Erythrocyte Alloimmunity and Genetic Variance: Results from the Collaborative Study of Alloimmunity to Antigen Diversity in Asian Populations (All ADP).

As an East-Asian international study, we evaluated erythrocyte alloimmunity by gender and history of transfusion or pregnancy. In total, data from more than 1,826,000 patients were analyzed, from whom 26,170 irregular erythrocyte antibodies were detected in 22,653 cases. Antibody frequencies in these cases were as follows: anti-E, 26.8%; anti-Lea, 20.0%; anti-P1, 7.1%; anti-M, 6.4%; anti-Mia, 5.6%; anti-c + E, 5.6%; anti-Leb, 4.6%; anti-D, 2.8%; anti-Fyb, 2.6%; anti-Lea+Leb, 2.5%; anti-Dia, 2.0%; and others. For pregnant patients, anti-D (12.7%) was statistically more frequent. For transfused patients, anti-E (37.3%), anti-c + E (9.5%), anti-C + e (3.3%) and anti-Jka (3.1%) were significantly more frequent.

Recommendations Regarding Practical DEL Typing Strategies for Serologically D-Negative Asian Donors.

BACKGROUND: DEL, the weakest D variant, is mistyped as D-negative by routine serological assays. Transfusion of red blood cells expressing the DEL phenotype has the potential to elicit anti-D alloimmunization in D-negative recipients. The goal of this study was to recommend DEL typing strategies for serologically D-negative Asian donors. METHODS: RhCE phenotyping and the adsorption-elution test were performed on 674 serologically D-negative samples. RHD genotyping using real-time polymerase chain reaction and melting curve analysis were also undertaken to identify DEL alleles. Costs and turnaround time of RhCE phenotyping, the adsorption-elution test, and RHD genotyping were estimated. RESULTS: Sensitivity and specificity of the adsorption-elution test for serologically D-negative samples were 94.9% (93/98) and 91.5% (527/576), respectively. C+ phenotypes were detected in all 98 samples with DEL alleles. Despite comparable costs, RHD genotyping was more accurate and rapid than the adsorption-elution test. CONCLUSIONS: Two practical DEL typing strategies using RhCE phenotyping as an initial screening method were recommended for serologically D-negative Asian donors. Compared with DEL typing using RHD genotyping, serological DEL typing using adsorption-elution test is predicted to increase the incidence of anti-D alloimmunization and decrease the D-negative donor pool without having any cost-competitiveness but can be used in laboratories where molecular methods are not applicable.

Genotyping of 22 blood group antigen polymorphisms and establishing a national recipient registry in the Korean population.

It is often difficult for standard blood banks in Korea to supply adequate amounts of blood for patients with rare phenotype. Moreover, the definition of a blood in need is ambiguous, and much remains to be learned. In this study, we determined the prevalence of various red blood cell (RBC) antigens from a donor viewpoint and estimated the demand for specific antigen-negative blood from a patient viewpoint. Our data will aid the establishment of a Rare Blood Program in Korea (KRBP). RBC genotyping of 419 blood donors was performed using a Lifecodes RBC/RBC-R typing kit (Immucor, Norcross, GA). A national recipient registry website has been established. Each hospital-based blood bank voluntarily enters data on antibodies detected and identified and the outcomes of specific antigen testing. We calculated the availabilities of specific antigen-negative blood components based on these registry data and predicted the prevalence of RBC antigens via RBC genotyping. The prevalences of various RBC antigens in the D-negative population were determined for the first time, and the Cartwright, Scianna, Dombrock, Colton, Landsteiner-Wiener, Cromer, and Knops blood group systems were identified. The availabilities of specific antigen-negative units differed when calculations were based on serotyping or genotyping, especially in the D-negative group. Data on the prevalences of various blood antigens are essential for estimating the availabilities of blood components that are appropriate for use by patients expressing relevant antibodies. Then, blood banks would be able to efficiently supply safe blood products.

Development of Real-time PCR and Melting Curve Analysis for the Rapid Detection of DEL with RHD (c.1222T>C) or RHD (c.1227G>A).

BACKGROUND: DEL, a variant of RhD, is difficult to detect in routine blood bank testing owing to its extremely low levels of D antigen expression. However, DEL is capable of alloimmunizing a patient when transfused into RhDnegative individuals. METHODS: In this study, we developed real-time PCR and melting curve analysis for the rapid detection of the DEL phenotype. RESULTS: Of the 325 serologically RhD-negative individuals involved in the study, 56 (17.2%) had melting temperatures distinguishable from complete RHD absence as follows: 53 RHD (c.1227G>A) DEL specimens had a plateau at 54 - 56°C and a peak at 61.95°C, while 3 RHD (c.1222T>C) DEL had a melting temperature of 62.62°C. All DEL results were identical to those obtained by multiplex single-base primer extension reactions. CONCLUSIONS: The rapid DEL genotyping method developed in this study will be useful for screening DEL in serologically RhD-negative donors and preventing the alloimmunization of RhD-negative individuals by DEL.

Influence of ABO type on global coagulation assay results: effect of coagulation factor VIII.

BACKGROUND: As ABO blood type influences the plasma level of coagulation factor VIII (FVIII), it likely also affects activated partial thromboplastin time (aPTT) and thrombin generation assay (TGA) values. Here, we aimed to investigate the effect of ABO type on the normal values of three global coagulation assays: prothrombin time (PT), aPTT, and TGA. METHODS: PT, aPTT, TGA [1 or 5 pmol/L tissue factor (TF)], coagulation factors, anticoagulation factors, and ABO type were measured in 200 healthy adults. RESULTS: aPTT was significantly prolonged in those with type O compared with those with type non-O, whereas PT was not significantly different between those with type O and type non-O. The time to peak induced by 5 pmol/L TF was significantly prolonged, and the peak thrombin level was decreased in those with type O compared with those with type non-O. FVIII was a major contributor to the ABO-specific reference range of aPTT, 5 pmol/L TF-induced time to peak, and peak thrombin level. CONCLUSIONS: The reference ranges of aPTT and TGA (time to peak and peak thrombin level) differed by ABO type. FVIII level is considered a major contributor to ABO type-specific differences with respect to aPTT and TGA.

Prominent protein Z-induced thrombin inhibition in cirrhosis: a new functional assay for hypercoagulability assessment.

BACKGROUND AND AIMS: Protein Z (PZ) is an anticoagulant that accelerates the inhibitory effect of PZ-dependent protease inhibitor (ZPI) on coagulation factor Xa. We assessed functional status of PZ system in 158 patients with liver cirrhosis and 59 healthy controls. METHODS: Plasma PZ and ZPI levels were measured by enzyme immunoassay. Thrombin generation assays (TGA) were performed with and without thrombomodulin (TM) or PZ, and the ratios were calculated by dividing TGA values with TM or PZ by values without TM or PZ. RESULTS: PZ and ZPI levels were reduced and elevated in advanced cirrhosis, respectively. The lag time ratio-PZ was significantly higher in cirrhosis patients than controls and correlated with the model for end-stage liver disease score. The peak thrombin ratio-PZ and endogenous thrombin potential (ETP) ratio-PZ were significantly lower in cirrhosis patients than controls and correlated with the severity of liver cirrhosis. The peak thrombin ratio-PZ was dramatically reduced in advanced cirrhosis. Cirrhosis patients had a significantly higher ETP ratio-TM than the controls, although the ratio was not correlated with cirrhosis severity. The lag time ratio-PZ and peak time ratio-PZ were significantly correlated with the levels of all coagulation and anticoagulation factors. Interestingly, the lag time ratio-PZ and peak thrombin ratio-PZ were significantly associated with thrombotic events. CONCLUSION: The anticoagulant role of PZ is insufficient in advanced stages of cirrhosis. Our newly developed functional assay for measuring the PZ system is expected to reflect the ongoing hypercoagulability of cirrhosis.

Therapeutic Plasmapheresis Enabling Radioactive Iodine Treatment in a Patient with Thyrotoxicosis.

Therapeutic plasma exchange (TPE) is one possible treatment for patients resistant to conventional antithyroid drugs or requiring urgent attention for thyrotoxicosis. We report a 35-yr-old man with thyrotoxicosis, ultimately attributed to Graves' disease in whom antithyroid drug used initially was soon discontinued, due to abnormal liver function, and replaced by Lugol's solution. Three weeks later, an escape phenomenon (to Lugol's solution) was apparent, so we performed TPE to control the thyrotoxicosis. Two courses of TPE by a centrifugal type machine resulted in diminished levels of thyroid hormone levels, which then rebounded after another two courses of membrane filtration type TPE. However, the patient could be treated with radioactive iodine therapy without any complications at present.

The minimum number of cord blood units needed for Koreans is 51,000.

BACKGROUND: The inventory size for cord blood (CB) depends on the ethnic diversity of human leukocyte antigen (HLA) and the size estimation is important for public health in each ethnicity. STUDY DESIGN AND METHODS: We estimate the CB inventory size in Koreans with stored CB units (CBUs) and patients who underwent allogeneic hematopoietic stem cell transplantation. Two-digit HLA specificities were determined using intermediate DNA typing. From 17,508 stored Korean CBUs, 1460 haplotypes with a frequency greater than 0.001% were used for reconstitution of the HLA. A total of 1002 transplanted patients' HLA was used for matching probability calculation. RESULTS: The best probability for 6/6 matching is 47% in 500,000 hypothetical size. Ninety-five percent probability is achieved with 51,000 CBUs in 5/6, and 2150 in 4/6 matching condition. Because 4/6 matched CB is rarely selected in the Korean situation, 51,000 units is the lowest limit of CBUs required and the number will be adjusted depending on the cell number required for patients and the resolution of HLA typing. CONCLUSION: Approximately 51,000 units could provide the minimum requirement for hematopoietic transplantation in Korea.

Proposal of standardized guidelines for the production and quality control of autologous serum eye drops in Korea: based on a nationwide survey.

BACKGROUND: Autologous serum eye drops (ASEDs) have been used to treat many eye diseases. However, there are no standardized guidelines for the production and quality control (QC) of ASEDs in Korea. Our aim was to propose standardized guidelines for the production and QC of ASEDs. STUDY DESIGN AND METHODS: We conducted a nationwide survey consisting of questions regarding the methods used in each hospital for the production and QC of ASEDs. The survey was sent by e-mail to 89 doctors responsible for the blood banks at different hospitals. RESULTS: Thirty-two hospitals replied, and 13 hospitals reported using the ASEDs in the treatment of patients with eye diseases. The screening test for patients, amount of blood sampling, type of bottle used for blood collection, details about the production of the eye drops, and storage methods and shelf life of unopened and opened bottles of eye drops varied between hospitals. CONCLUSION: Based on an analysis of the survey results and a review of the standard operating procedures and protocols for ASEDs used in Japan, Germany, England and Wales, and the United States, we proposed standardized guidelines for the production and QC of ASEDs in Korea. ASEDs are not cell therapy products in the strictest sense. However, because eye drops are composed of serum isolated from blood and are used in patients, we consider ASEDs to be the basis for cell therapy products. Therefore, ASEDs should be produced and stored according to standardized guidelines based on the Good Manufacturing Practice guidelines.

Association between red blood cell storage duration and clinical outcome in patients undergoing off-pump coronary artery bypass surgery: a retrospective study.

BACKGROUND: Prolonged storage of red blood cells (RBCs) leads to fundamental changes in both the RBCs and the storage media. We retrospectively evaluated the relationship between the RBC age and in-hospital and long-term postoperative outcomes in patients undergoing off-pump coronary artery bypass. METHODS: The electronic medical records of 1,072 OPCAB patients were reviewed and information on the transfused RBCs and clinical data were collected. The effects of RBCs age (mean age, oldest age of transfused RBCs, any RBCs older than 14 days) on various in-hospital postoperative complications and long-term major adverse cardiovascular and cerebral events over a mean follow-up of 31 months were investigated. Correlations between RBCs age and duration of intubation, intensive care unit, or hospital stay, and base excess at the first postoperative morning were also analyzed. RESULTS: After adjusting for confounders, there was no relationship between the RBCs age and in-hospital and long-term clinical outcomes except for postoperative wound complications. A significant linear trend was observed between the oldest age quartiles of transfused RBCs and the postoperative wound complications (quartile 1 vs. 2, 3 and 4: OR, 8.92, 12.01 and 13.79, respectively; P for trend = 0.009). The oldest transfused RBCs showed significant relationships with a first postoperative day negative base excess (P = 0.021), postoperative wound complications (P = 0.001), and length of hospital stay (P = 0.008). CONCLUSIONS: In patients undergoing off-pump coronary artery bypass, the oldest age of transfused RBCs were associated with a postoperative negative base excess, increased wound complications, and a longer hospital stay, but not with the other in-hospital or long-term outcomes.

Long-term trends in cycle threshold values: a comprehensive analysis of COVID-19 dynamics, viral load, and reproduction number in South Korea.

Background: With the emergence of COVID-19 cases, governments quickly responded with aggressive testing, contact tracing, isolation and quarantine measures. South Korea's testing strategy primarily relied on real-time reverse-transcriptase polymerase chain reaction (real-time RT-PCR), focusing on cycle threshold (Ct) values, indicative of viral load, to determine COVID-19 positivity. This study examined the long-term time series distribution of Ct values measured in the same laboratory using a nationally standardized testing type and sampling method in South Korea. It aimed to link Ct values, new COVID-19 cases, and the reproduction number (Rt), setting the stage for using Ct values effectively. Methods: This study analyzed nationally collected 296,347 samples Ct values from February 2020 to January 2022 and examined their associations with the number of new cases and Rt trends. The data were categorized into four COVID-19 periods for in-depth analysis. Statistical methods included time series trend analysis, local regression for smoothing, linear regression for association analysis, and calculation of correlation coefficients. Results: The median Ct values across four COVID-19 periods decreased gradually from 31.71 in the initial period to 21.27 in the fourth period, indicating higher viral load. The comparison of trends between Ct values and the number of new cases revealed that the decline in Ct values preceded the surge in new cases, particularly evident during the initial stages when new cases did not undergo a significant increase. Also, during variant emergence and vaccination rollout, marked shifts in Ct values were observed. Results from linear regression analysis revealed a significant negative relationship between Ct values and new cases (ß = -0.33, p < 0.001, R 2 = 0.67). This implies that as Ct values decrease, new case numbers increase. Conclusion: This study demonstrates the potential of Ct values as early indicators for predicting confirmed COVID-19 cases during the initial stages of the epidemic and suggests their relevance in large-scale epidemic monitoring, even when case numbers are similar.

RANTES polymorphisms and the risk of graft-versus-host disease in human leukocyte antigen-matched sibling allogeneic hematopoietic stem cell transplantation.

We investigated the association between RANTES (regulated upon activation, normal T cell expressed and secreted) polymorphisms and clinical outcomes in patients treated with allogeneic hematopoietic stem cell transplantation (allo-HSCT). Three RANTES gene polymorphisms, i.e., -403G/A (rs2107538), -28C/G (rs2280788) and In1.1T/C (rs2280789), were genotyped, and the effects of the genotypes and haplotypes of RANTES on clinical outcomes were analyzed. The competing risk regression analysis was used to investigate the relationship between the polymorphisms and the cumulative risk of graft-versus-host disease (GVHD). An AGC haplotype in a recessive model showed significant harmful effects on the cumulative risk of acute GVHD and relapse-free survival (adjusted hazard ratios 2.42 and 2.71, 95% confidence intervals 1.29-4.55 and 1.30-5.64; p = 0.018 and 0.024, respectively), whereas a GCT haplotype did not. RANTES polymorphisms were not significantly associated with overall survival and the risk of chronic GVHD. This study suggests that RANTES polymorphisms might be associated with the occurrence of acute GVHD rather than of chronic GVHD and also of relapse-free survival in the patients treated with allo-HSCT. Further larger prospective investigations are needed to establish the role of RANTES polymorphisms in patients treated with allo-HSCT.

Comparison of whole blood collection and double-unit erythrocytapheresis in preoperative autologous blood donation.

INTRODUCTION: We compared preoperative autologous blood donation (PABD) using serial manual whole blood (WB) and PABD using a single session, double-unit erythrocytapheresis in terms of the hemodynamic recovery and clinical outcomes. MATERIALS AND METHODS: This study included 56 donors in the WB PABD group and 117 donors in the double-unit erythrocytapheresis PABD group. All subjects were men with body weight >70 kg, Hb level >13.3g/dL, Hct >40%, and who were scheduled for oral and maxillofacial surgery. Three cycles of manual WB collection for PABD or a single session, double-unit erythrocytapheresis using the Alyx was performed. RESULTS: There were no significant differences in donor demographic variables including age, height, weight, Hb, Hct, or red cell mass between the 2 groups. The double-unit erythrocytapheresis was completed earlier than the last manual WB PABD (at 15.3 ± 4.7 days and 6.5 ± 3.2 days before surgery, p<0.001). Hct values before surgery were higher in the double-unit erythrocytapheresis PABD group than in the manual WB PABD group (39.7 ± 3.2 vs. 38.6 ± 2.7, p=0.024). ΔHct and %ΔHct before the first PABD and before surgery were lower in the double-unit erythrocytapheresis PABD group than in the manual WB PABD group (-5.6 ± 2.8 vs. -6.8 ± 2.7, p=0.010 and -12.3 ± 5.9 vs. -14.8 ± 5.6, p=0.008, respectively). The incidence of additional allogeneic blood transfusions during or after surgery and the post-operative Hb and Hct values were similar in the 2 groups. The length of hospital stay after surgery was significantly longer in the manual WB PABD group than in the double-unit erythrocytapheresis group (6.1 ± 2.5 vs. 5.4 ± 1.9, p=0.043). Of the 33 donors in the double-unit erythrocytapheresis PABD group, 7 (21.2%) reported discomforts related to the procedure, and 6 graded the discomforts (hypocalcemia, perioral tingling sense, paresthesia, dizziness, stuffiness, pain on the intravenous site, and muscle tension) as mild. CONCLUSION: The single session, double-unit erythrocytapheresis prolonged the time interval between PABD and surgery and led to better hemodynamic recovery than the serial manual WB PABD, and hypocalcemic symptoms were mild.

Increased numbers of total nucleated and CD34+ cells in blood group O cord blood: an analysis of neonatal innate factors in the Korean population.

BACKGROUND: We analyzed neonatal factors that could affect hematopoietic variables of cord blood (CB) donated from Korean neonates. STUDY DESIGN AND METHODS: The numbers of total nucleated cells (TNCs), CD34+ cells, and CD34+ cells/TNCs of CB in neonates were compared according to sex, gestational age, birth weight, birth weight centile for gestational age, and ABO blood group. RESULTS: With 11,098 CB units analyzed, blood group O CB showed an increased number of TNCs, CD34+ cells, and CD34+ cells/TNCs compared with other blood groups. Although TNC counts were lower in males, no difference in the number of CD34+ cells was demonstrated because the number of CD34+ cells/TNCs was higher in males. An increase in the gestational age resulted in an increase in the number of TNCs and decreases in the number of CD34+ cells and CD34+ cells/TNCs. The numbers of TNCs, CD34+ cells, and CD34+ cells/TNCs increased according to increased birth weight centile as well as birth weight. CONCLUSION: CB with blood group O has unique hematologic variables in this large-scale analysis of Korean neonates, although the impact on the storage policies of CB banks or the clinical outcome of transplantation remains to be determined.

Impact of vitamin D receptor gene polymorphisms on clinical outcomes of HLA-matched sibling hematopoietic stem cell transplantation.

We hypothesized that polymorphisms of the vitamin D receptor (VDR) gene might affect clinical outcomes of allogeneic hematopoietic stem cell transplantation (HSCT). Three VDR gene polymorphisms (BsmI G>A, ApaI G>T, and TaqI T>C) were genotyped in 147 patients who underwent HLA-matched sibling allogeneic HSCT. Frequencies of infection, graft-vs.-host disease (GVHD), overall survival (OS), and disease-free survival (DFS) were compared according to genotypes and haplotypes. Infection and acute GVHD had trends to be less frequent in patients with ApaI TT genotype than non-TT genotypes (p = 0.061 and p = 0.059, respectively). For TaqI genotypes, there were no statistical differences in frequency of infection and acute GVHD (p = 0.84 and p = 0.30, respectively), but TC genotype was associated with longer OS and DFS than TT genotype (p = 0.022 and p = 0.038, respectively). In the ApaI-TaqI haplotype analysis, patients with TC haplotype had significantly longer OS and DFS than those without TC haplotype (p = 0.022 and p = 0.038, respectively). In multivariable analysis, TaqI genotype and ApaI-TaqI haplotype of recipients were independent prognostic factors for both OS and DFS. This study suggests that the genotype and haplotype of VDR in recipient might be associated with clinical outcome of sibling HLA-matched HSCT.

Impact of cytokine gene polymorphisms on risk and treatment outcomes of aplastic anemia.

Autoreactive cytotoxic T cells play a key role in the pathogenesis of aplastic anemia (AA) by myelosuppressive cytokines including interferon-gamma, tumor necrosis factor alpha, and transforming growth factor beta. The purpose of this study is to determine which single nucleotide polymorphisms (SNPs) in cytokine genes were relevant to AA risk and whether the relevant SNPs were associated with response to immunosuppressive therapy (IST). Among 84 screened patients, 80 patients confirmed as having acquired AA, and 84 age- and sex-matched healthy controls were analyzed consecutively. We genotyped ten polymorphisms in three cytokine genes (IFNG, TNF, and TGFB1) and FAS gene. We assessed the association between polymorphisms and AA risk, and the association between polymorphisms and response to IST in three genetic models (dominant, recessive, and additive). The IFNG -2,353 T allele (dominant model, OR = 0.43, p = .012) and TCA haplotype (dominant model, OR = 0.50, p = .038) were significantly associated with the development of AA. In addition, this relevant IFNG -2,353 T allele and TCA haplotype were related to the response of IST (dominant model, OR = 0.076, p = .034). Concerning TGFB1, although its polymorphisms are not related to AA susceptibility, P10L T allele (recessive model, OR = 0.18, p = .038) and CT haplotype (dominant model, OR = 5.68, p = .038) were associated with response to IST. This exploratory study concurred with prior studies indicating that polymorphisms in IFNG are related to AA susceptibility. In addition, it was found that polymorphisms in IFNG and TGFB1 are associated with response to IST.

Thrombomodulin phenotype of a distinct monocyte subtype is an independent prognostic marker for disseminated intravascular coagulation.

INTRODUCTION: Thrombomodulin, which is expressed solely on monocytes, along with tissue factor (TF), takes part in coagulation and inflammation. Circulating blood monocytes can be divided into 3 major subtypes on the basis of their receptor phenotype: classical (CD14brightCD16negative, CMs), inflammatory (CD14brightCD16positive; IMs), and dendritic cell-like (CD14dimCD16positive DMs). Monocyte subtype is strongly regulated, and the balance may influence the clinical outcomes of disseminated intravascular coagulation (DIC). Therefore, we investigated the phenotypic difference in thrombomodulin and TF expression between different monocyte subtypes in coagulopathy severity and prognosis in patients suspected of having DIC. METHODS: In total, 98 patients suspected of having DIC were enrolled. The subtypes of circulating monocytes were identified using CD14 and CD16 and the thrombomodulin and TF expression in each subtype, expressed as mean fluorescence intensity, was measured by flow cytometry. Plasma level of tissue factor was measured by ELISA. In cultures of microbead-selected, CD14-positive peripheral monocytes, lipopolysaccharide (LPS)- or interleukin-10-induced expression profiles were analyzed, using flow cytometry. RESULTS: The proportion of monocyte subtypes did not significantly differ between the overt and non-overt DIC groups. The IM thrombomodulin expression level was prominent in the overt DIC group and was well correlated with other coagulation markers. Of note, IM thrombomodulin expression was found to be an independent prognostic marker in multivariate Cox regression analysis. In addition, in vitro culture of peripheral monocytes showed that LPS stimulation upregulated thrombomodulin expression and TF expression in distinct populations of monocytes. CONCLUSIONS: These findings suggest that the IM thrombomodulin phenotype is a potential independent prognostic marker for DIC, and that thrombomodulin-induced upregulation of monocytes is a vestige of the physiological defense mechanism against hypercoagulopathy.

Introducing pulsed low-intensity ultrasound to culturing human umbilical cord-derived mesenchymal stem cells.

The human umbilical cord (hUC) is a source of adult tissue-derived mesenchymal stem cells (MSCs). A pulsed low-intensity ultrasound (PLIUS) method is described for increasing the yield of MSCs from whole hUC without enzymatic digestion or growth factor supplementation. Analysis of the immunophenotype of cells and a differentiation study were performed to show the compatibility of MSCs. The mean number of cells recovered from primocultures of hUC was 6 x 10(5) cells/cm. PLIUS resulted in a 3.3-fold increase in MSC yield at passage 0. PLIUS exposure increases the yield of hUC-MSCs by promoting release and enhancing proliferation.

Differences in circulating dendritic cell subtypes in pregnant women, cord blood and healthy adult women.

Different subtypes of dendritic cells (DC) influence the differentiation of naíve T lymphocytes into T helper type 1 (Th1) and Th2 effector cells. We evaluated the percentages of DC subtypes in peripheral blood from pregnant women (maternal blood) and their cord blood compared to the peripheral blood of healthy non pregnant women (control). Circulating DC were identified by flow cytometry as lineage (CD3, CD14, CD16, CD19, CD20, and CD56)-negative and HLA-DR-positive cells. Subtypes of DC were further characterized as myeloid DC (CD11c(+)/CD123(+/-)), lymphoid DC (CD11c(-)/CD123(+++)) and less differentiated DC (CD11c(-)/CD123(+/-)). The frequency of DC out of all nucleated cells was significantly lower in maternal blood than in control (P<0.001). The ratio of myeloid DC/lymphoid DC was significantly higher in maternal blood than in control (P<0.01). HLA-DR expressions of myeloid DC as mean fluorescence intensity (MFI) were significantly less in maternal blood and in cord blood than in control (P<0.001, respectively). The DC differentiation factors, TNF-alpha and GM-CSF, released from mononuclear cells after lipopolysaccharide stimulation were significantly lower in maternal blood than in control (P<0.01). The distribution of DC subtypes was different in maternal and cord blood from those of non-pregnant women. Their role during pregnancy remains to be determined.

Aurintricarboxylic acid upregulates the thrombomodulin expression of endothelial cells and peripheral blood monocytes.

Thrombomodulin has a central role in the regulation of coagulation through its ability to promote generation of the potent anticoagulant, activated protein C. Aurintricarboxylic acid (ATA) has been reported to inhibit platelet function by blocking von Willebrand factor binding to platelet glycoprotein Ib and to impede thrombosis development in vivo. In the present study, we demonstrated a novel antithrombotic effect of ATA. The surface thrombomodulin expression of endothelial cells and peripheral blood monocytes was upregulated by ATA in a dose-dependent and time-dependent manner. ATA also increased the mRNA level of endothelial thrombomodulin in a dose-dependent manner. Tumor necrosis factor (TNF)-alpha (50 ng/ml) or lipopolysaccharide (20 microg/ml) downregulated the expression of endothelial thrombomodulin. Blocking of nuclear factor-kappaB by parthenolide effectively inhibited the TNF-alpha-induced thrombomodulin downregulation of endothelial cells. ATA increased endothelial thrombomodulin expression that was downregulated by TNF-alpha or lipopolysaccharide, in a dose-dependent manner. The inhibition of small G proteins of the Rho family by the Clostridium difficile toxin B-1,0643 did not increase thrombomodulin expression of endothelial cells, and ATA did not activate Rac1 in endothelial cells. These findings provide, at least in part, a novel platelet-independent mechanism of ATA that may explain the demonstrated antithrombotic efficacy of ATA.