Ciliary ultrastructure in primary ciliary dyskinesia and other chronic respiratory conditions: the relevance of microtubular abnormalities.

Twenty-eight subjects with chronic respiratory disease were investigated for clinical data, ciliary beat frequency of nasal mucosa (10 cases), and ciliary ultrastructure. The cases were divided into two groups: those considered compatible with primary ciliary dyskinesia (genetic), and those not fitting into this category (others). A case was defined as genetic if one or more of the following were present: dextrocardia, ciliary beat frequency less than 10 Hz, or an average dynein arm count (outer, inner, or both) of less than two per ciliary cross-section. In each of the genetic cases at least two of these parameters were present. The percentage of malformed microtubules was calculated from the total number of evaluated cross-sections for each case. Ciliary microtubular abnormalities of any kind were no more frequent in cases of primary ciliary dyskinesia than in other cases. The same was true for transposition and radial spoke defects.