Decreased diffusion capacity on lung function testing in asymptomatic patients with systemic lupus erythematosus does...

Area of Science:

• Rheumatology
• Pulmonology
• Clinical Medicine

Background:

• Previous study identified low diffusion capacity (DLCO) in 37.8% of asymptomatic patients with SLE and/or APS.
• These patients had no respiratory symptoms despite DLCO values ranging from 45% to 70%.

Purpose of the Study:

• To determine the clinical significance and predictive value of a low DLCO in asymptomatic SLE or APS patients.
• To assess if low DLCO predicts the development of future lung disease in this cohort.

Main Methods:

• 15 asymptomatic patients with prior low DLCO (SLE with APS, SLE without APS, primary APS) were reevaluated.
• Methods included medical history, physical exam, nail bed capillaroscopy, lab tests, and full lung function tests (including DLCO).

Main Results:

• No patients developed lung disease during a 9 ± 3.6-year follow-up.
• DLCO/VA significantly improved from 60.4% ± 7.0 to 76.1% ± 11.2 (p < 0.0001).
• Other lung function tests (TLC, FEV1) and capillaroscopy remained normal.

Conclusions:

• Low DLCO in asymptomatic SLE/APS patients lacks positive predictive value for future lung disease.
• Findings suggest low DLCO in this group may not require further investigation and can improve spontaneously.
• Larger studies are recommended to confirm these findings.