Increased B‐cell activity with consumption of activated monocytes in severe COVID‐19 patients

Abstract

The pathogenesis of autoimmune complications triggered by SARS‐CoV2 has not been completely elucidated. Here, we performed an analysis of the cellular immune status, cell ratios, and monocyte populations of patients with COVID‐19 treated in the intensive care unit (ICU) (cohort 1, N = 23) and normal care unit (NCU) (cohort 2, n = 10) compared with control groups: patients treated in ICU for noninfectious reasons (cohort 3, n = 30) and patients treated in NCU for infections other than COVID‐19 (cohort 4, n = 21). Patients in cohort 1 presented significant differences in comparison with the other cohorts, including reduced frequencies of lymphocytes, reduced CD8+T‐cell count, reduced percentage of activated and intermediate monocytes and an increased B/T8 cell ratio. Over time, patients in cohort 1 who died presented with lower counts of B, T, CD4+T, CD8+T‐lymphocytes, NK cells, and activated monocytes. The B/T8 ratio was significantly lower in the group of survivors. In cohort 1, significantly higher levels of IgG1 and IgG3 were found, whereas cohort 3 presented higher levels of IgG3 compared to controls. Among many immune changes, an elevated B/T8‐cell ratio and a reduced rate of activated monocytes were mainly observed in patients with severe COVID‐19. Both parameters were associated with death in cohort 1.

Immunopathology and Immunosenescence, the Immunological Key Words of Severe COVID-19. Is There a Role for Stem Cell Transplantation?

“…Thus, COVID-19 related B lymphocyte alterations determine not only disease severity but also the entity of long-term consequences and may have potential prognostic applications ( Detsika et al, 2021 ; Kim C.W. et al, 2021 ; Kos et al, 2021 ; Shuwa et al, 2021 ).…”

“…In gender pooled reports about the total number and percentage of B cells in COVID-19+ subjects, data vary from a study to another on the basis of both the choice of the confronted parameter (number of cells rather than percentage) and the adopted criteria to stratify the analyzed subjects according to severity ( Carsetti et al, 2020 ; Sosa-Hernández et al, 2020 ; Detsika et al, 2021 ; Kos et al, 2021 ; Shuwa et al, 2021 ; Xiong et al, 2021 ). Numerous papers are available documenting the invariability, the decrease and the increase of B cell numbers and frequency in various categories of COVID-19 patients ( Table 5 ).…”

Spatio-Temporal Modeling of Immune Response to SARS-CoV-2 Infection

“…Building on some biological observations and mathematical models (temporal approaches) [7,8,[10][11][12][13]16,22,28,[30][31][32][33][34][35][36], we develop a new spatio-temporal mathematical model to explore the interactions between the most essential components of the immune system and SARS-CoV-2 particles within a cellular perspective. This dynamical interaction occurs on a spatial domain ℵ ∈ R 2 over a time interval [0, T] and it involves the healthy host cells h(t, x), viral-infected cells i(t, x), SARS-CoV-2 molecules v(t, x), chemokines c(t, x), the effector T cells f (t, x), the regulatory T cells r(t, x), B-lymphocytes cells β(t, x) and antibodies α(t, x).…”

“…Although there is a lack of enough experimental studies about immune responses for people who have symptomatic/asymptomatic COVID-19 infections, there are some studies which investigate the interactions between the virus and many components of the immune system including the innate and the adaptive immune responses [5][6][7]. Once coronavirus-2 gains access inside the host cell using its spike protein (S) and the target cell receptor (ACE2) (in the same manner as SARS-CoV), it begins uncovering its genetic materials and producing some essential proteins such as envelope (E), nucleocapsid (N) and also spike (S) for motivating the interactions with target cells as well as assembling and releasing a new virus generation [8,9].…”

“…On other hand, there is no clue so far suggesting that the evolution of B cells over time will participate in this pathogenesis. However, we cannot generalize this scenario because it has been found that some of infected patients with SARS-CoV-2 who were treated in the ICU or who died have low levels of T cells as well as B cells [7].…”