Evaluation of the relationship between TREM‐1/TREM‐2 ratio and clinical course in COVID‐19 pneumonia

Abstract

Objective The inflammatory/anti‐inflammatory balance has an important role in the clinical course of SARS‐CoV‐2 infection (COVID‐19), which has affected over 100 million people since it first appeared in China in December 2019. The aim of this study was to investigate the relationship between triggering receptor expressed on myeloid cells (TREM)‐1/TREM‐2 ratio and COVID‐19 severity. Methods A total of 171 individuals were included in the study: 121 patients who were admitted to the chest diseases department and intensive care unit of our hospital and diagnosed with COVID‐19 by real‐time PCR of nasopharyngeal swab samples from December 2020 to March 2021 and a control group consisting of 50 asymptomatic health workers in our hospital who had negative real‐time PCR results during routine COVID‐19 screening. Results TREM‐1 level was significantly higher in patients with severe disease compared with the moderate and control groups ( P = .003, P = .001). TREM‐2 levels did not differ significantly in moderate and severe patients ( P = .36) but were significantly higher in both patient groups compared with the control group ( P = .001 for both). TREM‐1/TREM‐2 ratio was significantly higher in the severe patient group than in the moderate and control groups ( P = .001 for both). In receiver operating characteristic curve analysis of TREM‐1/TREM‐2 ratio in patients with moderate and severe COVID‐19, the area under the curve was 0.723. Using a cut‐off value of 0.125 for TREM‐1/TREM‐2 ratio in the Youden index calculation, the sensitivity was 60% and specificity was 71%. Conclusion Experience with the positive effects of medical treatments to restore inflammatory balance in the course of COVID‐19 is steadily increasing. TREM‐1 and TREM‐2 have an important role in inflammation and may serve as biomarkers and therapeutic targets in the early treatment and follow‐up of COVID‐19.

Role of triggering receptor expressed on myeloid cells-1 (TREM-1) in COVID-19 and other viral pneumonias: a systematic review and meta-analysis of clinical studies

“…Two additional records were identified in the gray literature. After screening titles and abstracts, 54 full-text articles were assessed for eligibility, and seven (Rohde et al 2012 ; Arriaga-Pizano et al 2015 ; Zhong and Zhao 2016 ; Yaşar et al 2021 ; de Nooijer et al 2021 ; Youngs et al 2021 ; Kerget et al 2021 ) studies were finally included in this systematic review (Fig. 1 ).…”

“…The included studies were published from 2012 to 2021 and the main characteristics are listed in Table 1 . Three studies were conducted in Europe (Rohde et al 2012 ; de Nooijer et al 2021 ; Youngs et al 2021 ), two studies in Turkey (Yaşar et al 2021 ; Kerget et al 2021 ), one study in Asia (Zhong and Zhao 2016 ), and one study in Latin America (Arriaga-Pizano et al 2015 ). Only one study was conducted including the pediatric population (Zhong and Zhao 2016 ).…”

“…Four studies included patients with COVID-19 (Yaşar et al 2021 ; de Nooijer et al 2021 ; Youngs et al 2021 ; Kerget et al 2021 ) and three studies analyzed patients with different viruses (Rohde et al 2012 ; Arriaga-Pizano et al 2015 ; Zhong and Zhao 2016 ). All studies reported that viral infections were confirmed by polymerase chain reaction (PCR).…”

“…Among the infected patients, 103 were diagnosed with mild-to-moderate COVID-19 and 143 with severe COVID-19. All four studies have measured the soluble form of TREM-1 in serum (Yaşar et al 2021 ; de Nooijer et al 2021 ; Youngs et al 2021 ; Kerget et al 2021 ).…”

“…The TREM-1 consists of an innate immune system receptor expressed on innate immune cells and is present in two forms, as a membrane-bound receptor (mTREM-1) and as a soluble protein (sTREM-1) (Bouchon et al 2000 ; Kerget et al 2021 ). The mTREM-1 has three domains in its structure: one that resembles Ig responsible for binding the ligand, one transmembrane-bound, and a cytoplasmic portion that associates with the DAP12 protein (Colonna 2003 ; Tammaro et al 2017 ).…”