INCREASE OF LUNG TRANSFER-FACTOR IN EARLY SARCOIDOSIS

Dynamic spirometry and the lung transfer factor for CO (TLCO) were det ermined in 41 non-smoking patients with sarcoidosis before and after s teroid treatment. Dynamic spirometry revealed usual stage-dependent re strictive and/or obstructive abnormalities; only maximal expiratory fl ow rate at 75% FVC (MEF(75)) was significantly increased after steroid treatment in stage 2 patients. The new finding is that TLCO was incre ased in stage 1 [on average 21% above the predicted values (p.v.)], bu t it was decreased in stage 2 (11% below p.v.) and stage 3 (27% below p.v.). The increase in TLCO in stage 1 was predominantly caused by an increase in TLCO membrane component (Dm) (33% above p.v.), while the p ulmonary capillary blood volume (Vc') increased less (19% above p.v.). Steroid treatment significantly reduced TLCO, Dm and Vc' in stage 1 ( for 14, 17 and 18% of the respective baseline values), whereas it caus ed TLCO and Dm increases in stage 2 (for 8 and 10% of the respective b aseline values). In conclusion, a TLCO in pulmonary sarcoidosis may no t only be decreased in its advanced stages, but also exhibit increased values, which appeared related to the subclinical inflammatory reacti on in the stage 1 patients.