Surveillance of Trend and Distribution of Stroke Mortality by Subtype, Age, Gender, and Geographic Areas in Tianjin, China, 1999–2006

Background

The purpose of this study was to analyze the epidemiological trend and distribution of stroke mortality in the city of Tianjin, China, in order to provide evidence for the prevention and control of stroke.

Methods

The study was based on 102 718 cases of stroke mortality in Tianjin between 1999 and 2006. The cause of death was coded according to the International Classification of Diseases into stroke subtypes. Standardized mortality rates were calculated for stroke and its subtypes, adjusted for age and gender using the year 2000 world standard population. The age, gender, and geographic distribution of stroke and subtype mortality were analyzed. χ2-tests were used to determine the statistical significance of differences in mortality trends.

Results

The stroke mortality rate in Tianjin declined from 133·52/100000/year in 1999 to 102·52/100000/year in 2006. The stroke mortality rate for males was higher than that for females. Stroke mortality rates increased with increasing age. The subtypes of stroke have changed considerably in Tianjin. Hemorrhagic was major in 1999–2001, while cerebral infarction attained the first rank and accounted for more than 50% of stroke mortality in 2002–2006. The most pronounced finding was that the proportion of ischemic stroke was 66·65% in the urban population and over 20% higher than that in the rural area. Stroke in the suburban area was mainly hemorrhagic stroke, up to 62·67%.

Conclusions

There are significant differences in the distribution of stroke mortality by subtype, age, gender, and geographic areas in Tianjin, China. Various subtypes of stroke are associated with different risk factors and therefore require different public health prevention and control measures. This study provides pertinent information for formulation of measures for the prevention and control of stroke.

MO19390 (SAiL): Incidence and management of hypertension (HTN) during bevacizumab (Bv)-based first-line therapy in patients (pts) with advanced non-small cell lung cancer (NSCLC)

e19002

Background: SAiL is an ongoing, multicenter, international, open-label trial investigating the safety and efficacy of first-line Bv in combination with a range of standard first-line chemotherapy regimens in >2,000 pts with advanced NSCLC. Methods: Eligible pts had locally advanced, metastatic or recurrent non-squamous NSCLC. Pts received Bv (7.5mg/kg or 15mg/kg q3w) with standard first-line chemotherapy for up to 6 cycles, then Bv monotherapy until disease progression. Pts with uncontrolled HTN (systolic >150mmHg and/or diastolic >100mmHg) or active cardiovascular disease at baseline were excluded. The primary endpoint was the incidence of serious adverse events (SAEs) related to Bv, and AEs of special interest, including hypertension. Bv was interrupted for persistent or symptomatic grade 3 HTN and discontinued if blood pressure remained uncontrolled by medication. Bv was discontinued for grade 4 hypertension. Results: This analysis was based on 2,008 pts who received at least 1 dose of study medication (data cut-off July 2008): median age was 59 and ECOG PS 0/1/2 (%) was 38.1/56.1/5.8. Antihypertensive medications at baseline included ACE inhibitors (11.3%), Angiotensin II receptor blockers (6.2%), beta-blockers (10.9%), calcium channel blockers (7.7%) and diuretics (8%). Pts received a median of 5 Bv cycles and 4 chemotherapy cycles. Overall, 388 patients (19.3%) had a total of 487 incidents of HTN (any grade), occurring equally in patients ≤65 and >65 years of age (18.9% and 20.2%, respectively). Only six pts (0.3%) had grade ≥3 HTN events related to Bv meeting the criteria for SAE. The overall incidence of HTN was consistent across the various types of chemotherapy regimens. Conclusions: The incidence of grade ≥3 HTN was low, and the overall HTN incidence was similar across age groups and chemotherapy regimens. Updated results will be presented, including data on HTN management and evolution of HTN events during administration of antihypertensive medication.

[Table: see text]

Phase I dose-escalation study of thoracic radiotherapy in combination with gefitinib in patients with IIIB/IV non-small cell lung cancer (NCT00497250)

e14581

Background: Cinical studies have confirmed that gefitinib, an EGFR-TKI, is effective for some advanced NSCLC patients. Patients with Asian ethnicity are reported to have a higher response rate with gefitinib monotherapy. However, a higher incidence of interstitial lung disease, sometimes lethal, is also found. The combination of gefitinib and radiotherapy has been observed to have a synergistic, anti-proliferative effect against NSCLC in vitro. This phase I study assessed the safety, clinical feasibility and optimally tolerated regimen (OTR) of this combination in patients with pretreated locally advanced or metastatic (IIIB/IV) NSCLC. Methods: Patients with stage IIIB or selected stage IV, failure of platinum-based chemotherapy regimen NSCLC were eligible. Four Cohorts of eight patients each were planned to be treated with escalating doses from 54 to 60 Gy of conformal or intensity- modulated radiotherapy (2Gy/Fx) administered in combination with gefitinib 250mg daily during RT and 60 days after the completion of RT to determine the OTR. Results: Since June 2007, 2 cohorts, a total of 16 patients, were enrolled and treated: 8 stage IIIB and 8 stage IV; 2 squamous-cell carcinoma and 14 adenocarcinoma; 8 smokers and 8 nonsmokers. Prior-chemotherapy regimen was consisted of NP, GP and TP for a median of 3.5 cycles (range, 1–5). Median follow-up time was seven months. Mean progression-free survival time was 5.2 months (median, 3.9; range, 1.7–12.3). Overall, adverse events were mild to moderate in severity. The most frequent grade 2 events included pneumonitis (31%) and dysphagia (19%). There were one treatment-related grade 3 event, which was nausea, and no grade 4 events. Most of the failure patterns were out-of-field (11/13) and the most common distant metastasis organ was the lungs. Three patients are progression-free to date. Conclusions: Thoracic radiotherapy up to 56 Gy concurrent with gefitinib 250 mg daily was well tolerated and clinically active in this group of pretreated Chinese NSCLC patients, including nonsmokers with adenocarcinoma. Accrual is continuing. Sponsorship: This work was partly supported by Program for New Century Excellent Talents in University (NCET), Ministry of Education.

No significant financial relationships to disclose.

Sequence analysis of the MSP 1 gene of Plasmodium falciparum isolates from Hainan, China

AIM

To obtain the complete sequence and analyze the diversity of the MSP 1 molecule from the Chinese isolates of Plasmodium falciparum.

METHODS

Genomic DNA was prepared directly from blood samples spotted on filter papers from 2 malaria patients from Baoting County, Hainan Province. PCR amplification of the target gene was carried out using 5 pairs of oligonucleotides specific for the MSP 1 gene. Direct sequencing of the target gene fragments was performed using ABI PRISM Dye Terminator Cycle Sequencing Ready Reaction Kit (Perkin Elmer) in a automatic ABI PRISM 310 Genetic Analyzer.

RESULTS

For the first time, two complete sequences of the MSP1 gene from two Chinese isolates of Plasmodium falciparum were obtained. A comparison with the previously reported sequences identified them as members of the MAD20 allelic family. The deduced amino acid sequences of the MSP1 from this two Chinese isolates were identical with each other except for Blocks 2, 4 and 8.

CONCLUSION

The sequences of the MSP 1 from two Chinese isolates of P. falciparum belong to the MAD20 allelic family. Minor variations through the whole sequences exist compared with the MAD20 sequence. The results provide the first evidence of the diversity of the MSP 1 molecule from Chinese isolates of Plasmodium falciparum.

Radiotherapeutic management of isolated local-regional recurrence following mastectomy

Abstract #5135

Background: Postmastectomy isolated local-regional recurrence(ILRR) remains a therapeutic challenge. This retrospective study aims to evaluate the role of radiotherapy(RT) in these patients and to analyze factors that influence local-regional control and survival.
 Methods: 255 pts with chest-wall(CW) and/or regional nodes recurrence(supraclavicular SC, axillary AXI and internal mammary nodes IMN) as first failure and received RT during 1990 and 2005 were analyzed, included 109 CW recurrence only, 114 regional nodes only and 32 pts with both, resulted in 304 recurrent sites. The median dose was 60Gy(47-74). Systemic treatment was give to 190 pts, including chemotherapy in 171, endocrine therapy(ET) in 69, and both in 41 pts.
 Results: The median disease-free interval(DFI) was 22 mo(2-260 mo), which were 37 and 17 mo in pts with positive hormonal receptor (HR) and negative HR respectively. Median follow-up was 45 mo (9 mo -15.5 yrs). The 2, 5 and 8-yr overall survival rate was 86.4%, 56.5% and 35% respectively. Median survival time after recurrence was 79 mo. The 2, 5 and 8-yr local control rate was 56.1%, 36.3% and 27.6% respectively. 79 second recurrence in the initial recurrent region and 83 subsequent recurrence in other local-regional sites were found.
 
 CW is the most common site of second recurrence. Multivariate analysis showed that no CW involvement, non-diffuse recurrence and radiation to the entire recurrent region were independent prognostic factors on local control of initial recurrent sites. ET proved to be the only independent prognostic factors on subsequent recurrence in other sites. In pts with CW recurrence, small field(67 pts) resulted in significantly lower 5-yrs local control compared to entire CW irradiation(74 pts) (33.6% vs 55.6%, p=0.023). Cox regression model found that DFI≥1yr, positive HR, solitary CW or non-supraclavicular nodal recurrence were independent favorable prognostic factors on overall survival .
 Conclusions: RT is an effective approach for ILRR after mastectomy. Radiation fields should cover the entire recurrent region. Elective irradiation to the CW in pts with nodal recurrence is recommended. Prognostic Index based on the positive multivariate analysis could be established as to stratify different prognostic sub-groups.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5135.

Thoracoscopic enucleation of esophageal leiomyoma: a retrospective study on 40 cases

Esophageal leiomyoma is the most common benign esophageal tumor. Thoracoscopic enucleation is currently a preferred approach to most of these lesions. We present our experiences of enucleation of these tumors using thoracoscopic approach. A retrospective review of 40 patients who underwent enucleation of esophageal leiomyoma from 1997 to 2007 in our institute was conducted. Presenting symptoms, operative approach, tumor size, tumor shape, outcomes, and indication for this approach were analyzed. Forty patients were identified. Postoperative histopathology confirmed the leiomyoma in all patients. The thoracoscopic enucleation was completed in 34 cases, and the operation was converted to open procedure in six cases. Reasons for conversion included too small tumors to be visualized in two cases, thoracic cavity adhesion in one case, and the too large tumors in three cases. The median operating time was 70 min (50 to 210 min). Mean tumor size was 3.7 cm (0.5-10 cm). There were no major postoperative complications. Symptoms especially dysphasia were relieved postoperatively. Short- and long-term follow-up was satisfactory with none of the patients having tumor recurrences or other problems. Thoracoscopic enucleation of esophageal leiomyoma is technically safe and effective. It is currently the best choice for management of esophageal leiomyoma 1 to 5 cm in diameter. It can also be tried on a tumor larger than 5 cm, although the possibility of conversion to thoracotomy increases along with tumor growing and surrounding the esophagus.

Solubilization and Pharmacokinetic Behaviors of Sodium Cholate/Lecithin-Mixed Micelles Containing Cyclosporine A

The purpose of this study was to investigate the solubilization capacity of sodium cholate/lecithin-mixed micelles and to evaluate the potential of mixed micelles as a carrier of cyclosporine A for intravenous infusion. The mixed micelles were prepared by coprecipitation technique. The formulation components and preparation procedures, which may affect the solubilization of cyclosporine A, were studied. The dilution stability of cyclosporine A-containing mixed micelles was investigated. Pharmacokinetic behaviors of mixed micelles in rabbits after intravenous infusion were compared with Sandimmun. Results showed the strategies to increase the solubility of cyclosporine A include lowering the molar ratio of sodium cholate to lecithin, increasing the concentration of lecithin, and reducing the ionic strength of the dispersion medium and temperature. The largest solubility was found to be 5.42 +/- 0.16 mg/ml. The leakage of mixed micelles in 5% glucose (5.84%) was much less than that in saline solution (36.7%). The relative bioavailability of mixed micelles versus Sandimmun was 112 +/- 20%, and statistical analysis demonstrated both preparations were bioequivalent. Sodium cholate/lecithin-mixed micelles are promising carriers in the intravenous delivery of cyclosporine A, considering their capability of large-scale production and low-toxic property.

[Therapeutic effects of chitosan/polyethylene glycols-succinate/mitomycin C film drug delivery system on epidural scarring tissues after laminectomy of SD rats]

OBJECTIVE

To investigate the therapeutic effect of the chitosan/polyethylene glycols-succinate/ mitomycin C (CH/PEG-SA/MMC) film on epidural scarring tissues.

METHODS

According to a specific proportion of respective materials, the film of CH/PEG-SA/MMC was developed under some condition. Thirty SD rats were selected and randomized into 6 groups with 5 rats in each group. A rat model of lumbar laminectomy was used. The amount of 20 mg of the CH film was implanted into the animals in group I, 20 mg of CH/PEG film in group II, 20 mg of CH/PEG-SA film in group III, 0.05 mg/mL of the MMC soaking for 5 minutes in group IV, 20 mg of CH/PEG-SA/MMC film in group V, and nothing was done in group VI. Specimens were harvested 4 weeks after the above procedures and were then subjected to immunohistochemical and histological examinations to compare their therapeutic effects on epidural cicatricial tissues.

RESULTS

All rats were in good conditions after operation, without gait abnormality, restlessness, infection and death. There was no significant difference among the 6 groups in the postoperative Rydell score (P < 0.05). The content of hydroxyproline in groups I, II, III, IV, V and VI was (0.570 8 +/- 0.345 0), (0.728 6 +/- 0.150 6), (0.553 4 +/- 0.122 3), (0.313 3 +/- 0.106 4), (0.261 9 +/- 0.102 1) and (1.020 1 +/- 0.120 6) microg/mg, respectively. There was a significant difference between groups IV, V and groups I, II, III (P < 0.05), and there was significant difference between group VI and the rest 5 groups (P < 0.05). According to the histological observation, group V had less collagenous fiber paralleling the dura mater, with few inflammatory cells infiltration, with few capillary vessels and no reaction of macrophages.

CONCLUSION

CH/PEG-SA/MMC films can effectively reduce the amount of Hyp in epidural scarring tissues after lumbar laminectomy and therefore is a good treating method in preventing scarring tissue adhesion.

[Development of chitosan/polyethylene glycols-succinate mitomycin C film drug delivery system and releasing character in vitro]

OBJECTIVE

To develop the chitosan/polyethylene glycols succinate (CH/PEG-SA) mitomycin C (MMC) film drug delivery system and its release effect in vitro.

METHODS

MMC loading in composite films was determined using a UV-visible spectrophotometer. Freeze-dried films (90 mg) were immersed in 1 mL PBS buffer (pH 7.4). The concentrations of MMC releasing in vitro were calculated refer to the standard curve of relationship between the concentrations of MMC and the value of UV-visible spectrophotometer. The curve of the concentrations of MMC releasing from the films in vitro was drawn at different time. The relationship between the films, structure and the drug releasing was revealed.

RESULTS

The films showed swelling without brittleness. The equation of Linear Regression was y=0.593x(3)-2.563x(2)+25.944x-0.236 (R2=1.000). The film had a good drug delivery capability. The samples weighing 20 mg were soaked into the liquid of PBS, the releasing concentrations of MMC were 14.9616 microg/mL at 12 days, 14.4824 microg/mL at 18 days and 11.4092 microg/mL at 32 days, which was higher than ID50 of MMC (10.4713 microg/L) to fibroblast. Then MMC was released at a low concentration. The releasing concentrations of MMC was 0.1793 microg/mL at 60 days until being delivered completely.

CONCLUSION

The flexibility is enhanced , and the mechanical function is improved, so that there is better nature of membrane. The initial burst is avoided more effectively, and the drug releasing would be maintained for a certain time.

Standardised quantitative morphometry: a modified approach for quantitative identification of prevalent vertebral deformities

Our approach for the quantitative identification of vertebral deformity (standardised quantitative morphometry, SQM) reduces problems associated with obtaining reference intervals from populations with high prevalence of fracture. In women with osteoporosis, agreement with radiological diagnosis (surrogate gold standard) was better for SQM than QM using the Eastell-Melton method.

INTRODUCTION

Use of reference intervals for quantitative vertebral morphometry (QM) derived by statistical trimming can be problematic in reference populations with high prevalence of deformity. We have developed a modified approach known as standardised quantitative morphometry (SQM), whereby vertebral height is standardised to eliminate variation between individuals. The aims of this study were to compare SQM to QM (Eastell-Melton method) for identification of prevalent vertebral deformities, using qualitative radiological diagnosis as the gold standard, and automate the process.

METHODS

Our study populations were a clinic-based sample of 80 women ages 48 to 87 years with a high prevalence of vertebral deformity and a general practice (GP)-based sample of 372 women ages 50 to 85 years. Agreement with the gold standard was tested for SQM and QM.

RESULTS

Agreement was better for SQM (kappa = 0.80) than for QM (kappa = 0.14) in the clinic sample using clinic-based reference data. The agreement was improved for QM using the GP-based reference data, kappa = 0.63. In the GP population, agreement was good for both SQM and QM (kappa = 0.59 and 0.54 respectively).

CONCLUSIONS

In our population with a high prevalence of vertebral fracture, SQM performs better than the Eastell-Melton method.

Is short vertebral height always an osteoporotic fracture? The Osteoporosis and Ultrasound Study (OPUS)

INTRODUCTION AND HYPOTHESIS

Diagnosis of prevalent osteoporotic vertebral fracture is complicated by normal or developmental variation in vertebral shape or size and non-osteoporotic deformities that appear to have 'reduced' height. Using our visual approach, the algorithm-based qualitative method (ABQ) a vertebra with apparent "reduced" height without evidence of osteoporotic endplate depression is classified as non-osteoporotic short vertebral height (SVH). We aimed to determine whether ABQ classification of SVH represents true or false negative diagnosis of osteoporotic vertebral fracture, by testing the associations with clinical outcomes of osteoporosis or vertebral fracture.

METHODS

The ABQ method was used to assess spinal radiographs acquired at baseline for a subset of 904 postmenopausal women participating in the Osteoporosis and Ultrasound Study (OPUS). The sample was enriched with vertebral fracture cases. Subjects were categorized by ABQ diagnosis as (i) normal, (ii) non-osteoporotic short vertebral height (SVH) or (iii) osteoporotic vertebral fracture.

RESULTS

Women were classified by ABQ as follows: osteoporotic vertebral fracture, n=231; SVH, n=376 and normal, n=297. Women with vertebral fracture were older, with lower height, weight and height loss than those classified as SVH or normal. Women with SVH were heavier and older, with greater historical height loss than normal women. Age-adjusted SD units (z-scores) for BMD were lower than expected among women with osteoporotic vertebral fracture, but not among those with SVH. There was a significant association between diagnosis of osteoporotic vertebral fracture and history of low-trauma non-vertebral and vertebral fracture (p<0.001, odds ratios=3.2 and 20.6, respectively). There was also an association between diagnosis of SVH and previous low-trauma non-vertebral fracture (p<0.05, odds ratio=1.7).

CONCLUSIONS

Short vertebral height without evidence of central endplate fracture in postmenopausal women is largely unrelated to osteoporosis. Quantitative morphometry should not be used alone for the assessment of vertebral fracture in clinical decision making: we recommend differential diagnosis of morphometric vertebral deformities by an expert reader to rule out non-osteoporotic deformities with short vertebral height.

The woodchuck hepatitis virus post-transcriptional regulatory element reduces readthrough transcription from retroviral vectors

The woodchuck hepatitis virus post-transcriptional regulatory element (WPRE) increases transgene expression from a variety of viral vectors, although the precise mechanism is not known. WPRE is most effective when placed downstream of the transgene, proximal to the polyadenylation signal. We hypothesized that WPRE likely reduces viral mRNA readthrough transcription by improving transcript termination, which in turn would increase viral titers and expression. Using a Cre-lox-mediated plasmid-based assay, we found significant readthrough transcription from gamma-retroviral vector (RV) long terminal repeat (wt RV-LTR) and RV LTR with a self-inactivating deletion (SIN RV-LTR). WPRE, when placed upstream of the RV LTRs, significantly reduced readthrough transcription. Readthrough, present at much lower levels with the SIN HIV-1 LV-LTR, was also reduced with WPRE. When placed in RV vectors, WPRE increased total RV genomic mRNA; and increased viral titers from transiently transfected 293T cells and stable PG13 producer cells by 7- to 15-fold. The mechanism of increased titers and expression was not due to increased nuclear mRNA export, increased rate of viral transcription or a significant increase in viral mRNA half-life. Our results showed that WPRE improved vector genomic transcript termination to increase titers and expression from RVs.

Glucagon receptor knockout mice are resistant to diet-induced obesity and streptozotocin-mediated beta cell loss and hyperglycaemia

AIMS/HYPOTHESIS

Under normal physiological conditions, glucagon signalling is important in glucose homeostasis. Hyperglucagonaemia or altered insulin:glucagon ratio plays a role in maintaining hyperglycaemia in subjects with type 2 diabetes. It has been reported that glucagon receptor knockout (Gcgr (-/-)) mice develop normally and have lower plasma glucose on a normal diet. The goal of the current research was to further investigate the role of glucagon signalling in metabolic control and glucose homeostasis.

METHODS

Gcgr (-/-) mice were challenged with a high-fat diet (HFD) and with streptozotocin, which induces beta cell damage. They were then analysed for whole-body and serum metabolic phenotypes as well as pancreatic islet morphology.

RESULTS

In comparison with wild-type mice, Gcgr (-/-) mice exhibited decreased body weight and food intake, reduced plasma glucose levels, and improved oral and intraperitoneal glucose tolerance. Elevated glucagon-like peptide-1 levels and reduced gastric emptying were also observed in Gcgr (-/-) mice, which also had reduced HFD-induced hyperinsulinaemia and hyperleptinaemia, and were resistant to the development of hepatic steatosis. In addition, Gcgr (-/-) mice were resistant to STZ-induced hyperglycaemia and pancreatic beta cell destruction.

CONCLUSIONS/INTERPRETATION

This study demonstrates that blocking glucagon signalling by targeted Gcgr gene deletion leads to an improvement in metabolic control in this mouse model.

Expression of Endo180 is spatially and temporally regulated during wound healing

AIMS

Interactions of cells with the extracellular matrix are important for normal wound healing and may play a role in scar formation. Remarkably, wound healing in human gingiva does not result in scar formation and serves as a model for wound regeneration. Endo180 (CD280) is a cell surface receptor that has novel functions to regulate cell migration and bind and internalize collagens that are key processes in wound healing. The aim of this study was to examine the expression of Endo180 during gingival wound regeneration.

METHODS AND RESULTS

Biopsies were collected from normal human gingiva and 1-60 days after wounding and expression of Endo180 was analysed by immunostaining. Expression of Endo180 by cultured fibroblasts and keratinocytes was studied by immunoblotting and semiquantitative reverse transcriptase-polymerase chain reaction. In normal gingiva, Endo180 was expressed by basal epithelial cells, fibroblasts, myofibroblasts, pericytes, macrophages and endothelial cells. In wounds, Endo180 expression was spatiotemporally increased in the migrating and differentiating wound epithelium, in subsets of myofibroblasts, pericytes, macrophages and endothelial cells. Growth factors involved in wound healing up-regulated the expression of Endo180 in keratinocytes and fibroblasts.

CONCLUSIONS

The findings suggest that Endo180 plays a role in re-epithelialization and connective tissue remodelling during wound regeneration.

B7-H1 expression is upregulated in peripheral blood CD14+ monocytes of patients with chronic hepatitis B virus infection, which correlates with higher serum IL-10 levels

Chronicity in hepatitis B virus (HBV) infection is maintained by increased type 2 T-helper cell response, possibly because of increased interleukin-10 (IL-10) productions. B7-H1 can negatively regulate T-cell responses via its receptor, programmed death 1. Ligation of B7-H1 to T-cells can result in the preferential secretion of IL-10. In this study, we investigated whether there was an upregulated expression of B7-H1 in peripheral blood mononuclear cells in patients chronically infected by HBV and further explored the correlation between B7-H1 expression and serum interleukin 2, interferon-gamma, IL-10, HBeAg, alanine aminotransferase (ALT) levels and viral load. Fifty-five patients with chronic HBV infection and 20 healthy controls (HCs) were enrolled in the present study. The results showed that in patients with chronic hepatitis B CD14+ monocytes but not CD3+ and CD19+ cells had a significantly increased expression of B7-H1 compared with HCs, which positively correlates with serum IL-10 levels and the presence of HBeAg and negatively correlates with serum ALT levels. In conclusion, chronic HBV patients harbour an increased B7-H1 expression in CD14+ monocytes compared with controls, which may be responsible for the increased serum IL-10 levels. This might be an important way by which HBV evades an adequate immune response, leading to viral persistence and disease chronicity.

Mycophenolic Acid Upregulates B7-DC Expression on Dendritic Cells, Which Is Associated With Impaired Allostimulatory Capacity of Dendritic Cells

In addition to its effects on lymphocytes, mycophenolic acid (MPA) may inhibit the allostimulatory capacity of dendritic cells (DC) via unknown mechanisms. B7-H1 and B7-DC surface markers on DC negatively regulate T-cell responses via the receptor PD-1. In this study, we sought to investigate whether B7-H1 and B7-DC are responsible for the inhibitory functions of MPA on DC. Mouse bone marrow-derived DC were cultured with recombinant granulocyte macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4 in the presence or absence of MPA (0.01 micromol and 0.1 micromol). The DC phenotype was assessed by flow cytometry, their immunostimulatory capacity measured by mixed lymphocyte reaction (MLR), and cytokine production by ELISA. The results showed that MPA not only inhibited the expression of major histocompatibility complex (MHC) class II and costimulatory molecules CD80 and CD86 but upregulated B7-DC expression on mature DC induced by LPS. These findings were associated with a reduced allostimulatory ability and an altered cytokine secretion pattern of DC. Thus, we suggest that MPA upregulates B7-DC expression during DC maturation induced by LPS in vitro, an effect that may be responsible for MPA-mediated inhibitory effects on the allostimulatory capacity of DC.