Table 1.

Results of pulmonary function tests

	Initial investigation	After 2-year follow-up
FVC	4.58 l (85%)	4.82 l (81%)
FEV1	4.48 l/min (101%)	4.45 l/min (93%)
MEF50	7.32 l/min (140%)	7.17 l/min (121%)
TLC	6.14 l (92%)	6.09 l (78%)
DLCO	87%	81%

Legend: The first examination was performed two weeks after disease manifestation, there were more than 10 tests performed in the follow-up, all showing similar values. The numbers are related to normal values (parenthesis); the reference cohort has changed during the follow-up (< 18 and > 18 years of age). The shape of expiratory/inspiratory flow curve suggested intermittently mild periphery obstruction. Abbreviations: FVC Forced vital capacity, FEV1 Forced expiratory volume in 1 second, MEF Maximal mid-expiratory flow, TLC Total lung capacity, DLCO Diffusing lung capacity.