Sarcoidosis: Test and Diagnosis

1st order laboratory parameters – obligatory laboratory tests.

  • Small blood count
  • Differential blood count
  • Inflammatory parameters – CRP (C-reactive protein) or ESR (erythrocyte sedimentation rate) [ESR: ↑ in acute course].
  • Serum calcium
  • Calcium in urine
  • Gamma globulins (IgG) [IgG ↑ in about 50% of cases].
  • Immunoglobulin G (IgG)
  • Activity parameters such as:
    • S-IL-2R (interleukin-2 receptor) [S-IL-2R ↑ in: approximately 80% of 70% of sarcoidosis cases].
    • ACE (angiotensin converting enzyme) [ACE ↑ in:
      • 60% of sarcoidosis diseases.
      • Exogenous allergic alveolitis (14%)
      • Silicosis (30%)
    • Neopterin (release by macrophages) [neopterin ↑ in:about 70% of sarcoidosis cases].
  • Liver parameters – alanine aminotransferase (ALT, GPT), aspartate aminotransferase (AST, GOT), gamma-glutamyl transferase (γ-GT, gamma-GT; GGT) – in liver involvement [increased cholestasis parameters].
  • Bronchoscopy (bronchoscopy) with bronchoalveolar lavage [BAL/method for obtaining samples used in bronchoscopy (bronchoscopy); high CD4:CD8 ratio, see below] and biopsies (tissue samples) for histological examination of the bronchial mucosa [granulomas]; if necessary, biopsies from other organs [histology is considered the gold standard; should be sought in unclear cases]
  • CSF analysis (examination of cerebrospinal fluid) incl. bacteriology and cytology (to exclude infectious or neoplastic differential diagnoses) – in case of suspected neurosarcoidosis

Laboratory parameters 2nd order – depending on the results of the history, physical examination and the obligatory laboratory parameters – for differential diagnostic clarification.

  • Tuberculin skin test
  • TB diagnostics
  • ACE
  • CD4/CD8 ratio (numerical ratio of lymphocyte subpopulations CD4 and CD8 at; = quotient of T helper to cytotoxic T cells) [CD4/CD8 quotient ↑ in: sarcoidosis, collagenoses, Crohn’s disease].
  • Beryllium-specific T lymphocytes – in suspected berylliosis.
  • CSF puncture (collection of cerebrospinal fluid by puncture of the spinal canal) for CSF diagnosis – if involvement of the central nervous system is suspected.