The distribution and assessment of electron-microscopic abnormalities of human cilia.

The aim of this study was to overcome difficulties of assessing the true incidence of electromicroscopic abnormalities of microtubular structure of cilia by examining large numbers of cilia from each case. The effects of different fixatives on the appearances of cilia were also studied. Bronchial biopsies were examined from 35 subjects who were being investigated for various lung diseases and nasal biopsies from 12 subjects (7 with retinitis pigmentosa (R.P.), and 5 healthy controls). Numerous pieces of normal looking bronchial wall from a lobectomy specimen were used to examine the effect of six different fixatives. 2.9% of bronchial cilia (mean of 890 cilia examined) and 2.4% of nasal cilia (mean of 808 cilia examined) showed microtubular abnormalities. Examining large numbers of cilia established that increased microtubular abnormalities were associated with smoking, chronic pulmonary infection and carcinoma of the lung. There was a significant increase (p less than 0.001) in microtubular abnormalities in nasal cilia in R.P. The appearances of cilia varied considerably with different fixatives. The numbers of dynein arms seen and the ease of recognising radial spokes and microtubules was particularly effected by fixation. The true incidence of microtubular abnormalities can only be ascertained by examining large numbers of cilia.