Initial Evaluation and Risk Stratification in Systemic Sclerosis

Serological Testing

ANA by indirect immunofluorescence is positive in 90–95 % of systemic sclerosis (SSc) patients and is recommended as the first‑line screening test by the EULAR and ACR classification criteria 1
Anti‑topoisomerase I (anti‑Scl‑70) antibodies are present in ~26 % of SSc patients and strongly predict diffuse cutaneous disease, interstitial lung disease, digital ulcers, and a poorer prognosis 2
Anti‑RNA polymerase III antibodies identify patients at risk for diffuse disease, rapid skin progression, scleroderma renal crisis, and a markedly increased malignancy risk [1][2]
When clinical features suggest overlap syndromes, testing for anti‑U1RNP, anti‑U3RNP (fibrillarin), anti‑Th/To, anti‑PM/Scl, and anti‑Ku is advised [1][2]
Anti‑SSA/Ro and anti‑SSB/La antibodies should be ordered if Sjögren’s syndrome overlap is suspected 1

Complete blood count should be obtained to monitor for cytopenias, particularly before initiating immunosuppressive therapy 2
Comprehensive metabolic panel (glucose, electrolytes, renal and hepatic function) is recommended at baseline 2
C‑reactive protein and erythrocyte sedimentation rate are useful inflammatory markers for assessing disease activity 1
Rheumatoid factor is positive in ~3 % of SSc patients, indicating possible overlap with rheumatoid arthritis [3][1]
Alkaline phosphatase screening helps detect primary biliary cholangitis, which occurs in ~8 % of limited cutaneous SSc, especially in anti‑centromere‑positive individuals [3][1]

Baseline pulmonary function tests (spirometry + DLCO) are mandatory because interstitial lung disease (ILD) affects 40–75 % of SSc patients and progresses in 15–18 % 4
High‑resolution chest CT is essential for ILD detection, particularly in high‑risk patients (anti‑Scl‑70‑positive or diffuse cutaneous disease) 4
Patients with anti‑Scl‑70 antibodies, diffuse cutaneous disease, or abnormal baseline PFTs should receive an immediate HRCT 4
If ILD is present or disease is early, repeat PFTs every 3–6 months 2
Annual HRCT is advised for the first 3–4 years in patients with SSc phenotypes or risk factors for ILD 4

Resting electrocardiogram is recommended to screen for arrhythmias 3
Transthoracic echocardiography should be performed to assess for pulmonary arterial hypertension, especially in patients with longer disease duration, older age, or reduced DLCO 3
NT‑proBNP measurement is indicated when arrhythmias or heart‑failure symptoms are present [1][2]
A 6‑minute walk test provides functional capacity data and helps risk‑stratify for pulmonary arterial hypertension 1

Urinalysis for proteinuria is required at baseline and annually; intensified monitoring is needed for anti‑RNA polymerase III‑positive patients due to high scleroderma renal crisis risk [1][2]
Home blood‑pressure monitoring should be instituted early in patients with diffuse cutaneous disease 1

Nailfold capillaroscopy with magnification is performed in all suspected SSc patients; it is incorporated into the 2013 EULAR/ACR classification criteria and detects early microvascular changes 1

Age‑appropriate cancer screening should be completed within three years of SSc diagnosis for anti‑RNA polymerase III‑positive patients, given their substantially increased malignancy risk [3][2]

Routine depression screening is advised because prevalence is elevated in SSc 3
Bone‑density assessment is recommended due to an increased risk of osteoporosis 3
Nutritional assessment should be performed in patients with severe gastrointestinal involvement, as malnutrition is the leading cause of GI‑related mortality 3

Anti‑Scl‑70 positivity mandates aggressive pulmonary monitoring (PFTs every 3–6 months and annual HRCT for 3–4 years) and surveillance for digital ulcers 4
Anti‑centromere positivity warrants focused monitoring for pulmonary arterial hypertension over longer disease duration and screening for primary biliary cholangitis 3
Anti‑RNA polymerase III positivity requires intensive renal monitoring (home BP checks), dedicated malignancy surveillance, and anticipation of rapid skin progression 3

Up to 40 % of patients with idiopathic pulmonary arterial hypertension have a positive ANA; therefore, ANA positivity alone is not diagnostic for SSc and must be interpreted in clinical context 1