[Impaired reparative regeneration in patients with acute appendicitis]

To study reparative potential (cellular effects and biological characteristics) of platelet-rich plasma (PRP) in patients with acute appendicitis (AA).

PRP was obtained by two-stage centrifugation of blood from patients with AA and healthy donors divided into age groups: group 1 (n=10) - healthy donors aged 30-40 years, group 2 (n=10) - healthy donors aged 60-70 years, group 3 (n=10) - patients with AA aged 30-40 years, group 4 (n=10) - patients with AA aged 60-70 years. The study was performed using hTERT-HDFa (d220) cell line of human dermal fibroblasts (HDF). Activated 10% PRP from donors was added to experimental wells. Samples without PRP were negative control (0 (K)), PRP samples with addition of 10% FBS - positive control. Metabolic activity of cells, viability of samples, ability to generate reactive oxygen species (ROS), migration activity and intensity of cellular aging were assessed. Biological characteristics of PRP were defined by ELISA of IL6, IL10, TGFB1, PAI-1, PDGF, VEGF proteins.

PRP from elderly patients with AA was characterized by elevated IL6 and IL10 relative to young patients with this pathology and increased TGFβ relative to healthy peers. On the first day after HDF stimulation with plasma, the lowest viability was found in samples stimulated with PRP from health elderly donors. There were no significant differences among patients with AA regardless of age. After 3 days, we observed high proliferative and metabolic activity of cells after stimulation with plasma from AA patients regardless of age. Antioxidant reserve of PRP in elderly patients with AA was significantly lower than in young patients with AA. Correlation analysis revealed significant relationships between biological profile of PRP, cellular responses and clinical data of patients with AA of different ages.

When comparing cellular responses with clinical data of patients, we found that significant prognostic markers of PRP in AA were IL6, IL10 and TGFβ. Their levels correlated with postoperative hospital-stay. Moreover, high IL6 and IL10 was associated with prolonged hospital-stay in elderly patients.