Cellular and humoral immunogenicity of the COVID-19 vaccine and COVID-19 disease severity in individuals with immunodeficiency.

Background: A well-coordinated adaptive immune response is crucial for limiting COVID-19 disease. Some individuals with immunodeficiency are at a high risk of developing severe COVID-19. Therefore, the development of standardized methods for measuring different arms of the vaccine response in the setting of immunodeficiency is of particular interest. In this study, we compared the vaccine response of individuals living with immunodeficiency with healthy controls in terms of interferon gamma (IFN-γ) production and spike protein-specific antibody level post primary COVID-19 vaccination and booster vaccines. Additionally, the disease severity of those individuals who contracted COVID-19 was assessed. Methods: Whole blood was stimulated overnight from 71 participants and 99 healthy controls. Commercially available PepTivator® peptide pool and trimeric spike protein stimulation were used. ELISA was used to analyze IFN-γ levels. The total SARS-CoV-2 spike protein antibody titre was measured using a Roche Elecsys® S total antibody assay. Patient characteristics, COVID-19 infection status and IDDA 2.1 'Kaleidoscope' scores were recorded. Vaccine responses were scored from zero to three. Results: 99% of healthy controls, 89% of individuals with IEI and 76% with secondary immunodeficiency (SID) had an IFN-γ level above the validated reference range after peptide mix stimulation following primary vaccination. There was an increase in IFN-γ levels in patients with inborn errors of immunity (IEI) following the booster vaccine (p = 0.0156). 100% of healthy controls, 70% of individuals living with IEI and 64% of individuals living with SID had detectable spike protein-specific antibody levels following the primary vaccination. 55% of immunodeficiency patients who had mild COVID-19 and 10% with moderate/severe COVID-19 had detectable antibody and IFN-γ levels post vaccine. The mean pre-infection IDDA 2.1 scores were higher in individuals who developed moderate/severe COVID-19 (25.2 compared to 9.41). Conclusions: Covid whole-blood IGRA is a highly accurate, straightforward and robust assay and can be easily adapted to measure cellular response to COVID-19. A complete evaluation of the vaccine response may be particularly important for individuals living with immunodeficiency. A clinical immunodeficiency score and a validated vaccine response score may be valuable tools in estimating COVID-19 disease risk and identifying individuals living with immunodeficiency who may benefit from enhanced vaccination schedules.

Association Between Ex Vivo Human Ulcerative Colitis Explant Protein Secretion Profiles and Disease Behaviour.

BACKGROUND: The clinical course of ulcerative colitis (UC) is variable. There is an unmet clinical need for biomarkers of UC disease behaviour. We aimed to evaluate the association between ex vivo human UC explant conditioned media (explant-CM) secreted protein profiles and UC disease behaviour. METHODS: UC patients undergoing endoscopy were prospectively recruited. Endoscopic biopsies were collected and explant-CM generated. Association between explant-CM protein secretion profiles and disease progression was evaluated. Disease progression was defined as the requirement for corticosteroid therapy, UC-related hospitalisation, UC-related surgery or the introduction of a new immunomodulatory agent. Association between explant-CM secreted protein profiles and anti-TNF failure status was also evaluated. p values < 0.05 were considered significant in analyses. RESULTS: Twenty-four UC patients were included (age [median, range]) 55 [21-72] years; 50% female. Disease progression during follow-up occurred in twelve (50%) patients. Multivariate analysis, including endoscopic remission status, demonstrated reduced IL-2 secretion to be independently associated with UC disease progression, p = 0.01. In univariate analysis, anti-TNF failure status was associated with significantly increased IL-17A/F (p = 0.015) and IL-12 / IL-23p40 (p = 0.044) concentrations. In multivariate analysis, there was a trend towards an association between IL-17A/F and anti-TNF failure status (p = 0.069); FLT-1 was demonstrated to be independently associated with anti-TNF failure status (p = 0.016). CONCLUSION: Reduced explant-CM secreted IL-2 is associated with UC disease progression. Increased secretion of IL-23 pathway-associated cytokines was observed in anti-TNF failure status consistent with previous reports. Ex vivo human UC explants, generated from endoscopic biopsies, have potential as precision medicine tools in inflammatory bowel disease.

Regional myocardial blood flow in regions of prior myocardial infarction before and after revascularization.

In 30 patients who received 102 saphenous vein bypass grafts, 91 were patent. Preoperative intracoronary injection of 99mTc-labeled albumin particles suspended in contrast revealed 81 regions of perfusion deficit which subsequently received successful revascularization. With postoperative graft injection of isotope, 48 of these regions no longer showed a perfusion deficit (59%), while 33 showed no change (41%). In these 30 patients, 16 of 17 (94%) revealed perfusion defects in regions of prior transmural myocardial infarction. Conversely, only 55 of 96 regions distal to coronary artery stenosis of greater than 50% revealed perfusion defects (57%). Thus, 99mTc-labeled microsphere studies seem to be valuable in detecting regions of prior infarction. After angiographically documented revascularization, the method continued to reveal perfusion deficits in 41% of abnormal regions noted preoperatively, even though almost half of these same specific regions showed improved postoperative regional contractility after postextrasystolic potentiation.