PO:25:074 | Capillaroscopic assessment in interstitial lung disease: a comparative study between connective tissue disease-associated interstitial lung disease, interstitial pneumonia with autoimmune features, and idiopathic pulmonary fibrosis

Daniele Vito Andrea Sabella¹, Marco Fornaro¹, Laura Coladonato¹, Marlea Lavista¹, Veronica Spedicato¹, Giuseppe Lopalco¹, Florenzo Iannone¹. | ¹University of Bari, Rheumatology Unit Department of Precision and Regenerative Medicine - Jonica Area DiMePRe-J, Bari, Italy.

Background. Nailfold videocapillaroscopy (NVC) is a validated, non-invasive tool for evaluating microvascular ab-normalities, increasingly explored in interstitial lung diseases (ILDs) with suspected autoimmune fea-tures. However, data on capillaroscopic patterns across ILD subtypes, especially in Caucasian popu-lations, are limited. Objectives: To compare NVC findings in patients with idiopathic pulmonary fibrosis (IPF), interstitial pneumonia with autoimmune features (IPAF), and connective tissue disease-associated ILD (CTD-ILD), and to assess correlations with autoantibody status—particularly myositis-specific antibodies (MSA – Jo-1, KS, PL7/PL12, NXP-2, MDA-5).

Materials and Methods. Fifty-nine Caucasian ILD patients underwent NVC during routine evaluation. Based on multidiscipli-nary diagnosis, they were classified as IPF (n=9), IPAF (n=10), or CTD-ILD (n=40), further subdivided into systemic sclerosis (SSc, n=20) and non-SSc CTD-ILD (n=20). A validated 6-item semiquantitative scoring system (range 0–3 per item, max 18) was used; individual items are listed in Table 1. Clinical data included demographics and autoimmune serology (ANA, ENA, MSA). Statistical comparisons employed ANOVA and Student’s t-test.

Results. Total capillaroscopic scores differed significantly across diagnostic groups: CTD-ILD (6.1±3.09), IPAF (4.6±3.31), and IPF (3.4±1.74) (p=0.0042). Within CTD-ILD, SSc patients showed higher scores than non-SSc (7.4±2.87 vs 4.8±3.22; p=0.0105). A four-group comparison confirmed this trend (p=0.0042). Among individual items, only “loss of capillaries” differed significantly across groups (p<0.0001), with highest scores in SSc. Subsequently, the total capillaroscopic score was analyzed in relation to autoimmune serology: it was not significantly different between MSA+ and MSA- pati-ents (5.21±3.51 vs 5.51±3.17; p=0.7805). After excluding the 9 patients with IPF, the comparison between MSA+ and MSA- subjects still revealed no significant difference in total score (5.21±3.51 vs 5.95±3.25; p=0.5052).

Conclusions. Nailfold videocapillaroscopy reveals distinct microvascular alterations among ILD subtypes, with sig-nificantly higher scores in CTD-ILD—particularly in SSc—compared to IPAF and IPF. While no signifi-cant differences emerged in relation to MSA, the observed gradient in capillaroscopic severity across autoimmune categories underscores the potential value of NVC as a complementary tool in the early diagnostic workup of ILD, especially in identifying autoimmune-driven forms and possibly refining IPAF classification. These findings support the integration of capillaroscopy into multidiscip-linary ILD assessment, where it may assist in detecting early autoimmune features and guiding im-munological testing. Moreover, expanding the cohort in future studies may help uncover more ro-bust associations between NVC findings and specific autoantibody subsets, particularly MSA.