TABLE 5.
Observed fluctuation in B cells in adult COVID-19 patients.
| B cells | Observation | Analyzed patients | Compared group(s) | References |
| Total peripheral blood B cells | No change (#) | Intubated | Non-intubated | Detsika et al., 2021 |
| No change (#) | Intubated (admission) | Intubated (recovery) | Detsika et al., 2021 | |
| No change (#) | Severe+ (admission) | Mild* (admission) | Jurado et al., 2020 | |
| No change (#) | Moderate& (admission) | Mild* (admission) | Jurado et al., 2020 | |
| No change (#) | Severe+ (admission) | Moderate& (admission) | Jurado et al., 2020 | |
| No change (#) | Critical§ | SevereŁ | Liu Y. et al., 2021 | |
| No change (#) | Cases | HD | d’Alessandro et al., 2021 | |
| No change (#) | Severe¿ | Non-severe¡ | d’Alessandro et al., 2021 | |
| Reduction (#) | Deceased | Survivors | Cantenys-Molina et al., 2021; Kos et al., 2021; Xiong et al., 2021 | |
| Reduction (#) | Critical§ | Moderate@ | Liu Y. et al., 2021 | |
| Reduction (#) | Severe° | Non-severe∧ | Zhang W. et al., 2020 | |
| Reduction (#) | Compositeα | Non-compositeβ | Zhang W. et al., 2020 | |
| Increase (#) | ICU | NCU | Kos et al., 2021 | |
| Increase (#) | ICU | NCU (non-COVID-19) | Kos et al., 2021 | |
| Increase (#) | ICU | ICU (non-COVID-19) | Kos et al., 2021 | |
| No change (%) | Convalescent | HD | Newell et al., 2021 | |
| No change (%) | Severe¿ | Non-severe¡ | d’Alessandro et al., 2021 | |
| No change (%) | Severe+ (admission) | Mild* (admission) | Jurado et al., 2020 | |
| No change (%) | Severe+ (discharge) | Mild* (discharge) | Jurado et al., 2020 | |
| No change (%) | Moderate& (admission) | Mild* (admission) | Jurado et al., 2020 | |
| No change (%) | Moderate& (discharge) | Mild* (discharge) | Jurado et al., 2020 | |
| No change (%) | Severe+ (admission) | Moderate& (admission) | Jurado et al., 2020 | |
| No change (%) | Severe+(discharge) | Moderate&(discharge) | Jurado et al., 2020 | |
| Reduction (%) | ICU | NCU | Kos et al., 2021 | |
| Reduction (%) | ICU | NCU (non-COVID-19) | Kos et al., 2021 | |
| Reduction (%) | ICU | ICU (non-COVID-19) | Kos et al., 2021 | |
| Reduction (%) | Severeγ | Mildδ | Shuwa et al., 2021 | |
| Reduction (%) | Severeγ | Moderateε | Shuwa et al., 2021 | |
| Reduction (%) | Severeζ | Asymptomatic | Carsetti et al., 2020 | |
| Increase (%) | Cases | HD | Woodruff et al., 2020 | |
| Increase (%) | Severeη | Mild/moderateθ | Sosa-Hernández et al., 2020 | |
| Increase (%) | Cases | Convalescent | Files et al., 2021 | |
| Bone marrow and spleen total B cells | Reduction (#) | Deceased | Controls$ | Ihlow et al., 2021 |
| BAL B cells | Reduction (%) | Severe/ | Mild/ | Kim C.W. et al., 2021 |
| Increase (%) | Mild/ | HD/ | Kim C.W. et al., 2021 | |
| Increase (#) | Severe/ | Mild/ | Kim C.W. et al., 2021 | |
| Increase (#) | Severe/ | HD/ | Kim C.W. et al., 2021 |
BAL, bronchoalveolar lavage; (%), as frequency values; (#), as absolute number; Cases, COVID-19 patients (irrespective of severity); ICU, intensive care unit patients; HD, healthy donors; 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. *Clinical mild symptoms with no abnormal radiological findings.
+Non-severe pneumonia.
&As defined by the physician in charge or meeting at least one of the following criteria: acute respiratory distress, shock, admission to the intensive care unit -ICU-; patients with a fatal outcome were also included in this group.
§With any of the following: (1) respiratory failure requiring mechanical ventilation; (2) shock; or (3) other organ failure requiring monitoring and treatment in ICU.
ŁIndividuals experiencing any of the following: (1) respiratory distress, respiratory rate ≥ 30 breaths/min; (2) oxygen saturation on room air ≤ 93% at rest; (3) oxygenation index PaO2/FIO2 ≤ 300 mmHg; or (4) lung infiltrates > 50% within 24–48 h.
$Age matched subjects who died for cardiac conditions.
¿ICU admission, mechanical ventilation, or high-flow oxygen therapy.
¡Patients who were not experiencing ICU admission, mechanical ventilation, or high-flow oxygen therapy.
@Fever and other respiratory tract symptoms with pneumonia on chest computed tomography. °Respiratory rate ≥ 30/min, a pulse oxygen saturation ≤ 93% on room air, oxygenation index ≤ 300 mmHg, respiratory failure for which invasive ventilation was necessary, signs of shock (circulatory failure), organ failure and ICU care. ∧Mild symptoms + normal radiology findings in both lungs, and fever, cough, and other respiratory symptoms + radiological signs of pneumonia.
αPatients experiencing admission to the ICU, mechanical ventilation, or death.
βPatients who did not experience admission to the ICU, mechanical ventilation, or death.
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.
/No stratification criteria neither statistically significance data provided.