Outcomes of kidney transplantation over a 16-year period in Korea: An analysis of the National Health Information Database

Background: This study investigated the outcomes of kidney transplantation (KT) over a 16-year period in Korea and identified risk factors for graft failure using a nationwide population-based cohort. Methods: We investigated the Korean National Health Insurance Service-National Health Information Database. Health insurance claims for patients who underwent KT between 2002 and 2017 were analyzed. Results: The data from 18,331 patients who underwent their first KT were reviewed. The percentage of antithymocyte globulin (ATG) induction continuously increased from 2.0% in 2002 to 23.5% in 2017. Rituximab began to be used in 2008 and had increased to 141 patients (9.6%) in 2013. Acute rejection occurred in 17.3% of all patients in 2002 but decreased to 6.3% in 2017. The rejection-free survival rates were 78.8% at 6 months after KT, 76.1% after 1 year, 67.5% after 5 years, 61.7% after 10 years, and 56.7% after 15 years. The graft survival rates remained over 80% until 12 years after KT, and then rapidly decreased to 50.5% at 16 years after KT. In Cox's multivariate analysis, risk factors for graft failure included being male, more recent KT, KT from deceased donor, use of ATG, basiliximab, or rituximab, tacrolimus use as an initial calcineurin inhibitor, acute rejection history, and cytomegalovirus infection. Conclusions: ATG and rituximab use has gradually increased in Korea and more recent KT is associated with an increased risk of graft failure. Therefore, meticulous preoperative evaluation and postoperative management are necessary in the case of recent KT with high risk of graft failure.ope

Perioperative blood usage and therapeutic plasma exchange in kidney transplantation during a 16-year period in South Korea

Background: The frequency of kidney transplantation (KT) is increasing. Blood transfusion plays an important role in the success of KT. Therapeutic plasma exchange (TPE) is also used for desensitisation in ABO-incompatible KT and treatment of antibody-mediated rejection. Materials and methods: We analysed red blood cell (RBC), platelet, and fresh frozen plasma (FFP) usage and the number of TPE procedures performed during the hospitalisation of KT patients from 2002 to 2017 using the Korean National Health Insurance Service-National Health Information Database. Results: A total of 18,331 KT patients were included in this study. The number of transfused RBCs continued to increase from 4,806 units in 2002-2005 to 12,390 units in 2014-2017. However, the average number of RBCs transfused per patient decreased from 2.17 to 1.79 units. Estimated platelet usage increased from 4,259 units in 2002-2005 to 11,519 units in 2014-2017, and the proportion of filtered platelets increased from 72.6% to 83.4% during the same period. There was a huge increase in the total number of FFP units used, from 2,255 units in 2002-2005 to 51,531 units in 2014-2017. The number of TPE procedures performed also increased from 296 to 6,479 during the same period. Patients with acute rejection accounted for 8.8% of all KT patients, and more RBC and FFP were used for these patients and a greater number of TPE procedures were performed compared to those who did not experience rejection. Discussion: Blood usage and TPE have increased steadily with the increasing numbers of KTs. Therefore, continuous efforts are needed to ensure appropriate perioperative blood preparation and usage for KT patients.ope

Evaluation of Automated Assays for Measuring Serum Hyaluronic Acid: For the Diagnosis of Rheumatoid Arthritis

Background : Hyaluronic acid (HA) is present in the connective tissues wherein it functions as a lubricant. HA is known to be increased in both synovial fluid and serum when inflammation occurs in the joint. We measured serum HA concentrations by automated assays and determined its reference interval and its usefulness as a diagnostic marker in patients with rheumatoid arthritis (RA). Methods : Serum specimens collected from 121 healthy individuals and 253 patients with various arthritis were used for measuring HA with two automated assays, namely, LPIAACE (Mitsubishi, Japan) and LT Auto Wako (Wako, Japan). The association between serum HA concentration and the diagnosis of RA was estimated by receiver operator characteristic (ROC) analysis and multivariate logistic regression. Results : The 95th percentile upper reference limit of serum HA was 57.28 ng/mL (90% confidence interval [CI], 46.30-68.20 ng/mL) for LPIAACE and 72.64 ng/mL (90%% CI, 57.30-85.70 ng/mL) for LT Auto Wako. Area under the ROC curve values of serum HA for discriminating the RA group from the non-RA group were 0.68 for LPIAACE and 0.70 for LT Auto Wako. The odds ratio for serum HA in predicting RA was 1.02 (95% CI, 1.02-1.04) for LPIAACE and 1.03 (95% CI, 1.02-1.05) for LT Auto Wako. Conclusions : This study provides a reference interval for serum HA concentrations in Koreans. This result suggests that the serum HA concentrations could be helpful as a complementary marker for discriminating RA from other types of arthritis, as well as distinguishing patients with RA from healthy controls.ope

Comparison of the Abbott RealTime High-Risk Human Papillomavirus (HPV), Roche Cobas HPV, and Hybrid Capture 2 assays to direct sequencing and genotyping of HPV DNA

Infection with high-risk (HR) human papillomavirus (HPV) genotypes is an important risk factor for cervical cancers. We evaluated the clinical performances of two new real-time PCR assays for detecting HR HPVs compared to that of the Hybrid Capture 2 test (HC2). A total of 356 cervical swab specimens, which had been examined for cervical cytology, were assayed by Abbott RealTime HR and Roche Cobas HPV as well as HC2. Sensitivities and specificities of these assays were determined based on the criteria that concordant results among the three assays were regarded as true-positive or -negative and that the results of genotyping and sequencing were considered true findings when the HPV assays presented discrepant results. The overall concordance rate among the results for the three assays was 82.6%, and RealTime HR and Cobas HPV assays agreed with HC2 in 86.1% and 89.9% of cases, respectively. The two real-time PCR assays agreed with each other for 89.6% of the samples, and the concordance rate between them was equal to or greater than 98.0% for detecting HPV type 16 or 18. HC2 demonstrated a sensitivity of 96.6% with a specificity of 89.1% for detecting HR HPVs, while RealTime HR presented a sensitivity of 78.3% with a specificity of 99.2%. The sensitivity and specificity of Cobas HPV for detecting HR HPVs were 91.7% and 97.0%. The new real-time PCR assays exhibited lower sensitivities for detecting HR HPVs than that of HC2. Nevertheless, the newly introduced assays have an advantage of simultaneously identifying HPV types 16 and 18 from clinical samples.ope

Associations of Perioperative Red Blood Cell Transfusion With Outcomes of Kidney Transplantation in Korea Over a 16-Year Period

Background: This study investigated the associations between transfusion of different types of RBC preparations and kidney allograft outcomes after kidney transplantation (KT) over a 16-year period in Korea using a nationwide population-based cohort. Methods: We investigated the reported use of RBCs during hospitalization for KT surgery, rejection, and graft failure status using nationwide data from the National Health Information Database (2002-2017). The associations between the type of perioperative RBC product and transplant outcomes were evaluated among four predefined groups: no RBC transfusion, filtered RBCs, washed RBCs, and packed RBCs (pRBCs). Results: A total of 17,754 KT patients was included, among which 8,530 (48.0%) received some type of RBC transfusion. Of the patients who received RBC transfusion, 74.9%, 19.7%, and 5.4% received filtered RBCs, pRBCs, or washed RBCs, respectively. Regardless of the type of RBC products, the proportions of acute rejection and graft failure was significantly greater in patients receiving transfusion (P < 0.001). Cox proportional hazards regression analyses showed that the filtered RBC and pRBC groups were significantly associated with both rejection and graft failure. The washed RBC group also had hazard ratios greater than 1.0 for rejection and graft failure, but the association was not significant. Rejection-free survival of the pRBC group was significantly lower than that of the other groups (P < 0.001, log-rank test), and graft survival for the no RBC transfusion group was significantly greater than in the other groups (P < 0.001, log-rank test). Conclusions: Perioperative RBC transfusion was associated with poor graft outcomes. Notably, transfusion of pRBCs significantly increased transplant rejection. Therefore, careful consideration of indications for RBC transfusion and selection of the appropriate type of RBCs is necessary, especially for patients at high risk of rejection or graft failure.ope

Evaluation of a fully automated treponemal test and comparison with conventional VDRL and FTA-ABS tests.

We evaluated analytic performances of an automated treponemal test and compared this test with the Venereal Disease Research Laboratory test (VDRL) and fluorescent treponemal antibody absorption test (FTA-ABS). Precision performance of the Architect Syphilis TP assay (TP; Abbott Japan, Tokyo, Japan) was assessed, and 150 serum samples were assayed with the TP before and after heat inactivation to estimate the effect of heat inactivation. A total of 616 specimens were tested with the FTA-ABS and TP, and 400 were examined with the VDRL. The TP showed good precision performance with total imprecision of less than a 10% coefficient of variation. An excellent linear relationship between results before and after heat inactivation was observed (R(2) = 0.9961). The FTA-ABS and TP agreed well with a κ coefficient of 0.981. The concordance rate between the FTA-ABS and TP was the highest (99.0%), followed by the rates between FTA-ABS and VDRL (85.0%) and between TP and VDRL (83.8%). The automated TP assay may be adequate for screening for syphilis in a large volume of samples and can be an alternative to FTA-ABS.ope

Evaluation of the Performance of an Adiponectin ELISA-based Test and Establishing Serum Adiponectin Reference Intervals for Korean Population

Background : Adiponectin is a plasma protein secreted by adipose tissues and low serum adiponectin concentration has been reported to be associated with insulin resistance and metabolic syndrome (MS). We evaluated the performance of an ELISA-based assay for measuring serum adiponectin levels and established reference intervals of adiponectin for Korean population. Methods : Laboratory performance, including precision and linearity, of the AdipoMark Human Adiponectin ELISA kit (Mesdia Co., Korea) was assessed. Reference intervals of adiponectin concentration were determined after evaluation of 1200 subjects with no history of MS. Adiponectin was also measured in 100 patients with MS. Results : The mean concentrations of serum samples tested for precision evaluation were 6.66, 12.61, and 23.42 µg/mL: the ELISA showed total imprecision of 13.6%, 9.3%, and 10.5% CV for the respective concentrations. The assay demonstrated linear responses in the range of 1.8-29.9 µg/mL serum adiponectin levels. The 95% reference intervals for Korean population were 3.6-19.2 µg/mL for men and 4.5-34.2 µg/mL for women. ROC-area under the curve values of adiponectin for the diagnosis of MS were 0.85 for men and 0.83 for women. Low adiponectin level was independently associated with MS in the multivariate analysis. Conclusions : The adiponectin quantitation assay evaluated in this study showed acceptable laboratory and clinical performances in an ELISA platform. To meet the ever-increasing demand for a reliable assay for measuring adiponectin levels in the study of various metabolic diseases, this assay could be further improved by the automation of the platform.ope

Performance Characteristics of the UniCel DxI 800 Immunoassay for the Maternal Serum Quadruple Test, Including Median Values for Each Week of Gestation, in Korean Women

BACKGROUND: Maternal serum prenatal quadruple screening includes testing for alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG), unconjugated estriol (uE3), and dimeric inhibin A (DIA). We evaluated quadruple screening using an automated platform and looked for any ethnic differences in the median values of each marker. METHODS: We measured the concentrations of each quadruple test analyte using the UniCel DxI 800 system (Beckman Coulter, USA) in 788 Korean mid-trimester maternal serum samples and calculated their median values using Benetech software (Benetech, Canada). We also compared the results with those obtained using the Immulite 2000 assay (Siemens Healthcare Diagnostics, USA) or ELISA (DSL, USA) in 442 samples. RESULTS: We obtained mid-trimester median values for each marker. The following are the comparative results for each test using the Immulite 2000 assay or ELISA (x) and the UniCel DxI 800 immunoassay (y): AFP, y=1.10x+0.01, r=0.925; uE3, y=0.28x+0.24, r=0.885; hCG, y=1.22x-3047.8, r=0.944; and DIA, y=0.86x+15.31, r=0.833. Assay results for each of the four markers showed good correlations. However, significant biases necessitated new median calculations of prenatal risk estimates in all four tests. CONCLUSIONS: We established gestational age-specific second-trimester median values for four markers in Korean samples using the UniCel DxI 800 immunoassay system. Despite significant bias, there were good correlations between the results obtained using the UniCel DxI 800 immunoassay and those obtained using the Immulite 2000 assay.ope

Performances of CYFRA 21-1, Carcinoembryonic Antigen and Their Combination for Lung Cancer Diagnosis

"Background: The aim of this study was to compare the efficiency of cytokeratin 19 fragment (CYFRA 21-1) and carcinoembryonic antigen (CEA) for the diagnosis of lung cancer and to establish the optimal cut-off values. Methods: We retrospectively reviewed the medical records of 1,176 subjects with CYFRA 21-2 and CEA data; they were classified into 93 lung cancer cases and 1,083 total controls, including 146 age-matched controls. Multivariate analysis was used to determine the relationship between the concentration of each tumor marker and lung cancer diagnosis. The diagnostic efficiencies of tumor markers were evaluated using receiver operating characteristic curve analysis and areas under the curve (AUCs) were calculated. The optimal cut-offs for CYFRA 21-1 and CEA were also estimated. Results: Age, CYFRA 21-1, and CEA concentrations were independently associated with lung cancer diagnosis. Diagnostic efficiency of each tumor marker and its’ combination was different according to the histological types of lung cancer. For non-small cell lung cancer, the AUCs for the two-marker combination were the highest: 0.8661 and 0.7559 for total and age-matched controls, respectively. For squamous cell carcinoma, the AUCs for CYFRA 21-1 were the highest: 0.9245 and 0.8428 for total and age-matched controls, respectively. The sensitivity and specificity of CYFRA 21-1 and CEA for lung cancer diagnosis were improved when the cutoffs determined based on this study were applied. Conclusions: CYFRA 21-1 and CEA could be useful markers for diagnosing lung cancer and single or combination of markers may be useful according to different histological types of lung cancer."22Nkc

Clinical Evaluation of Two Rapid Antigen Tests for Severe Acute Respiratory Syndrome Coronavirus 2 Detection

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