Inflammatory and Humoral Immune Response during Ebola Virus Infection in Survivor and Fatal Cases Occurred in Sierra Leone during the 2014–2016 Outbreak in West Africa

Abstract

Ebola virus (EBOV) infection is characterized by an excessive inflammatory response, a loss of lymphocytes and a general paralysis of the immune system, however pathophysiological mechanisms are not fully understood. In a cohort of 23 fatal and 21 survivors of ebola virus disease (EVD) cases admitted to the Emergency Ebola-Treatment-Center in Goderich (Freetown, Sierra Leone) during the 2014 to 2016 EBOV epidemic in Western Africa, we analyzed the pathway-focused gene expression profile of secreted proteins involved in the immune response and the levels of specific anti-EBOV IgM and IgG from the time of admission till discharge or death. We observed a dysregulated inflammatory response in fatal patients as compared to survivors, mainly consisting of the upregulation of inflammatory mediators, whose extent directly correlated with viremia levels. The upregulation persisted and intensified during the late phase of infection. Relevant differences were also found in humoral immunity, as an earlier and more robust EBOV antibody response was observed in survivor patients.

Performance evaluation of Abbott ARCHITECT SARS-CoV-2 IgG immunoassay in comparison with indirect immunofluorescence and virus microneutralization test

“…SARS-CoV-2 RNA performed by real-time RT-PCR on respiratory secretions, or on clinical symptoms plus the presence of SARS-CoV-2specific antibodies by the reference method employed in the laboratory. This method is an indirect immunofluorescence assay (IFA), established using home-made slides prepared with Vero E6 cells infected with SARS-CoV-2 isolate in the INMI BSL3 facility, as described elsewhere [7].…”

Long-lasting severe immune dysfunction in Ebola virus disease survivors

“…EBOV_S have robust EBOV-specific memory T cell responses. Characterization of EBOV-specific T cell responses in Ebola infection are still limited and most of the studies evaluated these responses either during the acute or the recovery phase of EBOV infection comparing EBOV_S and fatal cases [11][12][13][14][15][16][17] . We assessed whether EBOV-specific T cells would become detectable after antigen-specific in vitro T cell expansion.…”

“…The immune responses of EVD patients have been reported during acute-phase infection or soon after the resolution of infection [11][12][13][14][15][16][17] . These studies identified immune signatures associated with death from EVD rather than survival.…”

“…These studies identified immune signatures associated with death from EVD rather than survival. Fatal EVD was characterized by high inflammatory marker levels and a high viral load 12,16,17 . Conversely, survivors had significantly lower levels of inflammation 15 and robust EBOV-specific T cell responses 12 .…”

Ebola Virus Disease Survivors Show More Efficient Antibody Immunity than Vaccinees Despite Similar Levels of Circulating Immunoglobulins

“…These research efforts have significantly improved our understanding of EVD pathophysiology and immunity. Regarding the latter, findings from several laboratories indicate that acute EVD is characterized by exacerbated and sustained adaptive immune responses [2][3][4] and that both arms of the adaptive immunity are critical for recovery [5][6][7].…”