Hydroxyproline levels in nasal polyps

The effects of oral steroid therapy on prolidase enzyme activity in patients with nasal polyps

Objective

To compare prolidase enzyme activity (PEA) in serum and polyp specimens of patients with nasal polyps obtained before and after the oral steroid therapy.

Materials and methods

Thirty three patients with nasal polyps (39 ± 13 years) received 1 mg/kg of oral steroids. Serum samples were collected from each patient, but nasal polyp specimens could be obtained only from 23 patients (38 ± 13 years) before and after the oral steroid therapy. PEA was measured by ELISA method.

Results

Serum PEA values were 210 (176–242) U/L and 184 (147–217) U/L before and after the oral steroid therapy, respectively (p = 0.015). Polyp tissue PEA was 1337 (738–2130) U/g and 871 (590–1663) U/g before and after the oral steroid therapy, respectively (p = 0.429).

Conclusion

In patients with nasal polyps, significantly lower serum PEA after the oral steroid therapy may be a consequence of the role of prolidase enzyme in inflammatory processes which are important for the development of nasal polyps. More comprehensive studies with larger sample sizes are needed to elucidate the role of PEA in the pathogenesis of nasal polyps.

Perioperative changes in the plasma metabolome of patients receiving general anesthesia for pancreatic cancer surgery

Background: Modern anesthesia strives to offer personalized concepts to meet the patient’s individual needs in sight of clinical outcome. Still, little is known about the impact of anesthesia on the plasma metabolome, although many metabolites have been shown to modulate the function of various immune cells, making it particularly interesting in the context of oncological surgery. In this study longitudinal dynamics in the plasma metabolome during general anesthesia in patients undergoing pancreatic surgery were analyzed.

Materials and Methods: Prospective, observational study with 10 patients diagnosed with pancreatic (pre-) malignancy and subjected to elective resection surgery under general anesthesia. Plasma metabolites (n = 630) were quantified at eight consecutive perioperative timepoints using mass spectrometry-based targeted metabolomics.

Results: 39 metabolites significantly changed during the perioperative period. Tryptophan concentrations decreased by 45% with the maximum decrease after anesthesia induction (p = 6.24E-07), while taurine synthesis increased (p = 1.46E-04). Triacylglycerides and lysophosphatidylcholines were significantly reduced with increased liberation of free monounsaturated fatty acids (p = 0.03). Carnitine levels decreased significantly (p = 9.30E-04).

Conclusions: The major finding of this study was perioperative tryptophan depletion and increased taurine synthesis. Both are essential for immune cell function and are therefore of significant interest for perioperative management. Further studies are needed to identify influencing anesthetic factors.