Hematologic Characteristics and Hemoglobin Fraction Analysis by High Performance Liquid Chromatogaphy in Patients with Hypochromic Microcytosis: Trials for Detection of beta-thalassemia / 대한진단검사의학회지

BACKGROUND: In Korea, more than 20 cases of beta-thalassemia have been reported up to date. To detect -thalassemia. Hemoglobin (Hb) fractions were measured in patients with hypochromic microcytosis, and we analyzed the hematological characteristics of these patients. METHODS: Among 359, 369 CBCs performed at Asan Medical Center, 229 patients (0.064%) showed hypochromic microcytosis with less than 75 fL of mean corpuscular volume (MCV), less than 24 pg of mean corpuscular hemoglobin (MCH), and less than 18% of red cell distribution width (RDW). We analysed Hb fractions using high performance liquid chromatography (VARIANT(TM) Hemoglobin Testing System). Iron, total iron binding capacity (TIBC), ferritin, and reticulocyte counts were measured and medical history was searched on cases with Hb A2 and F fractions more than 3.5% and 2.0%, respectively. RESULTS: Among the 229 patients with hypochromic microcysis, 44 (19.2%) showed an increased level of Hb A2 and/or F fractions. With the exclusion of 28 patients (23 children <2 years old and 5 pregnant women), 16 (7.0%) showed a significantly increased level of Hb A2 and/or F. However, all 16 patients were diagnosed as having iron deficiency anemia based on their iron status and clinical findings. Three patients who had an increased level of Hb F at more than 5% needed a further study and follow-up to rule out the diagnosis of the hereditary persistence of the fetal hemoglobin. CONCLUSIONS: No thalassemia cases were found in the study. Incidence of beta-thalassemia should be very low, less than 1/359, 369 (0.00027%), in South Korea; a larger population should be screened to detect beta-thalassemia.

Quantitation of D-Dimer, Thrombin-Antithrombin III Complex and Prothrombin Fragment 1 2 in Patients with Disseminated Intravascular Coagulation and Venous Thrombosis / 대한임상병리학회지

BACKGROUND: The purpose of this study is to evaluate the diagnostic usefulness of the quantitation of D-dimer, thrombin-antithrombin III complex (TAT) and prothrombin fragment 1 2 (F1 2) in patients with DIC or venous thrombosis. METHODS: The quantitation of D-dimer, TAT and F1 2 by ELISA (Behring, Germany) were done with the specimens from eighty eight patient plasma. The patients were classified as DIC, probable DIC and non-DIC based on the DIC criteria by reserach committee in Japan, and the patients with deep vein thrombosis (DVT) or pulmonary embolism (PE) were included. RESULTS: All eighteen DIC patients showed the increased D-dimer ELISA and fourteen patients showed the increased TAT and F1 2. According to the results of quantitative D-dimer, TAT and F1 2 tests, probable DIC and the group with increased results of above three tests among non-DIC were considered as DIC. Two patients with PE showed increased results of above three tests. Among nine DVT patients, eight patients showed increased results of D-dimer ELISA and F1 2, but TAT was increased in only six patients. Among forty six patients with negative results of D-dimer semiquantitation (latex agglutination), twenty seven patients (59%) revealed increased results of D-dimer quantitation (ELISA). CONCLUSIONS: D-dimer quantitation by ELISA is the most sensitive test in the diagnosis of DIC and venous thrombosis. The quantitation of D-dimer, TAT and F1 2 can increase the diagnostic rate of DIC and venous thrombosis, and the developement of the new quatitating reagents with more rapid and individual procedures will contribute to the accurate and rapid diagnoses of them.

Identification of Mycobacterium tuberculosis Complex Using a Gene Probe method / 대한임상병리학회지

BACKGROUND: Rapid and accurate identification of Mycobacterium tuberculosis complex is important in the diagnosis, treatment, and assessment of prognosis of tuberculosis. But, the conventional identification procedures such as niacin test usually requires considerable time. In this study, we compared the diagnostic value of a gene probe method with that of the niacin test for the differentiation of M. tuberculosis complex from mycobacteria other than tuberculosis (MOTT). METHODS: Commercially available gene probe kit(AccuProbeTM, Gen-Probe, Inc. , San Diego, Calif.) and Niacin test strip were used to identify 78 strains of mycobacteria isolated from patients at Asan Medical Center. One ATCC strain (M. tuberculosis complex) and one MOTT strain were used as controls. Polymerase chain reaction(PCR) was used when the above two tests yielded discordant results. RESULTS: Fifty isolates were identified as M. tuberculosis complex by both gene probe method and niacin test. Likewise 25 isolates were identified as MOTT by the both methods. For the remaining 5 isolates, the results of the two tests differed from each other: M. tuberculosis complex by gene probe and MOTT by niacin test. By PCR, however. these strains were identified as M. tuberculosis. The time required for identification was 1 to 2 hours by gene probe method and 1 to 3 weeks by niacin test. CONCLUSION: Gene probe is simple, rapid and reliable and is a very practical diagnostic tool that can be used in any clinical laboratory.

Outbreak of Nosocomial infection caused by Klebsiella pneumoniae Producing Extended-spectrum beta-Lactamase in a Neonatal intensive care unit / 병원감염관리

BACKGROUND: Over the decade, Klebsiella pneumoniae resistant to broad-spectrum oephalosporins have been involved in hospital outbreaks, particulaly in intensive care units. Betwem March 20 and June 12. 1900. an outbreak of sepsis caused by multiresistant K. pneumoniae in the neonatal intensive care unit (NICU) of Asan Medical Center. This paper describes bacteriologic, molecular and epidemiologic features of the outbreak. METHODS: For surveillance purpose, stool specimens were obtained from all patients, nurses and house staff in NICU and cultured onto MacConkey agar medium containg cefotaxim, (10 microgram/ml). All K. pneumoniae isolated blood culture isolates form patients with sepsis were tested for antobiogram by microbroth dilution method and for detection of extended-spectrum beta-Iactamase (ESBL) by double disk synergy test and ESBL Etest. Restriction profiles of total genomic DNAs were compared by pulsed filed gel electrophoresis(PFGE) after cleavage by Xbal. beta-Lactamase was tested using nitroefin disks and characterized by transconjugation to Escherichia coli and isoelectric focusing. For infection control, all infected or colonized patients and nurses were cohorted into a separate room and strict barrier precautions were enforced. RESULTS: The outbreak involved 7 patients with sepsis form whom multiresistant. K. pneumoniae were isolated. Surveillance culture revealed that 9 of 37 patients and 2 of 48 nurses and house staff were colonized. The 18 isolates showed 8 different antimicrobial resistance patterns with cefotaxime resistance in all. Test for ESBL was positive in all 18 isolates but only 15 isolates by ESBL Etest. PFGE analysis showed that 6 of the 7 blood isolate from infected patient and 9 of the 11 fecal isolates from surveillance cultures were of the identical or very similar pattern. beta-Lactamase activities were transferable by conjugation in all but one isolate. No additional case of multiresistant. K. pneumoniae infection had been reproted for 6 months since the introduction of strict barrier precautious and other infection control measures. CONCLUSION: The outbreak was caused by ESBL-producing K. pneumoniae which appeared to be introduced into the NICU from multiple sources as was indicated by PFGE patterns. An optimal laboratory method for screening for ESBL remain to be developed as the double disk synergy test and ESBL Etest did not show complete agreement. As for infoction control our results emphasize the necessity of early recognition of outbreaks, cohorting of not only infected but also colonized patients and reinforcement of the barrier precuations for the prevention of further spread of cross-infections.

Six Cases of Iron Containing Plasma Cells / 대한임상병리학회지

Iron in plasma cells has been described in patients with diseases characterized by iron overload. We observed iron-containing plasma cells in the bone marrow aspirates of 6 patients with anemia. In five of these 6 patients, there were alcoholic liver disease and in one there was abdominal aortic occlusion. Medical records of patients and previous reports were reviewed. Marrow storage irons were adequate or increased, but other morphologic changes of alcoholism such as erythroid vacuolization or ringed sideroblasts were not the features. The presence of iron-containing plasma cells is suggestive of alcoholism and its complications, and diseases associated with iron overload or inability of RBCs to utilize iron. The exact mechanism of entry of iron into plasma cells is controversial.

Thawing Fresh Frozen Plasma Using a Microwave Oven / 대한수혈학회지

Thawing fresh frozen plasma(FFP) by waterbath(WB) requires about 30 minutes, which is too slow in emergency situations and carries the risk of bacterial contamination of FFP. To solve these problems, a new thawing method using a microwave oven(MWO) has been developed. Twenty units of equally divided plasma from 10 units of plasma were frozen, stored at -55 degrees C, and thawed in parallel using microwave oven or waterbath. Coagulation factors, plasma proteins and thawing time were measured. Except for antithrombin III(MWO: 85.2+/-6.94%, WB : 90.8+/-9.14%, p<0.05), no significant differences were observed in the 18 other coagulation parameters and the plasma proteins studied. Mean thawing time by MWO was 5.9 minutes per 1 unit, 10.4 minutes per 2 units and 12.5 minutes per 3 units; by WB, it was 19.0, 20.0 and 22.0 minutes, respectively. In conclusion, FFP can be thawed faster using a microwave oven than using 37 degrees C waterbath and the thawed plasma proteins were generally equivalent to those of FFP thawed by waterbath.