Seoyoung Yoon

Clinical Performance Evaluation of Four Automated Chemiluminescence Immunoassays for Hepatitis C Virus Antibody Detection

ABSTRACT Various automated chemiluminescence immunoassay (CLIA) analyzers for the detection of antibodies to hepatitis C virus (HCV) are now commercially available in clinical laboratories and are replacing conventional enzyme immunoassays. We investigated the performance of four anti-HCV CLIAs (the Architect Anti-HCV assay on the Architect i2000 system, the Vitros Anti-HCV assay on the Vitros ECiQ Immunodiagnostic System, the Access HCV Ab PLUS assay on the UniCel DxI 800 analyzer, and the newly developed Elecsys Anti-HCV assay on the Cobas e 411 analyzer). The total percent coefficient of variation values of imprecision were 3.5 to 5.7% with positive control materials and 7.2 to 10.2% with negative control materials. The agreement between the results of the Elecsys, Architect, Vitros, and Access CLIAs ranged from 94.5 to 98.1%. The clinical sensitivity of all CLIAs was 100%. Each CLIA showed excellent reproducibility and clinical sensitivity. The Elecsys, Architect, Vitros, and Access CLIAs showed clinical specificities of 98.2, 98.8, 96.5, and 98.2%.

Acute promyelocytic leukemia with insertion of PML exon 7a and partial deletion of exon 3 of RARA: a novel variant transcript related to aggressive course and not detected with real-time polymerase chain reaction analysis.

We report the case of a 38-year-old man with acute promyelocytic leukemia (APL) showing a distinct breakpoint cluster region 2 (bcr2) variant transcript. Findings from bone marrow, cytogenetic, fluorescence in situ hybridization, and qualitative reverse transcriptase-polymerase chain reaction (RT-PCR) analyses were consistent with the diagnosis of APL. Although PCR products of size 841 bp and 984 bp were amplified from bone marrow specimen, the quantitative PCR (RQ-PCR) findings were negative. Given the discrepancy in PCR results, sequencing of PCR products was performed to determine the detailed composition of these fusion transcripts. By cloning and sequencing, we discovered that these two bands were isoforms, in which one exon (exon 5, 144 bp) of the PML gene was spliced out of the smaller products (minor PCR products); one sequence (G) insertion and one base substitution (T-->C) of PML exon 4 generate a stop codon in the smaller fusion transcript. In addition, a search of the Ensembl database revealed that these variant PML/RARA fusion transcripts were composed of exon 7a insertion of the PML gene and partial deletion (46 bp) of exon 3 of the RARA gene, in addition to inserted sequences of intron 7 of PML and genomic sequence ATCT of unknown origin at the fusion junction site. Although the biological significance of most atypical transcripts remains unclear, sequence analysis of these atypical products should be performed, to reveal the composition of such a fusion transcript and elucidate the molecular mechanism.

First Report of Brain Abscess Associated with Pseudozyma species in a Patient with Astrocytoma

A yeast-like strain was isolated from the brain abscess of a patient diagnosed with astrocytoma. Morphological and molecular analysis on D1/D2 domain in the 26S rRNA gene and internal transcript spacer region of the strain revealed that the strain belonged to the genus Pseudozyma. To the best of our knowledge, this is the first report on the isolation of a Pseudozyma strain from brain abscess.

Acute erythroleukemia with der(1;7)(q10;p10) as a sole acquired abnormality after treatment with azathioprine

To our knowledge, at least 11 different unbalanced wholearm translocations including der(1;7)(q10;p10), der(1;15) (q10;q10), der(1;16)(q10;p10), and der(1;19)(q10;p10) have been reported in hematologic malignancies, and some whole-arm translocations have now been documented as primary changes associated with specific disease entities [1e4]. Among these whole-arm translocations, der(1;7) (q10;p10) is the karyotypic aberration most associated with a previous history of chemotherapy or radiation therapy (i.e., in more than half the cases). This aberration is extremely rare, however, in association with acute erythroleukemia (AMLM6); only three cases have been reported in the literature [1,5e7]. Here, we report on a novel case of AML-M6 with der(1;7)(q10;p10) as a sole acquired abnormality in a patient treated with azathioprine for a long duration. A 64-year-old Korean woman with edema and suspected cellulitis of her right third finger was admitted to Severance Hospital of Yonsei University in February 2008. During her hospitalization, she sustained severe neutropenia. Approximately 2 weeks later, a gradual increase in immature cells in the peripheral blood smear compelled us to perform a bone marrow examination. In bone marrow aspiration, erythroid hyperplasia was observed (O50% of all nucleated cells) with abnormal blasts, which constituted 44% of nonerythroid cells, consistent with a morphology of AML-M6 with multilineage dysplasia. The patient exhibited an unbalanced translocation between the whole arms of chromosomes 1 (long arm) and 7 (short arm); the detailed karyotype of this patient was 46,XX,þ1,der(1;7)(q10;p10),inv(9)(p11q13)c in 20 cells analyzed (Fig. 1). Fluorescence in situ hybridization (FISH) analysis for chromosome 7 (Vysis LSI D7S486 (7q31), SpectrumOrangeeCEP 7 SpectrumGreen probe set; Abbott Molecular, Des Plaines, IL) yielded nuc ish (D7S486 1),(CEP7 2)[249/ 300]. Thus, the FISH results were consistent with the cytogenetic karyotype. The patient was treated with fludarabine, cytarabine, and idarubicin, but failed to achieve remission and died of pulmonary hemorrhage and septic shock 38 days after the initial diagnosis of AML-M6. In 1989, the patient had been diagnosed with idiopathic hypereosinophilic syndrome and vasculitis, and was treated

A Case of Scedosporium apiospermum Keratitis Confirmed by a Molecular Genetic Method

A 54-yr-old male, who was treated by chemotherapy for gastric cancer 15 months ago, presented to Yongdong Severance Hospital, Seoul, with complaints of pain in his right eye caused by a foreign body from the ground in the previous week. He had been treated with topical and oral antibacterial in addition to antifungal agents, but did not show significant clinical improvement. After a positive corneal culture with mold, topical amphotericin B was added to the initial regimen. The mold was identified as Scedosporium apiospermum by macroscopic and microscopic morphologies and the nucleotide sequences of a fungal PCR product showing 99% homology with those of S. apiospermum (EF151349). He recovered with good results at 25 days after corneal epithelial debridement. The early diagnosis of S. apiospermum keratitis is very important for proper treatment. It is recommended that molecular diagnostic methods such as fungal PCR and sequencing be done with conventional cultures whenever a fungal infection is suspected.

Bacteremia Caused by Corynebacterium amycolatum with a Novel Mutation in gyrA Gene that Confers High-Level Quinolone Resistance

Although Corynebacterium amycolatum can cause opportunistic infections, it is commonly considered as contaminant. In this report, we present a case of bacteremia caused by C. amycolatum with a novel mutation in the gyrA gene that confers high-level quinolone resistance to the organism.

Three new nonsense mutations of MLH1 and MSH2 genes in Korean families with hereditary nonpolyposis colorectal cancer.

Hereditary nonpolyposis colorectal cancer (HNPCC) (MIM #114500), also called Lynch syndrome, is an autosomal dominantly inherited cancer syndrome accounting for 1-5% of all colorectal cancer cases. In a study of three Korean families with HNPCC consistent with the revised Bethesda criteria, DNA testing revealed three novel HNPCC germline mutations in two genes: namely, MLH1, with an insertion resulting in a frameshift and a premature stop codon; MSH2, with a deletion at nucleotide 633, exon 3, which results in stop of translation at codon 213; and MSH2, with a deletion at nucleotide 1413, exon 9, resulting in a frameshift and a premature stop codon. In the first two families, there were splice mutations at c.2006-6 thymine to cytosine. The clinical implications of a frameshift mutation are discussed, along with the significance of common underlying splice mutations existing within families with HNPCC.

Characterisation of abnormal lactate dehydrogenase isoenzyme with the semi-automated hydrasys electrophoresis system

Macroenzymes are complexes of serum enzymes with a plasma protein, having higher molecular weight with prolonged half-life. Their presence can cause an elevation in the serum enzyme levels, possibly leading to misdiagnosis. Herein we present a 30-year-old man found with persistent elevation of (lactate dehydrogenase) LDH level measuring 885–1083 IU/L in a routine health check-up. Other laboratory findings including complete blood counts, routine chemistries, liver function tests and serological tests for hepatitis virus were not remarkable. Radiological studies including abdominal ultrasonography also showed no significant finding. The electrophoresis of LDH isoenzymes was performed with the Hydragel Iso-LDH kit used in conjunction with the semi-automated Hydrasys gel electrophoresis system, and the electrophoretic separation showed abnormal migration patterns of LDH2 and 3 isoenzymes with densely stained LDH3. Immunoelectrophoresis of LDH isoenzyme with anti-human IgG, IgA, IgM, kappa and lambda light chain antibodies was performed to identify the antibodies bound to LDH. The patient’s LDH was presented to be bound to IgA and kappa light chain. This modified immunoelectrophoresis with semi-automated system could be useful to characterise these kinds of abnormal LDH isoenzyme patterns.

Use of EDTA-plasma gel-separating tubes for measurement of indocyanine green

Preoperative assessment of liver function is extremely important for decreasing mortality and morbidity following liver resection in cirrhotic and non-cirrhotic patients (1). Indocyanine green (ICG) retention at 15 min (ICG R15) has been used for many years to evaluate hepatic function reserve, to determine the limits of hepatectomy, and to monitor the functional capacity following hepatic resection (2–4). After a bolus injection of ICG, the dye is removed exclusively by the liver. Since ICG is removed exclusively by the liver and has a relatively high intrinsic clearance, ICG R15 indicates hepatic perfusion. The ICG concentration is usually measured using a spectrophotometer at a wavelength of 805 nm. At our hospital, ICG concentrations are measured manually using EDTA-plasma on a DU-650 spectrophotometer (Beckman Instruments, Inc., Miami, FL, USA). Depending upon the current trends in the laboratory automation, EDTA-plasma separating tubes with gel (EDTA-PST) are required to perform the ICG test using an automated analyzer, such as the Hitachi 7180 (Hitachi, Tokyo, Japan). EDTA-PST, originally used for testing plasma in molecular diagnosis and viral load detection, can be used directly on automated analyzers following centrifugation. However, there have been reports that the inert polymer gel within the serum separating tube (SST) can cause interferences on measurement of several drugs, hormones, and other proteins (5–8). In this study, we evaluated the usefulness of EDTA-PST for the ICG test. K2E K2EDTA tubes (Greiner Bio-One, Kremsmünster, Austria) were used to obtain EDTA-plasma and K2E K2EDTA Sep (Greiner Bio-One, Kremsmünster, Austria) for EDTA-PST. A total of 51 subjects (female, ns18; male, ns33) who were undergoing preopera-