Acute myeloid leukemia (AML-M2) associated with variant t(8;21): report of three cases.

Variants of the t(8;21)(q22;q22) involving chromosome 8, 21, and other chromosomes account for approximately 3% of all t(8;21)(q22;q22) found in patients with acute myeloid leukemia (AML). The clinicopathologic features of AML with the variant t(8;21) have not been well established. We report three cases of AML with variants of t(8;21) characterized, respectively, by derivative 8 with the interstitial inverted insertion of 21q and concurrent monosomy 21, t(8;18;21)(p22;q11.3;q22), and t(2;21;8)(q11.2;q22;q22). Fluorescence in situ hybridization or reverse transcriptase-polymerase chain reaction assay confirmed the presence of RUNX1-RUNX1T1 gene (previously AML1-ETO) rearrangements. Among these cases, three-way breakpoints 18p11.3 and 2q11.2 have not been previously reported. The present report deals with the results of hematologic, immunophenotypic, cytogenetic, fluorescence in situ hybridization, and molecular analyses of these variants. The possible role of the genes in this region in leukemogenesis, response to treatment, and clinical implications are discussed.

Absolute CD4+ cell count using a plastic microchip and a microscopic cell counter.

We have designed and evaluated the performance of a simple, rapid, and affordable method for counting CD4(+) T-cells with the use of plastic microchips. This new system is an adaptation of a "no-lyse, no-wash," volumetric single platform assay, and absolute CD4(+) counts are determined with the use of a microscopic scanning cell counter. To assess the CD4(+) count test precision and linearity of the system, measured CD4(+) counts were compared with two other reference assays (single and dual platform flow cytometry) with the use of 123 clinical samples including samples obtained from 35 HIV-infected patients, and artificially diluted samples. A correlation between the results from the use of the new method and from the use of the two other reference assays was r = 0.98 for the clinical samples. A dilution test of the new method demonstrated a linearity of r >or= 0.99, with coefficients of variation

Standardization of terminology in laboratory medicine II.

Standardization of medical terminology is essential in data transmission between health care institutes and in maximizing the benefits of information technology. The purpose of this study was to standardize medical terms for laboratory observations. During the second year of the study, a standard database of concept names for laboratory terms that covered those used in tertiary health care institutes and reference laboratories was developed. The laboratory terms in the Logical Observation Identifier Names and Codes (LOINC) database were adopted and matched with the electronic data interchange (EDI) codes in Korea. A public hearing and a workshop for clinical pathologists were held to collect the opinions of experts. The Korean standard laboratory terminology database containing six axial concept names, components, property, time aspect, system (specimen), scale type, and method type, was established for 29,340 test observations. Short names and mapping tables for EDI codes and UMLS were added. Synonym tables were prepared to help match concept names to common terms used in the fields. We herein described the Korean standard laboratory terminology database for test names, result description terms, and result units encompassing most of the laboratory tests in Korea.

Hematological profile of Korean very low birth weight infants.

For very low birth weight (VLBW) infants, diagnostic and therapeutic decisions widely depend on hematological values. Although ethnic differences for hematologic parameters have been reported, few studies have been reported for Korean VLBW infants. This study aimed at defining the hematological reference values for medical research and clinical practice. Retrospectively we selected 149 infants confirmed as healthy at birth and had no medical conditions that may have affected the hematological profile. Hematological values obtained within the first 4 h after birth were classified into gestational age and we determined the influence of gender, mode of delivery, sampling site, 1-min and 5-min Apgar scores on these values. Red blood cell (RBC), hemoglobin (Hb) and hematocrit (Hct) values increased, whereas the white blood cell (WBC) and platelets decreased as the gestational age increased. In relation to the mode of delivery and the 5-min Apgar score, WBC, neutrophil, mean corpuscular volume (MCV), RBC, Hb, Hct and the platelets differed selectively. No differences in any hematological values were observed in relation to gender, sampling site, and the 1-min Apgar score. This study should be useful as a guide to the reference range of these hematological values for Korean VLBW infants.

Enhanced detection of respiratory viruses using cryopreserved R-Mix ReadyCells.

BACKGROUND: R-Mix, which contains a fresh mixture of two cell lines, Mv1Lu (mink lung cells) and A549 cells, has shown good sensitivity and specificity for respiratory virus culture. However, it has until recently only been available in North America, in part due to the shipping constraints associated with cell aging and the difficulty in providing these cells to hard to reach regions. Recently, cryopreserved R-Mix ReadyCells for longer storage were developed. These cells, which are shipped on dry ice and have a shelf life as long as 6 months from date of manufacture, can be thawed and used as needed with minimal addition of refeeding media. OBJECTIVE: Assess the potential for cryopreserved R-Mix ReadyCells to replace conventional culture. STUDY DESIGN: Two hundred and twenty-three nasopharyngeal aspirates confirmed as respiratory virus-positive by conventional culture were inoculated into cryopreserved R-Mix ReadyCells and re-inoculated into conventional culture cells simultaneously. After 1 and 3 days of incubation cryopreserved R-Mix ReadyCells and conventional culture cells were screened using a respiratory virus fluorescent antibody pool for the detection of seven major respiratory viruses (influenza A and B viruses, parainfluenza 1, 2 and 3 viruses, respiratory syncytial virus and adenovirus). Positive pool results were further differentiated with specific monoclonal antibodies against the individual viruses. RESULTS: After 1 day of incubation detection rates for conventional culture were 25%, 39%, 39%, 49%, and 10% for influenza A virus, influenza B virus, parainfluenza viruses, respiratory syncytial virus, and adenovirus, respectively. Corresponding detection rates for cryopreserved R-Mix ReadyCells were 78%, 91%, 72%, 81%, and 65%. Average detection rates of cryopreserved R-Mix ReadyCells for all respiratory viruses were 80% after 1 day incubation and 95% after 3 days incubation, compared to 35% and 70% by conventional culture. CONCLUSION: The cryopreserved R-Mix ReadyCells system offers a highly sensitive and rapid method for detection of respiratory viruses that may allow it to replace conventional cell culture systems.

Identification of proteolipid protein 1 gene duplication by multiplex ligation-dependent probe amplification: first report of genetically confirmed family of Pelizaeus-Merzbacher disease in Korea.

Pelizaeus-Merzbacher disease (PMD) is a rare X-linked recessive disorder with a prototype of a dysmyelinating leukodystrophy that is caused by a mutation in the proteolipid protein 1 (PLP1) gene on the long arm of the X chromosome in band Xq22. This mutation results in abnormal expression or production of PLP. We here present a Korean boy with spastic quadriplegia, horizontal nystagmus, saccadic gaze, intentional tremor, head titubation, ataxia, and developmental delay. The brain magnetic resonance imaging (MRI) showed abnormally high signal intensities in the white matter tract, including a subcortical U fiber on the T2-weighted and fluid attenuated inversion recovery (FLAIR) image. The chromosomal analysis was normal; however, duplication of the PLP1 gene in chromosome Xq22 was detected when the multiplex ligation-dependent probe amplification (MLPA) method was used. We also investigated the pedigree for a genetic study related to PMD. This case suggests that the duplication mutation of the PLP1 gene in patients with PMD results in a mild clinical form of the disorder that mimics the spastic quadriplegia of cerebral palsy.

Alteration of platelet counts and lipid profiles after treatment of acute Plasmodium vivax.

During malaria infections, thrombocytopenia and low cholesterol levels are frequently observed changes. We compared these changes in patients admitted with fevers and infected with Plasmodium vivax, patients admitted with fevers with respiratory/urinary infections and afebrile normal (control) non-infected volunteers. Changes in the platelet count and lipid parameters are reported for malaria patients after treatment with hydroxychloroquine and primaquine for acute P. vivax malaria. Of a total 141 participants, 55 patients were diagnosed with malaria (positive blood smear) prior to treatment. Compared to the normal (n=52) and non-malaria fever groups (n=34), there was a significant decrease in five hematologic indices (white blood cell, red blood cell, hemoglobin, hematocrit and platelet) and three lipid parameters (total cholesterol, HDL-c and LDL-c) in the vivax malaria group at day 0 (pre-treatment). Following treatment, the platelet counts returned to normal limits (P<0.05) from 91,058/microL on day 0 to 246,833/microL by day 17 after treatment. However, changes in the lipid parameters of malaria patients showed a slow recovery to normal limits compared to the platelet counts. The HDL-c and LDL-c remained low for 1 month after treatment but increased at 3 and 6 months post-treatment. At 12 months after treatment, the levels of two lipid parameters had fully recovered to the normal limits. Thus, special attention should be applied when interpreting laboratory blood profiles of malaria patients, especially platelet and lipid based tests, until full recovery after treatment.

[Evaluation of automated architect syphilis TP as a diagnostic laboratory screening test for syphilis].

BACKGROUND: The aim of the study was to establish a new syphilis test algorithm using Architect Syphilis TP (Abbott Japan, Japan: AST), a fully automated treponemal antibody test, as a screening test in a university hospital laboratory. We evaluated performance characteristics of AST in various patient groups. METHODS: A total of 1,357 serum samples obtained from patients at a university hospital from June to August, 2008 were categorized into checkup, preoperative, other diseases, diagnosis (clinically suspected of syphilis), and follow up groups. We compared the results of AST with those of RPR (N=1,276) or Treponema pallidum hemagglutination assay (TPHA, N=81). Samples with discrepant results between RPR or TPHA and AST were retested by fluorescent treponemal antibody absorption test (FTA-ABS) and all patients' clinical records were thoroughly reviewed. RESULTS: The positive rate of AST was significantly higher than that of RPR in preoperative and other diseases groups and was the same as that of RPR in diagnosis group. There were no significant differences in check up and follow up groups. The results of AST showed 97.4% (1,243/1,276) and 97.5% (79/81) concordance rates with those of RPR and TPHA, respectively. Among 26 RPR-AST discrepant and FTA-ABS confirmed cases, there were 20 RPR false-negatives, 4 RPR false-positives, 1 AST false-negative, and 1 AST false-positive. CONCLUSIONS: Based on the results and literature review, we established a new syphilis test algorithm using AST as a screening test, which would be helpful for detection of more syphilis patients including latent infections.

[Survey results of medical insurance reimbursement system for independent medical laboratories in Korea].

BACKGROUND: A questionnaire survey was performed to perceive the problem of the current medical insurance reimbursement system for laboratory tests referred to independent medical laboratories; then, we intended to find a way to improve the reimbursement system. METHODS: Questionnaires were distributed to 220 independent medical laboratories and 700 laboratory physicians from July through October 2005. Frequency analysis was used to analyse the replies from 109 respondents to 25 questionnaire items regarding the current medical insurance reimbursement system for referral tests, problems with the system, and suggestions for the improvement of the system. RESULTS: Among the 109 respondents to this survey, 49 (45.8%) considered the current reimbursement system to be unsatisfactory, while only 16 (15.0%) answered satisfactory. The problem was that the referral clinics-not the laboratories that performed the tests--would first receive their reimbursement for the laboratory tests from Health Insurance Review Agency (HIRA) and then give a portion of the laboratory test fees to the independent medical laboratories after the deduction of administrative fees. They (62.5% of the respondents) would prefer a separated reimbursement system by which the referral clinic-as well as the independent medical laboratory-would receive their reimbursement directly from HIRA through an Electronic Data Interchange (EDI) system. In this new system, 34% of the respondents expected the quality of the laboratory tests to be improved; however, 41.6% answered that the income of the referral clinic is expected to decrease. CONCLUSIONS: For the improvement of the medical insurance reimbursement system, the administrative fee for the referral clinic and the test fee for the independent medical laboratory should be reimbursed directly to the respective organizations. These changes could be made possible with the proper analysis of medical costs and the development of an effective EDI reimbursement system.

Phenotypes and genotypes of macrolide-resistant Streptococcus pyogenes isolated in Seoul, Korea.

The mechanisms of resistance to macrolides in 51 erythromycin-resistant clinical isolates of Streptococcus pyogenes collected from 1997 through 2003 in Seoul, Korea were evaluated. They were characterized by their antimicrobial susceptibility, phenotype (using triple-disc and induction tests), resistance genotype, emm genotyping (M typing) and phylogenetic analysis. Erythromycin resistance was observed in 23% of isolates. Inducible phenotype was the most common (iMLS, 51%, 26 strains), followed by the constitutive phenotype (cMLS, 31%, 16 strains) and the M phenotype (18%, 9 strains). Eight of twenty-six iMLS isolates exhibited the iMLS-C phenotype. The remaining 18 isolates gave small inhibition zones (<12 mm) around all three discs, and mild blunting of the spiramycin and clindamycin zones of inhibition proximal to the erythromycin disc. They showed remarkable inducibility in erythromycin and clindamycin resistance. The MIC90 of erythromycin and clindamycin rose from 8 to >128 microg ml-1 and from 0.5 to >128 microg ml-1, respectively. Their resistance characteristics did not fit into any known iMLS subtype reported so far in the literature. So, it was named as an iMLS-D, new subtype. All of these iMLS-D strains harboured the erm(B) gene, demonstrated the emm12 genotype, except one, and formed a tight cluster in a phylogenetic tree, with 89.2 to 100% sequence homology, suggesting that they are closely related. Nine of sixteen cMLS strains had the emm28 genotype, which had been reported to be associated with multiple drug resistance.

[Epidemiology of respiratory viral infection in 2004-2006.].

BACKGROUND: The information on the incidence, seasonal variation and clinical pattern of respiratory virus infections is very important for clinicians in managing their patients. This study was aimed to define the epidemiology of respiratory viral pathogens in Seoul and the neighboring areas from March 2004 to February 2006. METHODS: A total of 6,533 specimens were cultured for respiratory viruses during the study period. Madin-Darby canine kidney (MDCK), LLC-MK2, and HEp-2 cells, or R-mix cells (Diagnostic Hybrids Inc., Athens, Ohio, USA) were used for culture. Influenza virus types A & B (Inf A & B), parainfluenza virus (PIV), respiratory syncytial virus (RSV), and adenovirus (ADV) were identified by indirect immuno-fluorescent staining. Medical records of the patients with positive virus cultures were reviewed retrospectively. RESULTS: One or more viral agents were isolated from 1682 specimens (25.7%). The pathogens identified were RSV 37.2%, ADV 19.9%, Inf A 18.9%, PIV 17.5% and Inf B 6.4%. The most frequent pathogen of pneumonia and acute bronchiolitis was RSV and that of croup was PIV. Upper respiratory tract infections were more prevalent in adults and the most frequently caused by influenza virus. Influenza virus itself was more frequently isolated in children less than six years old, which was different from previous reports. Influenza virus was mostly isolated in the winter and spring, while RSV was usually isolated from early fall with a peak incidence in the winter. Inf A and RSV showed a dampening effect on the occurrence of other viruses during their major epidemic. PIV was mostly detected in the spring and summer. ADV was isolated throughout the whole year. CONCLUSIONS: The epidemiological characteristics of respiratory virus infections in Seoul and the neighboring areas in 2004-2006, were similar to the findings of previous reports except for some minor changes. These findings could be useful to clinicians in managing their patients.

Bone marrow expression and plasma concentration of basic fibroblast growth factor in patients with idiopathic thrombocytopenic purpura.

BACKGROUND: Basic fibroblast growth factor (bFGF) is one of main regulators of hematopoiesis, including megakaryopoiesis. The main bone marrow finding of patients with idiopathic thrombocytopenic purpura (ITP) is increased megakaryopoiesis. The purposes of this study were to evaluate the change in the production of bFGF and its expression pattern in the bone marrow of patients with ITP and to correlate these characteristics with the plasma concentration of bFGF. METHODS: Paraffin sections of bone marrow biopsies from 17 patients with ITP and 5 healthy control subjects without pathologic alterations were investigated by immunohistochemistry for bFGF and CD68. bFGF messenger RNA (mRNA) in situ hybridization was performed with bone marrow biopsy sections, and the plasma levels of bFGF were evaluated by enzyme immunoassay. RESULTS: bFGF was expressed strongly in stromal cells and weakly in megakaryocytes. The density of bFGF-expressing stromal cells was decreased in 70% (12/17) of the patients with ITP but in none of the control subjects. The numbers of stromal cells and the cellular distributions of bFGF mRNA in patients with ITP were similar to those of the control subjects. The plasma levels of bFGF were significantly lower in almost all of the ITP patients relative to those of the control group. CONCLUSIONS: The results indicate that the concentrations of bFGF in plasma and bone marrow stromal cells in ITP cases are decreased, whereas the production of bFGF remains unchanged. Although the mechanism of low cellular and plasma concentrations of bFGF needs to be elucidated, these findings may complement the serologic and morphologic diagnosis of ITP.