Publications by authors named "Daniel M de Jong"

2 Publications

  • Page 1 of 1

Toward Reliable Uptake Metrics in Large Vessel Vasculitis Studies.

Diagnostics (Basel) 2021 Oct 26;11(11). Epub 2021 Oct 26.

Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands.

The aim of this study is to investigate the influence of sex, age, fat mass, fasting blood glucose level (FBGL), and estimated glomerular filtration rate (eGFR) on blood pool activity in patients with large vessel vasculitis (LVV). Blood pool activity was measured in the superior caval vein using mean, maximum, and peak standardized uptake values corrected for body weight (SUVs) and lean body mass (SULs) in 41 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scans of LVV patients. Sex influence on the blood pool activity was assessed with t-tests, while linear correlation analyses were used for age, fat mass, FBGL, and eGFR. Significantly higher SUVs were found in women compared with men, whereas SULs were similar between sexes. In addition, higher fat mass was associated with increased SUVs (r = 0.56 to 0.65; all < 0.001) in the blood pool, but no correlations were found between SULs and fat mass (r = -0.25 to -0.15; all > 0.05). Lower eGFR was associated with a higher FDG blood pool activity for all uptake values. In FDG-PET/CT studies with LVV patients, we recommend using SUL over SUV, while caution is advised in interpreting SUV and SUL measures when patients have impaired kidney function.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
October 2021

Plasma Pyruvate Kinase M2 as a marker of vascular inflammation in Giant Cell Arteritis.

Rheumatology (Oxford) 2021 Nov 3. Epub 2021 Nov 3.

Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.

Objectives: Giant Cell Arteritis (GCA) is a large vessel vasculitis in which metabolically active immune cells play an important role. GCA diagnosis is based on CRP/ESR and temporal artery biopsies (TABs), in combination with [18F]FDG-PET/CT relying on enhanced glucose uptake by glycolytic macrophages. Here, we studied circulating Pyruvate Kinase M2 (PKM2), a glycolytic enzyme, as a possible systemic marker of vessel wall inflammation in GCA.

Methods: Immunohistochemical detection of PKM2 was performed on inflamed (n = 12) and non-inflamed (n = 4) TABs from GCA patients and non-GCA (n = 9) patients. Dimeric PKM2 levels were assessed in plasma of GCA patients (n = 44), age-matched healthy controls (HC, n = 41), metastatic melanoma patients (n = 7) and infection controls (n = 11). CRP, ESR and macrophage markers calprotectin and YKL-40 were correlated with plasma PKM2 levels. To detect the cellular source of plasma PKM2 in tissue, double immunofluorescence staining was performed on inflamed GCA TABs. [18F]FDG-PET scans of 23 GCA patients were analyzed and maximum standard uptake values (SUVmax) and target to background ratios (TBR) were calculated.

Results: PKM2 is abundantly expressed in TABs of GCA patients. Dimeric PKM2 plasma levels were elevated in GCA and correlated with CRP, ESR, calprotectin, and YKL-40 levels. Elevated plasma PKM2 levels were downmodulated by GC-treatment. PKM2 was detected in both macrophages and T cells at the site of vascular inflammation. Circulating PKM2 levels correlated with average TBR PET scores.

Conclusion: Elevated plasma PKM2 levels reflect active vessel inflammation in GCA and may assist in disease diagnosis and in disease monitoring.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
November 2021