Performance evaluation of platelet counting of Abbott Alinity hq and Sysmex XN-9000 automated hematology analyzer compared with international reference method.

INTRODUCTION: Accurate platelet counting is essential for risk assessment of bleeding and thrombosis. Abbott Alinity hq hematology analyzer was recently introduced, and its performance in platelet counting has yet to be evaluated comprehensively. In this study, we evaluated the performance of the optical platelet counting of Abbott Alinity hq (Alinity-PLT) and the impedance and fluorescent platelet counting of Sysmex XN-9000 (XN-PLT-I and XN-PLT-F) compared with the international reference method. METHODS: Blood samples were analyzed via Alinity hq and XN-9000 with PLT-F channel. Immuno-platelet (ImmnoPLT) reference method was performed with CD41/CD61 antibodies using FACSLyricTM flow cytometer (BD). Precision was determined using 10 replicates in a single run, and the platelet counts of Alinity-PLT, XN-PLT-I, XN-PLT-F, and ImmnoPLT were compared. RESULTS: At a platelet count of 13 × 109 /L, the CVs of Alinity-PLT, XN-PLT-I, and XN-PLT-F were 4.2%, 6.7%, and 4.3%, respectively, and at a platelet count of 44 × 109 /L, all showed a CV of less than 3%. For the total 210 samples, all three methods showed a very strong correlation with ImmunoPLT (r > 0.99). For platelet levels below 20 × 109 /L, XN-PLT-F showed the strongest correlation with ImmunoPLT (r = 0.975), and for platelet levels of 20-100 × 109 /L, Alinity-PLT and XN-PLT-I were comparable to ImmunoPLT. For platelet levels of 100-450 × 109 /L, XN-PLT-I was the most comparable to ImmunoPLT, and for platelet levels above 450 × 109 /L, Alinity-PLT was comparable to ImmunoPLT. CONCLUSIONS: All three methods were highly correlated with ImmunoPLT, and each method had different performance advantages according to the platelet levels.

Comparative analysis of COVID-19 guidelines from six countries: a qualitative study on the US, China, South Korea, the UK, Brazil, and Haiti.

BACKGROUND: In late January, a worldwide crisis known as COVID-19 was declared a Public Health Emergency of International Concern by the WHO. Within only a few weeks, the outbreak took on pandemic proportions, affecting over 100 countries. It was a significant issue to prevent and control COVID-19 on both national and global scales due to the dramatic increase in confirmed cases worldwide. Government guidelines provide a fundamental resource for communities, as they guide citizens on how to protect themselves against COVID-19, however, they also provide critical guidance for policy makers and healthcare professionals on how to take action to decrease the spread of COVID-19. We aimed to identify the differences and similarities between six different countries' (US, China, South Korea, UK, Brazil and Haiti) government-provided community and healthcare system guidelines, and to explore the relationship between guideline issue dates and the prevalence/incidence of COVID-19 cases. METHODS: To make these comparisons, this exploratory qualitative study used document analysis of government guidelines issued to the general public and to healthcare professionals. Documents were purposively sampled (N = 55) and analyzed using content analysis. RESULTS: The major differences in the evaluation and testing criteria in the guidelines across the six countries centered around the priority of testing for COVID-19 in the general population, which was strongly dependent on each country's healthcare capacity. However, the most similar guidelines pertained to the clinical signs and symptoms of COVID-19, and methods to prevent its contraction. CONCLUSION: In the initial stages of the outbreak, certain strategies were universally employed to control the deadly virus's spread, including quarantining the sick, contact tracing, and social distancing. However, each country dealt with differing healthcare capacities, risks, threats, political and socioeconomic challenges, and distinct healthcare systems and infrastructure. Acknowledging these differences highlights the importance of examining the various countries' response to the COVID-19 pandemic with a nuanced view, as each of these factors shaped the government guidelines distributed to each country's communities and healthcare systems.

Effects of core balance training on Cobb angle, isokinetic torque, and balance in unilateral handed athletes.

This study aimed to provide fundamental data of core balance training (CBT) on Cobb angle and isokinetic torque and balance in unilateral exercised athletes. Forty-eight subjects were divided by control group (CON; n=16), non-CBT exercised group in unilateral handed athletes (NEG, n=16), and CBT exercised group in unilateral handed athletes (EG, n=16), respectively. Although the group by time interaction in the Cobb angle and in the isokinetic torque were not significantly changed in the EG, the balance of the EG showed significantly improved. As conclusions, these results informed that the 16-week CBT would provide a positive effect on the balance except for the Cobb angle and the isokinetic torque.

Distinct frequencies and mutation spectrums of genetic thrombophilia in Korea in comparison with other Asian countries both in patients with thromboembolism and in the general population.

Hereditary natural anticoagulant deficiencies are the major cause of genetic thrombophilia in Asia. Given the growing acknowledgment of the risk of venous thromboembolism in Asian populations, we investigated the frequency and mutation spectrums of natural anticoagulant deficiency in Korea. The group of patients consisted of consecutive patients with venous thromboembolism screened for thrombophilia. Genetic tests were performed on suspicion of natural anticoagulant deficiency. For the population group, >3,000 individuals were screened from routine check-ups, and those with a low level (<1(st) percentile) of natural anticoagulant underwent genetic tests. Mutations were detected by direct sequencing of PROC, PROS1, and SERPINC1, followed by additional multiplex ligation-dependent probe amplification for PROS1 and SERPINC1 for dosage mutations. Among 500 patients screened, 127 were suspected of having a natural anticoagulant deficiency, and this was genetically confirmed in 71: protein C deficiency in 36 (50.7%), antithrombin deficiency in 21 (29.6%), and protein S deficiency in 14 (19.7%). Among 3,129 individuals from the population who were screened, the frequency of natural anticoagulant deficiency was ~1.0%: antithrombin deficiency 0.49%, protein C deficiency 0.35%, and protein S deficiency 0.16%. Two PROC mutations causing type I protein C deficiency were prevalent (Arg211Trp and Met406Ile in patients and Arg211Trp in the population). Two SERPINC1 mutations causing type II antithrombin deficiency, Arg79Cys and Ser158Pro, were prevalent in the population group. This is the first study on the genetic epidemiology of natural anticoagulant deficiencies in Korea. The results demonstrated that the frequencies and spectrum of mutations underlying genetic thrombophilia in Korea are different not only from those in Caucasians but also those in other Asian populations.

Establishment of reference intervals for von Willebrand factor antigen and eight coagulation factors in a Korean population following the Clinical and Laboratory Standards Institute guidelines.

Establishment of reference intervals for coagulation molecules is important but is costly and sometimes not feasible. Since reference intervals from manufacturers or the literature are mostly out of date or involved Western populations, the authors determined reference intervals for VWF: Ag and eight factors in a Korean population. VWF: Ag, factor VIII (FVIII), FII, FV, FVII, FIX, FX, FXI, and FXII were determined in Korean individuals visiting for routine checkup following the CLSI (Clinical and Laboratory Standards Institute) guidelines. Reagents by Diagnostica Stago were used on the STA Compact Analyzer (Diagnostica Stago). Exclusion criteria were medical history or laboratory findings that could affect the factor levels. Influence of demographic factors was analyzed. Mean +/- 2 x SD or central 95 percentile was used, as appropriate. We obtained data from 266 adults for VWF: Ag, 371 adults for FVIII, and minimum 136 adults for the rest. Reference interval for VWF was 51-176% (52-155% in blood group O and 71-186% for non-O). Reference interval for FVIII was 64-197% (55-150% in O and 77-205% in non-O). Reference interval for FII was 77-121%, FV 81-160%, FVII 68-149%, FIX 67-154%, FX 69-126%, FXI 59-138%, and FXII 48-177%. The medians of VWF: Ag, FVIII, and FIX were significantly higher in the elderly group (> or =60 years). We established local reference intervals for VWF: Ag and eight coagulation factors in a Korean population according to the CLSI guidelines. Significantly, different reference intervals were obtained in blood group O vs. non-O for VWF: Ag and FVIII. The reference intervals obtained in this study could be adopted in other clinical laboratories after appropriate validation.

Severe factor XI deficiency in a Korean woman with a novel missense mutation (Val498Met) and duplication G mutation in exon 13 of the F11 gene.

Hereditary factor XI (FXI) deficiency is a rare bleeding disorder inherited in an autosomal recessive manner. The genetic background of FXI deficiency is the mutations in the F11 gene on the chromosome band 4q35. The prevalence is known to be particularly high in Ashkenazi Jews with well documented recurrent mutations; however, founder mutations in F11 have also been reported in non-Jewish patients. In this report, we describe a Korean patient with severe FXI deficiency whose causative mutations were identified by molecular genetic tests. The patient was a 33-year-old pregnant woman. Routine gynecologic workup revealed prolonged activated partial thromboplastin time. Her FXI level was severely decreased at 1% (reference range, 60-140%). Direct sequencing analysis of the F11 gene was performed to identify the causative mutations. The patient was shown to have two different mutations, c.1546 G>A (Val498Met) and c.1560dupG (Tyr503ValfsX32) in the F11 gene. Val498Met is a novel missense mutation, and the Tyr503ValfsX32 mutation was recently reported in a Japanese patient. Both mutations occurred in the exon 13 of F11 and were believed to disrupt the catalytic domain of the FXI protein, leading to severe FXI deficiency. To the best of our knowledge, this is the first genetically confirmed case of severe FXI deficiency in Korea, and more cases are needed to find any signature of founder effect in the Korean population and its potential relationship with other Asian populations.