TOPLINE:

Among patients with a very early diagnosis of systemic sclerosis (VEDOSS), a baseline diffusing capacity of the lungs for carbon monoxide by single breath (DLCO/SB) below 70% was associated with a higher rate of progression to definite systemic sclerosis (SSc) and a shorter time to progression.

METHODOLOGY:

• Researchers conducted a retrospective longitudinal study to examine whether baseline pulmonary function test (PFT) parameters predict progression to definite SSc in patients with VEDOSS.
• They included 73 patients (mean age, 57.6 years; 91.8% women) with VEDOSS, without imaging evidence of interstitial lung disease or other systemic autoimmune rheumatic diseases, each having at least one PFT performed at the study center.
• Data on the presence of SSc-specific antibodies, nailfold videocapillaroscopy patterns, and the presence of puffy fingers were collected at baseline. PFT parameters, including forced vital capacity (FVC), forced expiratory volume in one second, total lung capacity (TLC), and DLCO/SB, were assessed annually during the follow-up.
• The primary outcome was progression to definite SSc on the basis of the 2013 American College of Rheumatology/European Alliance of Associations for Rheumatology criteria; patients with reduced vs preserved pulmonary function were compared, using a cutoff of 70% for DLCO/SB%, FVC%, and TLC%.
• The secondary outcome was a decline in pulmonary function (a reduction of 10% or more in FVC or 15% or more in the DLCO/SB from baseline) among patients who had not transitioned to definite SSc.

TAKEAWAY:

• Over a median follow-up duration of 5 years, 9 (12%) patients with VEDOSS progressed to definite SSc; all progressors were positive for SSc-specific antibodies and had lower baseline DLCO/SB% predicted than those who remained stable (68.2% vs 81.2%; P = .004).
• Patients with a baseline DLCO/SB below 70% had higher rates of progression to definite SSc than those with values of 70% or above (33.3% vs 8.2%; P = .015) and had earlier progression, with a median time to transition of 7.7 vs 10.2 years.
• Among patients with stable VEDOSS, those who were positive for SSc-specific antibodies had shorter median times to DLCO/SB% decline than those who were negative for antibodies (8 vs 10.4 years).

IN PRACTICE:

“The [study] findings underscore the importance of integrating PFT into the routine evaluation and longitudinal monitoring of patients with VEDOSS. Even in the absence of overt ILD [interstitial lung disease] or definite SSc, early PFT abnormalities, particularly reduced DLCO/SB, may identify individuals at increased risk for progression and could warrant closer follow-up and prompt imaging monitoring or even consideration of early therapeutic intervention,” the authors wrote.

SOURCE:

This study was led by Eugenio Capparelli, MD, Rheumatology Unit, Azienda Socio Sanitaria Territoriale OVEST Milanese, Legnano Hospital, Milan, Italy. It was published online on March 30, 2026, in ACR Open Rheumatology.

LIMITATIONS:

The retrospective and single-center study design may have limited the generalizability of the findings. Not all patients underwent high-resolution chest CT scans.

DISCLOSURES:

The study did not receive any specific funding. One author reported funding support from the Italian Ministry of Health “Ricerca Corrente.”

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.