Background: Videocapillaroscopy (VC) has become a widely used tool due to its low cost, accessibility and no invasive nature. PANLAR study group proposes a semi-quantitative method to inform it, which includes four grades to categorize capillary density (methods). Previous studies found that capillary density is associated with microvascular damage, predicts disease progression and organ affection in systemic sclerosis (SSc) and can be useful as a follow-up tool (1-5).

Objectives: Describe the associations between the different patterns and grades of capillary density loss and the SSc diagnosis.

Methods: A cross sectional study was designed using clinical records, including outpatients attending to a VC consult between the March and October 2021. Descriptive data regarding patients demographics, presence of rheumatologic diagnosis and treatment was registered. The VC was performed by an experienced rheumatologist (RTR) (DinoLite), with a 200x amplification. Capillary density loss (CDL) was scored based on PANLAR recommendations: Grade 0 (no loss), Grade I (7-9 capillaries / lineal mm), Grade II (4-6 capillaries / lineal mm), Grade III (< 4 capillaries / lineal mm).

Descriptive statistics were performed and data was compared using Student´s T test, Mann-Whitney, Chi2 or exact Fisher´s test depending on the type of data and its distribution. A p value < 0.05 was considered as significative.

Results: One hundred and one patients were included, 91 (91%) female, mean age 43 years (SD 13.9), 72 (71,3%) had raynaud phenomenon (RP), with a mean evolution of 1 year (IQR 0.5-3.5). Rheumatologic diagnosis was: 19 rheumatoid arthritis (RA), 16 SSc, 11 systemic lupus erythematosus (SLE) and 27 no diagnosis, including 2 with digital necrosis and one with endocarditis suspicion. VC was normal in 40 (39.6%) patients, 34 (33.7% had non-specific findings, and 26 (26%) SD pattern. In the latter, the pattern was 2 were early pattern, 11 active and 13 late.

SD pattern was associated with SSc diagnosis, and the use RP medication (both p<0,001). Three patients with inflammatory idiopathic myopathy (IIM), 2 SLE, 2 primary sjögren syndrome (pSS) and 2 without diagnosis had also this pattern. LCD was found in 27% of the patients, and Grade III was associated with SSc diagnosis being 14 times more frequent compared with non-SSc. [ Table 1 ]

Conclusion: CDL was present in almost 1/3 of non selected patients attending to a VC study, and was strongly associated with SSc diagnosis. Future studies including this outcome can bring new data regarding microvascular damage and its implications.

REFERENCES:

[1]Emrani Z, Karbalaie A, Fatemi A, Etehadtavakol M, Erlandsson B-E. Capillary density: An important parameter in nailfold capillaroscopy. Microvasc Res. 2017 Jan;109:7–18.

[2]Gheorghiu AM, Oneata R, Ancuta I, Enuica A, Linte O, Macovei L, et al. Capillary loss reflects disease activity and prognosis in patients with systemic sclerosis. Exp Ther Med. 2020 Oct;20(4):3438–43.

[3]Hofstee HMA, Vonk Noordegraaf A, Voskuyl AE, Dijkmans BAC, Postmus PE, Smulders YM, et al. Nailfold capillary density is associated with the presence and severity of pulmonary arterial hypertension in systemic sclerosis. Ann Rheum Dis. 2009 Feb;68(2):191–5.

[4]Hudson M, Masetto A, Steele R, Arthurs E, Baron M. Reliability of widefield capillary microscopy to measure nailfold capillary density in systemic sclerosis. Clin Exp Rheumatol. 2010 Oct;28(5 Suppl 62):S36-41.

[5]Wildt M, Wuttge DM, Hesselstrand R, Scheja A. Assessment of capillary density in systemic sclerosis with three different capillaroscopic methods. Clin Exp Rheumatol. 2012 Apr;30(2 Suppl 71):S50-54.

Disclosure of Interests: None declared