@article{HeidtKaemmererFobkeretal.2023,
  author    = {Heidt, Christina and K{\"a}mmerer, Ulrike and Fobker, Manfred and R{\"u}ffer, Andreas and Marquardt, Thorsten and Reuss-Borst, Monika},
  title     = {Assessment of intestinal permeability and inflammation bio-markers in patients with rheumatoid arthritis},
  series = {Nutrients},
  volume    = {15},
  journal   = {Nutrients},
  number    = {10},
  issn      = {2072-6643},
  doi       = {10.3390/nu15102386},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-319377},
  year      = {2023},
  abstract  = {Increased intestinal permeability and inflammation, both fueled by dysbiosis, appear to contribute to rheumatoid arthritis (RA) pathogenesis. This single-center pilot study aimed to investigate zonulin, a marker of intestinal permeability, and calprotectin, a marker of intestinal inflammation, measured in serum and fecal samples of RA patients using commercially available kits. We also analyzed plasma lipopolysaccharide (LPS) levels, a marker of intestinal permeability and inflammation. Furthermore, univariate, and multivariate regression analyses were carried out to determine whether or not there were associations of zonulin and calprotectin with LPS, BMI, gender, age, RA-specific parameters, fiber intake, and short-chain fatty acids in the gut. Serum zonulin levels were more likely to be abnormal with a longer disease duration and fecal zonulin levels were inversely associated with age. A strong association between fecal and serum calprotectin and between fecal calprotectin and LPS were found in males, but not in females, independent of other biomarkers, suggesting that fecal calprotectin may be a more specific biomarker than serum calprotectin is of intestinal inflammation in RA. Since this was a proof-of-principle study without a healthy control group, further research is needed to validate fecal and serum zonulin as valid biomarkers of RA in comparison with other promising biomarkers.},
  language  = {en}
}
@article{GernertSchmalzingTonyetal.2022,
  author    = {Gernert, Michael and Schmalzing, Marc and Tony, Hans-Peter and Strunz, Patrick-Pascal and Schwaneck, Eva Christina and Fr{\"o}hlich, Matthias},
  title     = {Calprotectin (S100A8/S100A9) detects inflammatory activity in rheumatoid arthritis patients receiving tocilizumab therapy},
  series = {Arthritis Research \& Therapy},
  volume    = {24},
  journal   = {Arthritis Research \& Therapy},
  number    = {1},
  doi       = {10.1186/s13075-022-02887-7},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300523},
  year      = {2022},
  abstract  = {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.},
  language  = {en}
}