S Chen

CD14 is a myeloid differentiation Ag expressed primarily on peripheral blood monocytes and macrophages. Although its function is unknown, the CD14 gene maps to a region encoding several myeloid growth factors and receptors. Analysis of the CD14 protein sequence deduced from the cDNA shows that although the CD14 protein contains a characteristic leader peptide, it lacks a characteristic transmembrane region, suggesting that CD14 may be anchored to the membrane via glycosylphosphatidylinositol (PI). Treatment of monocytes as well as a CD14-expressing neuroglioma cell line with PI-phospholipase C removed CD14 from the cell surface. Furthermore, monocytes from a patient with paroxysmal nocturnal hemoglobinuria, a disease characterized by lack of expression of other PI-linked proteins, failed to express CD14. Interestingly, the CD14-expressing neuroglioma cell line, which had been transfected with a single CD14 cDNA, released a soluble form of CD14 into the supernatant. Soluble forms of CD14 have previously been observed in serum of normal individuals and in culture supernatants of CD14+ cells. Biosynthetic experiments reveal that this soluble form of CD14 (48 kDa), which is smaller than the form released from the membrane by PI-phospholipase C (53 kDa), does not contain ethanolamine, the first constitutent of the PI-anchoring system. These studies demonstrate that CD14 is a member of the family of PI-anchored proteins and suggest that soluble forms of CD14 represent molecules that completely lack the PI-anchoring system.

Objective: To investigate the clinical value of the peripheral blood monocyte human leukocyte antigen-DR (mHLA-DR) for assessment of degree of severity and the diagnosis of acute pancreatitis (AP). Methods: A case-control study was conducted. Eighty-six AP patients admitted to Shandong Liaocheng People's Hospital from June 2014 to May 2015 were enrolled. Patients were classified into four groups [mild (n = 33), moderate (n = 25), severe (n = 16), critical (n = 12)] according to the disease classification. Eighty healthy persons subjected to physical examination center of our hospital at the same time were served as controls. Acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) scores in patients were estimated. Flow cytometry was used to measure the expression of the peripheral blood mHLA-DR, and the Pearson method was used to analyze the relationship between the level of mHLA-DR and the APACHE Ⅱ score. The receiver-operating characteristic curve (ROC) was plotted, and then the clinical value of the peripheral blood mHLA-DR was analyzed for the diagnostic value in AP patients. Results: The expression of the mHLA-DR in patients with AP was significantly lower than that of healthy control group [(63.7±18.6)% vs. (86.4±8.3)%, t = 5.319, P < 0.001]. The expression levels of the mHLA-DR in mild group, moderate group, severe group, and critical group were (79.6±6.5)%, (66.4±9.4)%, (49.9±8.1)%, (32.5±12.0)%, respectively, and the APACHE Ⅱ score were 4.67±1.99, 5.88±2.05, 9.06±2.62, 12.33±3.96, respectively. Pair wise comparisons were statistically significant (all P < 0.05). The HLA-DR expression level in the peripheral blood of patients with AP was negatively correlated with the APACHE Ⅱ score (r = -0.695, P < 0.001). The area under the ROC curve (AUC) of mHLA-DR expression in peripheral blood for AP was 0.894 [95% confidence interval (95%CI) = 0.847-0.941, P < 0.001], and the cut-off point was 84.40%, with the sensitivity of 75.0%, the specificity of 90.7%, and the accuracy rate of 83.1%. The AUC of mHLA-DR expression for mild AP was 0.938 (95%CI = 0.889-0.987, P < 0.001), and the cut-off point was 72.70%, with the sensitivity of 87.9%, the specificity of 88.7%, and the accuracy rate of 88.4%. The AUC of mHLA-DR expression for severe and critical AP was 0.943 (95%CI = 0.881-1.005, P < 0.001), and the cut-off point was 57.85%, with the sensitivity of 84.0%, the specificity of 96.4%, and the accuracy rate of 90.6%. Conclusions: The expression levels of the peripheral blood mHLA-DR in AP patients can reflect the degree of disease, and contribute to the diagnosis of AP. The value of mHLA-DR may be used as a new biological indicator in the diagnosis and assessment for the severity of AP.%