must be noted, even if they are not posted. If you wish to include a figure (keep in mind that non-peer-reviewed data will not be posted), please contact the editors directly at firstname.lastname@example.org.