Proteomics-based identification of haptoglobin as a favourable serum biomarker for predicting long-term response to splenectomy in patients with primary immune thrombocytopenia.

BACKGROUND: Splenectomy is the most effective treatment for patients with primary immune thrombocytopenia (ITP) who fail to respond to steroid therapy. Thus far, there is no effective means to predict the long-term haematological response of the procedure. The purpose of this study was to identify serum biomarkers as predictors of long-term response based on a proteomics approach. METHODS: The serum samples of ITP patients were collected before splenectomy and seven days after surgery. After depletion of the abundant serum proteins, pooled preoperative serum samples from four responders to splenectomy, four nonresponders and four healthy controls were subjected to two-dimensional gel electrophoresis (2-DE). Nine protein spots with at least a five-fold alteration in expression between responders and nonresponders were all identified as haptoglobin (Hp) by matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometer (MS) analysis. The validation of serum Hp expression was performed using enzyme-linked immunosorbent assays (ELISA) in thirty-seven responders, thirteen nonresponders and twenty-one healthy controls. RESULTS: The preoperative serum levels of Hp in the nonresponders (925.9 ± 293.5 µg/ml) were significantly lower than those in the responders (1417.4 ± 315.0 µg/ml, p <0.001) and the healthy controls (1409.1 ± 354.2 µg/ml, p <0.001), while there was no significant difference between the latter two groups. The postoperative serum levels of Hp in responders and nonresponders were (1414.1 ± 225.0 µg/ml) and (952.9 ± 202.4 µg/ml), respectively. There were no significant differences between the serum Hp levels before and after surgery in both responders and nonresponders (p>0.05). The preoperative serum levels of Hp did not significantly correlate with preoperative platelet count of the same blood samples (r = 0.244, p = 0.087), while it positively correlated with postoperative peak platelet count (r = 0.622, p < 0.001). The optimal cutoff value of preoperative serum Hp levels (1173.80 µg/ml) derived from the receiver operating characteristic (ROC) curve led to 78.4% sensitivity and 84.6% specificity. CONCLUSIONS: These results suggest that serum Hp levels may serve as a favourable predictor for the long-term response to splenectomy in ITP and may help to understand the pathophysiological differences between responders and nonresponders.

Expression of heat shock protein 27 in the esophageal tissue of rats with reflux esophagitis.

BACKGROUND: Little attention has been paid to the expression of heat shock protein 27 (HSP27) in patients with reflux esophagitis (RE), and few studies of the importance of HSP27 in esophagitis have been carried out in animal models. This study aimed to explore the expression of HSP27 in the esophageal tissue of rats with RE. METHODS: Eighty female Wistar rats were randomly divided into experimental groups A and B and control groups C and D (n = 20 in each group). To establish RE, rats in the two experimental groups received pylorus and forestomach ligations, while rats in the control group received gastrostomy and gastric perforation repair. The rats in groups A and C were sacrificed 7 days after surgery, and the rats in groups B and D were sacrificed 14 days after surgery. In groups A and B, 10 and 8 rats were diagnosed with RE by pathological examination, respectively (they were included in groups A' and B', respectively). The histopathological diagnosis of all the lower esophageal tissues in groups C and D was normal and 20 normal specimens were randomly selected for groups C' and D' with 10 specimens in each group. Macroscopic and microscopic esophagitis scores were assessed for the specimens in groups A' and B'. Lower esophageal tissues were collected from groups A', B', C', and D', and paraffin-embedded slices were made using part of the tissues. The expression of HSP27 in the tissues was detected using the two-step streptavidin-peroxidase immunohistochemical method. Some collected tissues were frozen, and expressions of HSP27 mRNA were detected using fluorescence quantitative polymerase chain reaction (FQ-PCR). RESULTS: Median macroscopic and microscopic esophagitis scores in groups A' (n = 10) and B' (n = 8) were 1.0 and 1.5, and 2.0 and 2.5, respectively. There were no significant differences in the macroscopic or microscopic esophagitis scores between the two groups (Z = -0.330, P = 0.741; Z = -0.142, P = 0.887, respectively). Immunohistochemical staining showed that HSP27 was expressed in all layers of the esophageal epithelia in RE and control rats. FQ-PCR showed that HSP27 mRNA levels in the lower esophageal tissue in RE group (groups A' and B') were higher than those in control group (groups C' and D') (Z = -0.249, P = 0.001). HSP27 mRNA expression in the lower esophageal tissue was significantly different in groups B' and D' (Z = -3.027, P = 0.002). And the levels of HSP27 mRNA expression in severe RE group (microscopic esophagitis score: 3) were higher than in mild RE group (microscopic esophagitis score: 1-2) and control group (Z = -3.396, P = 0.001; Z = -3.855, P < 0.001). CONCLUSIONS: HSP27 mRNA expression in the lower esophageal tissue of rats with RE is significantly higher than in the normal controls. Although reflux is a persistent stimulating factor, increased expression of HSP27 in the lower esophageal tissue of rats with RE requires aggravated esophageal injury.