Acute vasoreactivity testing in pediatric idiopathic pulmonary arterial hypertension:an international survey on current practice

The aim of this study was to determine practice patterns and inter-institutional variability in how acute vasoreactivity testing (AVT) is performed and interpreted in pediatrics throughout the world. A survey was offered to physicians affiliated with the Pediatric & Congenital Heart Disease Taskforce of the Pulmonary Vascular Research Institute (PVRI), the Pediatric Pulmonary Hypertension Network (PPHNET), or the Spanish Registry for Pediatric Pulmonary Hypertension (REHIPED), from February to December 2016. The survey requested data about the site-specific protocol for AVT and subsequent management of pediatric patients with idiopathic pulmonary arterial hypertension (IPAH) or heritable PAH (HPAH). Twenty-eight centers from 13 countries answered the survey. AVT is performed in most centers using inhaled nitric oxide (iNO). Sitbon criteria was used in 39% of the centers, Barst criteria in 43%, and other criteria in 18%. First-line therapy for positive AVT responders in functional class (FC) I/II was calcium channel blocker (CCB) in 89%, but only in 68% as monotherapy. Most centers (71%) re-evaluated AVT-positive patients hemodynamics after 6-12 months; 29% of centers re-evaluated based only on clinical criteria. Most centers (64%) considered a good response as remaining in FC I or II, with near normalization of pulmonary arterial pressure and pulmonary vascular resistance, but a stable FC I/II alone was sufficient criteria in 25% of sites. Protocols and diagnostic criteria for AVT, and therapeutic approaches during follow-up, were highly variable across the world. Reported clinical practice is not fully congruent with current guidelines, suggesting the need for additional studies that better define the prognostic value of AVT for pediatric IPAH patients

Pituitary adenylate cyclase-activating polypeptide ameliorates experimental acute ileitis and extra-intestinal sequelae.

The neuropeptide Pituitary adenylate cyclase-activating polypeptide (PACAP) plays pivotal roles in immunity and inflammation. So far, potential immune-modulatory properties of PACAP have not been investigated in experimental ileitis.Mice were perorally infected with Toxoplasma (T.) gondii to induce acute ileitis (day 0) and treated daily with synthetic PACAP38 from day 1 to 6 post infection (p.i.; prophylaxis) or from day 4 to 6 p.i. (therapy). Whereas placebo-treated control mice suffered from acute ileitis at day 7 p.i. and succumbed to infection, intestinal immunopathology was ameliorated following PACAP prophylaxis. PACAP-treated mice exhibited increased abundance of small intestinal FOXP3+ cells, but lower numbers of ileal T lymphocytes, neutrophils, monocytes and macrophages, which was accompanied by less ileal expression of pro-inflammatory cytokines such as IL-23p19, IL-22, IFN-γ, and MCP-1. Furthermore, PACAP-treated mice displayed higher anti-inflammatory IL-4 concentrations in mesenteric lymph nodes and liver and higher systemic anti-inflammatory IL-10 levels in spleen and serum as compared to control animals at day 7 p.i. Remarkably, PACAP-mediated anti-inflammatory effects could also be observed in extra-intestinal compartments as indicated by reduced pro-inflammatory mediator levels in spleen (TNF-α, nitric oxide) and liver (TNF-α, IFN-γ, MCP-1, IL-6) and less severe histopathological sequelae in lungs and kidneys following prophylactic PACAP treatment. Strikingly, PACAP prolonged survival of T. gondii infected mice in a time-of-treatment dependent manner.Synthetic PACAP ameliorates acute small intestinal inflammation and extra-intestinal sequelae by down-regulating Th1-type immunopathology, reducing oxidative stress and up-regulating anti-inflammatory cytokine responses. These findings provide novel potential treatment options of inflammatory bowel diseases