Nailfold capillaroscopic changes predict early Interstitial Lung Disease in Systemic Sclerosis: IDOJ study

Systemic sclerosis (SSc) is an autoimmune connective tissue disease characterized by microvascular damage and fibrosis of the skin and internal organs. Endothelial and fibroblast dysfunction with microvascular abnormality leading to tissue hypoxia and altered immune responses play key roles in the pathogenesis of SSc. Interstitial lung disease (ILD) and pulmonary artery hypertension are the two main pulmonary manifestations of SSc. Nailfold capillaroscopy (NFC) is an established method for evaluation of microvasculature abnormalities. NFC changes may appear before appearance of systemic manifestations. There is dearth of data regarding the impact of NFC in predicting ILD, as well as the association between extent of ILD and the NFC changes in SSc. Recently a study demonstrating efficacy of NFC in prediction of early ILD in SSc patients was published in the Indian Dermatology Online Journal.

Materials and Methods

It was an observational cross‑sectional study carried out in a tertiary care hospital in Eastern India over a period of 2 years. Patients above 18 years of age fulfilling the American college of Rheumatology and European League against Rheumatism (ACR‑EULAR) criteria for SSc were included in the study after informed consent. Patients with hypertension, diabetes mellitus, history of smoking, thyroid disorder, malignancy, pregnant and lactating mother, and other autoimmune connective disorders like systemic lupus erythematosus, dermatomyositis, overlap syndromes were excluded from the study. Detailed clinical history regarding age, sex, duration, age of onset, progression, family history, systemic complaints and treatment history were taken. Baseline investigations, serology pulmonary function test, and HRCT of thorax were done.

NFC was done with Dermatoscope (DermLite DL3N) placing immersion oil (Cedarwood oil) on the nailfold bed after proper washing of the fingers for better visualization of the capillaries. On NFC, few enlarged/giant capillaries with relatively well‑preserved capillary distribution, no loss of capillaries is defined as early pattern. Active pattern is described as frequent giant capillaries and capillary hemorrhages, moderate loss of capillaries, disorganization of capillary architecture, absent or mild ramified capillaries. Late pattern includes absent giant capillaries and hemorrhages, severe loss of capillaries with extensive avascular areas, disorganization of the normal capillary array, and ramified or bushy capillaries.

On HRCT, early stage of ILD consists of few ground‑glass or fibro‑reticular opacities in lower lobes with mild subpleural reticulation. Active stage ILD includes ground glass opacities with reticulonodular interstitial thickening in periphery of both lung fields and bulla. Late stage ILD comprises of extensive subpleural reticulation with ground‑glass opacities and honey combing.

Photos were taken by a single observer, later the images were stored, processed, and interpreted by two independent observers. All 10 fingernails were examined for any abnormality after making the patient sit at ambient room temperature for 15 min. Fingers affected by recent local trauma were excluded. All relevant data were recorded in a pretested, predesigned, and semi-structured schedule and later imported to Microsoft excel sheet and computed by statistical software MedCalc version 20.

Results

A total 43 patients were selected, out of which 74.4% (n = 32) were female. Mean age was 35.05 ± 7.24 years, and mean duration was 4.28 ± 2.81 years. Diffuse and limited cutaneous SSc was found in 88.37% (n = 38) and 11.63% (n = 5) cases, respectively. On NFC, early patterns were found in 30.2% (n = 13), active patterns were seen in 25.6% (n = 11) and late patterns were observed in 44.2% (n = 19) of patients respectively. On HRCT, early ILD was found in 18.6% (n = 8), active ILD in 37.2% (n = 16) and late ILD in 30.2% (n = 13) patients respectively. ILD changes were absent in 14% (n = 6) though NFC changes were present in them.

Respiratory symptoms were absent in 20.93% (n = 9) patients, though all had features of early NFC changes and among them 9.3% (n = 4) showed early ILD changes on HRCT. It was noticed that there is significant association between NFC changes and ILD severity (P = 0.0003). Significant associations were also found between NFC changes and respiratory symptoms and between ILD changes with respiratory symptoms.

To conclude NFC is an inexpensive simple procedure to detect development of early ILD even before appearance of respiratory symptoms. It might provide a window of opportunity for initiation and escalation of treatment in SSc individuals. It can be used as a basic screening tool for the assessment of disease severity in the patients of SSc.

Source- Rudra O, Baisya S, Mallick S, Chatterjee G. Nailfold capillaroscopic changes as a marker of interstitial lung disease in systemic sclerosis: A cross-sectional study in a tertiary care hospital in Eastern India. Indian Dermatol Online J 2022;13:216-20.