Sarcoidosis Associated Pulmonary Hypertension

Drug Design in the Age of Network Medicine and Systems Biology: Transcriptomics Identifies Potential Drug Targets Shared by Sarcoidosis and Pulmonary Hypertension

Network medicine considers the interconnectedness of human diseases and their underlying molecular substrates. In this context, sarcoidosis and pulmonary hypertension (PH) have long been thought of as distinct diseases, but there is growing evidence of shared molecular mechanisms. This study reports on common differentially expressed genes (DEGs), regulatory elements, and pathways between the two diseases. Publicly available transcriptomic datasets for sarcoidosis (GSE157671) and PH (GSE236251) were retrieved from the Gene Expression Omnibus database. DEGs were identified using GEO2R, followed by pathway enrichment and gene interaction analyses via GeneMANIA and STRING. Importantly, a total of 13 common DEGs were identified between sarcoidosis and PH, with 7 upregulated and 6 downregulated genes. The SMAD2/3 nuclear pathway was a shared enriched pathway, suggesting a role in fibrosis and immune regulation. There were also divergences between sarcoidosis and PH. For example, gene set enrichment analysis indicated significant associations of the IFN-gamma signaling pathway with sarcoidosis and the TNF-alpha signaling with PH. miRNA network analysis identified hsa-miR-34a-5p, hsa-let-7g-5p, and hsa-miR-19a-3p as key shared regulators linked to common genes in both sarcoidosis and PH. Finally, DGIdb analysis revealed potential therapeutic candidates targeting these genes in both diseases. This study contributes to the field of drug design and discovery from a network medicine standpoint. The shared molecular links uncovered between sarcoidosis and PH in this study point to several potential biomarkers and therapeutic targets. Further experimental validation and translational medical research are called for diagnostics and drugs, which can effectively and safely help the clinical management of both diseases.

Outcomes of cardiac resynchronization therapy (CRT) in cardiac sarcoidosis patients with a range of ejection fractions

AIMS

In cardiac sarcoidosis (CS) patients, the benefit of cardiac resynchronization therapy (CRT) remains unclear. We sought to assess the short-term and long-term effects of CRT in CS patients with a range of left ventricular (LV) ejection fractions (LVEFs).

METHODS

Consecutive CS patients with heart failure with reduced ejection fraction (HFrEF; LVEF ≤ 40%), mildly reduced ejection fraction (HFmrEF; LVEF 41%-49%) and preserved ejection fraction (HFpEF; LVEF ≥ 50) treated with CRT under the care of a tertiary UK centre between 2008 and 2023 were reviewed. CRT response was defined by >5% improvement in serial LVEF. The primary endpoint was a composite of all-cause mortality, cardiac transplantation or unplanned hospitalization for decompensated heart failure. The secondary endpoint included ventricular arrhythmic events.

RESULTS

Of the 100 patients enrolled (age 58 ± 10 years; 71% male), 63 had HFrEF, 17 had HFmrEF and 20 had HFpEF. After short-term follow-up (9.8 ± 5.4 months), HFrEF patients demonstrated significant LVEF response (P < 0.01). On Kaplan-Meier analysis (follow-up 38 ± 32 months), HFrEF non-responders had significantly worse event-free survival compared with HFrEF responders for the primary (P < 0.001) and secondary (P = 0.001) endpoints. Despite short-term LV function improvement, CRT responders still had worse event-free survival compared with HFmrEF/HFpEF patients for the primary endpoint (P < 0.001). On multivariable Cox analysis, age [hazard ratio (HR) 1.05, 95% confidence interval (CI) 1.01-1.10, P = 0.008] and HFrEF CRT non-response (HR 12.33, 95% CI 2.45-61.87, P = 0.002) were associated with the primary endpoint.

CONCLUSIONS

In CS patients with HFrEF, CRT response is associated with a better long-term prognosis than non-response. However, HFrEF CRT responders still have worse long-term prognosis than HFmrEF/HFpEF patients.

Sarcoidosis-Associated Pulmonary Hypertension

Sarcoidosis-associated pulmonary hypertension (SAPH) is a very severe complication of the disease, largely impacting its morbidity and being one of its strongest predictors of mortality. With the recent modifications of the hemodynamic definition of pulmonary hypertension (mean arterial pulmonary pressure >20 instead of <25 mmHg,) its prevalence is presently not precisely known, but it affects from 3 to 20% of sarcoid patients; mostly, although not exclusively, those with an advanced, fibrotic pulmonary disease. Its gold-standard diagnostic tool remains right heart catheterization (RHC). The decision to perform it relies on an expert decision after a non-invasive work-up, in which echocardiography remains the screening tool of choice. The mechanisms underlying SAPH, very often entangled, are crucial to define, as appropriate and personalized therapeutic strategies will aim at targeting the most significant ones. There are no recommendations so far as to the indications and modalities of the medical treatment of SAPH, which is based upon the opinion of a multidisciplinary team of sarcoidosis, pulmonary hypertension and sometimes lung transplant experts.