{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T13:34:06Z","timestamp":1774964046748,"version":"3.50.1"},"reference-count":21,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,1,15]],"date-time":"2026-01-15T00:00:00Z","timestamp":1768435200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Background: Sarcoidosis is a multisystem inflammatory disorder characterized by non-caseating granulomas, most commonly affecting the lungs and intrathoracic lymph nodes. Angiotensin-converting enzyme (ACE) levels and calcium abnormalities are recognized biomarkers, while ^18F-fluorodeoxyglucose positron emission tomography\/computed tomography (FDG-PET\/CT) is increasingly used to assess disease activity. However, neither provides sufficient diagnostic accuracy alone. Therefore, this study aimed to investigate the relationship between FDG-PET\/CT metabolic findings and serum ACE and calcium (Ca2+) levels as surrogate indicators of inflammatory metabolic intensity in sarcoidosis. Methods: In this retrospective single-center study, 127 patients with pulmonary sarcoidosis who underwent PET\/CT at diagnosis were evaluated. Demographic and clinical data, ACE, and Ca2+ levels were recorded. FDG uptake in mediastinal, pulmonary, and extrapulmonary sites was analyzed, and correlations with biomarkers were assessed. Results: The cohort included 89 females (70.1%) and 38 males (29.9%), mean age 51.3 \u00b1 11.9 years. FDG uptake was most frequent in mediastinal lymph nodes (84.3%) and lung parenchyma (40.9%). ACE levels correlated weakly with total SUVmax (r = 0.214, p = 0.019). Calcium levels correlated with extrapulmonary SUVmax (r = 0.327, p = 0.001) and were higher in patients with extrapulmonary involvement (p = 0.045). No associations were found between symptom presence and biomarkers or SUVmax values. Conclusions: FDG-PET\/CT metabolic parameters, particularly total and extrapulmonary SUVmax, demonstrated modest yet statistically significant associations with ACE and calcium levels. These findings suggest that a combined biomarker-imaging approach may provide complementary information regarding inflammatory metabolic intensity and systemic involvement; however, the results should be interpreted as exploratory and require validation in prospective studies.<\/jats:p>","DOI":"10.3390\/diagnostics16020278","type":"journal-article","created":{"date-parts":[[2026,1,15]],"date-time":"2026-01-15T12:31:41Z","timestamp":1768480301000},"page":"278","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Association Between PET\/CT Metabolic Parameters and Serum ACE and Calcium Levels in Sarcoidosis"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1430-1571","authenticated-orcid":false,"given":"Ya\u015far","family":"Incekara","sequence":"first","affiliation":[{"name":"Department of Chest Diseases, Faculty of Medicine, Karamano\u011flu Mehmetbey University, 70100 Karaman, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0891-0020","authenticated-orcid":false,"given":"Erdo\u011fan","family":"Cetinkaya","sequence":"additional","affiliation":[{"name":"Department of Chest Diseases, Yedikule Chest Diseases and Thoracic Surgery Training and Research Hospital, University of Health Sciences, 34025 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5670-7748","authenticated-orcid":false,"given":"Ramazan","family":"Eren","sequence":"additional","affiliation":[{"name":"Department of Chest Diseases, Yedikule Chest Diseases and Thoracic Surgery Training and Research Hospital, University of Health Sciences, 34025 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9373-8693","authenticated-orcid":false,"given":"Re\u015fit","family":"Akyel","sequence":"additional","affiliation":[{"name":"Department of Nuclear Medicine, Yedikule Chest Diseases and Thoracic Surgery Training and Research Hospital, 34025 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6923-736X","authenticated-orcid":false,"given":"Mustafa","family":"Cortuk","sequence":"additional","affiliation":[{"name":"Department of Chest Diseases, Yedikule Chest Diseases and Thoracic Surgery Training and Research Hospital, University of Health Sciences, 34025 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"668","DOI":"10.1111\/joim.13629","article-title":"Sarcoidosis: Epidemiology and clinical insights","volume":"293","author":"Rossides","year":"2023","journal-title":"J. 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