Cystic fibrosis in Canada: A historical perspective

Abstract

Cystic Fibrosis Canada (CF Canada) is a productive model of collaboration between families and the scientific and medical communities. The impetus for this response to a rare and then poorly understood, inherited condition started with Doug and Donna Summerhayes who arranged a meeting for parents of children with CF at the Hospital for Sick Children (SickKids) in Toronto in 1959. The Canadian Cystic Fibrosis Foundation (now CF Canada) was founded the following year.

By that time, specialized CF clinics had been established to treat pediatric patients in Montreal, Toronto, and Halifax. The first CF clinic for young adults opened in Montreal in 1969 and the increase in clinics serving adult patients (now 24) over the last five decades is a testament to the ever-growing adult CF population. Today, there are 42 accredited clinics across Canada providing multidisciplinary care to over 4200 children and adults with CF.

In 1967, CF Canada began clinic accreditation, a national quality improvement effort involving peer-review by CF healthcare professionals. Accreditation site visits are designed to allow sharing of best practices among Canadian CF clinics. As a complement to this program, CF Canada offers annual Clinic Incentive Grants (CIGs) to enhance the standard of CF care by providing funds for patient care and teaching.

With the assistance of CF Canada’s CIGs and research grants, Canada has pioneered major improvements in CF knowledge and care. In 1972, Crozier recommended a revolutionary new diet high in saturated fat supplemented with high doses of pancreatic enzymes. Resultant mortality at the clinic decreased to a rate dramatically lower than clinics in the U.S.¹ In a subsequent study, patients receiving long-term inhaled tobramycin showed stable pulmonary function and better clinical status than patients receiving saline alone.² These key findings contributed to growing support for improved nutrition and control of endobronchial infection in the treatment of patients with CF, now key components of standard practice.

Canadian physicians also profoundly influenced the field of lung transplantation. After 44 unsuccessful attempts globally, surgeons at Toronto General Hospital performed the world’s first successful single and double lung transplants in 1983 and 1986, respectively, followed by the first successful double lung transplant for CF in 1988. In the 28 years that followed, 694 CF patients received lung transplants at one of five transplant centers in Canada, which have been supported, in part, by CF Canada’s Transplant Centre Incentive Grants.³

A key component of the direction of CF Canada has been the support of research initiatives; to-date, the organization has invested over $182 million in research programs. A singular landmark in the history of CF research was the identification of the gene responsible for CF. In 1989, SickKids’ Lap-Chee Tsui and John Riordan, together with Francis Collins at the University of Michigan, announced the discovery of the gene responsible for CF in three seminal articles simultaneously published in Science (Figure 1).^4–6

The discovery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene was a breakthrough viewed as one of the most outstanding achievements in the field of human genetics. With no information on the biochemical basis of the disease, the researchers were the first to use positional cloning to isolate the gene at a time when the human genome had not yet been mapped and sequenced. The successful strategy provided the impetus for the mapping of the entire human genome during the following decade, and was rapidly applied to many other diseases.⁷ This new knowledge provided extensive information on the structure and putative function of the protein product and propelled CF research ahead in Canada and around the world. Although the initial report described the F508del mutation and at least 7 other putative mutations, only months later, Tsui founded the Cystic Fibrosis Genetic Analysis Consortium to catalogue the rapidly growing list of mutations. The online Cystic Fibrosis Mutation Database, launched in 1995, underscores the astounding complexity of CF; as of December 2017, there were 2023 CFTR mutations listed.⁸

The Canadian CF Registry (CCFR; formerly, Canadian Patient Data Registry) was established by Mary Corey and records date back to 1967. By 1973, all 20 existing Canadian clinics were contributing data to an international registry and the first joint U.S.-Canada report was published in 1978.⁹ In 1984, CF Canada assumed responsibility for maintaining an exclusively Canadian registry. Today, all accredited CF clinics submit data to the CCFR as a condition for receiving CIGs from CF Canada; in turn, each clinic has access to national epidemiological information as well as data specific to their respective clinic. With the majority of the Canadian CF population represented in the CCFR, the Registry allows identification of national and local trends and helps to guide clinical care, basic research, design of clinical trials, and quality improvement.

These and many other exceptional Canadian achievements in CF research and care form the basis of several major new initiatives in research and knowledge translation aimed at correcting the basic defect that causes CF such that the estimated median age of survival of individuals born with CF will one day match that of the general population.

Keywords:

• Cystic fibrosis
• CF
• CFTR
• patient registry
• transplant

Acknowledgments

The authors acknowledge Cathleen Morrison, who provided extensive historical background information and guidance in the writing of this manuscript and Doug Summerhayes for sharing valuable details on the beginnings of CF Canada.