STAR SIGN study: Evaluation of COVID-19 vaccine efficacy against the SARS-CoV-2 variants BQ.1.1 and XBB.1.5 in patients with inflammatory bowel disease.

BACKGROUND: Vaccine-elicited immune responses are impaired in patients with inflammatory bowel disease (IBD) treated with anti-TNF biologics. AIMS: To assess vaccination efficacy against the novel omicron sublineages BQ.1.1 and XBB.1.5 in immunosuppressed patients with IBD. METHODS: This prospective multicentre case-control study included 98 biologic-treated patients with IBD and 48 healthy controls. Anti-spike IgG concentrations and surrogate neutralisation against SARS-CoV-2 wild-type, BA.1, BA.5, BQ.1.1, and XBB.1.5 were measured at two different time points (2-16 weeks and 22-40 weeks) following third dose vaccination. Surrogate neutralisation was based on antibody-mediated blockage of ACE2-spike protein-protein interaction. Primary outcome was surrogate neutralisation against tested SARS-CoV-2 sublineages. Secondary outcomes were proportions of participants with insufficient surrogate neutralisation, impact of breakthrough infection, and correlation of surrogate neutralisation with anti-spike IgG concentration. RESULTS: Surrogate neutralisation against all tested sublineages was reduced in patients with IBD who were treated with anti-TNF biologics compared to patients treated with non-anti-TNF biologics and healthy controls (each p ≤ 0.001) at visit 1. Anti-TNF therapy (odds ratio 0.29 [95% CI 0.19-0.46]) and time since vaccination (0.85 [0.72-1.00]) were associated with low, and mRNA-1273 vaccination (1.86 [1.12-3.08]) with high wild-type surrogate neutralisation in a ß-regression model. Accordingly, higher proportions of patients treated with anti-TNF biologics had insufficient surrogate neutralisation against omicron sublineages at visit 1 compared to patients treated with non-anti-TNF biologics and healthy controls (each p ≤ 0.015). Surrogate neutralisation against all tested sublineages decreased over time but was increased by breakthrough infection. Anti-spike IgG concentrations correlated with surrogate neutralisation. CONCLUSIONS: Patients with IBD who are treated with anti-TNF biologics show impaired neutralisation against novel omicron sublineages BQ.1.1 and XBB.1.5 and may benefit from prioritisation for future variant-adapted vaccines.

Systemic and T cell-associated responses to SARS-CoV-2 immunisation in gut inflammation (STAR SIGN study): effects of biologics on vaccination efficacy of the third dose of mRNA vaccines against SARS-CoV-2.

BACKGROUND: Immunosuppressed patients with inflammatory bowel disease (IBD) experience increased risk of vaccine-preventable diseases such as COVID-19. AIMS: To assess humoral and cellular immune responses following SARS-CoV-2 booster vaccination in immunosuppressed IBD patients and healthy controls. METHODS: In this prospective, multicentre, case-control study, 139 IBD patients treated with biologics and 110 healthy controls were recruited. Serum anti-SARS-CoV-2 spike IgG concentrations were measured 2-16 weeks after receiving a third mRNA vaccine dose. The primary outcome was to determine if humoral immune responses towards booster vaccines differ in IBD patients under anti-TNF versus non-anti-TNF therapy and healthy controls. Secondary outcomes were antibody decline, impact of previous infection and SARS-CoV-2-targeted T cell responses. RESULTS: Anti-TNF-treated IBD patients showed reduced anti-spike IgG concentrations (geometric mean 2357.4 BAU/ml [geometric SD 3.3]) when compared to non-anti-TNF-treated patients (5935.7 BAU/ml [3.9]; p < 0.0001) and healthy controls (5481.7 BAU/ml [2.4]; p < 0.0001), respectively. In multivariable modelling, prior infection (geometric mean ratio 2.00 [95% CI 1.34-2.90]) and vaccination with mRNA-1273 (1.53 [1.01-2.27]) increased antibody concentrations, while anti-TNF treatment (0.39 [0.28-0.54]) and prolonged time between vaccination and antibody measurement (0.72 [0.58-0.90]) decreased anti-SARS-CoV-2 spike antibodies. Antibody decline was comparable in IBD patients independent of anti-TNF treatment and antibody concentrations could not predict breakthrough infections. Cellular and humoral immune responses were uncoupled, and more anti-TNF-treated patients than healthy controls developed inadequate T cell responses (15/73 [20.5%] vs 2/100 [2.0%]; p = 0.00031). CONCLUSIONS: Anti-TNF-treated IBD patients have impaired humoral and cellular immunogenicity following SARS-CoV-2 booster vaccination. Fourth dose administration may be beneficial for these patients.

In vitro hepatotoxicity of Petasites hybridus extract (Ze 339) depends on the concentration, the cytochrome activity of the cell system, and the species used.

Ze 339, a CO2 extract prepared from the leaves of Petasites hybridus, possesses antispasmodic and anti-inflammatory effects and is proven to be effective in the treatment of allergic rhinitis. To study possible hepatotoxic effects of Ze 339, its main constituents and metabolites, a series of in vitro investigations were performed. Furthermore, different reconstituted fractions of extract (petasins and fatty acid fraction) were examined in three in vitro test systems using hepatocytes: Two human cell lines, with lower and higher activity of cytochrome P450 enzymes (HepG2, HepaRG) as well as a rodent cell line with high cytochrome P450 activity (H-4-II-E), were used. Metabolic activity, assessed by the WST-1 assay, was chosen as indicator of cytotoxicity. To assess potential bioactivation of Ze 339 compounds, metabolic experiments using S9 fractions from rats, dogs, and humans and isolated cytochromes (human/rat) were performed, and the formation of reactive metabolites was assessed by measuring cellular concentrations of glutathione and glutathione disulphide. Our data revealed that the cytotoxicity of Ze 339, its single constituents, and main metabolites depends on the concentration, the cytochrome activity of the cell system, and the species used.

Development of an in vitro screening method of acute cytotoxicity of the pyrrolizidine alkaloid lasiocarpine in human and rodent hepatic cell lines by increasing susceptibility.

ETHNOPHARMACOLOGICAL RELEVANCE: Pyrrolizidine alkaloids (PAs) are secondary plant ingredients formed in many plant species to protect against predators. PAs are generally considered acutely hepatotoxic, genotoxic and carcinogenic. Up to now, only few in vitro and in vivo investigations were performed to evaluate their relative toxic potential. AIM OF THE STUDY: The aim was to develop an in vitro screening method of their cytotoxicity. MATERIALS AND METHODS: Human and rodent hepatocyte cell lines (HepG2 and H-4-II-E) were used to assess cytotoxicity of the PA lasiocarpine. At concentrations of 25 µM up to even 2400 µM, no toxic effects in neither cell line was observed with standard cell culture media. Therefore, different approaches were investigated to enhance the susceptibility of cells to PA toxicity (using high-glucose or galactose-based media, induction of toxifying cytochromes, inhibition of metabolic carboxylesterases, and inhibition of glutathione-mediated detoxification). RESULTS: Galactose-based culture medium (11.1 mM) increased cell susceptibility in both cell-lines. Cytochrome P450-induction by rifampicin showed no effect. Inhibition of carboxylesterase-mediated PA detoxification by specific carboxylesterase 2 inhibitor loperamide (2.5 µM) enhanced lasiocarpine toxicity, whereas the unspecific carboxylesterase inhibitor bis(4-nitrophenyl)phosphate (BNPP, 100 µM)) had a weaker effect. Finally, the inhibition of glutathione-mediated detoxification by buthionine sulphoximine (BSO, 100 µM) strongly enhanced lasiocarpine toxicity in H-4-II-E cells in low and medium, but not in high concentrations. CONCLUSIONS: If no toxicity is observed under standard conditions, susceptibility enhancement by using galactose-based media, loperamide, and BSO may be useful to assess relative acute cytotoxicity of PAs in different cell lines.

In Vitro and In Situ Absorption and Metabolism of Sesquiterpenes from Petasites hybridus Extracts.

Petasites hybridus extract is used in the treatment of seasonal allergic rhinitis. The aim of this study was to evaluate the active constituent petasin and its isomers isopetasin and neopetasin (petasins) in the P. hybridus extract Ze 339 for liberation, dissolution, absorption, and metabolism. The determination of pH-dependent thermodynamic solubility was performed via the shake-flask method. Petasins exhibited a low solubility that was pH independent. In vivo, the concentration of solute drugs is decreased continuously by intestinal absorption. Therefore, low solubility is not assumed to be critical for in vivo performance. Additionally, dissolution of an herbal medicinal product containing P. hybridus extract Ze 339 was assessed. Furthermore, high permeability through Caco-2 monolayers was evident. Using an in situ rat model, absorption capacity for petasins was found in all tested intestinal segments, namely, duodenum, jejunum, and ileum. Besides, high metabolism was evident both in Caco-2 monolayers and in the rat intestine. To compare intestinal and hepatic metabolism of petasins, in vitro enzyme assays using liver and intestinal cytosol and microsomes (S9 fraction) of rats and humans were performed. A significantly higher metabolic rate was found in the liver S9 fraction of both species compared with the intestinal S9 fraction.

In Vitro and In Situ Characterization of Triterpene Glycosides From Cimicifuga racemosa Extract.

Cimicifuga racemosa products are widely used in the treatment of climacteric symptoms. The aim of this study was to evaluate C racemosa extract Ze 450 according to Biopharmaceutics Classification System (BCS). Triterpene glycosides served as analytical marker and were evaluated for solubility and absorption properties. pH-dependent thermodynamic solubility was tested via shake flask method, and dissolution performance of a herbal medicinal product containing C racemosa extract Ze 450 was assessed. Absorption was estimated by in vitro permeation through Caco-2 monolayers. Furthermore, different intestinal segments were screened for absorption performance using an in situ rat model. Over a physiological pH range, triterpene glycosides exhibited pH-dependent solubility with highest concentration at pH 7.5. Dissolution profiles showed rapid dissolution of actein and 23-epi-26-deoxyactein. Furthermore, 23-epi-26-deoxyactein as surrogate for contained triterpene glycosides showed a high permeability through Caco-2 monolayers. Results of in situ rat model showed absorption capacity for 23-epi-26-deoxyactein in duodenum, jejunum, ileum, and colon. The results indicate high bioavailability of triterpene glycosides from C racemosa extract Ze 450. With regard to BCS, triterpene glycosides can be classified into BCS class I (high solubility, high permeability).