Objective:Identify patient experience and preference towards thrombopoietin-receptor agonists (TPO-RAs) in treatment of immune thrombocytopenia (ITP) in the Netherlands.Methods:The Thrombopoietin... Show moreObjective:Identify patient experience and preference towards thrombopoietin-receptor agonists (TPO-RAs) in treatment of immune thrombocytopenia (ITP) in the Netherlands.Methods:The Thrombopoietin-Receptor Agonist Patient experience (TRAPeze) survey used a discrete choice experiment (DCE) to elicit patient preferences and a patient burden survey (PBS) to evaluate the clinical and social impact of ITP. TRAPeze collected responses from 6th October to 19th November 2021.Results:Seventy-six respondents completed the DCE: treatment preference appeared to be driven by method of administration (odds ratio [OR] 4.33; 95% confidence interval [CI] 2.88–6.52), frequency of dosing (OR 2.33; 95% CI 1.86–2.92) and drug–food interactions (OR 1.91; 95% CI 1.54–2.37). Respondents preferred therapies delivered orally over subcutaneous injection (OR 4.22; 95% CI 2.76–6.46), dosed once weekly over once daily (OR 2.37; 95% CI 1.58–3.54) and without food restrictions over with restrictions (OR 1.90; 95% CI 1.52–2.38). Sixty-nine respondents completed the DCE and PBS (mean [range] age 53 [19–83] years, 65% female). Seven incomplete PBS responses were excluded from analysis. Respondents were currently, or most recently, receiving eltrombopag (n = 43) or romiplostim (n = 26), of which 30% (n = 21/69) had previously received another TPO-RA. Loss (29%, n = 6/21) and lack (29%, n = 6/21) of response were the most common reasons for switching TPO-RA. Only 28% (n = 18/65) of respondents felt their TPO-RA increased energy levels.Conclusion:Patients preferred therapies delivered orally, dosed less frequently and without food restrictions. QoL of ITP patients on TPO-RAs can be improved; the burden analyses presented can inform future efforts towards this. Show less
Valk, S.J.; Caram-Deelder, C.; Evers, D.; Vooght, K.M.K. de; Kerkhof, D. van de; Wondergem, M.J.; ... ; Bom, J.G. van der 2023
Background and ObjectivesDonor characteristics have been implicated in transfusion-related adverse events. Uncertainty remains about whether sex, and specifically pregnancy history of the blood... Show moreBackground and ObjectivesDonor characteristics have been implicated in transfusion-related adverse events. Uncertainty remains about whether sex, and specifically pregnancy history of the blood donor, could affect patient outcomes. Whether storage duration of the blood product could be important for patient outcomes has also been investigated, and a small detrimental effect of fresh products remains a possibility. Here, we hypothesize that fresh red blood cell products donated by ever-pregnant donors are associated with mortality in male patients.Materials and MethodsWe used data from a cohort study of adult patients receiving a first transfusion between 2005 and 2015 in the Netherlands. The risk of death after receiving a transfusion from one of five exposure categories (female never-pregnant stored ≤10 days, female never-pregnant stored >10 days, female ever-pregnant stored ≤10 days, female ever-pregnant stored >10 days and male stored for ≤10 days), compared to receiving a unit donated by a male donor, which was stored for >10 days (reference), was calculated using a Cox proportional hazards model.ResultsThe study included 42,456 patients who contributed 88,538 person-years in total, of whom 13,948 died during the follow-up of the study (33%). Fresh units (stored for ≤10 days) from ever-pregnant donors were associated with mortality in male patients, but the association was not statistically significant (hazard ratio 1.39, 95% confidence interval 0.97–1.99). Sensitivity analyses did not corroborate this finding.ConclusionThese findings do not consistently support the notion that the observed association between ever-pregnant donor units and mortality is mediated by blood product storage. Show less
Vives, J.; Sánchez-Guijo, F.; Gnecchi, M.; Zwaginga, J.J. 2023
The development and production of cell gene and tissue (CGT)-based therapies requires a specialized workforce. Entering the CGT arena is complex because it involves different scientific and... Show moreThe development and production of cell gene and tissue (CGT)-based therapies requires a specialized workforce. Entering the CGT arena is complex because it involves different scientific and biomedical aspects (e.g., immunology, stem cell biology and transplantation), as well as knowledge of regulatory affairs and compliance with pharmaceutical quality standards. Currently, both industry and academia are facing a worldwide workforce shortage, whereas only a handful of educational and training initiatives specifically address the peculiarities of CGT product development, the procurement of substances of human origin, the manufacturing process itself and clinical monitoring and biovigilance. The training offered by traditional Master's and PhD programs is not suited for training a skilled workforce ready to enter the increasingly fast-growing CGT field. Indeed, typically these programs are of long duration and only partially cover the required competencies, whereas the demand for a specialized workforce relentlessly increases. In this paper, we (i) present and discuss our understanding of the roots of current growth acceleration of the CGT field; (ii) anticipate future workforce needs due to the expected increase of marketed CGT-based therapies and (iii) evaluate potential solutions that seek to adapt, develop and implement current educational and training initiatives. Importantly for these solutions, we call for scientific societies, such as the International Society for Cell & Gene Therapy, to play a more active role and act as catalysers for new initiatives, building bridges between academia and Industry to establish effective educational and training programs that will engage and prepare a new generation of qualified professionals for entry into the CGT field. Show less
Ouboter, L.F.; Barnhoorn, M.C.; Verspaget, H.W.; Plug, L.; Pool, E.S.; Szuhai, K.; ... ; Meulen-de Jong, A.E. van der 2023
BACKGROUND. Due to their immunoregulatory and tissue regenerative features, mesenchymal stromal cells (MSCs) are a promising novel tool for the management of ulcerative proctitis (UP). Here we... Show moreBACKGROUND. Due to their immunoregulatory and tissue regenerative features, mesenchymal stromal cells (MSCs) are a promising novel tool for the management of ulcerative proctitis (UP). Here we report on a phase IIa clinical study that evaluated the impact of local MSC therapy on UP. METHODS. Thirteen refractory UP patients, with an endoscopic Mayo score (EMS) of 2 or 3, were included. Seven patients received 20-40 million allogeneic MSCs (cohort 1), while 6 patients received 40-80 million MSCs (cohort 2). Adverse events (AEs) were assessed at baseline and on weeks 2, 6, 12, and 24. Clinical, endoscopic, and biochemical parameters were assessed at baseline and on weeks 2 and 6. Furthermore, we evaluated the engraftment of MSCs, the presence of donor -specific human leukocyte antigen (HLA) antibodies (DSAs), and we determined the impact of MSC therapy on the local immune compartment. RESULTS. No serious AEs were observed. The clinical Mayo score was significantly improved on weeks 2 and 6, and the EMS was significantly improved on week 6, compared with baseline. On week 6, donor MSCs were still detectable in rectal biopsies from 4 of 9 patients and DSAs against both HLA class I and class II were found. Mass cytometry showed a reduction in activated CD8+ T cells and CD16+ monocytes and an enrichment in mononuclear phagocytes and natural killer cells in biopsies after local MSC therapy. CONCLUSION. Local administration of allogeneic MSCs is safe, tolerable, and feasible for treatment of refractory UP and shows encouraging signs of clinical efficacy and modulation of local immune responses. This sets the stage for larger clinical trials.TRIAL REGISTRATION. EU Clinical Trials Register (EudraCT, 2017-003524-75) and the Dutch Trial Register (NTR7205). Show less
Paassen, J. van; Graaf-Dijkstra, A. de; Brunsveld-Reinders, A.H.; Jonge, E. de; Klautz, R.J.M.; Tsonaka, R.; ... ; Arbous, M.S. 2023
OBJECTIONS: Development of acute lung injury after cardiac surgery is associated with an unfavourable outcome. Acute respiratory distress syndrome in general is, besides cytokine and interleukin... Show moreOBJECTIONS: Development of acute lung injury after cardiac surgery is associated with an unfavourable outcome. Acute respiratory distress syndrome in general is, besides cytokine and interleukin activation, associated with activation of platelets, monocytes and neutrophils. In relation to pulmonary outcome after cardiac surgery, leucocyte and platelet activation is described in animal studies only. Therefore, we explored the perioperative time course of platelet and leucocyte activation in cardiac surgery and related these findings to acute lung injury assessed via PaO2/FiO(2) (P/F) ratio measurements. METHODS: A prospective cohort study was performed, including 80 cardiac surgery patients. At five time points, blood samples were directly assessed by flow cytometry. For time course analyses in low (< 200) versus high (>200) P/F ratio groups, repeated measurement techniques with linear mixed models were used. RESULTS: Already before the start of the operation, platelet activatability (P = 0.003 for thrombin receptor-activator peptide and P = 0.017 for adenosine diphosphate) was higher, and the expression of neutrophil activation markers was lower (CD18/CD11; P = 0.001, CD62L; P = 0.013) in the low P/F group. After correction for these baseline differences, the peri- and postoperative thrombin receptor-activator peptide-induced thrombocyte activatability was decreased in the low P/F ratio group (P = 0.008), and a changed pattern of neutrophil activation markers was observed. CONCLUSIONS: Prior to surgery, an upregulated inflammatory state with higher platelet activatability and indications for higher neutrophil turnover were demonstrated in cardiac surgery patients who developed lung injury. It is difficult to distinguish whether these factors are mediators or are also aetiologically related to the development of lung injury after cardiac surgery. Further research is warranted. Show less
Acute graft-versus-host disease (aGVHD) is an immune cell-driven, potentially lethal complication of allogeneic hematopoietic stem cell transplantation affecting diverse organs, including the skin,... Show moreAcute graft-versus-host disease (aGVHD) is an immune cell-driven, potentially lethal complication of allogeneic hematopoietic stem cell transplantation affecting diverse organs, including the skin, liver, and gastrointestinal (GI) tract. We applied mass cytometry (CyTOF) to dissect circulating myeloid and lymphoid cells in children with severe (grade III-IV) aGVHD treated with immune suppressive drugs alone (first-line therapy) or in combination with mesenchymal stromal cells (MSCs; second-line therapy). These results were compared with CyTOF data generated in children who underwent transplantation with no aGVHD or age-matched healthy control participants. Onset of aGVHD was associated with the appearance of CD11b(+)CD163(+) myeloid cells in the blood and accumulation in the skin and GI tract. Distinct T-cell populations, including TCR gamma delta(+) cells, expressing activation markers and chemokine receptors guiding homing to the skin and GI tract were found in the same blood samples. CXCR3(+) T cells released inflammation-promoting factors after overnight stimulation. These results indicate that lymphoid and myeloid compartments are triggered at aGVHD onset. Immunoglobulin M (IgM) presumably class switched, plasma-blasts, and 2 distinct CD11b(-) dendritic cell subsets were other prominent immune populations found early during the course of aGVHD in patients refractory to both first- and second-line (MSC-based) therapy. In these nonresponding patients, effector and regulatory T cells with skin- or gut-homing receptors also remained proportionally high over time, whereas their frequencies declined in therapy responders. Our results underscore the additive value of high-dimensional immune cell profiling for clinical response evaluation, which may assist timely decision-making in the management of severe aGVHD. Show less
Background Outpatient monoclonal antibodies are no longer effective and antiviral treatments for coronavirus disease 2019 (COVID-19) disease remain largely unavailable in many countries worldwide.... Show moreBackground Outpatient monoclonal antibodies are no longer effective and antiviral treatments for coronavirus disease 2019 (COVID-19) disease remain largely unavailable in many countries worldwide. Although treatment with COVID-19 convalescent plasma (CCP) is promising, clinical trials among outpatients have shown mixed results. Methods We conducted an individual participant data meta-analysis from outpatient trials to assess the overall risk reduction for all-cause hospitalizations by day 28 in transfused participants. Relevant trials were identified by searching Medline, Embase, medRxiv, World Health Organization COVID-19 Research Database, Cochrane Library, and Web of Science from January 2020 to September 2022. Results Five included studies from 4 countries enrolled and transfused 2620 adult patients. Comorbidities were present in 1795 (69%). The virus neutralizing antibody dilutional titer levels ranged from 8 to 14 580 in diverse assays. One hundred sixty of 1315 (12.2%) control patients were hospitalized, versus 111 of 1305 (8.5%) CCP-treated patients, yielding a 3.7% (95% confidence interval [CI], 1.3%-6.0%; P = .001) absolute risk reduction and 30.1% relative risk reduction for all-cause hospitalization. The hospitalization reduction was greatest in those with both early transfusion and high titer with a 7.6% absolute risk reduction (95% CI, 4.0%-11.1%; P = .0001) accompanied by at 51.4% relative risk reduction. No significant reduction in hospitalization was seen with treatment >5 days after symptom onset or in those receiving CCP with antibody titers below the median titer. Conclusions Among outpatients with COVID-19, treatment with CCP reduced the rate of all-cause hospitalization and may be most effective when given within 5 days of symptom onset and when antibody titer is higher.While this outpatient COVID-19 convalescent plasma meta-analysis indicated heterogeneity in participant risk factors and convalescent plasma titer, the combined efficacy for reducing hospitalization was significant, improving with transfusion within 5 days of symptom onset and high antibody neutralization levels. Show less
Gharbharan, A.; Jordans, C.; Zwaginga, L.; Papageorgiou, G.; Geloven, N. van; Wijngaarden, P. van; ... ; CoV-Early study grp 2023
Objectives: The potential benefit of convalescent plasma (CP) therapy for coronavirus disease 2019 (COVID-19) is highest when administered early after symptom onset. Our objective was to determine... Show moreObjectives: The potential benefit of convalescent plasma (CP) therapy for coronavirus disease 2019 (COVID-19) is highest when administered early after symptom onset. Our objective was to determine the effectiveness of CP therapy in improving the disease course of COVID-19 among high-risk outpatients. Methods: A multicentre, double-blind randomized trial was conducted comparing 300 mL of CP with non-CP. Patients were >= 50 years, were symptomatic for <8 days, had confirmed RT-PCR or antigen test result for COVID-19 and had at least one risk factor for severe COVID-19. The primary endpoint was the highest score on a 5-point ordinal scale ranging from fully recovered (score = 1) or not (score = 2) on day 7, over hospital admission (score = 3), intensive care unit admission (score = 4) and death (score = 5) in the 28 days following randomization. Secondary endpoints were hospital admission, symptom duration and viral RNA excretion. Results: After the enrolment of 421 patients and the transfusion in 416 patients, recruitment was dis-continued when the countrywide vaccination uptake in those aged >50 years was 80%. Patients had a median age of 60 years, symptoms for 5 days, and 207 of 416 patients received CP therapy. During the 28 day follow-up, 28 patients were hospitalized and two died. The OR for an improved disease severity score with CP was 0.86 (95% credible interval, 0.59-1.22). The OR was 0.58 (95% CI, 0.33-1.02) for patients with <5 days of symptoms. The hazard ratio for hospital admission was 0.61 (95% CI, 0.28-1.34). No difference was found in viral RNA excretion or in the duration of symptoms. Conclusions: In patients with early COVID-19, CP therapy did not improve the 5-point disease severity score. Arvind Gharbharan, Clin Microbiol Infect 2023;29:208 (c) 2022 The Authors. Published by Elsevier Ltd on behalf of European Society of Clinical Microbiology and Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/). Show less
IntroductionRestoration of immune tolerance may halt progression of autoimmune diseases. Tolerogenic dendritic cells (tolDC) inhibit antigen-specific proinflammatory T-cells, generate antigen... Show moreIntroductionRestoration of immune tolerance may halt progression of autoimmune diseases. Tolerogenic dendritic cells (tolDC) inhibit antigen-specific proinflammatory T-cells, generate antigen-specific regulatory T-cells and promote IL-10 production in-vitro, providing an appealing immunotherapy to intervene in autoimmune disease progression. MethodsA placebo-controlled, dose escalation phase 1 clinical trial in nine adult patients with long-standing type 1 diabetes (T1D) demonstrated the safety and feasibility of two (prime-boost) vaccinations with tolDC pulsed with a proinsulin peptide. Immunoregulatory effects were monitored by antigen-specific T-cell assays and flow and mass cytometry. ResultsThe tolDC vaccine induced a profound and durable decline in pre-existing autoimmune responses to the vaccine peptide up to 3 years after therapy and temporary decline in CD4 and CD8+ T-cell responses to other islet autoantigens. While major leukocyte subsets remained stable, ICOS(+)CCR4(+)TIGIT(+) Tregs and CD103(+) tissue-resident and CCR6(+) effector memory CD4(+) T-cells increased in response to the first tolDC injection, the latter declining thereafter below baseline levels. DiscussionOur data identify immune correlates of mechanistic efficacy of intradermally injected tolDC reducing proinsulin autoimmunity in T1D. Show less
Rijnhout, T.W.H.; Noorman, F.; Horst, R.A. van der; Tan, E.C.T.H.; Viersen, V.V.A.; Waes, O.J.F. van; ... ; Hoencamp, R. 2022
Background The Netherlands Armed Forces have been successfully using deep-frozen (- 80 degrees C) thrombocyte concentrate (DTC) for the treatment of (massive) bleeding trauma patients in austere... Show moreBackground The Netherlands Armed Forces have been successfully using deep-frozen (- 80 degrees C) thrombocyte concentrate (DTC) for the treatment of (massive) bleeding trauma patients in austere environments since 2001. However, high-quality evidence for the effectiveness and safety of DTCs is currently lacking. Therefore, the MAssive transfusion of Frozen bloOD (MAFOD) trial is designed to compare the haemostatic effect of DTCs versus room temperature-stored platelets (RSP) in the treatment of surgical bleeding. Methods The MAFOD trial is a single-blinded, randomized controlled non-inferiority trial and will be conducted in three level 1 trauma centres in The Netherlands. Patients 12 years or older, alive at hospital presentation, requiring a massive transfusion including platelets and with signed (deferred) consent will be included. The primary outcome is the percentage of patients that have achieved haemostasis within 6 h and show signs of life. Haemostasis is defined as the time in minutes from arrival to the time of the last blood component transfusion (plasma/platelets or red blood cells), followed by a 2-h transfusion-free period. This is the first randomized controlled study investigating DTCs in trauma and vascular surgical bleeding. Discussion The hypothesis is that the percentage of patients that will achieve haemostasis in the DTC group is at least equal to the RSP group (85%). With a power of 80%, a significance level of 5% and a non-inferiority limit of 15%, a total of 71 patients in each arm are required, thus resulting in a total of 158 patients, including a 10% refusal rate. The data collected during the study could help improve the use of platelets during resuscitation management. If proven non-inferior in civilian settings, frozen platelets may be used in the future to optimize logistics and improve platelet availability in rural or remote areas for the treatment of (massive) bleeding trauma patients in civilian settings. Show less
Oud, J.A.; Evers, D.; Haas, M. de; Vooght, K.M.K. de; Kerkhof, D. van de; Som, N.; ... ; Zwaginga, J.J. 2022
Data on convalescent plasma (CP) treatment in COVID-19 outpatients are scarce. We aimed to assess whether CP administered during the first week of symptoms reduced the disease progression or risk... Show moreData on convalescent plasma (CP) treatment in COVID-19 outpatients are scarce. We aimed to assess whether CP administered during the first week of symptoms reduced the disease progression or risk of hospitalization of outpatients. Two multicenter, double-blind randomized trials (NCT04621123, NCT04589949) were merged with data pooling starting when <20% of recruitment target was achieved. A Bayesian-adaptive individual patient data metaanalysis was implemented. Outpatients aged >= 50 years and symptomatic for <= 7days were included. The intervention consisted of 200-300mL of CP with a predefined minimum level of antibodies. Primary endpoints were a 5-point disease severity scale and a composite of hospitalization or death by 28 days. Amongst the 797 patients included, 390 received CP and 392 placebo; they had a median age of 58 years, 1 comorbidity, 5 days symptoms and 93% had negative IgG antibody-test. Seventy-four patients were hospitalized, 6 required mechanical ventilation and 3 died. The odds ratio (OR) of CP for improved disease severity scale was 0.936 (credible interval (CI) 0.667-1.311); OR for hospitalization or death was 0.919 (CI 0.592-1.416). CP effect on hospital admission or death was largest in patients with <= 5 days of symptoms (OR 0.658, 95%CI 0.394-1.085). CP did not decrease the time to full symptom resolution. Show less
Katiraei, S.; Diepen, J.A. van; Tavares, L.P.; Hoving, L.R.; Pronk, A.; Verschueren, I.; ... ; Harmelen, V. van 2022
Bone marrow transplantation (BMT) involves conditioning regimens which acutely induce side effects, including systemic inflammation, intestinal damage and shifts in the gut microbial composition,... Show moreBone marrow transplantation (BMT) involves conditioning regimens which acutely induce side effects, including systemic inflammation, intestinal damage and shifts in the gut microbial composition, some of which may persist chronically. As the gut microbiota affect systemic immune responses, we aimed to investigate whether, post-BMT, the peripheral immune system is modulated as a direct consequence of alterations in the gut microbiota. We show that 24 weeks post-BMT, splenocytes but not peritoneal macrophages display increased cytokine response patterns upon ex-vivo stimulation with various pathogens as compared to untreated controls. The pattern of BMT-induced cytokine responses was transferred to splenocytes, and not to peritoneal macrophages, of healthy controls via co-housing and transferred to germfree mice via transplantation of cecum content. Thus, BMT induces changes in gut microbiota that in their turn increase cytokine responsiveness of splenocytes. Thus, BMT establishes a dominant microbiota that attenuates normalization of the immune-response. Show less
Gootjes, C.; Zwaginga, J.J.; Roep, B.O.; Nikolic, T. 2022
Background: Intracranial hemorrhage is seen more frequently in acute leukemia patients compared to the general population. Besides leukemia-related risk factors, also risk factors that are present... Show moreBackground: Intracranial hemorrhage is seen more frequently in acute leukemia patients compared to the general population. Besides leukemia-related risk factors, also risk factors that are present in the general population might contribute to hemorrhagic complications in leukemia patients. Of those, cardiovascular risk factors leading to chronic vascular damage could modulate the occurrence of intracranial hemorrhage in these patients, as during their disease and treatment acute endothelial damage occurs due to factors like thrombocytopenia and inflammation. Objectives: Our aim was to explore if cardiovascular risk factors can predict intracranial hemorrhage in acute leukemia patients. Methods: In a case-control study nested in a cohort of acute leukemia patients, including 17 cases with intracranial hemorrhage and 55 matched control patients without intracranial hemorrhage, data on cardiovascular risk factors were collected for all patients. Analyses were performed via conditional logistic regression. Results: Pre-existing hypertension and ischemic heart disease in the medical history were associated with intracranial hemorrhage, with an incidence rate ratio of 12.9 (95% confidence interval [CI] 1.5 to 109.2) and 12.1 (95% CI 1.3 to110.7), respectively. Conclusion: Both pre-existing hypertension and ischemic heart disease seem to be strong predictors of an increased risk for intracranial hemorrhage in leukemia patients. Show less
Wojcik, I.; Schmidt, D.E.; Neef, L.A. de; Rab, M.A.E.; Meek, B.; Weerdt, O. de; ... ; Vidarsson, G. 2021
As a lymphoid organ, the spleen hosts a wide range of immune cell populations, which not only remove blood-borne antigens, but also generate and regulate antigen-specific immune responses. In... Show moreAs a lymphoid organ, the spleen hosts a wide range of immune cell populations, which not only remove blood-borne antigens, but also generate and regulate antigen-specific immune responses. In particular, the splenic microenvironment has been demonstrated to play a prominent role in adaptive immune responses to enveloped viral infections and alloantigens. During both types of immunizations, antigen-specific immunoglobulins G (IgGs) have been characterized by the reduced amount of fucose present on N-linked glycans of the fragment crystallizable (Fc) region. These glycans are essential for mediating the induction of immune effector functions. Therefore, we hypothesized that a spleen may modulate humoral responses and serve as a preferential site for afucosylated IgG responses, which potentially play a role in immune thrombocytopenia (ITP) pathogenesis. To determine the role of the spleen in IgG-Fc glycosylation, we performed IgG subclass-specific liquid chromatography-mass spectrometry (LC-MS) analysis of Fc glycosylation in a large cohort of individuals splenectomized due to trauma, due to ITP, or spherocytosis. IgG-Fc fucosylation was consistently increased after splenectomy, while no effects for IgG-Fc galactosylation and sialylation were observed. An increase in IgG1- and IgG2/3-Fc fucosylation level upon splenectomy has been reported here for the first time, suggesting that immune responses occurring in the spleen may be particularly prone to generate afucosylated IgG responses. Surprisingly, the level of total IgG-Fc fucosylation was decreased in ITP patients compared to healthy controls. Overall, our results suggest a yet unrecognized role of the spleen in either the induction or maintenance of afucosylated IgG responses by B cells. Show less
Khatri, I.; Diks, A.M.; Akker, E.B. van den; Oosten, L.E.M.; Zwaginga, J.J.; Reinders, M.J.T.; ... ; Berkowska, M.A. 2021
To mount an adequate immune response against pathogens, stepwise mutation and selection processes are crucial functions of the adaptive immune system. To better characterize a successful... Show moreTo mount an adequate immune response against pathogens, stepwise mutation and selection processes are crucial functions of the adaptive immune system. To better characterize a successful vaccination response, we performed longitudinal (days 0, 5, 7, 10, and 14 after Boostrix vaccination) analysis of the single-cell transcriptome as well as the B-cell receptor (BCR) repertoire (scBCR-rep) in plasma cells of an immunized donor and compared it with baseline B-cell characteristics as well as flow cytometry findings. Based on the flow cytometry knowledge and literature findings, we discriminated individual B-cell subsets in the transcriptomics data and traced over-time maturation of plasmablasts/plasma cells (PB/PCs) and identified the pathways associated with the plasma cell maturation. We observed that the repertoire in PB/PCs differed from the baseline B-cell repertoire e.g., regarding expansion of unique clones in post-vaccination visits, high usage of IGHG1 in expanded clones, increased class-switching events post-vaccination represented by clonotypes spanning multiple IGHC classes and positive selection of CDR3 sequences over time. Importantly, the Variable gene family-based clustering of BCRs represented a similar measure as the gene-based clustering, but certainly improved the clustering of BCRs, as BCRs from duplicated Variable gene families could be clustered together. Finally, we developed a query tool to dissect the immune response to the components of the Boostrix vaccine. Using this tool, we could identify the BCRs related to anti-tetanus and anti-pertussis toxoid BCRs. Collectively, we developed a bioinformatic workflow which allows description of the key features of an ongoing (longitudinal) immune response, such as activation of PB/PCs, Ig class switching, somatic hypermutation, and clonal expansion, all of which are hallmarks of antigen exposure, followed by mutation & selection processes. Show less
Oud, J.A.; Evers, D.; Haas, M. de; Vooght, K.M.K. de; Kerkhof, D. van de; Som, N.; ... ; Zwaginga, J.J. 2021
Maternal alloantibodies directed against fetal red blood cell (RBC) antigens may cause potentially life-threatening haemolytic disease of the fetus and newborn (HDFN). Dutch transfusion guidelines... Show moreMaternal alloantibodies directed against fetal red blood cell (RBC) antigens may cause potentially life-threatening haemolytic disease of the fetus and newborn (HDFN). Dutch transfusion guidelines therefore prescribe preventive cEK matching for all (pre-)fertile females. To quantify the impact of cEK matching, we compared overall and antigen-specific cumulative RBC alloimmunisation incidences in females and males aged <45 years. Among a multicentre cohort comprised of patients who received their first and subsequent RBC unit between 2005 and 2019, first-formed RBC alloantibodies were detected in 47 of 2998 (1 center dot 6%) females and 49 of 2507 (2 center dot 0%) males. Comparing females and males, overall alloimmunisation incidences were comparable (3 center dot 1% [95% confidence interval (CI) 2 center dot 1-4 center dot 4] versus 3 center dot 5% (95% CI 2 center dot 4-4 center dot 9, P = 0 center dot 853) after 10 units transfused). However, cEK alloimmunisation incidences were significantly lower among females (0 center dot 6% (95% CI 0 center dot 3-1.5) versus 2 center dot 2% (95% CI 1 center dot 5-3 center dot 4, P = 0 center dot 001) after 10 units transfused). Yet, despite cEK-matching guidelines being in effect, 6 center dot 5%, 3 center dot 6% and 0 center dot 2% of all RBC units remained mismatched for c, E or K antigens respectively. Most of these mismatches were almost always due to emergency settings. Even though cEK alloimmunisation was not prevented completely, implementation of cEK matching resulted in an alloantigen-exposure risk reduction of up to 98%. Show less
Cornelissen, L.L.; Caram-Deelder, C.; Fustolo-Gunnink, S.F.; Groenwold, R.H.H.; Stanworth, S.J.; Zwaginga, J.J.; Bom, J.G. van der 2021
Background Prophylactic platelet transfusions prevent bleeding in hemato-oncology patients, but it is unclear how any benefit varies between patients. Our aim was to assess if patients with... Show moreBackground Prophylactic platelet transfusions prevent bleeding in hemato-oncology patients, but it is unclear how any benefit varies between patients. Our aim was to assess if patients with different baseline risks for bleeding benefit differently from a prophylactic platelet transfusion strategy. Study design and methods Using the data from the randomized controlled TOPPS trial (Trial of Platelet Prophylaxis), we developed a prediction model for World Health Organization grades 2, 3, and 4 bleeding risk (defined as at least one bleeding episode in a 30 days period) and grouped patients in four risk-quartiles based on this predicted baseline risk. Predictors in the model were baseline platelet count, age, diagnosis, disease modifying treatment, disease status, previous stem cell transplantation, and the randomization arm. Results The model had a c-statistic of 0.58 (95% confidence interval [CI] 0.54-0.64). There was little variation in predicted risks (quartiles 46%, 47%, and 51%), but prophylactic platelet transfusions gave a risk reduction in all risk quartiles. The absolute risk difference (ARD) was 3.4% (CI -12.2 to 18.9) in the lowest risk quartile (quartile 1), 7.4% (95% CI -8.4 to 23.3) in quartile 2, 6.8% (95% CI -9.1 to 22.9) in quartile 3, and 12.8% (CI -3.1 to 28.7) in the highest risk quartile (quartile 4). Conclusion In our study, generally accepted bleeding risk predictors had limited predictive power (expressed by the low c-statistic), and, given the wide confidence intervals of predicted ARD, could not aid in identifying subgroups of patients who might benefit more (or less) from prophylactic platelet transfusion. Show less
