MicroRNA Profiling of Exosomes Derived from Red Blood Cell Units: Implications in Transfusion-Related Immunomodulation.

PURPOSE: To elucidate the microRNAs existent in exosomes derived from stored red blood cell (RBC) unit and their potential function. MATERIALS AND METHODS: Exosomes were isolated from the supernatant derived from stored RBC units by sequential centrifugation. Isolated exosomes were characterized by TEM (transmission electron microscopy), western blotting, and DLS (dynamic light scattering). MicroRNA (miRNA) microarray was performed to detect the expression of miRNAs in 3 exosome samples. Results revealed miRNAs that were simultaneously expressed in the 3 exosome samples and were previously reported to exist in mature RBCs. Functions and potential pathways of some detected miRNAs were illustrated by bioinformatic analysis. Validation of the top 3 abundant miRNAs was carried out by qRT-PCR (quantitative reverse transcription-polymerase chain reaction). RESULTS: TEM and DLS revealed the mean size of the exosomes (RBC-derived) as 64.08 nm. These exosomes exhibited higher abundance of short RNA than the long RNA. 78 miRNAs were simultaneously detected in 3 exosome samples and mature RBCs. Several biological processes might be impacted by these miRNAs, through their target gene(s) enriched in a particular signalling pathway. The top 3 (abundant) miRNAs detected were as follows: miR-125b-5p, miR-4454, and miR-451a. qRT-PCR revealed higher abundance of miR-451a than others. Only miR-4454 and miR-451a abundance tended to increase with increasing storage time. CONCLUSION: Exosomes derived from stored RBC units possessed multiple miRNAs and, hence, could serve various functions. The function of exosomes (RBC-derived) might be implemented partly by the predominantly enriched miR-451a.

Combination of Fresh Frozen Plasma and Cryosupernatant Plasma for Therapeutic Plasma Exchange in Thrombotic Thrombocytopenic Purpura: A Single Institution Experience.

PURPOSE: To evaluate the impact of a combination of fresh frozen plasma (FFP) and cryosupernatant plasma (CP) as a replacement fluid in therapeutic plasma exchange (TPE) on early therapeutic response and long-term survival of patients with thrombotic thrombocytopenic purpura (TTP). MATERIALS AND METHODS: A total of 44 patients with suspected TTP were screened by Bentley and PLASMIC scores. Twenty-seven patients treated with TPE using the FFP and CP combination as the replacement fluid were enrolled and divided into two groups: 11 patients who received TPE with CP-dominant replacement fluid (FFP/CP<1) and 16 patients who received TPE with FFP-dominant replacement fluid (FFP/CP>1). RESULTS: There were no significant differences in the demographic and clinicopathological characteristics between the two groups except for the international normalized ratio (INR). The number of TPE procedures was lower, and time to achieve complete response was shorter in the CP-dominant group than in the FFP-dominant group. There were no significant differences in overall survival between the two groups. CONCLUSION: The CP-dominant replacement fluid was superior to the FFP-dominant replacement fluid in early response to TPE in patients with TTP, but did not impact the patients' overall survival.

[Arginase Level in Apheresis Leukocyte-Reduced Platelets Stored for Different Time].

OBJECTIVE: To explore the effect of storage time on arginase level and possible source of arginase in apheresis leukocyte-reduced platelets(ALR-Plt). METHODS: The arginase level and myeloperoxidase(MPO) levels in ALR-Plt and control plasma were detected by ELISA. The relationship between arginase level and MPO level in ALR-Plt was analyzed by correlation analysis. RESULTS: There was no significant difference of arginase level between ALR-Plt stored less than 3 days and control plasma. However, arginase level in ALR-Plt stored over 3 days was significantly higher than that in ALR-Plt stored less than 3 days and control plasma(P<0.05). There was no significant difference of MPO level in ALR-Plt stored for different times, but the MPO level in ALR-Plt stored for different time was lower than that in control plasma. Correlation analysis showed that arginase level positively correlated with MPO level in ALR-Plt of different storage time (r=0.58). CONCLUSION: The arginase level in ALR-Plt stored over 3 days increase significantly. The main possible source of arginase in ALR-Plt is the residual white blood cells, especially neutrophils.

[Arginase Level in Suspended Red Blood Cells Storaged for Different Time].

OBJECTIVE: To explore the effect of storage time on arginase level, and the possible source of arginase in suspended red blood cells (RBC). METHODS: The arginase and myeloperoxidase (MPO) levels in suspended RBC and control plasma were detected by ELISA. The free hemoglobin level in suspended RBC and control plasma were detected by colorimetric method. The relationship between arginase level, MPO level and free hemoglobin level in suspended RBC was analyzed by the related methods. RESULTS: The arginase and free hemoglobin levels in suspended RBC were higher than those in control plasma. Otherwise, MPO level was not significantly different between suspended RBC and control plasma. All of them did not increase along with prolonging of storage time. There was not a significant correlation between arginase level and free hemoglobin level in suspended RBC of different storage time (r = 0.03), but arginase level positively correlated with MPO level in the suspended RBC of different storage time (r = 0.76). CONCLUSION: The arginase level in suspended RBC storaged for different time increases significantly, but not along with prolonging of storage time. The main possible source of arginase in the suspended RBC is the residual white blood cell, especially neutrophils.

[Impact of Toxoplasma gondii infection on pregnancy outcomes in early pregnant women].

OBJECTIVE: To explore the impact of Toxoplasma gondii infection on pregnancy outcomes in early pregnancy women. METHODS: Toxoplasma gondii IgM and IgG antibodies in the peripheral blood of 2 993 early pregnant women were detected by using enzyme-linked immunosorbent assay (ELISA). According to the test results, the infected ones were divided into an acute infection group, a previous infection group, and an active infection group, and 200 pregnant women without Toxoplasma infection were randomly chosen as a control group, and the pregnancy outcomes of the four groups were followed up and the results were compared. RESULTS: There were 286 women infected with Toxoplasma gondii, with the infection rate of 9.56% (286/2 993), in which 43 cases were diagnosed as acute infection, 156 were previous cases, and the other 87 were active infection ones. The incidences of adverse pregnancy outcomes in the above 3 groups and the control group were 13.95% (6/43), 1.92% (3/156), 5.75% (5/87) and 1.50% (3/200), respectively. The incidences of adverse pregnancy outcomes in the acute infection group and active infection group were both higher than that in the control group, the differences were statistically significant (both P < 0.05), while there was no significant difference between the previous infection group and control group (P > 0.05). CONCLUSION: Acute and active Toxoplasma gondii infections are closely associated with the occurrence of adverse pregnancy outcomes in early pregnant women; therefore, Toxoplasma gondii IgM antibody should be included in the routine inspection items of the pre-pregnancy physical examination for child-bearing age women.

[Efficiency of three methods for detecting Toxoplasma IgG antibody].

OBJECTIVE: To discuss the test efficiency of three methods for detecting Toxoplasma IgG antibody. METHODS: Totally 304 specimens were detected parallelly for Toxoplasma IgG antibody by using the gold marked method, indirect hemagglutination test (IHA), and enzyme-linked immunosorbent assay (ELISA), and the sensitivity, specificity and Youden index of these methods were compared. RESULTS: The detection sensitivities of gold marked method, IHA, and ELISA for Toxoplasma IgG antibody were 85.5%, 89.8% and 91.9% respectively (chi2 = 4.12, P > 0.05); the specificities were 92.4%, 96.6% and 97.5% respectively (chi2 = 4.06, P > 0.05). The detection efficiency and Youden index of ELISA were 94.1% and 0.89 respectively, being higher than those of IHA and gold marked method. CONCLUSION: The sensitivity and specificity of the ELISA method for Toxoplasma IgG antibody are higher, and in addition, it can be automated. Therefore, it is suitable for large-scale Toxoplasma IgG antibody screening.

Ischemia postconditioning and mesenchymal stem cells engraftment synergistically attenuate ischemia reperfusion-induced lung injury in rats.

BACKGROUND: It has been reported that ischemic postconditioning (IPO) or mesenchymal stem cell (MSC) engraftment could protect organs from ischemia/reperfusion (I/R) injury. We investigated the synergetic effects of combined treatment on lung injury induced by I/R. METHODS: Adult Sprague-Dawley rats were randomly assigned to one of the following groups: sham-operated control, I/R, IPO, MSC engraftment, and IPO plus MSC engraftment. Lung injury was assessed by arterial blood gas analysis, the wet/dry lung weight ratio, superoxide dismutase level, malondialdehyde content, myeloperoxidase activity, and tissue histologic changes. Cytokine expression was detected using real-time polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assay. Cell apoptosis was determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end assay and annexin V staining. RESULTS: MSC engraftment or IPO alone markedly attenuated the lung wet/dry weight ratio, malondialdehyde and myeloperoxidase production, and lung pathologic injury and enhanced arterial partial oxygen pressure, superoxide dismutase content, inhibited pro-inflammatory cytokine levels, and decreased cell apoptosis in lung tissue, compared with the I/R group. In contrast, IPO pretreatment enhanced the protective effects of MSC on I/R-induced lung injury compared with treatment alone. Moreover, in the combined treatment group, the number of MSC engraftments in the lung tissue was increased, associated with enhanced survival of MSCs compared with MSC treatment alone. Additional investigation showed that IPO treatment increased expression of vascular endothelial growth factor and stromal cell-derived factor-1 in I/R lung tissue. CONCLUSIONS: IPO might contribute to the homing and survival of transplanted MSCs and enhance their therapeutic effects through improvement of the microenvironment of I/R injury.