Franck Rahaghi

The prevalence of alpha-1 antitrypsin deficiency among patients found to have airflow obstruction.

Abstract Introduction: Alpha-1 antitrypsin deficiency (AATD) is a genetic disease that may be manifested by chronic obstructive pulmonary disease. Despite professional society guidelines that recommend broad testing of at-risk individuals, fewer than 10% of affected individuals have been identified. The goals of this study were to estimate the frequency of abnormal AAT genotypes among patients found to have fixed airflow obstruction and to assess the feasibility of having Pulmonary Function Laboratory personnel administer the study. Methods: Nineteen medical centers in the United States participated in the study. Eligible patients (> GOLD II, FEV1/FVC ratio < 0.7, with post-bronchodilator FEV1<80% predicted) were offered testing for AATD by the Pulmonary Function Laboratory personnel at the time of pulmonary function testing. Results: A total of 3,457 patients were tested, of whom 3152 were eligible. Deficient patients (ZZ, SZ) constituted 0.63% of subjects, while 10.88% were carriers (MS, MZ). Neither demographic (except African-American race) nor post-bronchodilator pulmonary function variables (FEV1, FVC, FEV1/FVC ratio, TLC, and FEV1/FVC) allowed us to predict AAT heterozygote or deficiency status. Conclusions: The prevalence of AATD among patients undergoing pulmonary function tests with fixed airflow obstruction was 0.63%. Pulmonary Function Laboratory personnel effectively conducted the study.

Imatinib in Pulmonary Arterial Hypertension: C-Kit Inhibition:

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by severe remodeling of the pulmonary artery resulting in increased pulmonary artery pressure and right ventricular hypertrophy and, ultimately, failure. Bone marrow–derived progenitor cells play a critical role in vascular homeostasis and have been shown to be involved in the pathogenesis of PAH. A proliferation of c-Kit+ hematopoietic progenitors and mast cells has been noted in the remodeled vessels in PAH. Imatinib, a tyrosine kinase inhibitor that targets c-Kit, has been shown to be beneficial for patients with PAH. Here we hypothesize that the clinical benefit of imatinib in PAH could be related to c-Kit inhibition of progenitor cell mobilization and maturation into mast cells. As a corollary to the phase 3 study using imatinib in PAH, blood samples were collected from 12 patients prior to starting study drug (baseline) and while on treatment at weeks 4 and 24. Eight were randomized to imatinib and 4 to placebo. Circulating c-Kit+ and CD34+ CD133+ hematopoietic progenitors as well as biomarkers of mast cell numbers and activation were measured. Circulating CD34+ CD133+ and c-Kit+ progenitor cells as well as c-Kit+/CD34+ CD133+ decreased with imatinib therapy (all P < 0.05). In addition, total tryptase, a marker of mast cell load, dropped with imatinib therapy (P = 0.02) and was related to pulmonary vascular resistance (R = 0.7, P = 0.02). The findings support c-Kit inhibition as a potential mechanism of action of imatinib in PAH and suggest that tryptase is a potential biomarker of response to therapy.

Long-term clinical outcomes following treatment with alpha 1-proteinase inhibitor for COPD associated with alpha-1 antitrypsin deficiency: a look at the evidence

Alpha-1 antitrypsin deficiency (AATD) is a common hereditary disorder caused by mutations in the SERPINA1 gene, which encodes alpha-1 antitrypsin (AAT; also known as alpha 1-proteinase inhibitor, A1-PI). An important function of A1-PI in the lung is to inhibit neutrophil elastase, one of various proteolytic enzymes released by activated neutrophils during inflammation. Absence or deficiency of A1-PI leads to an imbalance between elastase and anti-elastase activity, which results in progressive, irreversible destruction of lung tissue, and ultimately the development of chronic obstructive pulmonary disease with early-onset emphysema. AATD is under-diagnosed, patients can experience long delays before obtaining an accurate diagnosis, and the consequences of delayed diagnosis or misdiagnosis can be severe. Currently, A1-PI therapy is the only available treatment that addresses disease etiology in patients with AATD; however, demonstrating clinical efficacy of A1-PI therapy is challenging. In order to show therapeutic efficacy with traditional endpoints such as forced expiratory volume in one second and mortality, large sample sizes and longer duration trials are required. However, AATD is a rare, slow progressive disease, which can take decades to manifest clinically and recruiting sufficient numbers of patients into prolonged placebo-controlled trials remains a significant obstacle. Despite this, the Randomized, placebo-controlled trial of augmentation therapy in Alpha 1-Proteinase Inhibitor Deficiency (RAPID) and RAPID Extension trial, the largest clinical program completed to date, utilized quantitative chest computed tomography as a sensitive and specific measure of the extent of emphysema. Findings from the RAPID/RAPID Extension program definitively confirmed the benefits of A1-PI therapy in slowing disease progression and provided evidence of a disease-modifying effect of A1-PI therapy in patients with AATD. These findings suggest that the early introduction of treatment in patients with severe emphysema-related AATD may delay the time to death, lung transplantation or crippling respiratory complaints. In addition, there is now limited evidence that A1-PI therapy provides a gain of more than five life-years, supporting previous observations based on registry data. With the clinical efficacy of A1-PI therapy now demonstrated, further studies are required to assess long-term outcomes.

Recommendations for the use of oral treprostinil in clinical practice: A delphi consensus project pulmonary circulation

Oral treprostinil was recently labeled for treatment of pulmonary arterial hypertension. Similar to the period immediately after parenteral treprostinil was approved, there is a significant knowledge gap for practicing physicians who might prescribe oral treprostinil. Despite its oral route of delivery, use of the drug is challenging because of the requirement for careful titration and management of drug-related adverse effects. We aimed to create a consensus document combining available evidence with expert opinion to provide guidance for use of oral treprostinil. Following a methodology commonly used in business and social sciences (the ‘Delphi Process’), two investigators from the oral treprostinil (Freedom) studies created a series of statements based on available evidence and the package insert. The set of ‘best practice’ statements was circulated to nine other Freedom trial investigators. Their comments were incorporated into the document as new line items for further vote and comment. The subsequent document was put to vote line by line (scale of −5 to +5) and a final statement was drafted. Consensus recommendations include initial therapy with 0.125 mg for treatment na patients, three times daily dosing, aggressive use of antidiarrheal medication, and a strong preference for use of the drug in combination with other approved PAH therapies. This process was particularly valuable in providing guidance for the management of adverse events (where essentially no data is available). The Delphi process was useful to codify investigator experience and subsequently develop investigator consensus about practical issues for physicians who may wish to prescribe oral treprostinil.

The Rapid Initiation, Titration, and Transition from Intravenous to Oral Treprostinil in a Patient with Severe Pulmonary Arterial Hypertension

In patients who require urgent initiation of pulmonary arterial hypertension medications due to disease progression, it is customary to start intravenous prostacyclin therapy, typically during a hospital admission. If there are complicating factors or relative contraindications to intravenous and subcutaneous prostanoids, oral treprostinil provides another pathway to prostanoid therapy, but this usually requires a prolonged titration. We describe the case of a thirty-six-year-old male with severe pulmonary arterial hypertension and contraindication to intravenous and subcutaneous prostanoid therapy due to congenital deafness and the risk of not hearing the intravenous pump alarms. Intravenous treprostinil was initiated, titrated to high dose, and then rapidly transitioned to oral treprostinil. A rapid initiation, titration, and transition from intravenous to oral treprostinil can be safely performed under watchful supervision in order to achieve higher and more efficacious doses of oral treprostinil in a timely manner.

The safety and tolerability of inhaled treprostinil in patients with pulmonary hypertension and chronic obstructive pulmonary disease

The primary aim was to explore the safety and tolerability of inhaled treprostinil when used in patients with pulmonary hypertension (PH) with concomitant chronic obstructive pulmonary disease (COPD). Patients with a diagnosis of pre-capillary PH (defined as pulmonary artery mean pressure of ≥ 25 mmHg and pulmonary artery wedge pressure or left ventricular end diastolic pressure of ≤ 15 mmHg) who were being initiated on inhaled treprostinil and had concomitant COPD (defined as FEV1/FVC ratio ≤ 70% with FEV1 ≥ 40% predicted) were considered for inclusion in this pilot study. Assessments included adverse events, physical exam, World Health Organization (WHO) functional class, 6-minute walk test (6MWT), modified Borg dyspnea score, and concomitant medication. At baseline and week 16 St. George’s Respiratory Questionnaire (SGRQ), arterial blood gas (ABG), and pulmonary function test (PFT) were assessed. The median age was 65 years (age range, 56–80 years) and five patients (56%) were men. Among the nine patients, a majority had an increase in 6MWT from baseline to week 16 (median change, 19 m). Only three of the nine patients (33%) had an increase in A-a gradient at week 16 (median change, –7). There was no difference in any of the following: arterial blood gases, WHO functional class, 6MWT results, or SGRQ scores from baseline to week 16. There was a statistically significant decline in several of the PFT measures, including FEV1 (median change, –0.18 L; P = 0.004; median change, –7% of predicted; P = 0.016), FVC (median change, –0.23 L; P = 0.027), and diffusion capacity for carbon monoxide (DLCO) (median change, –5% of predicted; P = 0.023). The small number of patients limits firm conclusions; however, inhaled treprostinil did not seem to adversely impact oxygenation in the majority of the study patients with pre-capillary PH and COPD. While there may have an adverse impact on some pulmonary function parameters, the clinical significance is unclear.

Recommendations for the clinical management of patients receiving macitentan for pulmonary arterial hypertension (PAH): A Delphi consensus document

In patients treated with macitentan (Opsumit®, Actelion Pharmaceuticals Ltd., Basel, Switzerland) for pulmonary arterial hypertension (PAH), prevention and/or effective management of treatment-related adverse events may improve adherence. However, management of these adverse events can be challenging and the base of evidence and clinical experience for macitentan is limited. In the absence of evidence, consensus recommendations from physicians experienced in using macitentan to treat PAH may benefit patients and physicians who are using macitentan. Consensus recommendations were developed by a panel of physicians experienced with macitentan and PAH using a modified Delphi process. Over three iterations, panelists developed and refined a series of statements on the use of macitentan in PAH and rated their agreement with each statement on a Likert scale. The panel of 18 physicians participated and developed a total of 118 statements on special populations, add-on therapy, drug–drug interactions, warnings and precautions, hospitalization and functional class, and adverse event management. The resulting consensus recommendations are intended to provide practical guidance on real-world issues in using macitentan to treat patients with PAH.

Teppanyaki/Hibachi Pneumonitis: An Exotic Cause of Exogenous Lipoid Pneumonia

Exogenous lipoid pneumonia (ELP) is a rare type of inflammatory lung disease caused by aspiration and/or inhalation of fatty substances and characterized by a chronic foreign body-type reaction to intra-alveolar lipid deposits. The usual clinical presentation occurs with insidious onset of nonspecific respiratory symptoms and radiographic findings that can mimic other pulmonary diseases. Diagnosis of ELP is often missed or delayed as it requires a high index of suspicion and familiarity with the constellation of appropriate history and radiologic and pathologic features. We herein report a case of occupational exposure to tabletop “Teppanyaki” entertainment cooking as a cause of ELP, confirmed by surgical lung biopsies in a 63-year-old Asian woman who worked as a Hibachi-Teppanyaki chef for 25 years.

Unusual cause of shortness of breath after surgery for thoracic outlet syndrome

A 31-year-old postal worker was diagnosed with bilateral thoracic outlet syndrome and scheduled for the first of two surgeries. The first procedure involved removal of the right first cervical rib, anterior and middle scalenes. On postoperative day 4, he developed shortness of breath. Chest radiograph showed a new pleural effusion on the right. Thoracentesis revealed a yellowish-red thick effusion. Based on the initial look of the fluid it was thought to be a haemorrhagic effusion with a purulent component, further testing revealed that he had developed a chylothorax. The patient was placed on a medium-chain triglyceride diet followed by chest tube drainage. After one day, the chest tube was removed due to minimal drainage, and he was discharged home the next day. Keeping this patient without food, on total parental nutrition, or pursuing surgical intervention was not necessary, as he had an excellent outcome from a very rare surgical complication.