title: Somatostatin receptor scintigraphy in sarcoidosis: relation to selected clinical and laboratory markers.
abstract: BACKGROUND
  Discriminating between active and inactive sarcoidosis may be problematic in everyday clinical practice. There are numerous biochemical markers used in the diagnosis and monitoring of sarcoidosis. Somatostatin receptor (SR) scintigraphy with the use of 99mTc-octreotide may be used to estimate disease activity.
  
  
  OBJECTIVE
  The aim of the paper was to assess the value of traditional biomarkers (serum angiotensin-converting enzyme [SACE], C-reactive protein, markers of calcium metabolism, bronchoalveolar lavage fluid [BALF] lymphocytes) and a novel biomarker, 8-isoprostane (8-IP) in exhaled breath condensate (EBC), in the assessment of sarcoidosis activity in relation to somatostatin receptor scintigraphy.
  
  
  METHODS
  The study included 32 patients with sarcoidosis. Scintigraphy was performed using somatostatin analogue, 99mTc-HYNIC-TOC; planar and SPECT/CT images were recorded. The study group was divided into a subgroup with positive radiotracer uptake (n = 20) and without a visible uptake (n = 12). 8-IP levels were measured in EBC by an immunoenzymatic assay. RESULTS We observed a significantly higher EBC 8-IP levels in the subgroup with positive uptake compared with those with negative uptake (19.1 ± 19.8 vs. 5.4 ± 3.5 pg/ml, P = 0.02). The levels of SACE and the percentage of BALF lymphocytes were also nonsignificantly elevated. In the group of patients with positive scintigraphy results, a positive correlation was observed between the uptake ratio and SACE (r = 0.44, P = 0.041).
  
  
  CONCLUSIONS
  The results indicate low value of biochemical markers in the assessment of disease activity. SR scintigraphy may have practical usefulness in the monitoring of sarcoidosis.
authors.affiliation: Division of Pneumology and Allergy, Department of Internal Medicine, Medical University of Lodz, Łódź, Poland. wojciech.piotrowski@umed.lodz.pl
authors.forename: Wojciech J
authors.initials: WJ
authors.lastname: Piotrowski
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Bieńkiewicz
authors.forename: Izabella
authors.initials: I
authors.lastname: Frieske
authors.forename: Jerzy
authors.initials: J
authors.lastname: Marczak
authors.forename: Adam
authors.initials: A
authors.lastname: Antczak
authors.forename: Paweł
authors.initials: P
authors.lastname: Górski
authors.forename: Jacek
authors.initials: J
authors.lastname: Kuśmierek
authors.forename: Anna
authors.initials: A
authors.lastname: Płachcińska
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis* / Q000097:blood; D001944:Breath Tests; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D002097:C-Reactive Protein / Q000378:metabolism; D015237:Dinoprost / Q000031:analogs & derivatives / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000097:blood; D011877:Radionuclide Imaging; D017481:Receptors, Somatostatin / Q000097:blood*; D012507:Sarcoidosis / Q000097:blood* / Q000000981:diagnostic imaging*
chemical_list: D015415:Biomarkers; D017481:Receptors, Somatostatin; C075750:8-epi-prostaglandin F2alpha; D002097:C-Reactive Protein; D015237:Dinoprost; D007703:Peptidyl-Dipeptidase A