Peripheral Blood T Cells of Patients with IPAH Have a Reduced Cytokine-Producing Capacity.

Pulmonary arterial hypertension (PAH) is rare disease that is categorized as idiopathic (IPAH) when no underlying cause can be identified. Lungs of most patients with IPAH contain increased numbers of T cells and dendritic cells (DCs), suggesting involvement of the immune system in its pathophysiology. However, our knowledge on circulating immune cells in IPAH is rather limited. We used flow cytometry to characterize peripheral blood DCs and T cells in treatment-naive IPAH patients, compared with connective-tissue disease-PAH (CTD-PAH) patients and healthy controls (HCs). At diagnosis, T-helper (Th) cells of IPAH patients were less capable of producing TNFα, IFNγ, IL-4 and IL-17 compared to HCs. IPAH patients showed a decreased frequency of Th2 cells and significantly enhanced expression of the CTLA4 checkpoint molecule in naive CD4+ T cells and both naive and memory CD8+ T cells. Frequencies and surface marker expression of circulating DCs and monocytes were essentially comparable between IPAH patients and HCs. Principal component analysis (PCA) separated IPAH patients-but not CTD-PAH patients-from HCs, based on T-cell cytokine profiles. At 1-year follow-up, the frequencies of IL-17+ production by memory CD4+ T cells were increased in IPAH patients and accompanied by increased proportions of Th17 and Tc17 cells, as well as decreased CTLA4 expression. Treatment-naive IPAH patients displayed a unique T-cell phenotype that was different from CTD-PAH patients and was characterized by reduced cytokine-producing capacity. These findings point to involvement of adaptive immune responses in IPAH, which may have an implication for the development of therapeutic interventions.

Inoperable chronic thromboembolic pulmonary hypertension: Evolution of prognosis over 10 years of new emerging therapies.

Therapies for inoperable chronic thromboembolic pulmonary hypertension (CTEPH) include balloon pulmonary angioplasty (BPA) and PH-specific medical therapy. This study compares survival and its predictors before and after the introduction of BPA. BPA was independently associated with survival; however, there was no difference in overall survival between the two cohorts.

The evolution of survival of pulmonary arterial hypertension over 15 years.

The prognosis of pulmonary arterial hypertension (PAH) remains dismal. Over the years, multiple therapeutic advances have been introduced. This study evaluates the evolution of PAH survival over the past 15 years. We included 293 consecutive adult patients diagnosed with PAH between 2005 and 2019 (median age: 61.8 years, 70.3% female). Patients were divided into three cohorts based on the time of diagnosis: 2005-2009, 2010-2014, and 2015-2019 (2005-2009: n = 56; 2010-2014: n = 111; 2015-2019: n = 126). Transplant-free survival was measured from the date of right heart catheterization until patients reached the composite endpoint of lung transplant or death. Multivariable cox-pulmonary hypertension regression was used to study the effect of the time of diagnosis. The final cox model was fitted in both younger and older patients to evaluate the difference between these groups. During a median follow-up time of 4.1 (interquartile range: 2.2-7.3) years, 9 patients underwent lung transplantation and 151 patients died. The median overall transplant-free survival was 6.2 (5.5-8.0) years. Patients older than 56 years at baseline who were diagnosed in 2005-2009 showed better survival compared to patients diagnosed in 2010-2014 and 2015-2019 with an adjusted hazard ratio of, respectively, 2.12 (1.11-4.03) and 2.83 (1.41-5.69). Patients younger than 56 years showed neither an improved nor deteriorated survival over time. In conclusion, survival in patients with PAH did not improve over time, despite more available therapeutic options. This might be partly due to the changed demographic characteristics of the PAH patients and a still important diagnostic delay.

The influence of green tea extract on nintedanib's bioavailability in patients with pulmonary fibrosis.

Nintedanib is an oral small-molecule kinase inhibitor and first-line treatment for idiopathic pulmonary fibrosis. Nintedanib is a substrate of the drug efflux transporter ABCB1. Green tea flavonoids --especially epigallocatechin gallate (EGCG)-- are potent ABCB1 modulators. We investigated if concomitant administration of green tea extract (GTE) could result in a clinically relevant herb-drug interaction. Patients were randomized between A-B and B-A, with A being nintedanib alone and B nintedanib with GTE. Both periods lasted 7 days, in which nintedanib was administered twice daily directly after a meal. In period B, patients additionally received capsules with GTE (500 mg BID, >60% EGCG). Pharmacokinetic sampling for 12 h was performed at day 7 of each period. Primary endpoint was change in geometric mean for the area under the curve (AUC0-12 h). A linear mixed model was used to analyse AUCs and maximal concentration (Cmax). In 26 included patients, the nintedanib AUC0-12 h was 21% lower (95% CI -29% to -12%; P < 0.001) in period B (with GTE) compared to period A. Cmax did not differ significantly between periods; - 14% (95% CI -29% to +4%; P = 0.12). The detrimental effect was predominant in patients with the ABCB1 3435 C>T wild type variant. No differences in toxicities were observed. Exposure to nintedanib decreased with 21% when administered 60 min after GTC for only 7 days. This is a statistically significant interaction which could potentially impair treatment efficacy. Before patients and physicians should definitely be warned to avoid this combination, prospective clinical validation of an exposure-response relationship is necessary.