ABSTRACT
Background: Long COVID can be developed by individuals after an infection with SARS-CoV-2 as described by the WHO. Although this condition is more commonly described in adults, it can occur in children and adolescents with a wide range of estimated prevalence of 1-25%. Little is known about the role of the immune system in long COVID. However, one of the main hypotheses about the underlying mechanism in long COVID is that there is an immune and inflammatory dysregulation that persists after the acute infection. The objective of this study is to compare immune cells populations, and inflammatory biomarkers in paediatric populations with and without long COVID. Method(s): We analyzed 55 blood samples from the pediaCOVID cohort (Hospital Germans Trias i Pujol), which includes more than 130 children diagnosed with long COVID and 23 controls. We measured different immune cell populations using spectral cytometry with a panel of 37 cellular markers, and 42 inflammatory markers using Luminex or ELISA. EdgeR was used for statistical analysis of the spectral data;p-values of inflammatory markers were calculated using the likelihood ratio test and they were corrected for multiple comparisons. Result(s): The study cohort had a median age of 14.3 (IQR, 12.5-15.2) and 69.1% female. Patients had at least 3 symptoms associated with long COVID (median [IQR];10 [7-16]). The most common symptom was asthenia/fatigue (98.2%). Compared to the control cohort, children with long COVID had increased numbers of CD4+CD8+ T cells, IgA+CD21+CD27+ memory B cells, and IgA+CD21-CD27- memory B cells, while CD4+ TEMRA cells (CD45RA+, CCR7-), intermediate monocytes (CD14+, CD16+) and classical monocytes (CD14+, CD16-) were decreased (all p< 0.05;q=n.s.). None of the 42 inflammatory biomarkers showed significant differences between children with and without long COVID. Conclusion(s): The results of this study suggest that specific populations of peripheral blood immune cells might be involved in the mechanisms underlying prolonged COVID in children and adolescents. The increase in both IgA+CD21-CD27- and IgA+CD21+CD27+ memory B cells could be associated with the persistence of viral antigen in the gut and/or gut dysbiosis. Moreover, the decrease in CD4+ TEMRA cells could be related to autoantibodies against G-protein coupled receptors (GPCRs), since this cell population can express GPR56, and autoantibodies against GPCRs were previously reported to be elevated in adults with long COVID.
ABSTRACT
The pathogenesis of severe coronavirus infection COVID-19 is associated with activation of immune system, cytokine storm, impaired blood clotting, microvascular thrombosis, organ ischemia and multiple organ dysfunction syndrome. The role of various lymphocyte subpopulations in COVID-19 is still debated. The aim of our study was to analyze the subpopulational profile of peripheral blood lymphocytes in COVID-19 patients as compared with healthy donors. The study included 20 COVID-19 patients (11 males and 9 females,) and 26 healthy donors. Average age of the patients was 52 and 56 years, respectively. Clinical examinations were performed by standard laboratory methods. Peripheral blood lymphocytes were isolated in the Ficoll gradient. The cells were stained with antibodies to specific antigens of main lymphocyte populations, endothelial cells, and apoptotic cell markers. The analysis was performed by flow cytometry. The results showed that all patients had elevated C-reactive protein (14- to 35-fold), ferritin (1.2- to 13-fold), D-dimers (1.2- to 90-fold). 55% of men had a decrease in the absolute number of lymphocytes, in women this index was at the low normal limit. Cytometric analysis showed that, among peripheral blood lymphocytes, the proportion of functional cells expressing the CD45 marker ranged from 2 to 12% in 70% of patients, as compared with 80-99% among the donors. The proportion of CD45+ lymphocytes significantly correlated with the level of hemoglobin, but not with the levels of inflammatory biochemical markers. Among the functional lymphocytes of patients, there was a decrease in the proportion of CD3+, CD4+, CD8+T cells, increased proportion of natural killer CD56+ and the apoptotic (AnnexinV+) cell contents, but the proportion of CD19 and HLA-DR+B cells was not changed. Analysis of the lymphocyte (LC) subpopulations that did not express CD45 marker showed that this fraction contained different lymphocyte subsets with reduced expression of CD4, CD8, CD19, CD56 etc. in the blood of patients and donors. Higher percentage of endothelial cells expressing CD62P marker made the difference between patients and donors. Laboratory determination of lymphocyte subsets in blood samples of COVID-19 patients does not reflect the real severity pattern of the disease, thus requiring studies of the CD45-expressing functional cell populations.Copyright © Svirshchevskaya E.V. et al., 2023 The article can be used under the Creative Commons Attribution 4.0 License.
ABSTRACT
Background: Coronavirus disease 2019 (COVID-19) is an emerging respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARSCoV- 2). Recent studies have suggested numerous hypotheses that may explain multi-organ dysfunction during a COVID-19 infection. One possible hypothesis posits that the renin-angiotensin system dysregulation before SARS-CoV-2 infection could exacerbate disease symptoms and severity, especially in COVID-19 patients with underlying comorbidities. Objective: This study sought to investigate the effect of exogenous angiotensin II (Ang II) on peripheral blood mononuclear cells (PBMCs) stimulated with SARSCoV- 2 peptide pool. Methods: PBMCs from recovered COVID-19 patients (n = 18) were used in this study. SARS-CoV-2 specific t-cell responses were measured using activation induced cell marker assay and intracellular cytokine staining (ICS) assay, while enzyme-linked immunosorbent assay (ELISA) and ICS assays determined functional capability and polarization. Additionally, the relative level of protein phosphorylation in PBMCs was measured using a phosphokinase array. Results: Our results showed that in vitro Ang II treatment significantly increased the magnitude of SARS-CoV-2 specific t-cell response in stimulated PBMCs with SARS-CoV-2 peptide pool. Moreover, the phosphorylation level of numerous proteins implicated in cardiovascular diseases, inflammation, and viral infection showed significant increase in the presence of Ang II. Mitogenic stimulation of PBMCs after Ang II and SARS-CoV-2 peptide pool stimulation showed functional polarization of CD4+ and CD8+ t-cells toward Th1/Th17 and Th17 phenotypes, respectively. Meanwhile, ELISA showed an increased production of IL-1b and IL-6 in Ang II-stimulated PBMCs without affecting the reduction of IL-10 level resulting from SARS-CoV-2 peptide pool stimulation. Conclusion: To our knowledge, the present study is the first to demonstrate that Ang II exaggerates SARS-CoV-2 specific t-cells response. Therefore, during COVID-19 infection Ang II may aggravate the inflammatory response and change the immune response toward a more inflammatory profile against SARS-CoV-2 infection, leading to serious complications and worse outcomes during COVID-19 infection.
ABSTRACT
Einleitung The aging of the immune system is an individual process with high variability: Two persons of the same biological age may differ substantially in the response of their immune system towards diseases and further conditions. The goal of ImmunLearning is to identify cytokines that reflect the immune system's status and to subsequently use these biomarkers to assess a person's 'immuno-fitness' at home or at points-of-care. These could be used, for example, for personalized treatment scheduling without the need for elaborate clinical tests. Methoden To serve our objective of promoting the measurement of biomarkers at home, we studied technologies for cytokine measurement from small whole blood samples with low-end technologies at home and at points of care. We identified a small number of cytokines for which such mature technologies exist. To investigate age-related biomarkers we assessed ex-vivo T-cell marker and serum cytokines levels in samples collected from 74 healthy donors. To take account of the impact of the COVID-19 pandemic, we adapted the sampling procedure and the analytics' workflow, to include recovering COVID-19 patients. To investigate the relationship between cytokine levels and biological age we applied exploratory analysis techniques, regression and machine methods. Our machine learning toolbox encompasses classification algorithms that assess the expected (not biological) age of individuals on the basis of biomarkers, especially cytokine levels;workflows for dimensionality reduction, clustering, visualization and inspection of the association between age strata and cytokine levels;a workflow for the study of correlations among biomarkers in subsamples of individuals with different health conditions. Ergebnisse Our present results indicate a large variance in the biomarker profiles and in the relationship between biomarkers and age strata, both among healthy subjects and among subjects recovered from COVID-19. The correlations among different cytokines indicate that immuno-fitness predictors can be built from a small number of carefully cytokines. Schlussfolgerung Studies on larger samples are needed, especially involving subjects with chronic diseases.
ABSTRACT
Introduction:Plasmablastic lymphoma (PBL) is a rare and aggressive lymphoma most commonly seen in the setting of chronic immunosuppression, such as HIV infection and organ transplantation, or in patients with pre-existing lymphoproliferative or autoimmune disorders. PBL commonly presents at extranodal sites and carries a poor prognosis with a global overall survival of 9-15 months after initial diagnosis. Despite poor prognosis for patients with PBL, therapeutic strategies to target this disease are limited, as CHOP-like regimens have failed to produce durable remission, and no standard of care has been established. The cell of origin for PBL is believed to be the plasmablast, as PBL cells possess immunoblastic morphology and contain an immunohistochemical profile positive for plasmablast markers, such as CD38, CD138, and MUM1/IRF4, and negative for B cell markers, such as CD20, CD19, and PAX5. The similarities between PBL cells and multiple myeloma (MM) cells, a plasma cell neoplasm, have led to investigations of the efficacy of MM therapeutics for the treatment of PBL. Daratumumab is a first-in-class monoclonal antibody directed against CD38 that has shown efficacy in treating relapsed/refractory and newly diagnosed MM. Here, we describe the treatment of four patients with advanced-stage PBL in the context of varying degrees of immunosuppression using combination treatment with daratumumab and EPOCH. Methods:Four consecutive patients were treated with daratumumab plus chemotherapy. Three of the four patients were treated in the frontline setting and received low-dose EPOCH (vincristine, doxorubicin, etoposide daily for 4 days;cyclophosphamide day 5) with 16mg/kg daratumumab dosed on days 1 and 8 for 6 cycles. Patient #4 showed partial CD20 positivity, prompting Rituximab co-administration (R-EPOCH). Patient #3 was treated in the relapsed setting with 16mg/kg daratumumab in combination with lenalidomide, dexamethasone, and doxorubicin. She was treated for 12 months. Responses were followed by PET/CT imaging. Results:The four consecutive patients (2 female, 2 male) ranged in age from 26-88 and all had advanced-stage PBL (Table 1). Three of the four patients had some degree of immunosuppression (Patient #1- post-transplantation lymphoproliferative disorder (PTLD), Patient #2- HIV/AIDS, Patient #3- Chron's disease, Patient #4- no history of immunosuppression). All patients had a Ki67 proliferation index over 70% and demonstrated extranodal involvement of disease (bone n=3, intestine n=2, liver n=2;kidney n=1;adrenal n=1). The three patients that received daratumumab in combination with EPOCH demonstrated a complete response at their first disease assessment by PET/CT scan after cycle 2 (Patient #1) or cycle 4 (Patients #2,4) (Fig1). Patient #3, who demonstrated a mixed response to previous therapy, achieved a complete response 5 months after starting treatment with daratumumab in combination with chemotherapy. As of July 2021, three of the four patients continued to have no evidence of disease for a median of 17 months (range 15-19 months). Patient #4 relapsed in July 2021, 3 months after demonstrating a complete response. Adverse events that required hospitalization were rarely noted following daratumumab treatment but included neutropenic fever (n=2, one event following treatment cycle 4 and the other event 2 months after completion of daratumumab administration), COVID-19 infection (n=1), and a PICC line-associated thrombus (n=1). Minor events were also noted and included self-limiting bradycardia (n=1), neuropathy (n=1), and rigor (n=1). Conclusions:We describe four patients with varying degrees of immunosuppression and HIV-status with aggressive-stage PBL that achieved complete response following treatment with daratumumab in combination with low-dose EPOCH or other chemotherapy. Three of four patients obtained durable responses. At the time of this writing, three additional HIV +patients have initiated treatment with daratumumab but have not yet reached their first disease assessment. Disease progression for these patients will be monitored and presented as part of this study. Our findings suggest a potential efficacy and warrant further investigation of using daratumumab for the treatment of HIV +and HIV - PBLs. [Formula presented] Disclosures: Amengual: Epizyme, Inc.: Speakers Bureau;Appia Pharmaceuticals: Research Funding;Daiichi Sankyo, Inc: Consultancy;Seagen: Consultancy. OffLabel Disclosure: our work uses daratumumab, a first-in-class monoclonal antibody against CD38 for the treatment of plasmablastic lymphoma