Diagnostic blood test for sarcoidosis

A method for detecting an individual who has sarcoidosis or whose blood indicates the presence of sarcoidosis, the method comprising the steps of:

• a. creating a background test material comprising immune cells from a first aliquot of whole blood;
• b. creating a microbial catalase-peroxidase protein stimulated test material by contacting immune cells from a second aliquot of whole blood with a first composition comprising an antigenic fragment of a microbial catalase-peroxidase protein;
• c. creating a purified protein derivative (PPD)-stimulated test material by contacting immune cells from a third aliquot of whole blood with a second composition comprising PPD, where the PPD is of a mycobacterial species;
• d. incubating the test materials;
• e. determining concentrations of interferon-gamma (INFγ) released from each of the test materials;
• and
• f. evaluating the concentrations of INFγ, defining a positive result if the concentration of INFγ in the microbial catalase-peroxidase protein-stimulated material minus the concentration of INFγ in the background test material is greater than a first threshold level, and the concentration of INFγ in the microbial catalase-peroxidase protein-stimulated test material minus the concentration of INFγ in the PPD-stimulated test material is greater than a second threshold level,
• wherein the concentration of the microbial catalase-peroxidase protein is ≥0.1 mcg/ml and the concentration of PPD is ≥0.1 mcg/ml, and
• wherein the antigenic fragment of the microbial catalase-peroxidase protein comprises:
• (i) amino acids 321-335 of SEQ ID NO:
• 2, amino acids 328-340 of SEQ ID NO:
• 2,
• (ii) SEQ ID NO:
• 3,
• (iii) SEQ ID NO:
• 4,
• (iv) SEQ ID NO:
• 5,
• (v) SEQ ID NO:
• 6,
• (vi) SEQ ID NO:
• 7,
• (vii) SEQ ID NO:
• 8, or
• (viii) a combination thereof.