PO117 - A Single Disease, Multiple Patterns: The Spectrum of Pulmonary Function Tests in Sarcoidosis
Züleyha Bingöl (Turkey)1; Gökhan Altan (Turkey)1; Sama Hasanova (Turkey)1; Esen Kıyan (Turkey)1; Gülfer Okumuş (Turkey)1;
1 - Istanbul University, Istanbul Faculty of Medicine, Department of Chest Diseases, Istanbul, Türkiye;
Keywords: Obstructive pattern; Pulmonary Function Tests; Sarcoidosis;
Select the theme: Challenges in Sarcoidosis Diagnosis and Staging
Type: Original Papers
Presentation: Poster Presentation

Introduction: Although sarcoidosis is commonly regarded as a restrictive disease, obstructive patterns may also be observed in pulmonary function tests (PFTs) due to variable involvement of both large and small airways. 

Objectives: This study aimed to determine the frequency of obstructive patterns in sarcoidosis.

Materials and Methods: Demographic characteristics, exposure history, comorbidities, spirometric measurements, carbon monoxide diffusing capacity (DLCO), and radiological stages at the time of diagnosis were retrospectively evaluated.

Results: A total of 112 patients (female/male: 79/33; mean age: 52.2±11.9 years; mean follow-up duration: 115.7±79.2 months) were included. Among them, 24.1% (n=27) were current smokers and 25% (n=28) were former smokers. The most common comorbidities were hypertension (31.3%, n=35), diabetes mellitus (25%, n=28), and connective tissue diseases (11.6%, n=13).

Radiologically, 1.8% (n=2) were classified as stage 0, 52.7% (n=59) as stage 1, 25% (n=28) as stage 2, 11.6% (n=13) as stage 3, and 8.9% (n=10) as stage 4. Five patients (4.5%) were unable to perform PFTs adequately.

Among the remaining patients (n=107), mean forced vital capacity (FVC) was 96.8±18.7% of predicted [3.12±1.02 L], and forced expiratory volume in 1 second (FEV₁) was 93.1±20.1% of predicted (2.51±0.88 L). The mean FEV₁/FVC ratio was 79.7±7.3, forced expiratory flow between 25–75% of FVC (FEF₂₅–₇₅) was 75.9±29.2, forced expiratory flow at 50% of FVC (FEF₅₀) was 78.8±30.9, and DLCO was 78.7±16.7% of predicted.

Overall, 61 patients (57%) had FEV₁/FVC ≥80, whereas 46 (43%) had <80, 24 (22.4%) had <75, and 8 (7.5%) had <70. Among patients with FEV₁/FVC ≥80, reduced small airway flows were observed: 19 patients (31.1%) had FEF₂₅–₇₅ and FEF₅₀ <80, and 2 patients (3.2%) had FEF₂₅–₇₅ and FEF₅₀ <60.


Conclusions: Sarcoidosis is a heterogeneous interstitial lung disease that may lead to restrictive, obstructive, or mixed ventilatory patterns on PFTs depending on the localization, extent, and stage of disease involvement.