Investigations
1st investigations to order
serum auto-antibodies
Test
Should always be done in people with suspected scleroderma.
Important in differentiating subsets of disease, which also has prognostic value.
Some will have a centromere pattern: this is associated with limited disease.
Anti-Scl 70 or anti-topoisomerase I should also be checked; more commonly associated with diffuse disease and interstitial respiratory disease, respectively.
Anti-RNA polymerase 3 antibody testing is now commercially available. Its presence is associated with risk for early renal crisis and rapidly progressive skin disease.
Patients with inflammatory myositis may have anti-PM/Scl and anti-Sm/RNP antibodies.
Result
positive ANA in more than 90% of patients
FBC
Test
Diagnosis of chronic gastrointestinal (GI) blood loss from gastric antral vascular ectasia is made by typical appearance on upper GI endoscopy, chronic microcytic anaemia, or haem-positive stools.
Scleroderma renal crisis is characterised by the onset of acute renal failure; abrupt onset of moderate/marked hypertension; a urinary sediment that is frequently normal, or reveals only mild proteinuria with few cells or casts; and a micro-angiopathic haemolytic anaemia.
Result
may be normal; microcytic anaemia with chronic GI bleed; micro-angiopathic haemolytic anaemia with scleroderma renal crisis
urea and serum creatinine
Test
The onset of acute renal failure is a feature of scleroderma renal crisis.
Result
usually normal; elevated serum urea and creatinine with scleroderma renal crisis
ESR
Test
A non-specific indicator of inflammation.
A high ESR, thought to be related to scleroderma, is a poor prognostic factor.[23]
Result
usually normal, occasionally elevated
CRP
Test
A non-specific indicator of inflammation.
Result
occasionally elevated, particularly in severe disease
urine microscopy
Test
Urinary sediment is frequently normal.
Result
normal; mild proteinuria with few cells or casts occurs with scleroderma renal crisis
complete pulmonary function tests (spirometry, lung volumes, and diffusing capacity measurement)
Test
Important to evaluate for restrictive lung disease and for pulmonary hypertension.[17]
Should be done at onset and on a yearly basis.
If symptoms are progressing, should be done more frequently.
Referral to pulmonologist and/or rheumatologist should be made if the results are abnormal.
Result
interstitial lung disease (ILD): a decrease in forced vital capacity (FVC) and diffusing capacity of the lung for carbon monoxide (DLCO) plus an overall restrictive pattern; pulmonary hypertension: a disproportionate drop in DLCO compared with FVC
ECG
Test
Complaints of dyspnoea, dry cough, or decreased exercise tolerance should prompt further evaluation for pulmonary or cardiac involvement including an ECG.
Result
normal; may demonstrate cardiac involvement such as arrhythmias
echocardiogram
Test
Should be done at onset and on a yearly basis.
If symptoms are progressing, should be done more frequently.
An echocardiogram can estimate right ventricular systolic pressure (RVSP) based on the tricuspid/pulmonic regurgitation jet (TR/PR jet).
Pleural effusions are generally small without haemodynamic compromise, but are a marker of a poor prognosis.
Right ventricle (RV) or left ventricle (LV) diastolic dysfunction can be seen with cardiomyopathy of scleroderma, also a marker of poor prognosis.[24]
Referral for a right heart catheterisation and full evaluation should be done if RVSP is raised, as echocardiogram findings may not be indicative of true pulmonary artery pressures.
Result
pulmonary hypertension: a rise in RVSP; pericardial effusion, or RV or LV diastolic dysfunction, may be present
high-resolution CT scan of chest
Test
Important to evaluate ILD.[17]
Result
normal or evidence of ILD demonstrated by ground glass opacities, thickened interstitium (interstitial fibrosis); also traction bronchiectasis and honeycombing
barium swallow
Test
Can be helpful as an initial investigation to look for features consistent with scleroderma, including dysmotility and reflux.
Should also be done if symptoms of heartburn worsen or do not improve with appropriate therapy.
Result
diminished oesophageal peristalsis and gastroparesis; diminished muscle tone in the lower oesophagus, with reflux of barium; strictures
Investigations to consider
chest x-ray
Test
May be requested to investigate respiratory or cardiac symptoms (e.g., dyspnoea, dry cough, or decreased exercise tolerance)
Result
normal; evidence of ILD demonstrated by bibasilar interstitial infiltrates; cardiomegaly or signs of right heart failure may be present
upper gastrointestinal endoscopy ± biopsy
Test
Unexplained microcytic anaemia should be further investigated by upper endoscopy to exclude gastric antral vascular ectasia (GAVE).
Also indicated with new onset of dysphagia, to evaluate for stricture.
Needs to be performed with care due to possibility of oesophageal stricture.
Result
GAVE may be present; oesophageal inflammation, ulceration, strictures, Barrett's metaplasia, and adenocarcinoma may be present
serum muscle enzymes
Test
Elevated muscle enzymes may be observed, relatively commonly, without weakness in scleroderma patients. This is known as scleroderma myopathy.
If elevated, thyroid studies should also be checked to evaluate for an underlying myopathy from hypothyroidism.
Inflammatory myositis may be seen in a subset of scleroderma patients and is differentiated from scleroderma myopathy based on the presence of weakness (usually in the proximal muscles) and EMG/nerve conduction study and muscle biopsy findings.
Result
elevated in scleroderma myopathy
electromyogram/nerve conduction studies
Test
Indicated if weakness is present in the setting of elevated muscle enzymes and if the diagnosis of an inflammatory myositis is in question.
The identification of an inflammatory myositis is important as it requires treatment with immunosuppression.
Result
inflammatory myositis: abnormal with inflammatory features
muscle biopsy
Test
Indicated if weakness is present in the setting of elevated muscle enzymes and if the diagnosis of an inflammatory myositis is in question.
The identification of an inflammatory myositis is important as it requires treatment with immunosuppression.
Result
inflammatory myositis: abnormal with inflammatory features
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