TABLE 7.
Observed fluctuation in B cells in adult COVID-19 patients.
| B cells | Observation | Analyzed patients | Compared group(s) | References |
| CD21+CD27+ memory | Reduction (%) | Severeρ | HD | Kuri-Cervantes et al., 2020 |
| CD27+IgD+ unswitched memory | No change (%) | Severeγ | Moderateε | Shuwa et al., 2021 |
| No change (%) | Severeγ | Mildδ | Shuwa et al., 2021 | |
| No change (%) | Severeγ | HD | Shuwa et al., 2021 | |
| No change (%) | Moderateε | Mildδ | Shuwa et al., 2021 | |
| No change (%) | Moderateε | HD | Shuwa et al., 2021 | |
| No change (%) | Mildδ | HD | Shuwa et al., 2021 | |
| Increase (%) | Severeκ | Prepandemic controls | Acosta-Ampudia et al., 2021 | |
| Reduction (%) | Severeη | HD | Sosa-Hernández et al., 2020 | |
| Reduction (%) | Criticalι | HD | Sosa-Hernández et al., 2020 | |
| Reduction (%) | Cases | Recovered | Mathew et al., 2020 | |
| Reduction (%) | Cases | HD | Mathew et al., 2020 | |
| IgD+IgM+ unswitched memory | No change (%) | Severe | Mild | Ogega et al., 2021 |
| No change (%) | Severe | HD | Ogega et al., 2021 | |
| No change (%) | Mild | HD | Ogega et al., 2021 | |
| CD27+IgD- switched memory | No change (%) | Severeγ | Moderateε | Shuwa et al., 2021 |
| No change (%) | Severeγ | Mild δ | Shuwa et al., 2021 | |
| No change (%) | Severeγ | HD | Shuwa et al., 2021 | |
| No change (%) | Moderateε | Mild δ | Shuwa et al., 2021 | |
| No change (%) | Moderateε | HD | Shuwa et al., 2021 | |
| No change (%) | Mildδ | HD | Shuwa et al., 2021 | |
| Reduction (%) | Severeη | HD | Sosa-Hernández et al., 2020 | |
| Reduction (%) | Cases | Recovered | Mathew et al., 2020 | |
| Reduction (%) | Cases | HD | Mathew et al., 2020 | |
| CD27-IgM- switched memory | Reduction (%) | Severeζ | Mildπ | Carsetti et al., 2020; |
| CD38+/–IgM–IgD– switched memory | No change (%) | Severeλ | Mildμ | Ogega et al., 2021 |
| No change (%) | Severeλ | HD | Ogega et al., 2021 | |
| No change (%) | Mildμ | HD | Ogega et al., 2021 | |
| No change (#) | Cases | HD | Lenti et al., 2020 | |
| No change (#) | Cases | Hypofunctionν | Lenti et al., 2020 | |
| No change (#) | Cases | Splenectomyξ | Lenti et al., 2020 | |
| CD27+IgD-IgM-CD38+ switched memory | Increase (%) | Severeκ | Prepandemic controls | Acosta-Ampudia et al., 2021 |
| IgM+ memory | Reduction (%) | Severeζ | Asymptomatic | Carsetti et al., 2020 |
| Reduction (%) | Severeζ | Mildπ | Carsetti et al., 2020 | |
| Reduction (%) | Cases | HD | Lenti et al., 2020 | |
| IgM-IgG- memory | Increase (%) | Severeζ | Asymptomatic | Carsetti et al., 2020 |
| Increase (%) | Severeζ | Mildπ | Carsetti et al., 2020 | |
| CD27-IgD- double negative memory | Increase (%) | Severeγ | HD | Shuwa et al., 2021; |
| Increase (%) | Convalescent | HD | Shuwa et al., 2021; | |
| Increase (%) | Cases | Recovered | Mathew et al., 2020 | |
| Increase (%) | Cases | HD | Mathew et al., 2020 | |
| CD38–/+CD24–CD21+CD11c– DN1 | Reduction (%) | Severeη | Mild/moderateθ | Sosa-Hernández et al., 2020 |
| Reduction (%) | Critical ι | Mild/moderate θ | Sosa-Hernández et al., 2020 | |
| CD38–CD24-CD21–CD11c+ DN2 | Increase (%) | Severeη | Mild/moderateθ | Sosa-Hernández et al., 2020 |
| Increase (%) | Severeη | Criticalι | Sosa-Hernández et al., 2020 | |
| CD38–/+CD24–CD21–CD11c– DN3 | Increase (%) | Severeη | HD | Sosa-Hernández et al., 2020 |
| Increase (%) | Criticalι | Mild/moderateθ | Sosa-Hernández et al., 2020 | |
| Increase (%) | Criticalι | HD | Sosa-Hernández et al., 2020 |
B cell subset, peripheral blood B cell subset analyzed in the reported studies; BAL, bronchoalveolar lavage; (%), as frequency values; (#), as absolute number; Cases, COVID-19 patients (irrespective of severity); ICU, intensive care unit patients; Recovered, non-hospitalized subjects who had recovered from SARS-CoV-2 infection; HD, healthy donors; Outpatients, outpatients with milder disease; ARDS, acute respiratory distress syndrome; NCU, normal care unit patients; NCU (non-COVID-19), normal care unit patients treated for other reasons than COVID-19; ICU (non-COVID-19), intensive care unit patients treated for other reasons than COVID-19; Asymptomatic, patients who tested positive but had no symptoms.
ρincluded subjects were in the following condition(s): high flow nasal cannula–noninvasive, ventilator (non-ARDS), mild to severe ARDS, and ECMO.
γPatients with > 10L or 60% supplemental oxygen, managed in ICU.
δPatients with < 3L or 28% supplemental oxygen.
εPatients with < 10L or < 60% supplemental oxygen, requiring non-invasive ventilation (NIV) or continuous positive airway pressure (CPAP).
ζPatients with clinical signs of pneumonia with one of the following: respiratory rate > 30 breaths/min, severe respiratory distress, or SpO2 < 90% on room air.
ηPatients experiencing the following: respiratory failure, respiratory rate > 30 bpm, oxygen saturation < 92% at rest, arterial partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) (PaO2/FiO2) ratio < 300 mmHg.
θFever, signs of airway disease, with or without a tomographic image indicating pneumonia.
ιAny of the following: requirement for mechanical ventilation, shock, or concomitant organ failure.
κRespiratory distress, i.e., ≥ 30 breaths/min. in resting state, oxygen saturation of 90% or less on room air; or arterial partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) of 300 or less.
λHospitalized patients.
μAmbulatory patients.
νSpleen hypofunction patients.
ξPatients who underwent splenectomy for trauma.
πPatients requiring no hospitalization and experiencing symptoms like with fever, myalgia, and fatigue without obvious chest high resolution computed tomography findings for COVID-19.