Examining Bronchial Hyperresponsiveness in Primary Ciliary Dyskinesia

The purpose of this study is to look at children with PCD and see if they have another condition called "bronchial hyperresponsiveness". This is when some of the air tubes ("bronchi") are very sensitive ("hyperresponsive") to certain things in the environment such as pollen, mold, pet dander, changes in temperature, and viruses. Children with PCD are often prescribed daily inhaled steroids to help make their air tubes less sensitive, but there are few research studies showing that children with PCD really need this medication. In this study, the investigators will simulate the above triggers for sensitive air tubes with a medication called methacholine. Checking how fast children can breathe out after giving methacholine is sometimes done when doctors think a child may have asthma, a condition where the breathing tubes are very sensitive. By measuring the participant's breathing before and after giving this medication, the investigators will see whether their air tubes are sensitive, or "hyperresponsive". It is possible that methacholine could make the participants temporarily feel short of breath or start wheezing. To avoid this, the investigators will start by giving a small dose of methacholine and measuring the participants breathing, then give larger amounts of methacholine until the investigators see certain changes in the participants breathing or until the largest dose allowed is reached. If the participant starts to have symptoms such as shortness of breath, chest tightness, or wheezing, the investigators will give them a medicine called albuterol which immediately opens the air tubes and makes the symptoms go away. Any discomfort caused by the methacholine is temporary and there are no long-term effects associated with using it. If the participants agree to participate in the study, they will come to Riley Hospital for Children for at least two visits with the opportunity for a third visit. Each visit should take between 2 and 2.5 hours. During the visits, they will complete multiple breathing tests, inhale certain medications, complete a family history questionnaire, have skin allergy testing, and do a blood draw. The investigators will also collect information about the participants from your medical record, including demographic information, medical history, and disease history. If they have completed pulmonary function testing (testing that shows how well lungs are working) in the past, they may only be eligible for Visit 1. For scheduling convenience, visits 1 and 2 may occur on the same day. The participants will be in this study up to one month if they participate in visits 1 and 2, and up to five months if they are eligible for visit 3.