Widespread alterations in systemic immune profile are linked to lung function heterogeneity and airway microbes in cystic fibrosis.

BACKGROUND: Excessive inflammation and recurrent airway infections characterize people with cystic fibrosis (pwCF), a disease with highly heterogeneous clinical outcomes. How the overall immune response is affected in pwCF, its relationships with the lung microbiome, and the source of clinical heterogeneity have not been fully elucidated. METHODS: Peripheral blood and sputum samples were collected from 28 pwCF and an age-matched control group. Systemic immune cell subsets and surface markers were quantified using multiparameter flow cytometry. Lung microbiome composition was reconstructed using metatranscriptomics on sputum samples, and microbial taxa were correlated to circulating immune cells and surface markers expression. RESULTS: In pwCF, we found a specific systemic immune profile characterized by widespread hyperactivation and altered frequencies of several subsets. These included substantial changes in B-cell subsets, enrichment of CD35+/CD49d+ neutrophils, and reduction in dendritic cells. Activation markers and checkpoint molecule expression levels differed from healthy subjects. CTLA-4 expression was increased in Tregs and, together with impaired B-cell subsets, correlated with patients' lung function. Concentrations and frequencies of key immune cells and marker expression correlated with the relative abundance of commensal and pathogenic bacteria in the lungs. CONCLUSION: The CF-specific immune signature, involving hyperactivation, immune dysregulation with alteration in Treg homeostasis, and impaired B-cell function, is a potential source of lung function heterogeneity. The activity of specific microbes contributes to disrupting the balance of the immune response. Our data provide a unique foundation for identifying novel markers and immunomodulatory targets to develop the future of cystic fibrosis treatment and management.

Differences in toll-like receptor ligand-induced cytokine concentrations before and after solid organ transplantation: A prospective, observational cohort study in a clinical setting.

Reliable methods to assess immune function after solid organ transplantation (SOT) are needed to guide dosing of immunosuppression. We hypothesized that toll-like receptor ligand-induced cytokine concentrations would decrease post-transplantation due to the use of immunosuppressive medication. Furthermore, we hypothesized that induced cytokine concentrations pre-transplantation would be higher in recipients with episodes of acute rejection post-transplantation due to underlying immunological dispositions. We aimed to investigate toll-like receptor ligand-induced cytokine concentrations by TruCulture©, a standardized immunoassay, in SOT recipients before and 3 months after SOT and explored associations with methylprednisolone-treated acute rejections. We conducted a prospective, observational cohort study including 123 participants (67 liver, 32 kidney and 24 lung transplant recipients). Whole blood was stimulated for 22 h with: (A) Lipopolysaccharide (LPS), (B) Resiquimod, (C) Polyinosinic:polycytidylic acid (Poly I:C) and (D) a blank control. Cytokine concentrations (TNF-α, IL-1ß, IL-6, IL-8, IL-10, IL-12p40, IL-17A, IFN-α and IFN-γ) were measured by Luminex. 30 participants developed methylprednisolone-treated acute rejection at a median of 9 days (IQR 5-17) post-SOT. We found that all induced cytokine concentrations decreased post-SOT except from LPS-induced and Poly I:C-induced IL-10. The induced cytokine concentration pre-transplantation did not differ in recipients with or without acute rejection. In conclusion, the induced cytokine concentrations decreased for all stimuli post-SOT, except the anti-inflammatory cytokine IL-10. Importantly, recipients developing early acute rejection did not differ in induced cytokine concentrations pre-SOT. Thus, the use of a standardized assay in SOT is feasible in a clinical setting and may provide important information on the immune function post-SOT.

Herpes Virus Infections in Kidney Transplant Patients (HINT) - a prospective observational cohort study.

BACKGROUND: Kidney transplant recipients receive maintenance immunosuppressive therapy to avoid allograft rejection resulting in increased risk of infections and infection-related morbidity and mortality. Approximately 98% of adults are infected with varicella zoster virus, which upon reactivation causes herpes zoster. The incidence of herpes zoster is higher in kidney transplant recipients than in immunocompetent individuals, and kidney transplant recipients are at increased risk of severe herpes zoster-associated disease. Vaccination with adjuvanted recombinant glycoprotein E subunit herpes zoster vaccine (RZV) prevents herpes zoster in older adults with excellent efficacy (90%), and vaccination of kidney transplant candidates is recommended in Danish and international guidelines. However, the robustness and duration of immune responses after RZV vaccination, as well as the optimal timing of vaccination in relation to transplantation remain unanswered questions. Thus, the aim of this study is to characterize the immune response to RZV vaccination in kidney transplant candidates and recipients at different timepoints before and after transplantation. METHODS: The Herpes Virus Infections in Kidney Transplant Patients (HINT) study is a prospective observational cohort study. The study will include kidney transplant candidates on the waiting list for transplantation (n = 375) and kidney transplant recipients transplanted since January 1, 2019 (n = 500) from all Danish kidney transplant centers who are offered a RZV vaccine as routine care. Participants are followed with repeated blood sampling until 12 months after inclusion. In the case of transplantation or herpes zoster disease, additional blood samples will be collected until 12 months after transplantation. The immune response will be characterized by immunophenotyping and functional characterization of varicella zoster virus-specific T cells, by detection of anti-glycoprotein E antibodies, and by measuring cytokine profiles. DISCUSSION: The study will provide new knowledge on the immune response to RZV vaccination in kidney transplant candidates and recipients and the robustness and duration of the response, potentially enhancing preventive strategies against herpes zoster in a population at increased risk. TRIAL REGISTRATION: ClinicalTrials.gov (NCT05604911).

Implementation of a vaccination clinic for adult solid organ transplant candidates: A single-center experience.

Vaccination is an evidence-based strategy to prevent or reduce the severity of infectious diseases (ID). Here, we aimed to describe the experience of implementing a vaccination clinic specifically targeting liver, heart, lung, and combined dual organ transplantation at a single transplantation center in Denmark. In this cohort of 242 solid organ transplant (SOT) candidates, we investigated seroprotection and the proportion of recommended vaccinations documented before transplantation. Furthermore, we registered completed vaccinations after ID consultations. The median age in our cohort was 53 years (IQR, 42-60), 60% were males (n = 135), and liver transplants (n = 138; 57%) were the most frequently planned organ transplants. Before the consultation to the vaccination clinic, influenza and pneumococcal vaccines had the highest proportion of documented vaccination (58% and 37%, respectively). Serological protection was more frequently observed for measles, mumps, or rubella (MMR, approximately 90% for each), while only 30% (n = 72) of SOT candidates showed seroprotection against pneumococcal disease. All SOT candidates required at least one of the recommended vaccines, and over 90% required three or more. At least 10% of patients in our cohort needed a live attenuated vaccine for either MMR or yellow fever. The most frequently administered vaccine was the tetanus-diphtheria-acelullar pertussis (Tdap) booster (n = 217; 90%), influenza vaccination was either administered (n = 16; 7%) or recommended (n = 226; 93%), PCV13 was administered (n = 155; 64%) or recommended (n = 27; 11%), and PPSV23 was either administered (n = 18; 7.4%) or recommended (n = 140; 58%). All SOT candidates adhered completely to their vaccination schedules. Based on our findings, we recommend prioritizing vaccination before transplantation by providing ID consultations for SOT candidates.

Herpesvirus immunology in solid organ transplant recipients - liver transplant study (HISTORY): a retrospective and prospective observational cohort study.

BACKGROUND: Life-long immunosuppressive treatment after liver transplantation (LT) prevents graft rejection but predisposes the LT recipient to infections. Herpesvirus infections are associated with morbidity and mortality among LT recipients. Among those, especially cytomegalovirus (CMV) and varicella-zoster virus (VZV) pose challenges after LT. The aim of this study is to provide an in-depth characterization of the cellular immune response against CMV and VZV infections in LT recipients and identify potential risk factors for infection. METHODS: The Herpesvirus Infections in Solid Organ Transplant Recipients - Liver Transplant Study (HISTORY) consists of an epidemiological and immunological substudy. The epidemiological substudy is a retrospective observational cohort study that includes all patients who underwent LT in Denmark between 2010 and 2023 (N ≈ 500). Using data from nationwide hospital records and national health registries, the incidence of and clinical risk factors for CMV and VZV infections will be determined. The immunological substudy is an explorative prospective observational cohort study including patients enlisted for LT in Denmark during a 1.5-year period (N > 80). Participants will be followed with scheduled blood samples until 12 months after LT. CMV- and VZV-derived peptides will be predicted for their likelihood to be presented in participants based on their HLA type. Peptide-MHC complexes (pMHC) will be produced to isolate CMV- and VZV-specific T cells from peripheral blood mononuclear cells before and after CMV and VZV infection. Their frequency, T cell receptor sequences, and phenotypic characteristics will be examined, and in a subset of participants, CMV- and VZV-specific T cells will be expanded ex vivo. DISCUSSION: This study will provide novel insight into T cell immunity required for viral control of CMV and VZV and has the potential to develop a prediction model to identify LT recipients at high risk for infection based on a combination of clinical and immunological data. Furthermore, this study has the potential to provide proof-of-concept for adoptive T cell therapy against CMV and VZV. Combined, this study has the potential to reduce the burden and consequence of CMV and VZV infections and improve health and survival in LT recipients. TRIAL REGISTRATION: ClinicalTrials.gov (NCT05532540), registered 8 September 2022.

Erratum: Author Correction: Early stimulated immune responses predict clinical disease severity in hospitalized COVID-19 patients.

[This corrects the article DOI: 10.1038/s43856-022-00178-5.].

Improved induced innate immune response after cART initiation in people with HIV.

Introduction: Impairment of the innate immune function may contribute to the increased risk of bacterial and viral infections in people with HIV (PWH). In this study we aimed to investigate the induced innate immune responses in PWH prior to and after initiation of combinational antiretroviral therapy (cART). Furthermore, we aimed to investigate if the induced innate immune responses before initiation of cART were associated with CD4+ T-cell recovery one year after initiating cART. Material and method: The induced innate immune response was assessed by the TruCulture® whole blood technique in 32 PWH before cART initiation and after 1, 6 and 12 months. To mimic bacterial and viral infections we used a panel of three stimuli (lipopolysaccharide (LPS), resiquimod (R848), and polyinosinic:polycytidylic acid (Poly I:C)) to stimulate the extracellular Toll-like receptor (TLR) 4 and the intracellular TLR7/8 and TLR3, respectively. The following cytokine responses were analyzed by Luminex 200: Tumor Necrosis Factor (TNF)-α, Interleukin (IL)-1b, IL-6, IL-8, IL-10, IL-12p40, IL17A, Interferon (IFN)-α, and IFN-γ. Results: At baseline PWH with nadir CD4+ T-cell count <350 cell/µL had lower levels of LPS-, R848-, and Poly I:C-induced IL-6 and IFN-γ, LPS- and R848-induced TNF-α and IL-12, LPS induced IL-1b, and R848-induced IL-10 than PWH with nadir CD4+ T-cell count >350 cells/µL. The majority (>50%) had induced cytokine concentrations below the reference intervals at baseline which was most pronounced for the LPS- and Poly I:C-induced responses. The induced responses in the whole population improved after 12 months of cART, and more PWH had induced cytokine concentrations within the reference intervals after 12 months. However, the majority of PWH still had LPS-induced INF-α, INF-γ and Poly I:C-induced TNF-α and IL-6 below the reference interval. The induced innate immune responses before cART initiation were not associated with the CD4+ T-cell recovery after 12 months of cART. Conclusion: The innate immune response was impaired in PWH, with a more pronounced impairment in PWH with low nadir CD4+ T-cell count. Initiation of cART improved the innate immune response, but compared to the reference intervals, some impairment remained in PWH without viral replication.

Early stimulated immune responses predict clinical disease severity in hospitalized COVID-19 patients.

Background: The immune pathogenesis underlying the diverse clinical course of COVID-19 is poorly understood. Currently, there is an unmet need in daily clinical practice for early biomarkers and improved risk stratification tools to help identify and monitor COVID-19 patients at risk of severe disease. Methods: We performed longitudinal assessment of stimulated immune responses in 30 patients hospitalized with COVID-19. We used the TruCulture whole-blood ligand-stimulation assay applying standardized stimuli to activate distinct immune pathways, allowing quantification of cytokine responses. We further characterized immune cell subsets by flow cytometry and used this deep immunophenotyping data to map the course of clinical disease within and between patients. Results: Here we demonstrate impairments in innate immune response pathways at time of COVID-19 hospitalization that are associated with the development of severe disease. We show that these impairments are transient in those discharged from hospital, as illustrated by functional and cellular immune reconstitution. Specifically, we identify lower levels of LPS-stimulated IL-1ß, and R848-stimulated IL-12 and IL-17A, at hospital admission to be significantly associated with increasing COVID-19 disease severity during hospitalization. Furthermore, we propose a stimulated immune response signature for predicting risk of developing severe or critical COVID-19 disease at time of hospitalization, to validate in larger cohorts. Conclusions: We identify early impairments in innate immune responses that are associated with subsequent COVID-19 disease severity. Our findings provide basis for early identification of patients at risk of severe disease which may have significant implications for the early management of patients hospitalized with COVID-19.

Humoral and T-cell response 12 months after the first BNT162b2 vaccination in solid organ transplant recipients and controls: Kinetics, associated factors, and role of SARS-CoV-2 infection.

Introduction: We investigated humoral and T-cell responses within 12 months after first BNT162b2 vaccine in solid organ transplant (SOT) recipients and controls who had received at least three vaccine doses. Furthermore, we compared the immune response in participants with and without previous SARS-CoV-2 infection. Methods: We included adult liver, lung, and kidney transplant recipients, and controls were selected from a parallel cohort of healthcare workers. Results: At 12th-month, the IgG geometric mean concentrations (GMCs) (P<0.001), IgA GMCs (P=0.003), and median IFN-γ (P<0.001) were lower in SOT recipients than in controls. However, in SOT recipients and controls with previous infection, the neutralizing index was 99%, and the IgG, and IgA responses were comparable. After adjustment, female-sex (aOR: 3.6, P<0.009), kidney (aOR: 7.0, P= 0.008) or lung transplantation (aOR: 7.5, P= 0.014), and use of mycophenolate (aOR: 5.2, P=0.03) were associated with low IgG non response. Age (OR:1.4, P=0.038), time from transplantation to first vaccine (OR: 0.45, P<0.035), and previous SARS-CoV-2 infection (OR: 0.14, P<0.001), were associated with low IgA non response. Diabetes (OR:2.4, P=0.044) was associated with T-cell non response. Conclusion: In conclusion, humoral and T-cell responses were inferior in SOT recipients without previous SARS-CoV-2 infection but comparable to controls in SOT recipients with previous infection.

A simple, safe and sensitive method for SARS-CoV-2 inactivation and RNA extraction for RT-qPCR.

The SARS-CoV-2 pandemic has created an urgent need for diagnostic tests to detect viral RNA. Commercial RNA extraction kits are often expensive, in limited supply, and do not always fully inactivate the virus. Together, this calls for the development of safer methods for SARS-CoV-2 extraction that utilize readily available reagents and equipment present in most standard laboratories. We optimized and simplified a RNA extraction method combining a high molar acidic guanidinium isothiocyanate (GITC) solution, phenol and chloroform. First, we determined the GITC/RNA dilution thresholds compatible with an efficient two-step RT-qPCR for B2M mRNA in nasopharyngeal (NP) or oropharyngeal (OP) swab samples. Second, we optimized a one-step RT-qPCR against SARS-CoV-2 using NP and OP samples. We furthermore tested a SARS-CoV-2 dilution series to determine the detection threshold. The method enables downstream detection of SARS-CoV-2 by RT-qPCR with high sensitivity (~4 viral RNA copies per RT-qPCR). The protocol is simple, safe, and expands analysis capacity as the inactivated samples can be used in RT-qPCR detection tests at laboratories not otherwise classified for viral work. The method takes about 30 min from swab to PCR-ready viral RNA and circumvents the need for commercial RNA purification kits.