Rare lung disease research: strategies for improving identification and recruitment of research participants

The utilisation of primary health care system concepts positively impacts the assistance of patients with rare diseases despite limited knowledge and experience by health care professionals: A qualitative synopsis of the evidence including approximately 78 000 individuals

Background

Individuals with rare diseases (RD) have been historically understudied. Previous publications reported that existing primary health care (PHC) workforces and associated infrastructure had been shown to improve their access and health-related outcomes in low- and middle-income countries (LMICs). As current evidence about the impact of PHC on patients diagnosed with RD is yet highly dispersed, this scoping review aimed to collate available evidence of the impact of PHC on patients with RD and summarize published information from multiple stakeholders about the perceived usefulness and barriers to effective use of the PHC system.

Methods

We searched Embase, Health System Evidence, PubMed, LILACS / BVS, and The Cochrane Library, from inception to September 1, 2022, for publications providing clear expert- or experience-based insights or data from patients living with RD at the PHC level of care. We included publications highlighting barriers to integrated care of patients with RD, reported by multiple social actors involved in caring for patients with RD. Two investigators screened publications, extracted data, and clustered information among records deemed eligible for inclusion. Data synthesis was performed using narrative and thematic-based analysis. Major findings identified and coded through a semantic-driven analysis were processed in vosViewer software and reported using descriptive statistics.

Findings

Eighty publications were included in this review. Quali-quantitative analyses evidenced that the PHC level is essential for approaching patients with RD, mainly due to its longitudinal, multidisciplinary, and coordinated care delivery. In addition, several publications highlighted that the medical curriculum is inappropriate for preparing health care providers to deal with patients presenting unusual signs and symptoms and being diagnosed with RD. PHC teams are essential in orienting patients and families on emergency events. Technology-related concepts were reported in 19 publications, emphasizing their effectiveness on early diagnosis, optimal treatment definition, improvement of quality of life, and long-lasting follow-up.

Conclusions

We provided valuable information on the effectiveness of the PHC in fostering a creative, integrative, and supportive environment for patients living with RD. Our results can be helpful to several stakeholders in deciding what actions are still pending to achieve a solid and positive experience for patients with RD in the PHC.

Registration

PROSPERO (CRD42022332347).

NARCOMS and Other Registries in Multiple Sclerosis: Issues and Insights

Observational studies and registries can play a critical role in elucidating the natural and treated history of multiple sclerosis (MS) and identifying factors associated with outcomes such as disability and health-related quality of life. The North American Research Committee on Multiple Sclerosis (NARCOMS) Registry is one of multiple registries worldwide that focuses on people with MS, but one of the very few patient-driven MS registries. On the 25th anniversary of the first data collection for the NARCOMS Registry, we discuss the importance of disease registries in the MS field, describe key concepts related to registry design and management, and highlight findings from MS registries relevant to clinical care or health policy.

Educational aspects of rare and orphan lung diseases

People with rare lung diseases often suffer the burden of delayed diagnosis, limited treatment options, and difficulties in finding expert physicians. One of the reasons for the delay in diagnosis is the limited training for healthcare practitioners on rare diseases. This review explores the main concerns and needs for education on rare lung diseases from the perspectives of both patients and professionals. Despite the increasing interest in rare lung disorders and some recent breakthrough developments on the management of several diseases, healthcare professionals, including general practitioners and hospital workers, receive little education on this topic. Nonetheless, many healthcare professionals show much interest in receiving further training, especially on diagnosis. Patients and families want easier access to high-quality education materials to help them manage their own disease. Well-educated patients are better equipped to deal with chronic diseases, but patient education can be challenging as patients' individual health issues, and diverse backgrounds can create significant barriers. Raising more awareness for rare lung diseases and further development of patient-centred international expert networks like the European Reference Network on Rare Lung Diseases (ERN-LUNG), which includes both experts and patient representatives, are essential for improving care and education on rare lung diseases. Initiatives such as the Rare Disease Day, have been successful in increasing awareness for rare conditions. The development of online tools for accessing information has had positive effects and should be further supported and extended in the future.

A Role for Alveolar Exhaled Nitric Oxide Measurement in the Diagnosis of Hepatopulmonary Syndrome

GOALS

The authors sought to characterize predominantly alveolar exhaled nitric oxide (eNO) in hepatopulmonary syndrome (HPS) compared with non-HPS, changes after liver transplantation, and diagnostic properties.

BACKGROUND

HPS is defined by liver disease, intrapulmonary vascular dilatations (IPVDs), and hypoxemia. Rat models and small human studies suggest that NO overproduction may cause IPVDs.

STUDY

A retrospective review of the Canadian HPS Database (2007 to 2017) and prospective eNO measurement (main outcome) in healthy controls (measurement expiratory flow, 200 mL/s). HPS was defined as: (1) liver disease; (2) contrast echocardiography consistent with IPVDs; and (3) partial pressure of arterial oxygen <70 mm Hg with alveolar-arterial gradient >20 mm Hg; subclinical HPS as criteria (1) and (2) only; and no HPS as criterion (1) only. Current smokers and subjects with asthma or pulmonary hypertension were excluded. A linear mixed effects model was used to compare eNO between groups and before and after transplantation.

RESULTS

eNO was 10.4±0.7 ppb in HPS (n=26); 8.3±0.6 ppb in subclinical HPS (n=38); 7.1±1.0 ppb in no HPS (n=15); and 5.6±0.7 ppb in controls (n=30) (P<0.001). eNO decreased from 10.9±0.8 ppb preliver to 6.3±0.8 ppb postliver transplant (n=6 HPS, 6 subclinical HPS) (P<0.001). eNO <6 ppb was 84.4% (73.1% to 92.2%) sensitive and ≥12 ppb was 78.1% (69.4% to 85.3%) specific for HPS (vs. subclinical HPS).

CONCLUSIONS

HPS subjects have higher alveolar eNO than non-HPS subjects, levels normalize with liver transplantation. Applying eNO cutoff values may aid in HPS diagnosis.

Epidemiology of Rare Lung Diseases: The Challenges and Opportunities to Improve Research and Knowledge

Rare lung diseases encompass a broad spectrum of conditions and affect an estimated 1.2-2.5 million people in North America and 1.5-3 million people in Europe. While individual rare lung diseases affect less than 1 in 2000 individuals, collectively they have a significant impact upon the population at large. Hence it is vital to understand firstly the epidemiology and subsequently the pathogenesis and clinical course of these disorders. Through a greater understanding of these aspects of disease, progress can be made in reducing symptoms, containing healthcare costs and utilizing resources efficiently. Furthermore, a greater understanding of the pathobiology of rare lung diseases can inform both the pathogenesis and management of more common pulmonary disorders.In this chapter we review how epidemiological approaches and the utilization of patient registries has improved the knowledge and management of rare lung diseases. We further focus on the epidemiology of several of the more widely known rare pulmonary disorders, including idiopathic pulmonary fibrosis (IPF), cystic fibrosis (CF) and alpha-1 antitrypsin deficiency (AATD). To conclude we describe how patient advocacy groups and foundations have driven advances in research and management of ultra-rare lung diseases, namely, the major strides made in the management and understanding of lymphangioleiomyomatosis (LAM) and pulmonary alveolar proteinosis (PAP).We conclude that the models used to study some of the rarest of diseases may be successfully adopted by other rare and common disease communities, leading to improved care and the possibility of novel therapeutic options.

Involving patients in reducing decision uncertainties around orphan and ultra-orphan drugs: a rare opportunity?

INTRODUCTION

Uncertainty influences the amount of risk in decision making, and is typically related to clinical benefit, value for money, affordability, and/or adoption/diffusion of the technology (e.g., drug, device, procedure, etc.). Although evidence-based review processes within each stage of the technology lifecycle have been implemented to minimize uncertainty, high-quality information addressing that related to orphan and ultra-orphan drugs is often unavailable. The role that patients, as experts in their disease, may play in providing such information has yet to be fully explored.

OBJECTIVE

The objective of this systematic review was to identify existing and proposed opportunities for patients with rare diseases and their families to provide input aimed at reducing decision uncertainties throughout the lifecycle of an orphan or ultra-orphan drug.

METHODS

A comprehensive review of published and gray literature describing roles for patients and families in activities related to orphan and ultra-orphan drugs was conducted. In addition, the websites of regulatory and centralized reimbursement decision-making bodies in the top 22 OECD (Organisation for Economic Cooperation and Development) countries by gross domestic product (GDP) were scanned to identify current opportunities for patients with rare diseases in both stages. The websites of umbrella patient organizations for rare diseases in these countries were also scanned. These roles were then mapped onto a matrix to determine the stage in the technology lifecycle and types of uncertainties they directly or indirectly addressed.

RESULTS

Across the 22 countries, nine roles for patients within regulatory related processes were identified, with at least one in each country. These roles were not specific to patients with rare diseases. Similarly, six different opportunities for patient input in centralized drug review processes were identified, all of which applied to patients, in general, rather than just those with rare diseases. 'Real-world' examples of patient involvement explicitly related to rare diseases centered around 11 different themes. Seven fell within the research and development or clinical trial stages of a drug's lifecycle. Of the remaining four, three were associated with education and advocacy. All of the proposed roles identified focused on greater involvement in (1) the design and conduct of clinical trials, or (2) the 'valuation' of evidence during reimbursement decision making. When mapped onto the matrix of decision uncertainties, almost all of the existing and proposed roles addressed 'clinical benefit'. Roles for patients in reducing 'value for money', affordability, or adoption/diffusion uncertainties were mainly indirect, and a result of patient involvement in activities aimed at generating information on clinical benefit, which is then used to inform discussions around these uncertainties.

CONCLUSIONS

While patient involvement in activities that directly address uncertainties in clinical benefit may not be 'rare', opportunities for reducing those related to 'value for money', affordability, and adoption/diffusion remain scarce.

Variability of oxygenation in possible hepatopulmonary syndrome: effects of requiring two abnormal arterial blood gas results for diagnosis

BACKGROUND AND AIMS

Hepatopulmonary syndrome (HPS) affects 10-32 % of patients with cirrhosis and is defined by liver abnormalities, intrapulmonary vascular dilatations (IPVDs), and abnormal oxygenation. However, published criteria for abnormal oxygenation are inconsistent. We sought to evaluate variation in oxygenation over time and to compare various diagnostic criteria for validity, based on their diagnostic stability over time and ability to identify patients with clinically relevant findings.

METHODS

We retrospectively analyzed oxygenation and diffusion capacity in patients with liver abnormalities and IPVDs who had ≥ 2 arterial blood gases (ABGs) at the University of Toronto or Universite de Montreal. We compared the performance of nine possible oxygenation criteria for HPS and for each explored whether validity improved when requiring two consecutive abnormal ABGs on different days.

RESULTS

Mean PaO2 was 68.4 mmHg and annual within-patient coefficient of variation 6.3 % (58 patients). Applying published criteria, 8.6-15.5 % of patients initially diagnosed with HPS no longer met the criterion for HPS on a subsequent ABG (re-classified). Requiring two consecutive abnormal ABGs on different days: (1) reduced the proportion of re-classified patients (9/9 criteria); (2) identified patients with more rapid progression in hypoxemia and greater difference in rate of progression between HPS and non-HPS (7/9 criteria); and (3) identified patients with lower diffusion and a larger difference in diffusion between HPS and non-HPS (8/9 criteria).

CONCLUSIONS

Oxygenation is variable in this population, and requiring two abnormal results might reduce misdiagnosis and better differentiate patients with and without HPS according to clinically relevant markers of disease.

Lymphangioleiomyomatosis - a wolf in sheep's clothing

Lymphangioleiomyomatosis (LAM) is a rare progressive lung disease of women. LAM is caused by mutations in the tuberous sclerosis genes, resulting in activation of the mTOR complex 1 signaling network. Over the past 11 years, there has been remarkable progress in the understanding of LAM and rapid translation of this knowledge to an effective therapy. LAM pathogenic mechanisms mirror those of many forms of human cancer, including mutation, metabolic reprogramming, inappropriate growth and survival, metastasis via blood and lymphatic circulation, infiltration/invasion, sex steroid sensitivity, and local and remote tissue destruction. However, the smooth muscle cell that metastasizes, infiltrates, and destroys the lung in LAM arises from an unknown source and has an innocent histological appearance, with little evidence of proliferation. Thus, LAM is as an elegant, monogenic model of neoplasia, defying categorization as either benign or malignant.