Time and Temperature Stability of TGF-β1, EGF and IGF-1 in 20% and 100% Human Serum

Autologous serum eye drops (ASEDs) are used as a treatment for severe dry eye disease. The concentration and stability of various growth factors in ASEDs is determinative for their efficiency. We therefore assessed the concentrations of transforming growth factor beta 1 (TGF-β1), epidermal growth factor (EGF) and insulin-like growth factor 1 (IGF-1) in ASEDs following storage at 4-8, -20, -80 and -156 °C. Twenty % and 100% sera from eight healthy volunteers were analysed by the sandwich enzyme immunoassay at different time intervals up to seven months. The mean levels of TGF-β1 and EGF in undiluted and 20% serum did not differ significantly from the baseline levels in fresh serum for any storage conditions after 7 days at 4-8 °C, as well as after 4- and 7-month preservation at sub-zero temperatures. In 20% serum, no IGF-1 concentration decrease was found following 7 days of preservation at 4-8 °C. However, a decrease to 78 % and 81 % (P < 0.01) of baseline values was found in 20% serum after 4-month storage at -20 °C and 7-month storage at -156 °C, respectively. A more pronounced decrease in IGF-1 was observed in undiluted serum. All assessed growth factors present in 20% frozen serum remained stable for up to 7 months. The highest stability was achieved at -80 °C. At -20 and -156 °C, some decrease in IGF-1 occurred. Our results indicate that 20% ASEDs can be stored frozen up to 7 months under proper conditions.

The significance of calprotectin, CD147, APOA4 and DJ-1 in non-invasive detection of urinary bladder carcinoma

Aim of the study is to define the diagnostic accuracy of selected urinary protein biomarkers in the non-invasive detection of primary and recurrent urothelial carcinoma of the urinary bladder. The urinary levels of calprotectin, CD147, APOA4 and protein deglycase DJ-1 were examined in 255 individuals, including 60 controls with non-malignant urological disease, 61 patients with a history of urinary bladder cancer with negative cytology and negative cystoscopy and 134 patients with urinary bladder cancer. Urinary concentrations of biomarkers were determined by Enzyme-Linked Immunosorbent Assay (ELISA). During the follow-up of patients with non-muscle invasive bladder cancer (NMIBC), a group of 44 patients with cancer recurrence was compared to the group of 61 patients with a history of NMIBC but with no evidence of disease. Urinary concentrations of the evaluated markers did not reveal any significant difference between these groups. During the primary diagnosis, a group of 90 patients with primary bladder cancer and 60 subjects with benign disease were compared. Urinary levels of CD147 were not significantly higher in patients with tumors. The greatest diagnostic accuracy was observed in APOA4 (sensitivity 55.6, specificity 83.3, AUC 0.75), and lesser in calprotectin (sensitivity 39.4, specificity 87.7, AUC 0.66) and in DJ-1 (sensitivity 61.1, specificity 66.7, AUC 0.64), respectively. Apolipoprotein A4 may be used potentially as a supplemental urinary marker in the diagnosis of primary bladder cancer.