Spirometric and anthropometric improvements in response to elexacaftor/tezacaftor/ivacaftor depending on age and lung disease severity.

Introduction: Triple-combination cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy with elexacaftor/tezacaftor/ivacaftor (ETI) was introduced in August 2020 in Germany for people with CF (pwCF) ≥12 years (yrs.) of age and in June 2021 for pwCF ≥6 yrs of age. In this single-center study, we analyzed longitudinal data on the percent-predicted forced expiratory volume (ppFEV1) and body-mass-index (BMI) for 12 months (mo.) after initiation of ETI by linear mixed models and regression analyses to identify age- and severity-dependent determinants of response to ETI. Methods: We obtained data on 42 children ≥6-11 yrs, 41 adolescents ≥12-17 yrs, and 143 adults by spirometry and anthropometry prior to ETI, and 3 and 12 mo. after ETI initiation. Data were stratified by the age group and further sub-divided into age-specific ppFEV1 impairment. To achieve this, the age strata were divided into three groups, each according to their baseline ppFEV1: lowest 25%, middle 50%, and top 25% of ppFEV1. Results: Adolescents and children with more severe lung disease prior to ETI (within the lowest 25% of age-specific ppFEV1) showed higher improvements in lung function than adults in this severity group (+18.5 vs. +7.5; p = 0.002 after 3 mo. and +13.8 vs. +7.2; p = 0.012 after 12 mo. of ETI therapy for ≥12-17 years and +19.8 vs. +7.5; p = 0.007 after 3 mo. for children ≥6-11 yrs). In all age groups, participants with more severe lung disease showed higher BMI gains than those with medium or good lung function (within the middle 50% or top 25% of age-specific ppFEV1). Regression analyses identified age as a predictive factor for FEV1 increase at 3 mo. after ETI initiation, and age and ppFEV1 at ETI initiation as predictive factors for FEV1 increase 12 mo. after ETI initiation. Discussion: We report initial data, which suggest that clinical response toward ETI depends on age and lung disease severity prior to ETI initiation, which argue for early initiation of ETI.

Pulmonary Alveolar Microlithiasis: A novel patient and brief review of the literature.

Pulmonary Alveolar Microlithiasis (PAM) is a rare hereditary lung disease caused by biallelic pathogenic variants (pV) in the solute family 34 member 2 gene (SLC34A2; Izumi et al., Am J Respir Crit Care Med 2007; 175: 263-268). pVs in this sodium phosphate co-transporter gene lead to accumulation of calcium phosphate crystals within pulmonary alveoli. More than 1000 cases of PAM were thus far reported, with high variance in disease courses (Stamatis et al., Ann Thorac Surg 1993; 56: 972-975). Frequently, asymptomatic cases are observed, and often times slow disease progression until respiratory insufficiency in middle age occurs (Kosciuk, Eur Respir Rev 2020; 29: 200024). Treatment options for PAM are scarce and largely ineffective, and lung transplantation is the only effective therapy in end-stage disease (Stamatis et al., Ann Thorac Surg 1993; 56: 972-975). Here, we report a novel PAM case in an adolescent migrant from East Africa and discuss current diagnostic and therapeutic options.

Evaluation of suitable target antigens and immunoassays for high-accuracy immune monitoring of cytomegalovirus and Epstein-Barr virus-specific T cells as targets of interest in immunotherapeutic approaches.

Adoptive immunotherapy with donor-derived antiviral T cells can prevent viral complications such as with cytomegalovirus (CMV) and Epstein-Barr virus (EBV). In this context accurate monitoring of cellular immunity is essential and requires suitable quantitative and qualitative assays for high-throughput screening. We comparatively analyzed 57 HLA-typed healthy donors for memory T-cell responses to CMV- and EBV-derived proteins, peptide pools and single HLA-restricted peptides by five commonly used immunoassays in parallel: enzyme-linked immunospot (ELISPOT), cytokine secretion assay (CSA), intracellular cytokine staining (ICS), enzyme-linked immunosorbent assay (ELISA) and pMHC multimer staining. T-cell responses varied greatly between the different target antigens in the investigated assays. IFN-γ ELISPOT consistently detected the highest T-cell response levels against CMV and EBV. CMV-specific T cells were detected in 100% of CMV-seropositive donors tested using CMVpp65 protein and/or overlapping CMVpp65 peptide pool. CMV-specific T cells in HLA-A*02:01-positive/CMV-seropositive donors were identified directly by HLA-A02/CMVpp65 (A02pp65) multimer staining and, after short in vitro stimulation with HLA-A*02:01-restricted pp65 peptide, by ELISPOT, ELISA, ICS and CSA. A peptide-specific T-cell response was detected in only 4 HLA-A*02:01-positive donors (50%). Despite A02pp65 peptide negativity, T-cell responses to CMVpp65 protein and/or overlapping peptide pool were detected. Comparing the specific immune response against EBV antigens in healthy donors overall, BZLF1-specific T cells (<92.9% peptides, <56.3% peptide pool) were more frequent than EBNA-specific T cells (<64.3% peptides, <46.9% peptide pool) with higher percentage of positive findings for single HLA-restricted EBV peptides. T-cell response against HLA-B*08 peptide epitopes was predominant (multimer staining: EBNA3A: 9/14 and BZLF1: 7/14, IFN-γ ELISPOT: EBNA3A: 13/14 and BZLF1: 11/14). The fact that responses to EBV-specific antigens were not detected in every single EBV-seropositive donor as well as that the T-cell frequencies in response to the investigated EBV antigens differed strongly in the donor cohort indicates that these epitopes are less immunodominant than CMVpp65. Taken together, precise monitoring of T-cell immunity against infectious agents in potential T-cell donors and post-transplant recipients requires individual selection of antigens and immunoassays for the efficient detection and generation of clinically relevant T cells. Due to its lower detection limit and direct visualization of each IFN-γ-secreting cell we identified ELISPOT analysis to be preferable for high-throughput pre-screening. CSA was found to be advantageous for a more detailed analysis of antigen-specific T-cell subsets.

CMV-, EBV- and ADV-specific T cell immunity: screening and monitoring of potential third-party donors to improve post-transplantation outcome.

Adoptive immunotherapy with virus-specific T lymphocytes can efficiently reconstitute antiviral immunity against cytomegalovirus (CMV), Epstein-Barr virus (EBV), and adenovirus (ADV) without causing acute toxicity or increasing the risk of graft-versus-host disease. To gain insight into antiviral T cell repertoires and to identify the most efficient antigens for immunotherapy, the frequencies of CMV-, EBV- and ADV-specific T cells in 204 HLA-typed healthy donors were assessed using viral peptides and peptide pools. Confirmatory testing for CMV serology by Western blot technique revealed 19 of 143 (13%) false-positive results. We observed highly significant individual and overall differences in T cell frequencies against CMV, EBV, and ADV antigens, whereas antigen-specific T cells were detected in 100% of CMV- seropositive donors, 73% of EBV- seropositive donors, and 73% of ADV-seropositive donors. At least 124 (61%) potential T cell donors were identified for each virus. Among the tested antigens, frequencies for CMVpp65 and EBVBZLF1 peptide pools were highest. Short-term in vitro peptide stimulation revealed that a donor response to a certain ADV- and EBV-derived peptide may not be determined without prior stimulation. A modified granzyme B ELISpot was used to detect T cell specificity and alloreactivity. Treatment with allogeneic virus-specific cytotoxic T lymphocytes from seropositive third-party donors may be a feasible therapeutic option for infections following cord-blood stem cell transplantation or hematopoietic stem cell transplantation from virus-seronegative donors.