Use of combined chemotherapy and immunotherapy improves pulmonary arterial hypertension

Dear Editor,
We thank Drs. Perros, Chaveroux, and Montani for their interest in our articles describing the activation of the integrated stress response (ISR) pathway as a mechanism underlying the pathogenesis of pulmonary veno-occlusive disease (PVOD), based on the rat mitomycin C (MMC) model of PVOD.

To the Editor,
We read with great interest the recent paper by Prabhakar et al., “Mechanisms underlying age-associated exacerbation of pulmonary veno-occlusive disease,”1 which investigates the role of the integrated stress response (ISR) in pulmonary veno-occlusive disease (PVOD).

Pulmonary arterial hypertension (PAH) is a severe disease caused by progressive distal pulmonary artery obstruction. One cause of PAH are loss-of-function mutations in the potassium channel subfamily K member 3 (KCNK3). KCNK3 encodes a two-pore domain potassium channel, which is crucial for pulmonary circulation homeostasis. 

The objective of this analysis was to compare clinician-based and formally calculated risk assessments by REVEAL Lite 2 and COMPERA 2.0 and to characterize parenteral prostacyclin utilization within 90 days of baseline in high-risk patients. A multisite, double-blind, retrospective chart review of patients with pulmonary arterial hypertension (PAH) was conducted with an index period of January 2014–March 2017.