Overview
What is PCD?
Primary Ciliary Dyskinesia (PCD) is a rare inherited disorder caused by defects in the structure and/or function of cilia. Cilia are tiny hair-like structures, which are required to move fluids and particles in various parts of the body, including the airways.
If there are defects in the cilia lining the airways, the body is unable to expel foreign material and clear mucus. This can lead to pulmonary complications, including frequent infections of the lungs, ears, throat and sinuses.
People with PCD may have persistent or recurrent infections, which can significantly disrupt their quality of life and sometimes lead to permanent damage and life-threatening complications.
What is KARTAGENER Syndrome?
About 50% of patients with PCD have laterality defects (e.g. situs inversus totalis where the heart appears in the right side of the chest instead of the left). When defects in the cilia are accompanied by the triad of situs inversus, chronic sinusitis, and bronchiectasis (dilation of the small airways), the condition is known as Kartagener’s syndrome.
Diagnosis
Diagnosis is only made in only a few specialized centers around the world. In Cyprus, the PCD Center: Respiratory Physiology Lab at the Medical School of the University of Cyprus and the Department of Cancer Genetics, Therapeutics & Ultrastructural Pathology at the Cyprus Institute of Neurology and Genetics.
First-line diagnostic test is available, via a non-invasive test measuring the level of nitric oxide [NO] from the nose. Very low levels of nasal NO are very specific for PCD, but the diagnosis can only be confirmed by analyzing the ciliary function and ultrastructure from a nasal brush biopsy.
Abnormal Ciliary motility or defects in the ciliary ultrastructure provide a diagnosis in the majority of cases, although in some patients who have clinical PCD it may not yet be possible to confirm the diagnosis in this way. Research is ongoing to develop more advanced techniques to assist in these more difficult to diagnose cases.
All suspect patients in Cyprus are referred to the Pediatric Pulmonology clinic in Archbishop Macarios III (full accredited member of ERN-LUNG) and appointments are usually available within two weeks. Initial nasal NO and ciliary function results are available the same day, but ultrastructural analysis takes about 4-6 weeks from the time of nasal brushing.
For a small number of patients it may be difficult to confirm the diagnosis using current methods of diagnosis. In these situations where the clinical picture is typical and other evidence exists, such as low nasal NO levels or an abnormal ciliary beat pattern, patients should be treated in exactly the same way as confirmed cases.
The advent of genotyping for all PCD gene mutations, advanced electron microscopy techniques and molecular staining will hopefully overcome these diagnostic challenges for many such cases as well as greatly enhance our knowledge of the underlying disease mechanisms.
FAQ
Some frequently answered questions regarding Primary Ciliary Dyskinesia (PCD).
When was PCD first described?
PCD was first recognised over 100 years ago. It was first described in 1904 by Dr A. K Siewert who reported a patient with situs inversus who also had bronchiectasis. It was not until 1933, however, that Dr. Manes Kartagener published a case series of similar patients leading to the term “Kartagener syndrome”.
What is the cause of PCD?
Defects of dynein arms are a common cause of PCD. Dynein arms are critical structural components of cilia. Dynein defects are often also the easiest to detect on ciliary biopsy. The first PCD gene identified, DNAH5 is a common cause of PCD due to dynein defects.
How many genes are associated with PCD?
To date, there are 50 genes known to be associated with PCD. These 50 genes are believed to be responsible for 70-75% of all cases of PCD. We do not know how many PCD genes will ultimately be discovered, but PCD gene identification is an international research priority.
What is the difference between pcd and kartagener syndrome
People with PCD can have some or all of their internal organs reversed. Cilia play a significant role in the placement of organs during the embryonic development. Because of motile cilia defects, about 50% of PCD patients have laterally defects in which their internal organs flipped (situs inversus totalis) or randomly positioned (situs ambiguous).
Is there a cure for PCD?
PCD is a genetic disorder for which there is no cure yet. There are only therapies to assist with symptom management and stabilisation of the disease.
What are the available treatments for pcd?
Treatment is focused on the symptoms. People with PCD may be treated with chest physical therapy and breathing exercises to help remove excess mucus. Other treatments may include inhalants to help with breathing, and antibiotics to help treat and prevent infections.
Can PCD cause fertility problems?
Individuals with PCD may experience infertility (inability to conceive naturally) or subfertility (delayed natural conception) due to genetic changes that impact the function of cilia in the fallopian tubes in women and the flagella of sperm cells in men.
is assisted reproduction available for pcd patients?
In male patients, sperm flagella may show impairment in or complete absence of the ability to swim, which ultimately results in male infertility. Assisted reproductive technology will certainly benefit such patients. For PCD/KS patients with completely immotile sperm, intracytoplasmic sperm injection may be very important and even indispensable.
is pcd associated with adverse psychological effects?
Health studies have not sufficiently analysed the role of psychological variables in rare diseases such as PCD.