A Case of Splenic Marginal Zone Lymphoma / 대한진단검사의학회지

Splenic marginal zone lymphoma (SMZL) is a rare B-cell neoplasm characterized by massive splenomegaly, moderate lymphocytosis, bone marrow intrasinusoidal involvement of lymphocytes and a relatively indolent course. We report a case of SMZL diagnosed by bone marrow studies using immunophenotyping and immunohistochemical stain, and confirmed by splenectomy. The patient was a 61-year old male, who showed mild lymphocytosis in peripheral blood and bone marrow aspirates. Immunophenotyping of bone marrow aspirates showed lymphocytes positive for CD19, CD20, CD22 (dim), CD23 (dim) and negativie for CD5 and CD10. The immunohistochemistry of bone marrow and spleen also showed lymphocytes positive for CD20 and negative at for cyclin D1. Now he is being treated for chronic obstructive pulmonary disease and will receive chemotherapy.

Ox-LDL suppresses PMA-induced MMP-9 expression and activity through CD36-mediated activation of PPAR-gamma

During chronic inflammatory response, mono- cytes/macrophages produce 92-kDa matrix metalloproteinase-9 (MMP-9), which may contribute to their extravasation, migration and tissue remodeling. Activation of peroxisome proliferator- activated factor receptor-gamma (PPAR-gamma) has been shown to inhibit MMP-9 activity. To evaluate whether ox-LDL, a PPAR-gamma activator, inhibits PMA-induced MMP-9 expression and activity, and if so, whether CD36 and PPAR-gamma are involved in this process, we investigated the effect of ox-LDL on MMP-9 expression and activity in PMA-activated human monocytic cell line U937. PMA-induced MMP-9 expression and activity were suppressed by the treatment with ox-LDL (50 micrigram/ml) or PPAR-gamma activators such as troglitazone (5 micrometer), ciglitazone (5 micrometer), and 15d- PGJ2 (1 micrometer) for 24 h. This ox-LDL or PPAR-gamma activator-mediated inhibition of micrometer P-9 activity was diminished by the pre-treatment of cells with a blocking antibody to CD36, or PGF2a (0.3 micrometer), which is a PPAR-gamma inhibitor, as well as overexpression of a dominant-negative form of CD36. Taken together, these results suggest that ox-LDL suppresses PMA-induced MMP-9 expression and activity through CD36-mediated activation of PPAR-gamma.

Diagnosis of Malaria Using Automatic Hematology Analyzer / 임상검사와정도관리

BACKGROUND: For the diagnosis of malaria, examination of blood smear slides by light microscopy is used as standard, and commercial kits detecting malarial antibodies and antigens are available, and molecular methods such as polymerase chain reaction (PCR) are used additionally. But, these diagnostic methods can be performed when clinicians request them, so problems of misdiagnosing the patients who are not suspected malaria may be occurred. METHODS: In 42 Korean patients with malaria, the author analyzed the characteristic signals of malaria using granularity (90 degrees depolarized) versus lobularity (90 degrees polarized) graph of Cell-Dyn 4000 (CD4000) automatic hematologic analyzer. And, the author examined the presence of malaria in 421 random samples by CD4000 and Giemsa stain. RESULTS: The usefulness of CD4000 in diagnosing malaria are as follows, 93.0% sensitivity, 99.3% specificity, 93.0% positive-predictive value, and 99.3% negative-predictive value. CONCLUSION: CD4000 automatic hematology analyzer has high diagnostic sensitivity and specificity in diagnosing malaria. Because complete blood count (CBC) is the routine test for most patients, this method has advantage of time and cost effectiveness and can even detect malaria in unsuspected cases.

The Seroprevalence of IgM and IgG Antibodies to Helicobacter pylori Among Maternal, Neonatal, and Cord Bloods in Korea / 임상검사와정도관리

BACKGROUND: Helicobacter pylori (H. pylori) infection has been known closely related with gastritis, duodenal ulcer and gastric cancer and is prevalent among Koreans. However, the infection route and the time are unclear, especially during perinatal period. The aim of this study is to investigate the relationship of H. pylori IgG and IgM antibody prevalences and titers between maternal, neonatal, and cord blood. METHODS: We collected 45 simultaneous maternal, neonatal, and cord bloods and 150 single cord bloods during delivery. The specific H. pylori IgG and IgM antibody levels were measured by enzyme-linked immunosorbent assay (ELISA) method. RESULTS: The H. pylori IgG antibody-positive rate for maternal, neonatal, and cord bloods were equal as 35.6% (16/45). The H. pylori IgG antibody levels of neonatal and cord bloods were 52.7% and 70.7% of maternal blood level. The H. pylori IgG antibody levels between maternal and cord bloods (r2 = 0.9725, p<0.05), maternal and neonatal bloods (r2 = 0.8569, p<0.05), and neonatal and cord bloods (r2 = 0.9437, p<0.05) were well correlated. Only one case of maternal blood was H. pylori IgM antibody positive and it's antibody level was 52.3 U/mL. CONCLUSIONS: In this study, we provided the sero-prevalence of H. pylori IgG and IgM antibodies and the relationship of antibody level of H. pylori IgG in maternal, neonatal and cord bloods. To elucidate the exact route and time of H. pylori infection, further studies including serial measurement of H. pylori IgG and IgM level in neonates will be needed.

The genotyping of Kell, Duffy, and Kidd System in Korean / 대한수혈학회지

BACKGROUND: Among human blood group antigens, the genes for Kell, Duffy, and Kidd antigens have been recently identified, and those can play an important role in unexpected acute and delayed hemolytic transfusion reactions or hemolytic disease of newborns. The determination of blood group polymorphism at the genomic level facilitates the resolution of clinical problems that cannot be addressed by hemagglutination. They are useful to determine antigen types for which currently available antibodies are weakly reactive, type patients who have been recently transfused, identify fetuses at risk for hemolytic disease of the newborn and to increase the reliability of repositories of antigen negative RBCs for transfusion. METHODS: Two hundred peripheral blood samples were collected from normal population. Primer sets were used with slight modification from Reid M.E, et al. Bsm I, Ban I, and Mnl I were used from digestion of 5 uL PCR products. 10 uL of each digested-PCR products were electrophoresed on agarose or polyacrylamide gel with ethidium bromide staining. Kell, Duffy, and Kidd phenotypes (serologic types) were compared with respective genotypes by PCR-RFLP. RESULTS: The concordance rate was 100%: between genotype and phenotype 0 case(0%) K, 187 cases(100%) k; 22 cases(11.4%) Fy(a+b+), 171 cases(88.1%) Fy(a+b-), 1 case(0.5%) Fy(a-b+), 0 case(0%) Fy(a-b-); 95 cases(50.8%) Jk(a+b+), 39 cases(20.9%) Jk(a+b-), 53 cases(28.3%) Jk(a-b+), 0 case(0%) Jk(a-b-). In this study, Fyb frequency was 11.9% and it was equal to that of Japan and China. We analyzed each digested PCR product from 200 patients; Kell(187 cases), Duffy(194 cases), and Kidd(187 cases). CONCLUSIONS: The PCR-RFLP method can be effectively used for the Kell, Duffy, and Kidd typing and is particularly useful in cases where serological typing method is difficult as in autoimmune hemolytic anemia or recently transfused red blood cells in their circulation. Also, it is useful in cases of hemolytic disease in newborns and hemolytic transfusion reaction.

The Reduction Effect of Leukocyte Fragments by Leukodepletion Filter / 대한수혈학회지

BACKGROUND: The efficiency of leukocyte removal filter is influenced by many factors. But, filtration efficiency of leukocyte fragments was not well known. We performed this study to evaluate whether the filtration efficiency for packed red blood cells can be influenced by leukocyte fragments according to storage time. METHODS: Leukocyte fragments in packed red blood cells (three units) which were artificially made by incubation for 4 hrs at 56degrees C and each four units of packed red blood cells according to storage time (0 days, 10 days, 20 days, and 30 days) were filtered using Sepacell R-500A (Asahi medical Co, Japan). The leukocyte concentrations of the pre-leukodepleted samples were estimated using an automated hematology analyzer (XE-2100, Sysmex, Japan). The ratio between the number of normal leukocytes and leukocyte fragments on Wright Giemsa stained slide was used in the analysis. The leukocyte concentrations of the post-leukodepleted samples were performed by the conventional counting methods using Nageotte hemocytometer. RESULTS: The ratios of fragmented to total leukocytes in packed red blood cells at pre- and post leukoreduction according to storage times were 1.5% and 16.3% within 1 days, 4.5% and 30.0% at 10 days, 6.3% and 35.0% at 30 days, and 8.3% and 42.5% at 40 days, respectively. Leukoreduction efficiencies of normal leukocytes in packed red blood cells were 99.99 +/- 0.01%, 99.97 +/- 0.02%, 99.98 +/- 0.01%, and 99.86 +/- 0.09%, respectively. The 36.0% of leukocytes in packed red blood cells were changed to fragmented leukocytes, residual fragmented leukocytes ratio was 95.0% and filter efficiencies of normal leukocytes was low(99.28%, p<0.05). CONCLUSIONS: The leukodepleted efficiency for leukocyte fragments were lower than for normal leukocytes. Leukocytes fragments may be influenced to lower the leukodepleted efficiency of normal leukocytes with storage time elapse.

Two Cases of ABO Discrepancy due to Hypogammaglobulinemia / 대한수혈학회지

Two cases of ABO discrepancy were observed in thirty-year old woman with gall bladder abscess and fifty-five-year old woman with hepatocellular carcinoma. Their red cells were typed as group O and their serum had only anti-A antibody. Absence of A and B antigens on their RBCs were confirmed by adsorption elution test and saliva test. The B transferase activities were not demonstrated in their serum. Their ABO genotypes were O/O by sequence specific polymerase chain reaction. Their serum protein electrophoresis showed hypogammaglobulinemia pattern, and immunoglobulin levels (IgG, IgA, IgM) were decreased (39 mg/dL, 46 mg/dL, <5 mg/dL and 63 mg/dL, 65 mg/dL, 12 mg/dL, respectively).

Evaluation of the RBC Lewis Blood Group Phenotypes and Genotypes of the FUT3 and FUT2 Gene / 대한진단검사의학회지

BACKGROUND: The Lewis and secretor gene determine the Lewis phenoytpe. Conventional Lewis blood grouping is difficult because of the presence of nongenuine Lewis negative individuals. Recently, the Lewis gene (FUT3), the secretor gene (FUT2), and several mutations that cause the Lewis negative and the nonsecretor phenotypes were identified. The purpose of this study was to compare Lewis phenotypes determined by commercially available three pairs of monoclonal antibodies with the Lewis and secretor genotypes. METHODS: RBCs for phenotyping and peripheral blood leukocytes for genotyping of FUT3 and FUT2 gene were obtained from 184 apparently healthy volunteers. Lewis phenotypes were determined on K3EDTA-stablized fresh blood samples using three pairs of commercially available monoclonal antibodies, one of which was the column agglutination method and the others were the tube agglutination methods. Lewis blood group genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to detect T59G, G428A, C357T, and A385T mutations. RESULTS: The frequencies of the Lewis blood group phenotype were Le(a+b-) 15.0%, Le(a-b+) 65.8%, Le(a-b-) 14.8%, and Le(a+b+) 4.3%, respectively. The Lewis blood group phenotypes determined by three pairs of monoclonal antibodies were 93.5%, 93.5% and 89.1% in accordance with the genotypes. The frequencies of Le, le, Se and se alleles were 64.4%, 35.6%, 48.6%, and 51.4% and we have newly detected 4 cases with only one A385T mutation. All of the Le(a+b+) phenotype cases have both C357T, and A385T homozygotic mutations. CONCLUSIONS: The PCR method may be effectively used for the genotyping of the FUT3 and FUT2 genes and offers an attractive alternative to Lewis phenotyping using hemagglutination method.

Antibody Responses to the Recombinant Circumsporozite Protein, Merozoite Surface Protein, and Duffy Binding Protein Antigens of Plasmodium vivax in Korea / 대한진단검사의학회지

BACKGROUND: Plasmodium vivax circumsporozoite protein (CSP), merozoite surface protein (MSP) and Duffy binding protein (DBP) are functionally important conserved proteins and may have an important role in developing antigens. The aim of this study was to develop recombinant CSP, MSP, and DBP antigens, to evaluate their diagnostic usefulness, and to analyze the prevalence of seroreactivity against P. vivax in five different regions in Korea. METHODS: To construct recombinant CSP, MSP, and DBP antigens from P. vivax, DNA obtained from specimens previously diagnosed as P. vivax was used. To evaluate diagnostic usefulness of recombinant CSP, MSP, and DBP antigens from P. vivax, sera from 45 patients with P. vivax and 48 normal controls including 4 patients with Plasmodium falciparum were used. For the epidemiologic study, a total of 1, 014 serum samples obtained from five different regions in Korea were used. RESULTS: The sensitivity of the IgG antibody against the P. vivax recombinant CSP, MSP, DBP antigens and the antigens mixture of these proteins were 75.6%, 62.2%, 68.9%, and 97.8%, and the specificity were 92.1%, 84.2%, 81.6%, and 97.4%, respectively. The seropositivity against P. vivax recombinant antigens was highest in Cheolwon province. The IgG seropositivity against P. vivax recombinant CSP, MSP and DBP was 2.0%, 1.2%, and 1.5%, respectively. There were no significant differences in seroreactivity against P. vivax between each recombinant protein and each five different regions in Korea. CONCLUSIONS: Newly constructed recombinant CSP, MSP and DBP were useful in the detection of antibodies against the P. vivax antigen.

Management of Clinical Laboratory Staffs in Korea (II) / 임상검사와정도관리

BACKGROUND: For the efficient management of clinical pathology laboratory, not only the economic side but also the quality of test should be considered. Therefore, the authors investigated the status of laboratory in the management point including the status of technical personnel by survey and tried to find out the fundamental status of work environment, laboratory automation, computerization, and to evaluate the efficiency of management of clinical pathology laboratories in Korea. METHOD: The questionnaires included those for investigating laboratory management status, qualities of laboratory personnels, workloads, test items and numbers of tests performed annually. It contained 22 items with 32 detailed sub-questionnaires for laboratory personnel survey, and 9 items with 106 detailed sub-questionnaires for facilities. We sent those three times to 400 laboratories that were participating in the National External Quality Assessment Scheme in Korea and analysed the answers by descriptive statistics, ANOVA, t-test and correlation analysis. RESULTS: The replies were from 96 laboratories and 326 technical personnels. Among the 96 laboratories, there were 71 full time employed clinical pathologists. The annually performed number of tests were increased with the increased the size of laboratory, that was classified by number of personnels. As the laboratory size was increased, part time personnels, cases of test per technical personnel, automation and computerization, satisfaction for their work (58,2%) were increased but decreased satisfaction of salaries. CONCLUSIONS: We surveyed the present employee status of laboratory personnels and status of laboratory and offered fundamental data of clinical laboratory management in Korea.

Evaluation of leukoreduction filter Bio R02 plusTM for packed RBC / 대한수혈학회지

BACKGROUND: As universal WBC filtration of RBCs prior to storage is currently under consideration, few data are available on the performance of WBC-reduction filtration in routine practice. The pre-leukodepletion is thought to minimize the incidence of transfusion associated adverese effects such as HLA alloimmunization, non-hemolytic febrile reactions, platelet refractoriness, transfusion associated graft versus host disease and transmission of infections. The aim of this study was to evaluate the one of pre-storage and bedside leukocyte removal filter, leukocytes Bio R02 plusTM (Fresenius HemoCare, Germany) for packed RBCs. METHODS: In order to evaluate leukocyte removal filter of leukocytes Bio R02 plusTM, thirteen units of red blood cells were prepared and filtered using Bio R02 plusTM, and were measured the WBC count, RBC count, volume, sodium, and pH before and after filtration, respectively and the reduction power of white blood cell and biochemical changes in red blood cell units were analysed. RESULTS: There were 99.99% reduction in WBC counts, residual leukocyte content of 0.06 +/- 0.08 106 per unit and 8.69% of RBC loss after filtration, and there was no difference in the sodium and pH. CONCLUSION: The leukocyte removal filter Bio R02 plusTM showed sufficient leukocyte removal and RBC recovery efficiency for RBC units.

The Genotyping of the Secretory Gene (Sec2) in the Korean Population / 대한임상병리학회지

BACKGROUND: The expression and secretion of ABH antigens in epithelial cells of glands are controlled by secretor type alpha (1,2)fucosyltrasnferase activity and the human secretor alpha (1,2)fucosyltransferase gene (Sec2) determines the ABH secretor status and influences the Lewis phenotype of an individual. Homozygosity of the mutation for this allele is responsible for the nonsecretor phenotype in nonsecretor individual. The aim of this study was to investigate the status and the distribution of the Sec2 genotype in the Korean population. METHODS: In order to explore the secretory genotypes of the Korean population, the 158 specimens were analyzed by the PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) method designed for the detection of the A385T, the C357T and the G428A mutations of Se alleles. RESULTS: The frequencies of Se1, Se2 and sej among 316 alleles examined in a random sample of 158 Korean individuals were 11.1%, 40.5% and 48.4%. The frequencies of Se1/Se1, Se1/Se2, Se2/Se2, Se1/sej, Se2/sej and sej/sej among 158 genotypes were 3.2%, 3.2%, 20.3%, 12.7%, 37.3% and 23.4%. The G428A nonsense mutation discovered in the Sec2 gene of nonsecretors in Caucasian was not found in any of 158 Korean population. CONCLUSIONS: The distribution of the genotypes of the Sec2 gene in the Korean population showed a rather wide distribution of the sej allele than the Caucasian population and was similar to the Japanese population. PCR-RFLP method can be effectively used for the genotyping of the Sec2 gene.

Chemical Modification of RBC Surface Antigen with Methoxy Polyethylene Glycol / 대한임상병리학회지

BACKGROUND: Today, blood group antigens are a strong barrier of safe transfusion. We evaluated the change of agglutinability of antibody to RBC surface antigen before and after activated methoxy polyethylene glycol (mPEG) modification. METHODS: We collected blood from healthy volunteers and the blood were treated by activated mPEG (MW 5,000, Sigma, USA). Agglutinability of RBC was measured using anti-sera (Green Cross, Korea) in ABO and Rh(D) groups, and compared the agglutinability changes before and after mPEG treatment. RESULTS: The agglutinability of Rh(D) surface antigen (n=20) was disappeared after mPEG treatment. However, ABO antigens showed variable agglutinability against antisera, some of which showed no change at all. CONCLUSIONS: In the case of Rh(D) antigen, it would be useful to apply mPEG treated RBCs for clinical use, if the safety problem were solved. But in the case of ABO antigen, the more evaluation of the condition of reaction and the concentration of mPEG should be needed.

The Characteristics of Residual Leukocyte in Sepacell PLS-5A Filtered Platelet Concentrates / 대한혈액학회지

BACKGROUND: We evaluated residual leukocytes characteristics of white cell(WBC) reduction filter in platelet concentrates. Differential count and lymphocyte subset changes were measured before and after leukocyte filtration in platelet concentrates. MATERIAL AND METHODS: Ten units of platelet concentrates were prepared and were filtered with WBC-reduction filter(Sepacell PLS 5A, Japan). After filtration of blood products, WBC and differential leukocyte count and lymphocyte subsets were counted by microscopic examination of Wright-Giemsa stained smear and Facscan(Becton-Dickinson, USA). Monoclonal antibodies used for lymphocyte subset test were CD3(FITC), CD4(FITC), CD8(PE), CDl4(PE), CDl6(PE), CDl9(PE), CD33(PE), CD56(PE), IgGl(FITC), IgG2(PE). RESULTS: The main population of residual leukocytes after filtration was mainly lymphocytes(96.7%), and CD3 positive T lymphocytes showed 23.8% positivity of residual leukocyctes and the next were NK cell(8.7%). B lymphocytes were rarely found(<0.01%) and CD4/ CD8 ratio was within normal limits. CONCLUSION: The leukocyte reduction filters(Sepacell PLS-5A) would be effective for prevention of platelet alloimmunization but not sure about the effect for prevention of TA GVHD.

Sequencing Analysis of Penicillin-Binding Protein 2B Gene of Streptococcus pneumoniae Isolated in Korea / 대한임상병리학회지

BACKGROUND: The resistance of Streptococcus pneumoniae to penicillin has been rapidly increasing during the recent three decades. In Korea, we found the incidence of penicillin resistance (PR) to pneumococci was 81% for the clinical isolates in our hospital, and 89% for the colonizing isolates of day-care center around Seoul. Alterations in penicillin-binding protein (PBP) 2B gene have been known to be associated with a resistance to penicillin. We tried to reveal the characteristics of PR of Korean pneumococcal strains through sequencing analysis of PBP 2B gene. METHODS: We determined the nucleotide sequences of 346 bp of a variable region among PBP 2B gene for 12 PR strains and 6 penicillin susceptible (PS) strains isolated in Korea. Phylogenetic tree using PAUP program was made to compare our DNA sequences with those of South African strains. RESULTS: Sequence homology of PS strains was ranged from 99.4% to 100% in Korean PS strain compared to reference strain, R6, except one strain (93.9%). PR strains showed homology of 95.1% to 100% compared to the South African 56762 strain. Phylogenetic analysis based on 346 bp of PBP 2B gene showed that Korean and South African strains formed different monophyletic groups according to the PR/PS patterns. Five specific amino acid changes compared to the PS R6 strain in the position 228, 232, 233, 244, and 261 were noted with a decreased hydrophilicity by Kyte-Doolittle assay. CONCLUSIONS: Our data suggest that the amino acid changes in the PBP 2B are associated with PR in S. pneumoniae, and that a part of Korean PR strains might be originated from a South African PR strain.

Removal of Yersinia enterocolitica from Packed RBCs with WBC-Reduction Filters / 대한임상병리학회지

BACKGROUND: Aseptic technique and cold storage of blood can reduce the incidence of transfusion-associated infections. But, none of these precautions eliminates the potential of drawing contaminated blood from an asymptomatic carrier with psychrophilic organisms such as Yersinia enterocolitica. We evaluated the ability of WBC-reduction filters to prevent the growth of bacteria in packed RBCs that are artificially inoculated with Y. enterocolitica. METHODS: Twenty units of packed RBCs donated from 20 healthy individuals were divided into 4 groups. Group A and B were inoculated with 10 CFU/mL of Y. enterocolitica and group C and D were inoculated with 100 CFU/mL of Y.enterocolitica. After 24 hours of cold storage, group A and C were filtered through WBC-reduction filter (Sepacell R 500A: Asai medical, Japan) and returned them to storage. Group B and D served as unfiltered controls. We collected blood weekly from day 1 to day 35 of storage. Bacterial growths were compared between 4 groups. RESULTS: The prefiltration WBC count was 8,880/ L (SD 1464.2/ L, n=20). After filtration residual WBC count was 210/ L (SD 99.8/ L, n=10). All cases of group B & D (10 & 100 CFU/mL inoculation without filtration) showed growth over 105 CFU/mL after 3 weeks storage. But in filtered groups, only 1/5 (20%) of group C (100 CFU/mL inoculation with filtration) and 4/5 (80%) of group A (10 CFU/mL inoculation with filtration) showed growth over 105 CFU/mL after 3 weeks. CONCLUSIONS: The use of WBC-reduction filter have ability to reduce the risk of transfusion transmitted bacteremia in packed RBCs.

Comparison of the Flowcytometric HLA-B27 Determination Methods / 대한임상병리학회지

BACKGROUND: The flowcytometric analysis of HLA-B27 gives more objective results and is performed more rapidly than traditional serologic methods. We have used a flowcytometric method using only anti-HLA-B27 monoclonal antibody, but it gave frequently borderline mean fluorescence intensity (MFI) results. The authors compared the method using anti-HLA-B27 antibody (HLA- ABC-m3, Serotec) with the Becton Dickinson (BD) method which uses different HLA-B27 antibody (GS145.2) with CD3 antibody. METHODS: The 59 patients that requested HLA-B27 testing were measured by two methods. In the former method, the mononuclear cells were stained with HLA-B27-FITC and the MFIs were determined in lymphocytes. In the BD method, the whole blood was directly stained with CD3-PE and HLA-B27-FITC. The MFIs were determined in the CD3+ cells, and compared with the MFI of the standard. For the cases showing discrepancy in the two methods or borderline values, the HLA-ABC typing was done. RESULTS: Of 21 showing discrepancy, 10 samples had undergone HLA typing. Among nine samples that were positive by the Serotec method but negative by the BD method, four samples were B7, one B40, one B54 and three B7 CREG negative. One that was negative by the Serotec method but positive by the BD method was confirmed as HLA-B27. CONCLUSIONS: The Serotec method showed significant overlap between the MFIs of HLA-B27 and non B27 samples that resulted in a relatively low efficiency compared with the BD method. The discrepant results of the two methods seem to be due to maily the specificity of the antibody used.

Chemical modification of RBC surface antigen with glutaraldehyde crosslinking / 대한수혈학회지

BACKGROUND: The chemical modification of RBC surface antigen has many advantages for safe transfusion practice. We evaluated the change of antibody reactivity to RBC surface antigen before and after glutaraldehyde crosslinking. MATERIALS AND METHODS: The 10 mL of blood were collected from 20 volunteers and were treated by 2-3% glutaraldehyde at 4degrees C. After 30 minute incubation, Agglutinability of various RBC surface antigen (ABO, Rh-C, c, D, E, e) was measured by titration using anti-sera (Green Cross, Korea, Dade, USA), and compared the agglutinability changes before and after glutaraldehyde crosslinking. RESLUTS: The agglutinability of Rh surface antigens (D, C, c, E, e) was disappeared after glutaraldehyde crosslinking. However, ABO antigens (n=20) still showed strong agglutinability against antisera with some decreased. CONCLUSIONS: It would be useful to apply glutaraldehyde crossliked RBCs for rare blood group transfusion practice, if the safety problem were solved.

Detection of Methicillin Resistance in Staphylococcus aureus by 2% NaCl Mueller-Hinton Agar and Mannitol Salt Agar / 감염

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) has a heteroresistant nature, so methicillin resistance is influenced by various culture conditions, such as temperature, incubation time, and NaCl content in the medium. Mueller Hinton (MH) agar containing 2% NaCl and mannitol salt agar (MSA) with oxacillin disk were evaluated for the detection of methicillin resistance. METHODS: Disk diffusion test on plain Mueller- Hinton (MH) agar, 2% NaCl MH agar, and MSA with 1 microgram oxacillin disk was performed in 70 Stap hylococcus aureus isolates. Oxacillin MIC was determined by E-test. As a gold standard of methicillin resistance, mecA gene was amplified by PCR and detected by agarose gel electrophoresis. RESULTS: Plain MH agar could not detect heterogeneous resistance in 12 S. aureus isolates (18%), but 2% NaCl MH agar and MSA could correctly detect homogeneous and heterogeneous resistance. S. aureus isolates from stool have as much as 48% heterogeneous resistance, while those from non-stool specimen have 5%. CONCLUSION: 2% NaCl and MSA can be used reliably for accurate susceptibility testing of methicillin resistance in routine laboratory.

A Case of Vivax Malaria Who Showed only Released Merozoites and Ruptured Schizonts Form / 감염

We report a case of vivax malaria that showed ruptured form of merozoite only in the peripheral blood. A 28-year old man was admitted to Korea University hospital because of irregular high fever, chill and abdominal pain. The peripheral blood smear, showed only small merozoites which seemed to have been recently released from schizonts and destroyed remnants form of schizonts and did not show any forms of malaria parasite such as ring forms, mature trophozoites, schizonts, and gametocytes. On acridine orange fluorochrome stain, we could not find any suspected forms of malaria. However, we detected parasite LDH which is specific to Plasmodium vivax. Malaria treatment was done to the patient, and he is now under follow up in local hospital.