Clinical and Immunologic Correlates of Vasodilatory Shock Among Ebola Virus-Infected Nonhuman Primates in a Critical Care Model.

Background: Existing models of Ebola virus infection have not fully characterized the pathophysiology of shock in connection with daily virologic, clinical, and immunologic parameters. We implemented a nonhuman primate critical care model to investigate these associations.

Methods: Two rhesus macaques received a target dose of 1000 plaque-forming units of Ebola virus intramuscularly with supportive care initiated on day 3. High-dimensional spectral cytometry was used to phenotype neutrophils and peripheral blood mononuclear cells daily.

Results: We observed progressive vasodilatory shock with preserved cardiac function following viremia onset on day 5. Multiorgan dysfunction began on day 6 coincident with the nadir of circulating neutrophils. Consumptive coagulopathy and anemia occurred on days 7 to 8 along with irreversible shock, followed by death. The monocyte repertoire began shifting on day 4 with a decline in classical and expansion of double-negative monocytes. A selective loss of CXCR3-positive B and T cells, expansion of naive B cells, and activation of natural killer cells followed viremia onset.

Conclusions: Our model allows for high-fidelity characterization of the pathophysiology of acute Ebola virus infection with host innate and adaptive immune responses, which may advance host-targeted therapy design and evaluation for use after the onset of multiorgan failure.