[Mucociliary function of 10 patients with ankylosing spondylarthritis with normal lung radiographs]

Bi-apical pulmonary fibrosis particular to ankylosing spondylitis is found in 1 to 10% of cases. The non-specific fibrosis or fibrosis of a more specific character such as iritis or the aortic disease are discussed. The fibrosis may be provoked by repeated infections which would favour an eventual hypoventilation at the apices secondary to the rigidity of the thoracic cage. To test this hypothesis we have studied muco-ciliary clearance in 10 subjects presenting with ankylosing spondylitis without any pulmonary radiological lesion and have compared these to 7 control subjects. No statistical difference was found in the clearance rate between the control subjects and the patients on the one hand (whether or not they had extra articular manifestations) and between the different areas of the lung (notably superior and inferior) in patients on the other hand. Thus this bi-apical fibrosis does not seem to explain the phenomena repeated infections at the apices which might have been favoured by any secondary deficiency in muco-ciliary clearance and hypoventilation of the apices. It seems most likely that the fibrosis has a specific origin related to the nature of the disease.