FREQUENTLY ASKED QUESTIONS
GENERAL QUESTIONS
WHERE DOES PCD GET ITS NAME?
CLINICAL QUESTIONS
WHAT IS AIRWAY CLEARANCE THERAPY (ACT) AND WHICH TYPE OF ACT SHOULD I DO?
WHAT ARE PULMONARY FUNCTION TESTS (PFTs)?
PFTs have proven to be a very reliable tool for measuring and predicting disease progression in conditions like cystic fibrosis, asthma and COPD. Their utility in PCD is not as clear at this point, but the European Respiratory Task Force on PCD still recommends that PFTs be done every 3-6 months.
HOW DO I FIND A PCD CLINICAL CENTER?
WHAT IS THE LIFE EXPECTANCY FOR INDIVIDUALS WITH PCD?
It is also important to note that number of years aside, PCD is associated with significant illness and quality of life deficits throughout the lifespan. This is why research that will lead to better diagnosis, treatments and cures are so critical for the population.
HOW IS SEVERE LUNG DISEASE MANAGED IN PCD?
It is also important to note that number of years aside, PCD is associated with significant illness and quality of life deficits throughout the lifespan. This is why research that will lead to better diagnosis, treatments and cures are so critical for the population.
ARE THERE RESEARCH OPPORTUNITIES FOR PCD PATIENTS?
Research in PCD falls into two broad categories: 1) Basic science, and 2) Clinical research. Both are critically important in finding a cure for PCD. Basic science does not involve human beings, although it may rely on human tissue or cells. Clinical research refers to any type of study or trial that involves actual people. The PCD community has been so small and so geographically dispersed that it has been challenging to conduct clinical research—until now. By collaborating with PCD investigators and patient groups around the world, the international PCD community will now have the opportunity to participate in research aimed at better understanding the disorder (e.g. long term—or ‘longitudinal’ observational studies of the natural history of PCD), determining whether existing therapies used in other disorders will work for PCD (e.g. azithromycin trial in Europe), identifying potential new therapies (e.g. CLEAN-PCD trial in North America and Europe). With a growing patient community and growing interest on the part of researchers and drug developers, we anticipate that there will be many other research opportunities in the near future.
Having a verified diagnosis, especially knowing your genetics, will be very important in PCD research trials going forward. It is also important to note that number of years aside, PCD is associated with significant illness and quality of life deficits throughout the lifespan. This is why research that will lead to better diagnosis, treatments and cures are so critical for the population.
WHAT DOES RESISTANCE MEAN?
WHAT IS BRONCHIECTASIS?
WHAT IS PSEUDOMONAS AERUGINOSA AND HOW IS IT TREATED?
WHAT ARE SURVEILLANCE CULTURES?
WHY DO I SEEM HEALTHIER/SICKER THAN OTHERS WITH PCD?
In PCD, the picture is much more complex. First, we have more genes, some of them much larger than the CF gene, and we do not even have a clear picture of how many variants may be on each gene. Because there are so many genes involved, we also have different forms of inheritance depending on gene, and a complex picture of variants by gene.
There is limited data demonstrating that some genes involved in PCD may result in more or less severe disease, so the gene involved may be one explanation for why someone with PCD is sicker or healthier. But that is not the complete picture. The specific type of variant on any gene may also contribute to overall severity. Additionally, non-PCD-related genes may also contribute to disease severity. Sometimes other genes may provide additional function that makes up for the loss of function in PCD, resulting in milder disease (*please note—this has been demonstrated in CF, but not in PCD yet so we don’t really know if this happens). Sometimes, other individual genetic factors contribute to worse disease expression.
Finally, individual environmental exposures may affect outcomes, producing either milder or worse disease expression.
WHAT IS AZITHROMYCIN THERAPY?
WILL I BE ABLE TO HAVE CHILDREN? WILL MY CHILDREN HAVE PCD?
Subfertility in PCD is a mechanical issue—a matter of being unable to get the necessary reproductive components where they need to be. This should be distinguished from ‘sterility,’ which implies that the components themselves are not viable. Because most people with PCD have sperm and egg cells that are perfectly fine, just unable to travel due to ciliary inactivity, IVF, ICSI and other assisted reproductive services have been used with a high level of success in PCD.
A person with PCD has two ‘bad’ copies of a PCD gene. Thus, they have no ‘good’ copy to pass on. All of their children will inherit one of these mutated copies, so all will be a PCD carrier. If the other parent is also a carrier (has one copy with a pathogenic PCD mutation ON THE SAME PCD GENE AS THE PCD PARENT), there is a 50/50 chance that the child will inherit the bad copy from the carrier parent. Since the PCD parent only has bad copies to contribute, the child will inherit two bad copies and have PCD. However, this is only an issue if the carrier parent’s pathogenic mutation is on the same gene as the PCD parent. The odds of this, while not impossible, tend to be very, very low given how rare PCD is. There are actually no documented incidences of this occurring to date outside of communities that practice familial intermarriage.
So all children of a PCD parent will be PCD carriers. Under certain conditions, if a PCD parent and a PCD-carrier parent have children, there is a 50/50 chance a child could be born with PCD, but this is a very rare occurrence.
IS LUNG TRANSPLANT AN OPTION IN PCD? HOW WILL I KNOW IF/WHEN TO CONSIDER IT?
The decision to proceed to transplant is not easy and should be undertaken with a trusted medical adviser. Transplant is a process and certain conditions must be met before an individual is even eligible to be worked up or listed for transplant. There are fewer lungs available for transplant than there are people who need them, so allocation of organs is based on a scoring system designed to ensure that available lungs are used in a way that is most likely to be successful. This means that some people will not get lungs and every effort should be made to avoid getting to the point where transplant is required.
DIAGNOSTIC QUESTIONS
HOW MANY PEOPLE HAVE PCD?
WHAT TESTS ARE USED TO DIAGNOSE PCD?
WHAT IS HIGH-SPEED VIDEOMICROSCOPY?
WHAT IS NASAL NITRIC OXIDE (nNO) TESTING?
I HAVE ALL THE SYMPTOMS OF PCD DOES THIS MEAN I HAVE IT?
Read more about symptoms and diagnosis in this blog post by PCDF Executive Director Michele Manion.
WHAT IS A CILIARY BIOPSY?
When performed by experienced technologists and analyzed by pathologists familiar with ciliary defects, TEM can yield usable diagnostic results in about 70% of cases. In reality, however, this ‘ideal’ situation is very rare and the yield of reliable results is much lower at most centers. Therefore, the PCD Foundation recommends that all patients with suspected PCD be directed to PCD Foundation Clinical and Research Network Centers for TEM as part of a larger PCD diagnostic workup.
ARE PCD GENETIC TESTS RELIABLE?
WHAT IS MEANT BY 'PROBABLE' OR 'LIKELY' PCD VS. 'UNLIKELY' TO BE PCD?
WHY IS EXPERT DIAGNOSIS IMPORTANT IN PCD?
Although gene-specific therapies are not available at this time, it is important to confirm (or rule out) a PCD diagnosis so that patients can be on an optimal treatment regimen to manage their disease. Therefore, it is critical that all diagnostic tests are performed by experienced technicians, preferably at one of our many PCDF Clinical Centers located all across the U.S. and Canada.
I HAVE BEEN DIAGNOSED WITH IMMOTILE CILIA SYNDROME OR KARTAGENER SYNDROME, NOT PCD. WHY ARE THESE LUMPED TOGETHER?
These patients looked identical in all respects, except the situs issue. Because he had noted distinct changes in the internal ultrastructure of the cilia of these patients, he theorized (and turned out to be correct) that all their symptoms–infertility, respiratory disease and situs inversus–were caused by a single factor–underlying ciliary defects–and that situs inversus was, in fact, just a random manifestation of this dysfunction (correct again). Because microscopes of that time were not particularly sensitive, ciliated samples from these patients appeared to be completely immotile, so he called this ‘immotile cilia syndrome,’ a name that stuck for decades. This was progress and we were getting closer to the underlying cause, but it was still a syndromic diagnosis based on observation.
‘Kartagener syndrome,’ is an older term commonly used to describe PCD with situs inversus. Since this presentation of PCD is just one of three possible organ placements, the term ‘Kartagener’s’ is somewhat limiting. Nevertheless, it persists because it has been in the medical literature for over a century. Individuals with PCD and situs solitus or PCD with situs ambiguus do not have ‘Kartagener syndrome’ as the term is only used for PCD with situs inversus. For more information on the terms used to describe PCD, please check out ‘What’s in a Name? A Brief History of PCD Terminology.’
GENETICS & BIOLOGY QUESTIONS
HOW IS PCD INHERITED?
WHAT ARE MOTILE CILIA?
WHY DO SOME PEOPLE WITH PCD HAVE ORGAN PLACEMENT/LATERALITY ISSUES?
WHAT OTHER ASSOCIATED PROBLEMS CAN INHERITED MOTILE CILIA DEFECTS CAUSE?
Gastric issues and headaches have been reported by many people with PCD. Of note, THERE ARE NO MOTILE CILIA IN THE GI TRACT. Microvilli found in the GI tract look like cilia, but they are structurally and genetically different. There are primary/sensory cilia in the GI tract, but their role, if any, in the GI complaints seen in PCD is not currently known. Headaches that are not sinus in nature are also a common complaint in PCD and the possible reasons for these headaches are currently being explored.
DISEASE MANAGEMENT QUESTIONS
HOW IMPORTANT IS EXERCISE IN MANAGING PCD?
HOW CAN I WORK WITH OUR SCHOOL TO MANAGE MY CHILD'S EDUCATION?
HOW CAN I GET AN IEP FOR MY CHILD?
HOW CAN I MAINTAIN A JOB WITH PCD? WHEN SHOULD I CONSIDER DISABILITY?
ADMINISTRATIVE QUESTIONS
WHY ISN'T THERE AN INSURANCE CODE FOR PCD?
The current version of the ICD codes used in the US is ICD 10. ICD 11 is in use in other parts of the world and offers the opportunity to petition for a diagnostic code. There is an international effort to get a code for PCD and other motile ciliopathies and we are optimistic there will be a PCD code in 2020/2021.