A primigravid woman with Covid-19 related respiratory insufficiency was admitted into a tertiary Intensive Care Unit at 23 3/7 weeks' gestation. Highly sensitive flow cytometry of peripheral... Show moreA primigravid woman with Covid-19 related respiratory insufficiency was admitted into a tertiary Intensive Care Unit at 23 3/7 weeks' gestation. Highly sensitive flow cytometry of peripheral leukocytes indicated significantly suppressed naive T- and B-cell compartments. The suppressed immune cell responses led us keep the initially started administration of corticosteroids for fetal and maternal indication at a low dose. After three weeks her B-cell response peaked, SARS-CoV-2 was cleared and clinical improvement ensued a week later. At 28 weeks' gestation, a son of 1570 g was born by cesarean section. She was extubated two days postpartum and discharged from hospital 5.5 weeks postpartum. Show less
Mankor, J.M.; Disselhorst, M.J.; Poncin, M.; Baas, P.; Aerts, J.G.J.V.; Vroman, H. 2020
Background: Combined immune checkpoint inhibitor (ICI) treatment targeting PD-1 and CTLA-4 was suggested to yield clinical benefit over chemotherapy in malignant pleural mesothelioma (MPM), whereas... Show moreBackground: Combined immune checkpoint inhibitor (ICI) treatment targeting PD-1 and CTLA-4 was suggested to yield clinical benefit over chemotherapy in malignant pleural mesothelioma (MPM), whereas aPD-1 monotherapy failed to provide benefit in phase-Ill trials. Success of ICI depends on the presence and activation of tumor-specific T cells. Therefore, we investigated whether T-cell characteristics are underlying clinical efficacy of ICI treatment in MPM.Methods: Comprehensive immune cell profiling was performed on screening and on treatment peripheral blood samples of mesothelioma patients treated with nivolumab (aPD-1) monotherapy (NCT02497508), or a combination of nivolumab and ipilimumab (aCTLA-4) (NCT03048474).Findings: aPD-1 /aCTLA-4 combination treatment induced a profound increase in proliferation and activation of T cells, which was not observed upon aPD-1 monotherapy. Moreover, patients that responded to combination treatment had low frequencies of naive CDS T cells and high frequencies of effector memory CDS T cells that re-expressed RA (TEMRA) at screening. The frequency of Granzyme-B and Interferon-y producing TEM-RAs was also higher in responding patients.Interpretation: High proportions of TEMRAs and cytokine production by TEMRAs before treatment, was associated with a better clinical outcome. TEMRAs, which likely comprise tumor-specific T cells, tend to require blockage of both aPD-1 and aCTLA-4 to be reactivated. In conclusion, peripheral blood TEMRAs can play a key role in explaining and predicting clinical benefit upon aPD-1/aCTLA-4 combination treatment. (C) 2020 Published by Elsevier B.V. Show less
Blanco, E.; Perez-Andres, M.; Sanoja-Flores, L.; Wentink, M.; Pelak, O.; Martin-Ayuso, M.; ... ; Orfao, A. 2019
The clinical value of assessing immunoglobulin (Ig)G and IgA subclasses in addition to the isotypes of soluble Igs in serum has been well established. > 20 years ago, the International Union of... Show moreThe clinical value of assessing immunoglobulin (Ig)G and IgA subclasses in addition to the isotypes of soluble Igs in serum has been well established. > 20 years ago, the International Union of Immunological Societies and the World Health Organization performed collaborative studies in order to validate antibody (Ab) clones for the detection of IgG and IgA subclasses for a broad range of laboratory assays, except for flow cytometry. Here we analyzed the performance of commercially available Ab clones to detect IgG and IgA subclasses in memory B-cells and plasma cells (PCs) by flow cytometry. In a first step, 28 Ab clones were evaluated in peripheral blood from healthy donors. Only 17/28 clones showed reactivity against IgG and IgA subclasses expressed on the B-cell and PC surface membrane, including Ab clones for IgG(1) (SAG1, HP6188, HP6001 and HP6186), IgG(2) (SAG2, HP6014 and HP6002), IgG(3) (SAG3, HP6095 and HP6050), IgG(4) (SAG4), IgA(1) (SAA1, H69-11.4 and B3506B4) and IgA(2) (SAA2, 2E2, and A9604D2). In a second step, for each Ig subclass a single clone was selected according to its specificity and fluorescence intensity (resolution power), for further more detailed validation (SAG1, SAG2, SAG3, SAG4, SAA1 and SAA2). This validation process was carried out in 4 different laboratories by testing the selected Ab clones in human peripheral blood, bone marrow and tonsil samples, using different staining protocols (e.g. surface membrane and/or cytoplasmic staining). All selected Ab clones displayed strong positivity, high specificity and optimal resolution between negative and positive cells. Alternative Ab clones were also validated. Thus, our results show the feasibility of using the validated Ig subclass Ab clones in combination with other B cell-associated markers for detailed dissection of the memory B-cell and PC compartments that express distinct Ig subclasses in different human tissues. Show less
