Thrombocytopenia Experienced by Healthy Peripheral Blood Stem Cell Donors at a Tertiary Hospital in Korea / 대한수혈학회지

In healthy peripheral blood stem cell (PBSC) donors, rare cases of transient thrombocytopenia have been reported due to the administration of granulocyte colony-stimulating factor (G-CSF) or the apheresis itself. Meanwhile, differentiating pseudothrombocytopenia induced by anticoagulants is crucial, as it can result in false low platelet counts. This study aimed to investigate the causes of thrombocytopenia in healthy PBSC donors. We investigated PBSC donors who experienced thrombocytopenia during transplantation at St. Mary’s Hospital, Seoul. Three donors were identified and donor workup studies were within the normal limits. After G-CSF administration prior to transplantation, the donors experienced a significant reduction in platelet counts. Apheresis resulted in lower levels, yet platelet counts returned to normal levels approximately two weeks later. In donor 3, thrombocytopenia was seen during the donor workup and ethylenediaminetetraacetic acid (EDTA)-induced pseudothrombocytopenia was identified after the supplementation of amikacin. For donor 3, we investigated whether his recipient’s sample showed EDTA-induced pseudothrombocytopenia through a review of any platelet clumping in the apheresis product and the presence of immunoglobulin M (IgM) or IgG antiplatelet antibodies in the recipient’s peripheral blood. In conclusion, the risk of severe thrombocytopenia with G-CSF administration in PBSC donors should be considered and accurate differentiation of pseudothrombocytopenia is imperative.

Transfusion support in hematopoietic stem cell transplantation

Transfusion support for hematopoietic stem cell transplantation (HSCT) is an essential part of supportive care, and compatible blood should be transfused into recipients. As leukocyte antigen (HLA) matching is considered first and as the blood group does not impede HSCT, major, minor, bidirectional, and RhD incompatibilities occur that might hinder transfusion and cause adverse events. Leukocyte reduction in blood products is frequently used, and irradiation should be performed for blood products, except for plasma. To mitigate incompatibility and adverse events, local transfusion guidelines, hospital transfusion committees, and patient management should be considered.

Three Cases of Anti-LW Antibody Identification at a Tertiary Hospital in Korea / 대한수혈학회지

The Landsteiner–Wiener (LW) antigen is a type of red blood cell antigen. Anti-LW appears in various situations, including alloantibodies, autoantibodies, and even transiently occurring antibodies. Anti-LW has similar characteristics to anti-D, so it can interfere with interpreting pre-transfusion tests and finding compatible blood. This paper introduces three cases in whom anti-LW was detected through antibody identification tests. All three cases were examined using the column agglutination technique with ID-DiaPanel (Bio-Rad, Hercules, CA, USA) on a LISS/Coombs card, ID-DiaPanel p (Bio-Rad) on a NaCl/Enzyme card, and ID-DiaPanel (Bio-Rad) on a LISS/Coombs card using red blood cells treated with dithiothreitol. The auto-control test, direct antiglobulin test, and umbilical cord blood test were also performed. In all three cases, the reaction with D-positive panel cells was stronger than that with the D-negative panel cells, and two of them showed a pan-agglutinated reaction in ID-DiaPanel p (Bio-Rad) with NaCl/Enzyme card. They were reported as anti-LW, and as in these cases, anti-LW can occur under a range of conditions and interfere with proper transfusion. Therefore, it is important to identify anti-LW accurately, and if anti-LW is present, the transfusion of D-negative ABO matched blood should be recommended because of the low expression of the LW-antigen. On the other hand, D-positive blood is not a contraindication when an urgent transfusion is needed.

Evaluating Diagnostic Tests for Helicobacter pylori Infection Without a Reference Standard: Use of Latent Class Analysis

Evaluation of diagnostic tests requires reference standards, which are often unavailable. Latent class analysis (LCA) can be used to evaluate diagnostic tests without reference standards, using a combination of observed and estimated results. Conditionally independent diagnostic tests for Helicobacter pylori infection are required. We used LCA to construct a reference standard and evaluate the capability of non-invasive tests (stool antigen test and serum antibody test) to diagnose H. pylori infection compared with the conventional method, where histology is the reference standard. A total of 96 healthy subjects with endoscopy histology results were enrolled from January to July 2016. Sensitivity and specificity were determined for the LCA approach (i.e., using a combination of three tests as the reference standard) and the conventional method. When LCA was used, sensitivity and specificity were 83.8% and 99.4% for histology, 80.0% and 81.9% for the stool antigen test, and 63.6% and 89.3% for the serum antibody test, respectively. When the conventional method was used, sensitivity and specificity were 75.8% and 71.1% for the stool antigen test and 77.7% and 60.7% for the serum antibody test, respectively. LCA can be applied to evaluate diagnostic tests that lack a reference standard.

Performance Evaluation of a Point of Care SelexOnTM B-Type Natriuretic Peptide Immunoassay

Background@#This study was conducted to evaluate the analytical performance of the SelexOnTM B-type natriuretic peptide (BNP) assay (Osang Healthcare Inc., Korea), a new rapid lateral flow immunoassay for point of care (POC) testing using whole blood. @*Methods@#The imprecision, linearity, and method comparison of SelexOnTM BNP assay were evaluated. Two commercial BNP assays, the ADVIA Centaur® BNP (Siemens Health Care diagnostics Inc., USA) and the Triage® BNP assays (Alere, USA), were included for method comparison using 100 whole blood samples from patients. The reference interval was verified using 120 residual samples from health examination participants. @*Results@#The SelexOn BNP had total CVs of 20.3%, 13.3%, and 10.3% in BNP concentrations of 89.44 pg/mL, 480.71 pg/mL, and 1,201.84 pg/mL of control materials, respectively. Linearity was observed from 56 pg/mL to 1544 pg/mL. The SelexOn BNP (y) regression equation was y=0.9706x-21.68 with Centaur BNP (x) (r=0.930) and y=0.7600x+0.0506 with Triage BNP (x) (r=0.845), respectively. The predicted mean difference (%) of the SelexOn BNP at the clinical decision levels (100 pg/mL) was up to 25% lower than the two comparative methods. The SelexOn BNP levels were below 50 pg/mL in 114 (95%) of the 120 samples. @*Conclusions@#The SelexOn BNP using EDTA was developed as a POC test for differential diagnosis or treatment monitoring for acute heart failure. However, clinical decision values must be improved to be compatible with other BNP methods.

Usefulness of Reference Change Values for Delta Check Limits in Clinical Laboratory Testing

Background@#In this study, the usefulness of within-subject biological coefficient of variation (CVI) and reference change values (RCVs) for delta check limits were investigated by comparing the population distributionbased delta check limits. @*Methods@#For six tests, including aspartate aminotransferase, alanine aminotransferase, γ-glutamyl transferase, glucose, creatinine, and hemoglobin, the RCV95%, RCV99%, and RCV99.9% delta limits were obtained. The nonparametric 95% and 99% delta limits were obtained from the population distribution of the delta percentage difference of the health examination group (January 2014 to December 2018) and the outpatient and inpatient groups (January to December 2018). Delta check alerts (%) in total and all three subgroups were examined according to the five different delta check limits. Additionally, we analyzed the correlation of the median CVIF estimates with population-delta check limits for the six tests. @*Results@#The delta percentage difference of the six tests showed a nonnormal distribution, and median value significantly differed among the health examination, outpatient, and inpatient groups (all, P <0.001). The overall delta check alerts of six tests decreased in the order of RCV95%, RCV99%, and RCV99.9%, population distribution -95%, and -99% delta limits; the proportion of the health examination group gradually decreased and that of inpatients increased. A good correlation was observed between median CVI (range, 2.7% to 10.1%) and population distribution delta limits (r =0.96 to 0.99). @*Conclusions@#The RCV delta check limits should be applied differently depending on the health and disease group. CVI can be useful for estimating the delta check limits of the population.

Enumeration of CD34-positive Stem Cells Using the ADAMII Image-based Fluorescence Cell Counter

BACKGROUND: It is very important to accurately enumerate CD34-positive (CD34+) cells for successful hematopoietic stem cell transplantation (HSCT). We evaluated the ability of the newly developed image based-immunofluorescence cell counter ADAMII (NanoEntek, Seoul, Korea) to enumerate CD34+ cells, which was improved through simultaneous CD45 analysis. METHODS: We enumerated CD34+ cells with ADAMII using 19 peripheral blood (PB) and 91 leukapheresis samples from HSCT donors. Analytical performance, including precision and linearity, was analyzed, and sample stability during storage was evaluated. Viable CD34+ cell count (vCD34) and viable CD45+ cell count (vCD45) and the percentage of viable CD34+ cells among viable CD45+ cells (CD34/CD45) as measured by ADAMII were compared with the corresponding values from two flow cytometry assays, using regression analysis. RESULTS: ADAMII demonstrated acceptable precision, as CV values of vCD34 from six samples with different counts were all < 10% (range: 3.49–9.51%). CV values of the vCD45 and CD34/45 ranged from 4.03% to 9.67% and from 2.48% to 10.07%, respectively. The linearity of vCD34 showed an excellent R 2 value (0.99) when analyzed using the intended count and flow cytometry data. The ADAMII and two flow cytometry-based assays generated very similar data for the PB and leukapheresis samples. CONCLUSIONS: ADAMII demonstrated excellent performance for use as a routine clinical assay in terms of CD34+ cell enumeration from PB and leukapheresis samples. Moreover, it could be used as a point-of-care-test for determining mobilization time and predicting an adequate apheresis stem cell product.

Clinical Significance of Inflammatory Biomarkers in Acute Pediatric Diarrhea / 대한소아소화기영양학회지

PURPOSE: The aim of this study was to evaluate the clinical significance of inflammatory biomarkers in acute infectious diarrhea among children. METHODS: Clinical parameters including fever, bacterial and viral etiology based on stool culture and multiplex polymerase chain reaction, and nine biomarkers including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and leukocytes in blood and calprotectin, lactoferrin, myeloperoxidase, polymorphonuclear elastase, leukocytes, and occult blood in feces were evaluated in children who were hospitalized due to acute diarrhea without underlying disease. RESULTS: A total of 62 patients were included. Among these patients, 33 had fever, 18 showed bacterial infections, and 40 patients were infected with 43 viruses. Of all the biomarkers, CRP was significantly correlated with fever (p<0.001). CRP, ESR, calprotectin, lactoferrin, myeloperoxidase, fecal leukocytes, and occult blood were significantly associated with infection with bacterial pathogens (p<0.001, p=0.04, p=0.03, p=0.003, p=0.02, p=0.03, p=0.002, respectively). The combination of CRP and fecal lactoferrin at their best cut-off values (13.7 mg/L and 22.8 µg/mL, respectively) yielded a sensitivity of 72.2%, and a specificity of 95.5% for bacterial etiology compared with their individual use. CONCLUSION: Blood CRP is a useful diagnostic marker for both fever and bacterial etiology in acute pediatric diarrhea. The combination of CRP and fecal lactoferrin yields better diagnostic capability for bacterial etiology than their use alone for acute diarrhea in children without underlying gastrointestinal disease.

Clinical Presentation with High Penetrance in a Korean Family with Pulmonary Arterial Hypertension Associated with a BMPR2 Intron 3 Splice Site Pathogenic Variant

Pathogenic variants of bone morphogenic protein receptor type 2 gene (BMPR2) are related to the majority of cases of heritable pulmonary arterial hypertension (PAH). Over 400 pathogenic variants have been identified. However, clinical characterization of PAH is still incomplete. We present a case of heritable PAH in a Korean family showing serious clinical presentation with high penetrance. Genetic sequencing revealed a known heterozygous BMPR2 pathogenic variant, c.418+5G>A, at a splice site of intron 3. Serious clinical presentation with high penetrance suggested that the interplay of other factors with pathologic variants might be in genotype-phenotype correlation. Further studies are needed to clarify these issues for the development of personalized medicine approaches for PAH.

Diagnosis of Liver Fibrosis With Wisteria floribunda Agglutinin-Positive Mac-2 Binding Protein (WFA-M2BP) Among Chronic Hepatitis B Patients

BACKGROUND: Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA-M2BP) is a protein with altered glycosylation that reacts with lectin, and was recently identified as a useful non-invasive biomarker for the diagnosis of liver fibrosis in patients with hepatitis C virus infection.This study aimed to evaluate the diagnostic efficacy of WFA-M2BP for liver fibrosis in the context of hepatitis B virus (HBV). METHODS: We enrolled 151 patients infected with HBV. Liver biopsy and elastography (Fibroscan) were performed during the initial visit. Fibrosis was graded according to the Knodell histologic activity index (F0–3). WFA-M2BP levels were determined with an automated immunoassay analyzer (M2BPGi, HISCL-5000, Sysmex, Japan). The diagnostic efficacy of WFA-M2BP was compared with those of various conventional or composite biomarkers, including enhanced liver fibrosis (ELF) score, Fibroscan, aspartate transaminase (AST)-to-platelet ratio index (APRI), and FIB-4, based on the area under the ROC curve (AUC) value. RESULTS: The majority of patients were at fibrosis stages F1 and F2. The F2 and F3 AUC values for WFA-M2BP were similar to those for FIB-4, APRI, ELF, and Fibroscan, although the latter showed the best diagnostic efficacy. The diagnostic accuracy of all tested biomarkers for F2 and F3 was 60–70%. In multivariate analysis, WFA-M2BP, ELF, and platelet count significantly predicted stage ≥F2, whereas only platelet count significantly predicted F3. CONCLUSIONS: WFA-M2BP can support a diagnosis of liver fibrosis with similar diagnostic efficacy to other biomarkers, and predicted liver fibrosis stage ≥2 among patients with chronic hepatitis B.

Evaluation of the Automated Immunohematology Analyzer DAYMATE M

BACKGROUND: An automated immunohematology analyzer, DAYMATE M (DAY Medical, Switzerland), has been recently developed. The potential of this analyzer to improve test results has been evaluated. METHODS: A total of 300 blood samples from Seoul St. Mary's hospital and Incheon St. Mary's hospital were tested for ABO and RhD typing. In addition, 336 antibody screening test (AST) samples and 82 patients treated with hematopoietic stem cell transplantation (HSCT) were included. AST results by DAYMATE M were compared with those obtained by a manual method using DS-Screening II (Bio-Rad Laboratories, Switzerland) and red blood cells from Selectogen (Ortho-Clinical diagnostics Inc., USA). RESULTS: Of the 300 patients enrolled, 87, 73, 79, and 61 had type A, B, O, and AB blood, respectively. The concordance rate was 99.9% for cell typing and 97.0% for serum typing. One discordant case was classified as type B instead of AB, and six discordant serum-typing cases were type A, but classified as type AB. Among the 336 AST samples, the concordance rate was 93.2%. From 136 positive cases, six were discordant. Within the 82 HSCT-treated patients, the concordance rate for ABO blood typing was 92.2%. Among the six discordant cases, DAYMATE M typed four cases as donor type where the standard method typed them as the recipient blood type. CONCLUSIONS: The DAYMATE M automated immunohematology analyzer performs reliably for ABO and RhD typing, as well as for ASTs and on samples from patients treated with HSCT.

Survey of Fungal Cultures and the Identification Tests Used by Diagnostic Laboratories in Korea

BACKGROUND: The aim of this study was to investigate the current status of fungal cultures and the identification tests used by diagnostic laboratories in Korea. METHODS: From 22 October to 30 November 2013, we surveyed 76 laboratories, participating in the regular proficiency survey program of The Korean Association of Quality Assurance for Clinical Laboratory, with a questionnaire on fungal cultures and their identification tests. In March 2014, five mold were distributed to ninety-one participating laboratories, as an educational challenge. RESULTS: Fifty-six (73.7%) out of seventy-six laboratories replied to the survey questionnaire. Yeast was identified using commercial kits in all laboratories and to species level in 82.1% of the laboratories, whereas moulds were mainly identified by morphological examinations, to species level in 41.1% of the laboratories. The response rate to the five proficiency specimens was 67.0%–71.1%. The percentage of correctly identified dermatophytes was lower than that of Aspergillus species. CONCLUSIONS: An improvement is required in the mould culturing and identification techniques used in diagnostic laboratories in Korea.

Genetic–pathologic characterization of myeloproliferative neoplasms

Myeloproliferative neoplasms (MPNs) are clonal hematopoietic stem cell disorders characterized by the proliferation of one or more myeloid lineages. The current study demonstrates that three driver mutations were detected in 82.6% of 407 MPNs with a mutation distribution of JAK2 in 275 (67.6%), CALR in 55 (13.5%) and MPL in 6 (1.5%). The mutations were mutually exclusive in principle except in one patient with both CALR and MPL mutations. The driver mutation directed the pathologic features of MPNs, including lineage hyperplasia, laboratory findings and clinical presentation. JAK2-mutated MPN showed erythroid, granulocytic and/or megakaryocytic hyperplasia whereas CALR- and MPL-mutated MPNs displayed granulocytic and/or megakaryocytic hyperplasia. The lineage hyperplasia was closely associated with a higher mutant allele burden and peripheral cytosis. These findings corroborated that the lineage hyperplasia consisted of clonal proliferation of each hematopoietic lineage acquiring driver mutations. Our study has also demonstrated that bone marrow (BM) fibrosis was associated with disease progression. Patients with overt fibrosis (grade ⩾2) presented an increased mutant allele burden (P<0.001), an increase in chromosomal abnormalities (P<0.001) and a poor prognosis (P<0.001). Moreover, among patients with overt fibrosis, all patients with wild-type JAK2/CALR/MPL (triple-negative) showed genomic alterations by genome-wide microarray study and revealed the poorest overall survival, followed by JAK2-mutated MPNs. The genetic–pathologic characteristics provided the information for understanding disease pathogenesis and the progression of MPNs. The prognostic significance of the driver mutation and BM fibrosis suggests the necessity of a prospective therapeutic strategy to improve the clinical outcome.

Identification of Compound Heterozygous Mutations in the BBS7 Gene in a Korean Family with Bardet-Biedl Syndrome

No abstract available.

Clinical Significance of Fecal Lactoferrin and Multiplex Polymerase Chain Reaction in Patients with Acute Diarrhea

BACKGROUND/AIMS: The diagnostic yield of fecal leukocyte and stool cultures is unsatisfactory in patients with acute diarrhea. This study was performed to evaluate the clinical significance of the fecal lactoferrin test and fecal multiplex polymerase chain reaction (PCR) in patients with acute diarrhea. METHODS: Clinical parameters and laboratory findings, including fecal leukocytes, fecal lactoferrin, stool cultures and stool multiplex PCR for bacteria and viruses, were evaluated prospectively for patients who were hospitalized due to acute diarrhea. RESULTS: A total of 54 patients were included (male, 23; median age, 42.5 years). Fecal leukocytes and fecal lactoferrin were positive in 33 (61.1%) and 14 (25.4%) patients, respectively. Among the 31 patients who were available for fecal pathogen evaluation, fecal multiplex PCR detected bacterial pathogens in 21 patients, whereas conventional stool cultures were positive in only one patient (67.7% vs 3.2%, p=0.000). Positive fecal lactoferrin was associated with presence of moderate to severe dehydration and detection of bacterial pathogens by multiplex PCR (21.4% vs 2.5%, p=0.049; 100% vs 56.5%, p=0.032, respectively). CONCLUSIONS: Fecal lactoferrin is a useful marker for more severe dehydration and bacterial etiology in patients with acute diarrhea. Fecal multiplex PCR can detect more causative organisms than conventional stool cultures in patients with acute diarrhea.

Impact of Genetic Abnormalities on the Prognoses and Clinical Parameters of Patients with Multiple Myeloma

BACKGROUND: We reviewed patients with multiple myeloma (MM) in order to assess the incidence of genetic abnormalities and their associations with clinical parameters, risk groups, and prognosis. METHODS: A total of 130 patients with MM were enrolled. The incidences of genetic abnormalities were determined in all patients. The relationships of the genetic abnormalities and clinical parameters were investigated. In addition, a survival analysis was performed. RESULTS: Abnormal karyotypes were detected in 42.3% (N=55) of the patients, and this was increased to 63.1% (N=82) after including the results determined with interphase FISH. Hypodiploidy was observed in 7.7% (N=10) of the patients, and all were included in the group with complex karyotypes (30.8%, N=40). The 14q32 rearrangements were detected in 29.2% (N=38) of the patients, and these most commonly included t(11;14), which was followed by t(4;14) and t(14;16) (16.2%, 11.5%, and 0.8%, respectively). Abnormal karyotypes and complex karyotypes were associated with disease progression markers, including low hemoglobin levels, low platelet counts, high plasma cell burden, high beta2-microglobulin, and high international staging system stages. A high free light chain (FLC) ratio and FLC difference were associated with abnormal karyotypes, complex karyotypes, and higher plasma cell burden. Hypodiploidy and low platelet counts were significant independent prognostic factors and were more important in patient outcome than any single abnormality. CONCLUSIONS: Genetic abnormalities were associated with disease progression markers and prognosis of MM patients.

Comparative Evaluation of Three Chromogenic Media Combined with Broth Enrichment and the Real-Time PCR-Based Xpert MRSA Assay for Screening of Methicillin-Resistant Staphylococcus aureus in Nasal Swabs

BACKGROUND: We evaluated the performance of three chromogenic media (Brilliance agar I [Oxoid, UK], Brilliance agar II [Oxoid], and ChromID MRSA [Biomerieux, France]) combined with broth enrichment and the Xpert MRSA assay for screening of methicillin-resistant Staphylococcus aureus (MRSA). METHODS: We obtained 401 pairs of duplicate nasal swabs from 321 patients. One swab was suspended overnight in tryptic soy broth; 50-microL aliquots of suspension were inoculated on the three chromogenic media. Brilliance agar I and II were examined after 24 hr, and ChromID MRSA, after 24 and 48 hr. The paired swab was processed directly using real-time PCR-based Xpert MRSA assay. RESULTS: True positives, designated as MRSA growth in any of the culture media, were detected with the prevalence of 17% in our institution. We report the sensitivity, specificity, positive predictive value, and negative predictive value of MRSA growth as follows: 92.3%, 94.0%, 75.9%, and 98.4% in Brilliance agar I (24 hr); 92.7%, 97.9%, 90.0%, and 98.5% in Brilliance agar II (24 hr); 95.6%, 95.8%, 82.3%, and 99.1% in ChromID MRSA (24 hr); 100%, 92.5%, 73.1%, and 100% in ChromID MRSA (48 hr); 92.6%, 96.7%, 85.1%, and 98.5% in Xpert MRSA assay. The agreement between the enriched culture and Xpert MRSA assay was 96.0%. CONCLUSIONS: Three chromogenic culture media combined with enrichment and Xpert MRSA assay demonstrated similar capabilities in MRSA detection. The Xpert MRSA assay yielded results comparable to those of culture methods, saving 48-72 hr, thus facilitating earlier detection of MRSA in healthcare settings.

Prevalence of p16 Methylation and Prognostic Factors in Plasma Cell Myeloma at a Single Institution in Korea

BACKGROUND: The primary purpose of this study was to investigate the prevalence and characteristics of p16 methylation and determine the prognostic implications of the clinical data, hematologic data, and p16 methylation changes in plasma cell myeloma (PCM). METHODS: We reviewed clinical characteristics and results of laboratory tests and investigated the response to combination chemotherapy and survival time. DNA methylation of the p16 gene was tested by methylation-specific PCR. Clinical significance was evaluated. RESULTS: A total of 103 patients were enrolled in this study. The median patient age was 59.0 yr at diagnosis and the male to female ratio was 1.15:1. According to the International Staging System (ISS), patients were diagnosed as stage: I (N=17, 16.5%), II (N=41, 39.8%), III (N=39, 37.9%), or not classified (N=6). Forty-five (43.7%) patients and 36 (35.0%) patients showed abnormal karyotype and complex karyotype, respectively, on the chromosome study. The p16 methylation was observed in 39 (37.9%) of 103 patients, but there was no significant association between p16 methylation status and other clinical or laboratory factors and survival outcome. Male gender, albumin, and complex karyotype were independent prognostic factors for overall survival according to multivariate analysis (P<0.05). CONCLUSIONS: The male gender, low serum albumin level, and complex karyotype were independent poor prognostic factors for PCM. p16 methylation was relatively common in PCM, but did not influence the survival outcome.

Experience of a Performing Alternative Assessment Procedure for Tests without External Proficiency Test Program / 대한수혈학회지

BACKGROUND: Proficiency testing is part of a total quality management program that provides objective evidence of clinical laboratory testing competence for customers, accrediting bodies, and regulatory agencies. Performing alternative assessment procedures for clinical tests, without proficiency testing, is recommended by Clinical and Laboratory Standards Institute (CLSI) guideline. In our study, an alternative assessment procedure was performed for blood bank tests that do not have an external proficiency program. METHODS: The laboratory for development and an evaluation center, supervised the program. Proficiency testing by seven institutions was performed 3 times at 6 month intervals by evaluating isoagglutinin and anti-D titers, and Weak D, Rh C and E typing, using ID-Internal Quality Control (Bio-Rad Laboratories) kits. RESULTS: Isoagglutinin and anti-D titer results were within one fold dilution range for all seven participating institutions, and Weak D, Rh C and E typing results all demonstrated identical antigenic reference patterns. CONCLUSION: An alternative assessment procedure was successfully performed without a proficiency testing program. Commercially manufactured reference materials could be an alternative method to support commutable, external, proficiency testing program.

JAK2 V617F mutation in myelodysplastic syndrome, myelodysplastic syndrome/myeloproliferative neoplasm, unclassifiable, refractory anemia with ring sideroblasts with thrombocytosis, and acute myeloid leukemia / 대한혈액학회지

BACKGROUND: The JAK2 V617F mutation has been noted in the cases of polycythemia vera, essential thrombocythemia, and primary myelofibrosis patients. This mutation occurs less frequently in acute myeloid leukemia (AML) and other hematologic diseases, such as myelodysplastic syndrome (MDS); myelodysplatic syndrome/myeloproliferative neoplasm, unclassifiable (MDS/MPN-U); and refractory anemia with ring sideroblasts with thrombocytosis (RARS-T). METHODS: Patients diagnosed with hematologic diseases other than MPN who visited Seoul St Mary's Hospital from January 2007 to February 2010 were selected. A total of 43 patients were enrolled in this study: 12 MDS, 9 MDS/MPN-U, 7 RARS-T, and 15 AML patients. The diseases were diagnosed according to the 2008 WHO classification criteria. Data obtained from JAK2 V617F mutation analysis and cytogenetic study as well as complete blood count and clinical data were analyzed. RESULTS: Of the 43 patients, 6 (13.9%) harbored the JAK2 V617F mutation. The incidence of the JAK2 V617F mutation in each patient group was as follows: 8.3% (1/12), MDS; 22.2% (2/9), MDS/MPN-U; 14.3% (1/7), RARS-T; and 13.3%, (2/15) AML. The platelet count was higher than 450x10(9)/L in 3 of the 6 patients (50%) harboring the JAK2 V617F mutation, and it was in the normal range in the remaining 3 patients. Among the 6 patients, 1 MDS and 1 MDS/MPN-U patients had the 46,XX,del(20)(q11.2) karyotype. CONCLUSION: The JAK2 V617F mutation is associated with an increased platelet count in MDS, MDS/MPN-U, RARS-T, and AML patients. Cytogenetic abnormalities of del(20)(q11.2) occurred in 1/3 of patients with the JAK2 V617F mutation but further studies are required to confirm this association.