BACKGROUND: Platelet antigen and antibody tests have been used in platelet immunological disorders, such as neonatal alloimmune thrombocytopenia (NAIT) and post-transfusion purpura (PTP). Mixed passive hemagglutination (MPHA) method has several advantages, including frozen preservation of platelets, ability to differentiate between anti-HLA and platelet-specific antibodies, and quick and easy interpretation without expensive equipment. In this study, we intended to develop the MPHA method using indicator cells of anti-Rh(D) sensitized group O, Rh+ RBCs. METHODS: We made indicator cells sensitized with anti-Rh(D) with various strengths (1:32 to 1:256) and determined the optimal strength. We determined the sensitivity of the MPHA and compared the results using flow cytometry. We observed the changes of the reaction according to the storage time of indicator cells. RESULTS: The optimal sensitization strengths of the indicator cells were 1:192 and 1:256. MPHA showed strong positive results with 1:8,192 diluted positive control, while the detection limit of flow cytometry was 1:128. Until the second week (mean 16 days), the indicator cells showed good results comparable to those of fresh ones. CONCLUSION: We developed the MPHA method using indicator cells of anti-Rh(D) sensitized group O, Rh+ RBCs. We produced the indicator cells in our own laboratory and obtained platelet panels with rare antigen typing using frozen-stored platelets. This technology will be used effectively for detection of platelet antigens and identification of platelet antibodies and also for platelet crossmatching.
Antibodies ; Blood Platelets* ; Flow Cytometry ; Hemagglutination* ; Limit of Detection ; Purpura ; Thrombocytopenia, Neonatal Alloimmune

Objective: The aim of this study was to investigate the atherothrombotic and bleeding risk of discontinuing both components of dual antiplatelet therapy (DAPT) before surgery in patients with an intracoronary stent after 1 year. Methods: We retrospectively enrolled 212 patients who received an evaluation of perioperative cardiac risk and underwent surgery from March 2017 to March 2019. We divided them into 2 groups: the discontinuation of both antiplatelet agents group (DCAP, no use of any antiplatelet agent) and the continuation of at least 1 antiplatelet agent group (CAP). The primary composite endpoint was the occurrence of major adverse cardiovascular events (MACE), including death, angina, postoperative coronary angiography, stroke, and readmission within 30 days postoperatively. The second endpoint was bleeding requiring the transfusion of ≥2 packs of red blood cells (RBCs)Result: A total of 136 patients were enrolled in the study, with 68 in the DCAP group and 68 in the CAP group. The occurrence of MACE did not significantly differ between the groups (25% vs. 17.6%, p=0.295). The incidence of bleeding that required a transfusion was higher in the CAP group (16.2% vs. 30.9%, p=0.044). The postoperative change in hemoglobin levels (−1.9 g/dL vs. −1.8 g/dL, p=0.742), and the number of transfused packs of RBCs (3.5 vs. 5.3, p=0.347) were not significantly different between the groups. Conclusion Preoperative discontinuation of DAPT did not increase the risk of MACE. However, continuation of at least 1 antiplatelet agent increased the incidence of bleeding requiring RBC transfusion. Further research with a large cohort is warranted.

BACKGROUND: In pregnant women, the frequency of irregular antibodies that cause hemolytic disease of the fetus and newborn (HDFN) vary between study populations. The clinical manifestations of HDFN differ according to the specificities and degree of irregular antibodies. This study examined the frequency and nature of maternal alloimmunization and neonatal outcomes. METHODS: Pregnant women, who underwent irregular antibody screening for prenatal testing at an obstetrics clinic in a single center, were enrolled. Those who screened positive for irregular antibodies were selected as the test group, and age- and obstetrics history-matched pregnant women were selected as the control group to evaluate the pregnancy outcomes according to irregular antibodies. RESULTS: The prevalence of irregular antibodies was 2.78% (42/1,508). With the exception of an unidentified antibody, anti-D was the most frequently identified antibody, followed in order by anti-E and anti-Le(a). The rate of fetal death was higher in the test group (6/37, 16.2%) than in the control group (1/37, 2.7%) (P=0.047). Eight pregnant women had anti-C or anti-D, one woman had a stillbirth, and four living neonates developed hyperbilirubinemia. Of six pregnant women with anti-E alone or with other alloantibodies, three experienced a spontaneous abortion or stillbirth. Among the six newborns with maternal anti-Le(a) and anti-Jk(a), four developed hyperbilirubinemia, but their mothers did not experience a spontaneous abortion or stillbirth. CONCLUSION: The prevalence of unexpected antibodies among pregnant Korean women was 2.78%. A significant difference in neonatal outcomes was observed, including the death rate, prematurity, and hyperbilirubinemia, depending on the specificity of the unexpected antibody.
Abortion, Spontaneous ; Antibodies ; Female ; Fetal Death ; Fetus ; Humans ; Hyperbilirubinemia ; Infant, Newborn ; Isoantibodies ; Mass Screening ; Mortality ; Mothers ; Obstetrics ; Pregnancy ; Pregnancy Outcome ; Pregnant Women ; Prevalence ; Sensitivity and Specificity ; Stillbirth

No abstract available.
Actinobacteria/genetics/*isolation & purification ; Bacteremia/*diagnosis/microbiology ; Humans ; Male ; Middle Aged ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/chemistry/genetics ; Republic of Korea ; Sequence Analysis, RNA ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

We present a case of abrupt-onset hemorrhagic tendency in a patient with amyloidosis who also had asymptomatic plasma cell myeloma. The patient was a 66-yr-old man with no previous history of hemorrhagic tendency and no family history of hemorrhagic disease. On examination, the prothrombin time and activated partial thromboplastin time were found to be prolonged and were not corrected even after a mixing test; moreover, the levels of coagulation factors I, II, V, VII, and X were almost normal. We therefore considered the presence of a nonspecific coagulation inhibitor. Although the von Willebrand factor (vWF) activity and vWF antigen level were normal due to sampling following transfusion, the increased closure time on PFA-100 (Siemens) analysis and the absence of ristocetin-induced platelet aggregation suggested the presence of acquired von Willebrand syndrome (vWS). After chemotherapy, the patient showed alleviation in the bleeding symptoms. Therefore, testing for acquired vWS should be considered when a patient has a history of recent bleeding with underlying amyloidosis.
Amyloidosis ; Blood Coagulation Factors ; Hemorrhage ; Humans ; Light ; Multiple Myeloma ; Partial Thromboplastin Time ; Plasma ; Plasma Cells ; Platelet Aggregation ; Prothrombin Time ; von Willebrand Factor

Fanconi anemia (FA) is a rare genetic disorder affecting multiple body systems. Genetic testing, including prenatal testing, is a prerequisite for the diagnosis of many clinical conditions. However, genetic testing is complicated for FA because there are often many genes that are associated with its development, and large deletions, duplications, or sequence variations are frequently found in some of these genes. This study describes successful genetic testing for molecular diagnosis, and subsequent prenatal diagnosis, of FA in a patient and his family in Korea. We analyzed all exons and flanking regions of the FANCA, FANCC, and FANCG genes for mutation identification and subsequent prenatal diagnosis. Multiplex ligation-dependent probe amplification analysis was performed to detect large deletions or duplications in the FANCA gene. Molecular analysis revealed two mutations in the FANCA gene: a frameshift mutation c.2546delC and a novel splice-site mutation c.3627-1G>A. The FANCA mutations were separately inherited from each parent, c.2546delC was derived from the father, whereas c.3627-1G>A originated from the mother. The amniotic fluid cells were c.3627-1G>A heterozygotes, suggesting that the fetus was unaffected. This is the first report of genetic testing that was successfully applied to molecular diagnosis of a patient and subsequent prenatal diagnosis of FA in a family in Korea.
Base Sequence ; Child, Preschool ; Exons ; Fanconi Anemia/*diagnosis/genetics ; Fanconi Anemia Complementation Group A Protein/genetics ; Fanconi Anemia Complementation Group C Protein/genetics ; Fanconi Anemia Complementation Group G Protein/genetics ; Female ; Frameshift Mutation ; Genetic Testing ; Heterozygote ; Humans ; Karyotyping ; Male ; Pregnancy ; Prenatal Diagnosis ; RNA Splice Sites ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA

BACKGROUND: Blood transfusions are complicated procedures, and are highly sensitive to mistakes that could seriously endanger the life of patients. The failure mode and effect analysis (FMEA) can be used to inspect and improve high risk processes. Here, we aimed to identify the risk factors of a blood transfusion process and to improve its safety by optimizing the process. METHODS: We conducted a weekly meeting from March to April 2014. We investigated the frequency of events for 2013 (before FMEA) and 2015 (after FMEA). The FMEA process was performed in eight steps and the improvement priorities were determined in accordance with the magnitude of calculated fatalities (multiplied by severity, occurrence, and detection scores). RESULTS: The whole process of blood transfusion was analyzed by detailed steps: Decision of blood transfusion, blood transfusion request, pre-transfusion test, blood product discharge, delivery, and administration process. Then, we identified the types of failures and likelihood of occurrence, discovery, and severity. Based on the calculated risk priority number, strategies to improve the highest failure modes were developed. Eleven transfusion-related events occurred before FMEA, and three events occurred after FMEA. CONCLUSION: In this study, we analyzed the failure modes that may occur during a transfusion procedure. The FMEA was a useful tool for analyzing and reducing the risks associated with a blood transfusion procedure. Continuous efforts to improve the failure modes would be helpful to further improve the safety of patients undergoing blood transfusion.
Blood Transfusion ; Healthcare Failure Mode and Effect Analysis* ; Hematologic Tests ; Humans ; Patient Safety ; Risk Factors ; Transfusion Medicine*

BACKGROUND: Alloimmunization of human platelet antigens (HPA) is associated with clinically significant disease, such as platelet refractoriness, neonatal alloimmune thrombocytopenia, or posttransfusion purpura. It is determined by single nucleotide polymorphism of genes for platelet membrane glycoprotein. To date, approximately 27 HPAs have been discovered, and their frequencies differ depending on ethnicity and country. METHODS: We conducted an investigation of prevalence of HPA in the Korean population using a multiplex single-base primer extension reaction (SNaPshot). With 84 specimens from healthy donors, HPA genotyping was performed on 11 different HPAs, including HPA-1, -2, -3, -4, -5, -6, -7, -8, -9, -13, and -15. RESULTS: A total of 90 blood samples were genotyped. The genotype frequencies of HPA were as follows: HPA-1a/1a: 100.0%, -2a/2a: 83.3%, -2a/2b: 14.3%, -2b/2b: 2.4%, -3a/3a: 39.3%, -3a/3b: 52.4%, -3b/3b: 8.3%, -4a/4a: 100.0%, -5a/5a: 95.2%, -5a/5b: 4.8%, -6a/6a: 94.0%, -6a/6b: 6.0%, -7a/7a: 100.0%, -8a/8a: 100.0%, -9a/9a: 97.6%, -9a/9b: 2.4%, -13a/13a: 100.0%, -15a/15a: 23.8%, -15a/15b: 51.2%, and -15b/15b: 25.0%. CONCLUSION: The SNaPshot assay was employed for detection of SNPs in various clinically significant HPA genes. In addition to well-known frequencies of previously reported HPA-1 to -8, this study showed frequencies of HPA-9, -13, and -15 in Koreans for the first time. The SNaPshot technique might be suitable for use in actual clinical testing in patients with platelet alloimmunization.
Antigens, Human Platelet ; Blood Platelets ; Genotype ; Humans ; Membrane Glycoproteins ; Polymorphism, Single Nucleotide ; Prevalence ; Purpura ; Purpura, Thrombocytopenic ; Thrombocytopenia, Neonatal Alloimmune ; Tissue Donors

BACKGROUND/AIMS: MDCT, which provides high resolution and various reconstructing images, has recently become widely available and is a promising tool for imaging the bile duct with precision. In order to evaluate the diagnostic value of multidetector computerized tomography (MDCT) for a common bile duct (CBD) stone, this study compared the diagnostic accuracy of MDCT with that of ERCP. METHODS: The medical records of the patients undergoing both MDCT and ERCP consecutively from June 2006 to January 2007 were retrospectively reviewed. One hundred and sixty four patients (164 cases) were enrolled in this study. The final diagnoses were based mainly on the ERCP findings. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of MDCT and ERCP for choledocholithiasis were identified and compared. RESULTS: Of the 164 cases, 47 cases were diagnosed with choledocholithiasis. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for choledocholithiasis were 89.4%, 98.3%, 95.5%, 95.8%, 95.7% in MDCT and 97.9%, 99.1%, 97.9%, 99.1%, 98.8% in ERCP, respectively. There were no statistically significant differences in the diagnostic accuracy between the two methods (p=0.206). CONCLUSIONS: MDCT has high sensitivity and specificity for diagnosing stones in the bile duct and should be performed in preference to ERCP in patients suspected of having choledocholithiasis.
Bile Ducts ; Cholangiopancreatography, Endoscopic Retrograde* ; Choledocholithiasis ; Common Bile Duct* ; Diagnosis ; Humans ; Medical Records ; Retrospective Studies ; Sensitivity and Specificity