* Patients with primary ciliary dyskinesia (PCD) have trouble with clearing their bronchi from mucus, which in the long-term may produce severe damage to the lungs. Currently, there is no specific treatment for PCD beyond supportive measures such as airway hydration and postural drainage. * Glycine is an amino acid with anti-inflammatory properties that proved to be beneficial in another disease with problematic airway clearance, cystic fibrosis. * Magnesium participates in many crucial chemical reactions, including some that might favor fluidification and mobilization of mucus. Thiamine (vitamin B1) co-participates with magnesium in some mitochondrial enzymatic reactions occurring in the citric acid cycle. * Thus, oral supplements of glycine and magnesium+thiamine might improve symptoms and lung function of patients with PCD, and these effects may even be better if these supplements are combined. * In this study, in addition to their usual care, patients with PCD will receive for 6 months one of the following treatments: 1) an oral supplement of 0.5 g/kg/day glycine, 2) an oral supplement of up to 400 mg/day elementary magnesium plus up to 10 mg/day thiamine, according to the subject's age, 3) glycine plus magnesium+thiamine supplements, as described, or 4) a placebo, which is an inert substance. All treatments will be administered as a whitish powder contained in similar bottles. * The investigators will evaluate whether glycine and/or magnesium+thiamine reduce exacerbations of the disease, improve pulmonary function and quality of life, and reduce some pro-inflammatory compounds measured in saliva.
Any sex.
Age of 5 years or more.
Diagnosis of primary ciliary dyskinesia (PCD) established according to international recommendations (Shapiro et al. Am J Respir Crit Care Med 2018;197(12):e24-e39, and Shapiro et al. Ped Pulmonol 2016;51:115-132).
Without respiratory exacerbations of PCD in the previous 30 days.
None
Parallel
Glycine
Dietary supplementPatients will receive for 6 months an oral supplement of 0.5 g/kg/day glycine, up to 25 g/day, divided in three daily intakes.
Magnesium+thiamine
Dietary supplementPatients will receive for 6 months an oral supplement of up to 400 mg/day, according to age, of elementary magnesium (formulated as magnesium citrate) plus up to 10 mg/day of thiamine (formulated as benfotiamine), divided in three daily intakes.
Placebo
Other interventionPatients will receive for 6 months placebo (sugar glass), in a similar daily amount as in experimental arms, and divided in three daily intakes.
Number of respiratory exacerbations
A respiratory exacerbation will be defined as: 1) any increase in respiratory symptoms that motivated the initiation of antibiotic therapy, or 2) a 10% or more decrease in FEV1 with respect to the FEV1 value at recruitment. A blinded pediatric pulmonologist will review all cases to corroborate whether a suspected episode was indeed a respiratory exacerbation.
Quality of life-Primary ciliary dyskinesia questionnaire (QOL-PCD)
The quality of life will be assessed weekly by the Spanish version of the QOL-PCD questionnaire, as well as by some questions on possible side effects, filled online.
Weight-for-height
The z score of weight-for-height will be used as a proxy for assessing the child's growth and development every two months.
Height-for-age
The z score of height-for-age will be used as a proxy for assessing the child's growth and development every two months.
SpO2
Peripheral blood oxygen saturation, as measured by pulse oximetry every two months.
Click on the lead sponsor to view all of their trials.
