Ciliated air-liquid cultures as an aid to diagnostic testing of primary ciliary dyskinesia
The diagnosis of primary ciliary dyskinesia (PCD) can prove difficult because of secondary damage of ciliated tissue. Here we audit culturing cells, obtained by nasal brushing, to a ciliated phenotype using an air-liquid interface method to determine if the effects of secondary damage on cilia were reduced following culture. Of 231 patients consecutively referred for diagnostic testing, culture was attempted in 187, with 101 (54%) becoming ciliated. Of the 90 brush biopsy samples with a low dyskinesia score (< 40%), 71 grew cilia after culture (79% success). Significant secondary damage (> 40% dyskinesia) was present in 69 (43%) of the initial brush biopsy samples, and of these, 18 (26%) became ciliated after culture. In these samples, ciliary dyskinesia was significantly (P < .001) reduced (64% ± 6.8% before culture, 31% ± 4.5% after culture). Ciliary beat frequency (CBF) after cell culture was similar to CBF before culture. Cell culture helped to exclude PCD in eight patients for whom ciliary dyskinesia was present in > 70% of the initial brush biopsy sample, a level at which a rebiopsy would normally be requested. In six patients in whom no cilia were found in the initial brush biopsy samples, ciliated cell culture was successful and excluded the diagnosis. PCD was diagnosed in 28 patients and ciliated cell culture was successful in 12 (43%) showing identical ciliary beat pattern and electron microscopy findings. Ciliary dyskinesia was reduced following cell culture to a ciliated phenotype compared with the initial brush biopsy sample. The specific PCD phenotype was maintained after culture.