The influence of the blood handling process on the measurement of circulating TGF-ß1.

In order to evaluate the impact of blood sample handling processes on circulating TGF-ß1 levels, blood specimens were obtained from 13 healthy volunteers using different handling processes (kept at room temperature (RT) or on ice before centrifugation, using different centrifugal forces). TGF-ß1 levels were measured using an enzyme-linked immunosorbent assay. A paired-T test was used for statistical analysis. The TGF-ß1 level in on-ice serum was significantly lower than that in room-temperature serum (P<0.001), and both were significantly higher than that found in on-ice plasma (P<0.001). Compared with on-ice plasma samples, the longer the samples were kept at RT, the higher the levels of TGF-ß1 in plasma (P=0.268, 0.040, and 0.0015 for 5 min, 30 min, and 60 min in RT, respectively). Compared with plasma centrifuged at 2,500×g for 30 min, the TGF-ß1 levels were much lower than those found in plasma centrifuged at 1,200×g for 10 min (P=0.003); and a double centrifugation before TGF-ß1 detection, significantly decreased the level (P<0.001). It is suggested that the optimal sampling conditions for the detection of TGF-ß1 should be plasma prepared on ice and spun down at a higher centrifugal force.

Changes of circulating transforming growth factor-beta1 level during radiation therapy are correlated with the prognosis of locally advanced non-small cell lung cancer.

INTRODUCTION: We hypothesized that plasma transforming growth factor-beta1 (TGF-beta1) level and its dynamic change are correlated with the prognosis of locally advanced non-small cell lung cancer (NSCLC) treated with radiation therapy (RT). METHODS: Patients with stage IIIA or IIIB NSCLC treated with RT with or without chemotherapy were eligible for this study. Platelet poor plasma was collected from each patient within 1 week before RT (pre-RT) and at the 4th week during RT (during-RT). TGF-beta1 level was measured with enzyme-linked immunosorbent assay. The primary end point was overall survival (OS) and the secondary end point was progression-free survival (PFS). Kaplan-Meier and Cox regression were used for risk factor evaluation. RESULTS: A total of 65 patients were eligible for the study. The median OS and PFS were 17.7 and 13.7 months, respectively. In univariate analysis, performance status, weight loss, radiation dose, and TGF-beta1 ratio (during-RT/pre-RT TGF-beta1 level) were all significantly correlated with OS. In the multivariate analysis, performance status, radiation dose, and TGF-beta1 ratio were still significantly correlated with OS. The median OS was 30.7 months for patients with TGF-beta1 ratio