ABSTRACT
Objective To evaluate the performance of diluted thrombin time (dTT) assay for detecting Dabigatran levels and observe whether this assay may meet the requirements of clinical laboratory.Methods According to EP15-A2,EP6-A,EP7-A and C-24 documents of the Clinical and Laboratory Standards Institute (CLSI),the precision,trueness,analytical measurement range,carryover rate and anti-biological interference of dTT assay were evaluated and the stability of specimen for dTT assay was observed.Results Both the within-day and between-day coefficient of variation (CV) of dTT assay for detecting Dabigatran levels were consistent with manufacturer's stated CV.Compared with target values of Dabigatran,the relative bias of 3 levels of proficiency test materials from College of American Pathologists (CAP) were less than 10％.The results meet linear verification when Dabigatran concentration was between 30.92 and 249.13 ng/mL.The carryover rate was-0.84％.There was no interference for Dabigatran levels by dTT assay for detecting Dabigatran when Hb≤3 g/L,triglyceride≤873 mg/dL,heparin≤2.2 IU/mL and FDP≤29 mg/L.The results of stability showed that plasma specimens for dTT could not be stored at room temperature more than 4 hours,at 4 ℃ more than 4 days,at-20 ℃ exceed 1 month,while at-80℃ the plasma specimens could be stored at least 6 months for dTT assay.Conclusion The precision,trueness,analytical measurement range,carryover rate,anti-biological interference of dTT assay may meet the requirement of clinical laboratory.The stability of the specimen can fulfill the clinical requirements.
ABSTRACT
<p><b>BACKGROUND</b>Superficial urothelial carcinoma (SUC) of the bladder is a common urinary tract tumor in China. There is a high recurrence rate of this tumor even after surgery and intravesical instillation. Previous reports have described a suppression of the immune system in cancer patients. Dendritic cells (DCs) play a pivotal role in the induction of an effective antitumor immune response. The aim of this study was to investigate the effects of surgery and epirubicin intravesical chemotherapy (IC) on peripheral blood DCs in subsets of patients with bladder SUC.</p><p><b>METHODS</b>A total of 66 SUC patients and 38 healthy controls were enrolled in this study. All the patients had undergone transurethral resection (TUR) of their cancer and adjunctive IC after tumor removal. The patients were divided into a non-recurrence group (n = 40) and a recurrence group (n = 26) based on the presence or absence of tumor recurrence. Blood samples were taken preoperatively (PreOP), on postoperative days (POD) 1 and 7, and at postoperative month (POM) 3. Flow cytometric analysis was used for the determination and quantitation of the surface markers CD80 and CD86 in circulating DC subsets.</p><p><b>RESULTS</b>The preoperative percentages of myeloid dendritic cells (mDCs) and expression of CD80 and CD86 were impaired in SUC patients compared to healthy controls (P < 0.05). The percentages of mDCs and these surface markers decreased significantly on POD 1 and increased on POD 7, remaining higher than the preoperative values in POM 3 (P < 0.05). The percentages of mDCs, and CD80 and CD86 in the non-recurrence group on PreOP, POD 7, and POM 3 were higher than those in recurrence group.</p><p><b>CONCLUSIONS</b>Surgical removal of SUC and adjunctive IC were associated with improved circulating mDC counts and function. Persistent depression of mDC counts and function after treatment in recurrence patients indicated lower antitumor immunity that may lead to tumor recurrence.</p>