FAQ

FREQUENTLY ASKED QUESTIONS

Everything you need to know about primary ciliary dyskinesia (PCD)!

GENERAL QUESTIONS

WHERE DOES PCD GET ITS NAME?

The terminology surrounding genetic motile cilia defects can be confusing. There have been a number of changes that reflect an evolving understanding of what causes the symptoms in what is now called primary ciliary dyskinesia (PCD). With the explosion of information about motile cilia genetics in the past two decades, it is possible that the name will continue to evolve to more accurately reflect the underlying genetic/functional picture. For more information about the history of PCD and its terminology, click here.

CLINICAL QUESTIONS

WHAT IS AIRWAY CLEARANCE THERAPY (ACT) AND WHICH TYPE OF ACT SHOULD I DO?

Airway clearance therapy (ACT) is just what its name implies—therapies or activities designed to help clear mucus from the airway. ACT can be done in many ways. Hand clapping (also called CPT for ‘chest physiotherapy’) and vest therapy are the two main forms used in CF and PCD, primarily because these conditions have the need for daily, comprehensive ACT and CPT and the vest are thought to be better at moving mucus from both the large and small airways (although no one knows if this is actually true). Acapella, Flutter, Quake and others are ACT devices in the category of ‘positive expiratory pressure’ or ‘PEP’devices. These devices are good for holding the airways open (or ‘stenting’ them) to facilitate clearance. Some of them vibrate the airways as well, which can help move mucus from smaller airways to larger one where it is easier to cough it out or swallow it. They can be used in combo with the vest and their stenting action can help airways remain open while the oscillation of the vest moves mucus. The last very important form of ACT is exercise. It’s a ‘two-fer,’ moving mucus and also naturally opening the airways.

WHAT ARE PULMONARY FUNCTION TESTS (PFTs)?

Pulmonary function testing or PFTs (aka ‘spirometry’) is a surveillance technique that measures how effectively your lungs are performing by tracking the amount (volume) and speed (flow) of air being inhaled and exhaled. To perform PFTs, the patient is asked to blow into a mouthpiece while a computer records the force of the expelled air, how long it takes to fully empty the lungs and a number of other values that give an overall picture of lung function . The two values of most interest to doctors treating PCD are the FEV1 (forced expiratory volume in 1 second), which measures how effectively your lungs are able to expel a large volume of air in the first second of exhalation and FVC (forced vital capacity) which shows the total amount of time required to expel all air from the lungs.

 

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?

Please visit the ‘Find a Center‘ page to find a PCD clinical center near you.

WHAT IS THE LIFE EXPECTANCY FOR INDIVIDUALS WITH PCD?

There is no reliable demographic data to indicate the overall life expectancy for individuals with PCD. However, anecdotal reports indicate that in some people, PCD may be associated with a reduced lifespan due to chronic respiratory disease. This reduction is not as severe as that seen in cystic fibrosis, a similar disorder, and some individuals with PCD have lived into their seventh or eighth decade of life.

 

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?

Chronic infections and progressive bronchiectasis can lead to severe lung disease for some patients with PCD. Because there currently are no cures or regenerative therapy options for PCD, treatment and management of severe lung disease in PCD is focused on managing symptoms, including aggressively treating infections (often requires IV medications and permanent venous access lines), using supplemental oxygen, and keeping the airways as clear as possible. If these measures are not sufficient and the patient progresses to respiratory failure, lung transplantation may be an option. Lung transplants have been successfully performed in PCD, even in individuals with situs anomalies.

 

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?

Yes! Please visit the ‘Clean PCD Trial‘ page for more information.

 

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.

DIAGNOSTIC QUESTIONS

HOW MANY PEOPLE HAVE PCD?

There have been roughly 3,000 confirmed diagnoses of PCD in North America, however, delayed or missed diagnosis is quite common with this disease and there could be upwards of 25,000 people who are affected and don’t know it. This not only speaks to how difficult it can be to get a diagnosis of PCD, but also why the PCDF Clinical Centers are so important.

WHAT TESTS ARE USED TO DIAGNOSE PCD?

Please visit the ‘Diagnosis‘ page to learn what diagnostic tools are used in PCD.

WHAT IS HIGH-SPEED VIDEOMICROSCOPY?

Per the 2015 consensus statement, high-speed videomicroscopy, which is an examination of cilia waveform from a ciliary biopsy, can be sufficient in providing a clinical diagnosis for PCD. However, there is a caveat: this test must be performed by a qualified medical professional who has experience with high speed videomicroscopy technology. If this test is performed by a medical technician who is not an expert, there is a chance of either a false-negatives or a false-positive result, both of which can potentially be harmful to the patient.

WHAT IS NASAL NITRIC OXIDE (nNO) TESTING?

For reasons not yet known, the vast majority of individuals with PCD have very low levels of a gas called nitric oxide (not ‘nitrous’) in their sinus cavities. This is not just a small difference, it is a marked and significantly lower level than seen in people without PCD.* Because this finding has been verified in numerous studies around the world, measuring the nasal nitric oxide (nNO) level in individuals thought to have PCD can be a useful screening tool to help a physician decide whether or not PCD is a likely diagnosis. In the US, nNO testing cannot be used to make the diagnosis; nor can it be used to exclude PCD. It is a screening test only that will help prioritize decisions about next diagnostic steps. For more information about nNO screening, or other diagnostic tests for PCD, please visit ‘Diagnosing PCD.’

GENETICS & BIOLOGY QUESTIONS

WHY DO SOME PEOPLE WITH PCD HAVE ORGAN PLACEMENT/LATERALITY ISSUES?

‘Laterality’ is a term describing the dominance or difference between the sides of the body. The body is not identical on both sides (called ‘asymmetry’), and the process by which the body knows how to organize laterality/asymmetry is very complex. One important factor appears to be the motion of unique cilia on the embryonic node (called ‘nodal cilia’) which only appear once in our life. The activity of these unique motile cilia plays an important role in determining the placement of organs within the thoracic and abdominal cavities. In the absence of this ciliary motion, organ placement becomes a random event, giving each affected embryo a 50/50 chance of having typical placement (known as situs solitus), mirror-image placement with reversed organs (known as situs inversus) or an unusual pattern of unique organ development or placement (situs ambiguous or heterotaxy).  Many PCD genetic mutations also impact the motility of the nodal cilia. With these mutations, approximately 50% of PCD patients present with situs solitus and the remaining patient population having either situs inversus or situs ambiguus (‘ambiguous’)/heterotaxy.

WHAT OTHER ASSOCIATED PROBLEMS CAN INHERITED MOTILE CILIA DEFECTS CAUSE?

In addition to lung, ear & sinus disease, genetic defects that cause PCD can affect all areas that rely on ciliary motility, including reproductive organs (sperm tails in males and fallopian tubes in females) and ventricles of the brain (rare reports of ventriculomegaly or hydrocephalus). It is important to note that not all individuals with PCD will have issues with infertility or subfertility and that motile cilia dysfunction and brain/central nervous system disorders appear to be very rare in humans. There are isolated reports of other associated disorders in PCD which are currently being investigated.

 

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?

Although there is no specific data on the effects of exercise as it relates to PCD, we encourage all patients to be active within their own physical limitations. Please visit ‘Living with PCD‘ for more information.

HOW CAN I WORK WITH OUR SCHOOL TO MANAGE MY CHILD'S EDUCATION?

One of the most important things you can do to help your child with PCD get the most from school is to educate his/her teacher about the disorder. Here is a sample letter you can use with your child’s teachers and other school officials. Feel free to adapt for your personal use. For more information, click here.

HOW CAN I GET AN IEP FOR MY CHILD?

Please visit our ‘PCD at School‘ page.

HOW CAN I MAINTAIN A JOB WITH PCD? WHEN SHOULD I CONSIDER DISABILITY?

Many people with PCD pursue fulfilling careers and are able to support themselves through employment. However, some are not, and the chronic infections and daily therapies required to maintain health in PCD can make full-time employment difficult to manage. As PCD lung disease progresses it may be necessary to consider disability. Parents of children with PCD can experience excessive missed work days for issues related to their children’s health, as well. For more information, click here.

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