A Personalized Randomized Trial of Validation and Restoration of Immune Dysfunction in Severe Infections and Sepsis

Sepsis is a life-threatening organ dysfunction that results from the dysregulated host response to an infection. Accumulating knowledge suggests that this dysregulated host response has a broad spectrum where some patients lie to the two extremes of this spectrum whereas the majority of patients lie in between. The first extreme encompasses patients who are dominated from a hyper-inflammatory response to an infectious insult. On the other extreme lie patients who do not have any hyper-inflammatory response; instead these patients are dominated by an exhausted immune response to an infectious stimulus. The remaining patients have features of both hyper- and hypo-inflammatory responses.

Randomized clinical trials (RCTs) that have investigated the effects of immunotherapy in sepsis have all failed to establish beneficial effects for the patients. The reasons for that are multiple but one of the most important is the current notion that sepsis is a complex disorder with heterogeneity regarding patient characteristics. Thus, it is necessary to try and find ways to personalise the immunomodulatory treatment of sepsis. In the clinical trial proposed here, two personalised approaches will be investigated.

Some 25 years ago, there were high expectations of the blockade of interleukin (IL)-1 in sepsis using the human recombinant IL-1 receptor antagonist, anakinra. The expectations were based on animal experiments as well as positive results in a single-centre clinical trial. However, in a large international trial, anakinra did not show benefit over placebo. Still, it became clear from this study, enrolling 906 patients that intravenous anakinra was a very safe drug: there was neither excess mortality in these critically ill patients, nor increased susceptibility to secondary infections. In a post-hoc analysis of this trial published in 2016, it was demonstrated that a subgroup of 34 patients showed a clinical picture compatible with macrophage activation syndrome. Since bone marrow was not performed in these patients, the investigators prefer to call this macrophage activation like syndrome (MALS). MALS is a dreaded complication with a mortality rate in the order of 70%. The post-hoc analysis showed that patients receiving anakinra had 30% significant survival benefit compared to those receiving placebo. From these data it can be concluded that it is important to recognize patients with this complication of sepsis and that anakinra might be a beneficial drug.

A survey of the database of sepsis patients in the Hellenic Sepsis Study Group revealed that 5% of the patients with septic shock suffered from MALS. It was found in this study that MAS can be easily and reliably diagnosed by measuring ferritin in the blood. A cut off of 4.420ng/ml had specificity more than 97%.

Another important clinical phenomenon in sepsis is that patients may run into a phase of immunoparalysis. In this situation, the immune cells do not produce any more proinflammatory cytokines and switch to production of anti-inflammatory cytokines such as IL-10; they also loose important functional markers such HLA-DR. Patients with immunoparalysis have a 50% risk of dying in the subsequent 28 days. There is evidence from preclinical studies and from the endotoxin challenge model in human volunteers that immunoparalysis is reversible at least to some extent. The best candidate drug for this would be interferon gamma (IFNγ). Immunosuppression established in healthy volunteers after experimental endotoxemia was reversed after administration of recombinant human interferon-gamma (rhIFNγ). rhIFNγ was also investigated for this purpose in nine patients at septic shock in a small open-label and non-randomized clinical trial; reversal of immunoparalysis was achieved. The extensive experience with IFNγ teaches that it is a safe drug, the main side effect being fever and flu-like syndrome, which can be mitigated by premedication with a prostaglandin inhibitor like paracetamol. In patients with autoimmune diseases like systemic lupus erythematosus (SLE) and multiple sclerosis flares of the disease induced by IFNγ have been described. So these diseases are contraindications for the drug.