Blind quantitative electron microscopy of cilia from patients with primary ciliary dyskinesia and from normal subjects.

Cilia from the nasal cavity of 27 patients with congenital ciliary dyskinesia (immotile cilia syndrome) and of 15 normal persons were examined by transmission electron microscopy. The patients had on average a significantly higher number of cilia with absent or markedly reduced numbers of outer or inner dynein arms, of cilia with various types of abnormal configuration of the microtubules, except for compound cilia, and of cilia with an abnormally large variation of the beating axis. Compound cilia were equally frequent in patients and controls. The main structural defect in 9 patients was absent or abnormality low number of outer dynein arms in 4 in conjunction with an abnormally large axis variation and in 1 with a markedly reduced number of inner dynein arms also in 1 with supernumerous axonemal microtubules also. In 9 patients the main defects were abnormal configuration of the axonemal microtubules and a large axis variation. Seven of these had eccentrically located central pairs of microtubules and radial spoke defects, 5 in conjunction with abnormally low numbers of inner dynein arms. In one patient there were various types of abnormal configuration of the axonemal microtubules together with absent inner dynein arms, in another cilia with supernumerous microtubules only were present. The only abnormal finding in 1 patient was an extreme variation in the ciliary axes. Completely normal ciliary ultrastructure was found in 8 patients.