TY - JOUR A1 - Strunz, Patrick-Pascal A1 - Vuille-Dit-Bille, Raphael N. A1 - Fox, Mark R. A1 - Geier, Andreas A1 - Maggiorini, Marco A1 - Gassmann, Max A1 - Fruehauf, Heiko A1 - Lutz, Thomas A. A1 - Goetze, Oliver T1 - Effect of high altitude on human postprandial \(^{13}\)C-octanoate metabolism, intermediary metabolites, gastrointestinal peptides, and visceral perception JF - Neurogastroenterology and Motility N2 - Objective At high altitude (HA), acute mountain sickness (AMS) is accompanied by neurologic and upper gastrointestinal symptoms (UGS). The primary aim of this study was to test the hypothesis that delayed gastric emptying (GE), assessed by \(^{13}\)C-octanoate breath testing (OBT), causes UGS in AMS. The secondary aim was to assess post-gastric mechanisms of OBT, which could confound results under these conditions, by determination of intermediary metabolites, gastrointestinal peptides, and basal metabolic rate. Methods A prospective trial was performed in 25 healthy participants (15 male) at 4559 m (HA) and at 490 m (Zurich). GE was assessed by OBT (428 kcal solid meal) and UGS by visual analogue scales (VAS). Blood sampling of metabolites (glucose, free fatty acids (FFA), triglycerides (TG), beta-hydroxyl butyrate (BHB), L-lactate) and gastrointestinal peptides (insulin, amylin, PYY, etc.) was performed as well as blood gas analysis and spirometry. Statistical analysis: variance analyses, bivariate correlation, and multilinear regression analysis. Results After 24 h under hypoxic conditions at HA, participants developed AMS (p < 0.001). \(^{13}\)CO\(_{2}\) exhalation kinetics increased (p < 0.05) resulting in reduced estimates of gastric half-emptying times (p < 0.01). However, median resting respiratory quotients and plasma profiles of TG indicated that augmented beta-oxidation was the main predictor of accelerated \(^{13}\)CO\(_{2}\)-generation under these conditions. Conclusion Quantification of \(^{13}\)C-octanoate oxidation by a breath test is sensitive to variation in metabolic (liver) function under hypoxic conditions. \(^{13}\)C-breath testing using short-chain fatty acids is not reliable for measurement of gastric function at HA and should be considered critically in other severe hypoxic conditions, like sepsis or chronic lung disease. KW - acute hypobaric hypoxia KW - beta-oxidation KW - gastric emptying KW - stable isotope breath tests Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259611 VL - 34 IS - 3 ER - TY - JOUR A1 - Gernert, Michael A1 - Schmalzing, Marc A1 - Tony, Hans-Peter A1 - Strunz, Patrick-Pascal A1 - Schwaneck, Eva Christina A1 - Fröhlich, Matthias T1 - Calprotectin (S100A8/S100A9) detects inflammatory activity in rheumatoid arthritis patients receiving tocilizumab therapy JF - Arthritis Research & Therapy N2 - Background Assessing serological inflammation is difficult in tocilizumab (TCZ)-treated rheumatoid arthritis (RA) patients, as standard inflammation parameters, like erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), are influenced by interleukin-6-receptor inhibition. Calprotectin in the serum, also named S100A8/S100A9, might be a more useful inflammation parameter in TCZ-treated patients. Methods Sixty-nine RA patients taking TCZ were included. Serum-calprotectin levels were assessed, as well as ESR, CRP, need for a change in disease-modifying anti-rheumatic drugs due to RA activity (= active RA), and the RA clinical disease activity score (CDAI). Forty-five RA patients taking tumor-necrosis factor-inhibitors (TNFi) were investigated for the same parameters. Results TCZ-treated patients with active RA had higher calprotectin values than not active RA patients (4155.5 [inter quartile range 1865.3–6068.3] vs 1040.0 [676.0–1638.0] ng/ml, P < 0.001). A calprotectin cut-off value of 1916.5 ng/ml resulted in a sensitivity and specificity of 80.0 %, respectively, for the detection of RA disease activity. Calprotectin values correlated with CDAI-scores (r = 0.228; P = 0.011). ESR and CRP were less suitable to detect RA activity in TCZ-treated patients. Also TNFi-treated patients with active RA had higher calprotectin values compared to not active RA (5422.0 [3749.0–8150.8] vs 1845.0 [832.0–2569.0] ng/ml, P < 0.001). The calprotectin value with the best sensitivity and specificity for detecting RA activity was 3690.5 ng/ml among TNFi-treated patients. Conclusion Calprotectin in the serum can be a useful inflammation parameter despite TCZ-treatment. KW - calprotectin KW - inflammation marker KW - c-reactive protein KW - tocilizumab KW - rheumatoid arthritis KW - S100A8/S100A9 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300523 VL - 24 IS - 1 ER - TY - JOUR A1 - Gernert, Michael A1 - Tony, Hans-Peter A1 - Schwanek, Eva Christina A1 - Gadeholt, Ottar A1 - Fröhlich, Matthias A1 - Portegys, Jan A1 - Strunz, Patrick-Pascal A1 - Schmalzing, Marc T1 - Lymphocyte subsets in the peripheral blood are disturbed in systemic sclerosis patients and can be changed by immunosuppressive medication JF - Rheumatology International N2 - Systemic sclerosis (SSc) is a severe chronic disease with a broad spectrum of clinical manifestations. SSc displays disturbed lymphocyte homeostasis. Immunosuppressive medications targeting T or B cells can improve disease manifestations. SSc clinical manifestations and immunosuppressive medication in itself can cause changes in lymphocyte subsets. The aim of this study was to investigate peripheral lymphocyte homeostasis in SSc with regards to the immunosuppression and to major organ involvement. 44 SSc patients and 19 healthy donors (HD) were included. Immunophenotyping of peripheral whole blood by fluorescence-activated cell sorting was performed. Cytokine secretions of stimulated B cell cultures were measured. SSc patients without immunosuppression compared to HD displayed lower γδ T cells, lower T helper cells (CD3+/CD4+), lower transitional B cells (CD19+/CD38++/CD10+/IgD+), lower pre-switched memory B cells (CD19+/CD27+/IgD+), and lower post-switched memory B cells (CD19+/CD27+/IgD-). There was no difference in the cytokine production of whole B cell cultures between SSc and HD. Within the SSc cohort, mycophenolate intake was associated with lower T helper cells and lower NK cells (CD56+/CD3-). The described differences in peripheral lymphocyte subsets between SSc and HD generate further insight in SSc pathogenesis. Lymphocyte changes under effective immunosuppression indicate how lymphocyte homeostasis in SSc might be restored. KW - mycophenolate KW - systemic sclerosis KW - scleroderma KW - memory B cells KW - B cell culture KW - cytokines KW - γδ T cells KW - immunophenotyping Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-266482 SN - 1437-160X VL - 42 IS - 8 ER -