ABSTRACT
Thrombosis is the most common and a life-threatening complication in patients with Paroxysmal Nocturnal Hemoglobinuria. One-third of patients with PNH experience at least one thromboembolic event during the course of the disease, with thrombosis being the most common cause of death in these patients. The mechanism of thrombosis in PNH is complex and continues to be of great research interest. Since the introduction of C5 complement inhibitors in the treatment of PNH, the incidence of thromboembolic events has decreased substantially. We retrospectively analyzed data concerning the thrombotic episodes of 41 patients with PNH from 14 different national hematology centers in Greece. Sixteen patients (39%) experienced at least one episode of thrombosis, including, seven (43.8%) at diagnosis, seven (43.8%) during the course of the disease and two (12.5%) patients prior to PNH diagnosis. Nearly half of these individuals (n=7, 43.8%) had multiple episodes of thrombosis during the course of their disease. The most common sites of thrombosis were intra-abdominal veins. Three out of 26 patients developed thrombosis while on eculizumab. In none of the 16 patients, the thrombotic event was fatal. Our findings, despite the small number of patients, confirmed that thrombosis continues to be a significant complication of PNH affecting more than one third of the patients.
ABSTRACT
Introduction: Recent data suggest a suboptimal antibody response to COVID-19 vaccination in patients with hematological malignancies, especially under therapy with monoclonal antibodies targeting B-cells. Herein, we evaluated the development of neutralizing antibodies (NAbs) against SARS-CoV-2 in patients with chronic lymphocytic leukemia (CLL), Non-Hodgkin Lymphoma (NHL) and Hodgkin's Lymphoma (HL) after vaccination with the mRNA BNT162b2 vaccine, up to 50 days post their first vaccine dose. Methods: This is a large prospective study (NCT04743388) evaluating the kinetics of anti-SARS-CoV-2 antibodies after COVID-19 vaccination in healthy subjects and patients with hematological malignancies. We report here the results in CLL, NHL and HL patients in comparison to age- and gender-matched controls who were vaccinated at the same time period (January to May 2021). After vein puncture, the serum of both patients and controls was collected on day 1 (D1;before the first BNT162b2 dose), on day 22 (D22;before the second dose of the BNT162b2) and on day 50 (D50;3 weeks post second dose of the BNT162b2). Serum was separated within 4 hours from blood collection and stored at -80°C until the day of measurement. NAbs against SARS-CoV-2 were measured using FDA approved methodology (ELISA, cPass™ SARS-CoV-2 NAbs Detection Kit;GenScript, Piscataway, NJ, USA) on the abovementioned timepoints. A NAb titer of at least 30% is considered as positive, according to manufacturer, whereas a NAb titer of at least 50% has been associated with clinically relevant viral inhibition [Walsh et al. N Engl J Med 2020, 383, 2439-50]. Samples of the same individual were measured in the same ELISA plate. Results: We evaluated 132 patients with CLL/Lymphomas after vaccination with the BNT162b2. Patient population included 53 with CLL, 57 with NHL and 22 with HL, while 214 healthy controls, of similar age and gender, were also studied. At the time of vaccination, 30% (n=40) of patients had asymptomatic disease and out of 92 symptomatic patients, 49% (n=45) were on active treatment. Vaccination with two doses of the BNT162b2 led to lower production of NAbs against SARS-CoV-2 in patients compared with controls, both on day 22 and on day 50 (P<0.001 for all comparisons) for all subgroups. After the first dose of the vaccine, on D22, the patient group had lower NAb titers compared with controls: the median NAb inhibition titer was 18% (IQR: 8.5-29%) for patients versus 41.6% (IQR: 25.3-59%) for controls;p<0.001. On D50, the median NAb inhibition titer was 32.5% (IQR: 13.5-93%) for patients versus 94.7% (IQR: 89-97%) for controls;p<0.001. More specifically, only 50.8% (67/132) of the patients versus 98.1% (210/214) of the controls developed NAb titers ≥30% and 43.9% (58/132) of patients versus 95.3% (204/214) titers ≥50% (high protective titers) at day 50 (p<0.0001 for all comparisons;Figure-left part). Importantly, active treatment (which included anti-CD antibodies, Bruton's tyrosine kinase inhibitors, a combination of the above, chemotherapy-only regimens or Bcl-2 inhibitors) was an independent prognostic factor for suboptimal antibody response at day 50 (<50%) in the patient subgroup (p<0.001). Rituximab administration in the last 12 months correlated with decreased antibody response at day 50 (p<0.01). Patients with HL were more likely to achieve humoral responses (>50% at day 50) compared to other disease types (p<0.05;Figure-right part). Disease-related immune dysregulation and therapy-related immunosuppression were therefore involved in the low humoral responses seen in patients. Regarding adverse events, 9% and 9.8% patients reported mild reactions after the first and second dose of the BNT162b2 vaccine, respectively. Conclusion: Patients with CLL/NHL/HL have a low humoral response following SARS-CoV-2 vaccination, particularly patients who are on active treatment with rituximab or BTK inhibitors. These patient subgroups therefore should continue utilizing protective measures against SARS-CoV-2 (masks, social distancing, etc) as they re at high risk for COVID-19. Further studies on the kinetics of immune subpopulations following COVID-19 vaccination will elucidate the underlying immune landscape and determine the potential need for additional booster vaccine doses or protective administration of antibodies against SARS-CoV-2 in CLL/NHL/HL patients with poor response after full vaccination. [Formula presented] Disclosures: Terpos: Sanofi: Consultancy, Honoraria, Research Funding;Novartis: Honoraria;Celgene: Consultancy, Honoraria, Research Funding;Janssen-Cilag: Consultancy, Honoraria, Research Funding;GSK: Honoraria, Research Funding;Genesis: Consultancy, Honoraria, Research Funding;Takeda: Consultancy, Honoraria, Research Funding;BMS: Honoraria;Amgen: Consultancy, Honoraria, Research Funding. Gavriatopoulou: Janssen: Honoraria;GSK: Honoraria;Genesis: Honoraria;Takeda: Honoraria;Sanofi: Honoraria;Amgen: Honoraria;Karyopharm: Honoraria. Baltadakis: Amgen: Honoraria;Bristol-Myers Squibb: Honoraria;Alexion: Honoraria;Astellas: Honoraria;Pfizer: Honoraria, Other: Travel Grants;Gilead: Honoraria;Novartis: Honoraria;Abbvie: Honoraria;Genesis Pharma: Other: Travel Grants;Gilead: Other: Travel Grants;WinMedica: Other: Travel Grants;Baxalta Hellas: Other: Travel Grants. Dimopoulos: BMS: Honoraria;Amgen: Honoraria;Janssen: Honoraria;Takeda: Honoraria;Beigene: Honoraria.
ABSTRACT
Background: Elucidating the characteristics of human immune response against SARS-CoV-2 is of high priority for determining vaccine strategies. The duration of the persistence of anti-SARS-CoV-2 antibodies in individuals who suffered from COVID-19 is not clearly defined yet. Aims: The aim of this study was to assess the kinetics of anti-SARS-CoV-2 antibodies and neutralizing antibodies among convalescent plasma donors during an 8-month period from their first symptoms of COVID-19. Methods: Participants were enrolled in a phase 2 study of plasma donors (NCT04408209) for the use of convalescent plasma for the treatment of COVID-19 in Greece. For the detection of anti-SARS-CoV-2 antibodies, we used four in-house ELISA assays measuring antibodies to (i) trimeric Spike (S), (ii) Spike Receptor Binding Domain (Spike-RBD), (iii) Nucleocapsid, and (ii) Nucleocapsid RNA Binding Domain (N-RBD). For the Neutralizing Antibody (NAb) assay using SARS-CoV-2 pseudotyped virus, serial dilutions of heat-inactivated sera were incubated with an equal volume of the pseudotyped virions (pHIVNLEnv-Nanoluc) and the virion-Ab mixture was used to transduce HEK293T/ACE2wt cells. Two days later, the luciferase levels were measured in the cell extracts and the ID50 (50% Inhibitory Dose) was calculated using GraphPad Prism version 8.0 for MacOS X (GraphPad Software, Inc, La Jolla, CA) with nonlinear regression curve fit using inhibitor vs responses variable slope (four parameters). Results: In total, 148 convalescent plasma donors (median age: 50 years, range: 18-65) with a median follow-up of 8.3 (range 6.8-10.5) months post their first disease symptoms were included in this analysis. Ninetyone patients did not need hospitalization and 57 were hospitalized due to COVID-19. At the initial screen, all patients showed positive antibody responses recognizing trimeric Spike, Spike-RBD, Nucleocapsid and N-RBD. At the 6-month follow-up, we continue to detect positive responses to Spike, Spike-RBD, Nucleocapsid and N-RBD in all plasma donors but at lower levels compared to screening (p<0.001). At the 8-month follow-up, no significant reduction was observed compared to 6-month values. A piecewise, random-effects, generalized least squares multivariate regression analysis showed a two-phase pattern of antibody responses, with more pronounced decrease during the first 6 months and a plateau phase after the 6th month post-symptoms onset. Spike antibodies showed better persistence than Nucleocapsid antibodies, whereas antibodies recognizing only the Spike-RBD or N-RBD persisted less than the mixture of antibodies recognizing the respective complete proteins. Neutralization ability contracted faster, since neutralizing antibodies persisted in 76% of patients at the last time point. In the multivariate analysis, older age and hospitalization were independently associated with higher antibody Spike, Spike-RBD, Nucleocapsid, N-RBD and NAb levels. Summary/Conclusion: We found persistence of anti-SARS-CoV-2 antibodies, especially against Spike and Spike-RBD, up to 8 months post-symptoms onset. However, a loss of neutralizing antibodies became evident in 24% of convalescent donors at 8 months from initial symptoms of COVID-19. A prolonged follow-up of the donors is necessary to further characterize the kinetics of anti-SARS-CoV-2 B-cell mediated immunity over time and to establish a link between the presence of antibodies and the level of protection against re-infection. Such data should help to optimize vaccination strategies and public health decisions.
ABSTRACT
COVID-19 is a global pandemic associated with increased morbidity and mortality. Convalescent plasma (CP) infusion is a strategy of potential therapeutic benefit. We conducted a multicenter phase II study to evaluate the efficacy and safety of CP in patients with COVID-19, grade 4 or higher. To evaluate the efficacy of CP, a matched propensity score analysis was used comparing the intervention (n = 59) to a control group (n = 59). Sixty patients received CP within a median time of 7 days from symptom onset. During a median follow-up of 28.5 days, 56/60 patients fully recovered and 1 patient remained in the ICU. The death rate in the CP group was 3.4% vs. 13.6% in the control group. By multivariate analysis, CP recipients demonstrated a significantly reduced risk of death [HR: 0.04 (95% CI: 0.004-0.36), p: 0.005], significantly better overall survival by Kaplan-Meir analysis (p < 0.001), and increased probability of extubation [OR: 30.3 (95% CI: 2.64-348.9), p: 0.006]. Higher levels of antibodies in the CP were independently associated with significantly reduced risk of death. CP infusion was safe with only one grade 3 adverse event (AE), which easily resolved. CP used early may be a safe and effective treatment for patients with severe COVID-19 (trial number NCT04408209).