Chronic cutaneous circumscritic scleroderma.
1st order laboratory parameters – obligatory laboratory tests.
- Autoantibodies: antinuclear antibodies (ANA), direct immunofluorescence (DIF).
Systemic scleroderma
Laboratory parameters 1st order – obligatory laboratory tests.
- Autoantibodies: ANA (antinuclear antibodies); subsets of scleroderma:
- Anti-Scl-70 antibody (anti-Scl70-AK (= anti-topoisomerase-I-AK); typical for the diffuse cutaneous form (dSSc)); specific, but positive in only about 15-30%.
- AK against extractable antigens (ENA).
- Anti-centromere antibodies (anti-centromere AK; typical of the limited-sediment cutaneous form (lSSc) as well as CREST syndrome) (frequency: 20-30%).
- Anti-RNA polymerase III AK (typical of diffuse cutaneous scleroderma) (frequency: 1-10%).
- Inflammatory parameters – CRP (C-reactive protein) or ESR (erythrocyte sedimentation rate).
- Urine status (rapid test for: pH, leukocytes, nitrite, protein, glucose, ketone, urobilinogen, bilirubin, blood), sediment, if necessary urine culture (pathogen detection and resistogram, that is, testing suitable antibiotics for sensitivity / resistance).
- Protein in 24h urine
- Renal parameters – urea, creatinine, cystatin C or creatinine clearance, if applicable.
- CK (creatine kinase)
- NT-proBNP (N-terminal pro brain natriuretic peptide) – for suspected pulmonary arterial hypertension (PAH; pulmonary hypertension).
Laboratory parameters 2nd order – depending on the results of the history, physical examination, etc. – for differential diagnostic clarification.
- Liver parameters – alanine aminotransferase (ALT, GPT), aspartate aminotransferase (AST, GOT), albumin in serum [liver cirrhosis: albumin ↓, as a sign of liver synthesis disorder], glutamate dehydrogenase (GLDH) and gamma-glutamyl transferase (gamma-GT, GGT), alkaline phosphatase, bilirubin – if cholestasis (biliary congestion) or itching is suspected.
- Biopsy (tissue sampling) – in case of organ involvement.
- Rheumatoid factor, anti-CCP-AK – in arthralgias (joint pain) joint swelling.
- Myositis-AK, creatine kinase – in myalgias (muscle pain), muscle weakness.