Primary ciliary dyskinesia: Diagnosis in children with inconclusive ultrastructural evaluation

The purpose of this study was to distinguish between acquired and genetical ly determined ciliary abnormalities in children with severe chronic respira tory diseases. Samples of nasal ciliated epithelium from 50 subjects (25 ma le. 25 female: age-range 2-19 years) with severe chronic respiratory diseas es were examined using transmission electron microscopy (TEM). Based on TEM findings, patients were divided into two groups: A and B. Group A comprise d 39 children with ciliary alterations compatible with a condition probably occuring secondary to chronic inflammation (alterations of peripheral pair s, swollen cilia, and compound cilia). The other 11 patients, Group B, exhi bited a greater number of alterations of the central pair and dynein arms ( p <0.001), which were qualitatively similar to, but less numerous than. tho se observed in primary ciliary dyskinesia (PCD). In both groups, analysis o f ciliary beat frequency and waveform was performed by phase contrast micro scopy (PCM). All the children with a ciliary beat frequency of <7 Hz were t reated with daily physiotherapy and with antibiotics, as recommended for PC D, for a 6-month period. After this treatment. the children were reexamined by PCM. Almost 50% of the children from Group B (i.e. those with a small p roportion of specific ultrastructural defects) showed permanence of low cil iary beat frequency. This was also observed in two children of Group A. The se children were considered to be affected by PCD. Our study describes a me thod for the diagnosis of PCD in the absence of specific ultrastructural de fects or when these defects are present in only a small proportion of the c ilia.