Performance Evaluation of MassTrak LC/MS/MS Tacrolimus Kit / 임상검사와정도관리

BACKGROUND: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) are used increasingly for tacrolimus monitoring. However, there are still variability of results due to home-brew reagents, so which cannot be warrantable data. We evaluated the analytical performance and clinical usefulness of a newly introduced MassTrak LC/MS/MS Tacrolimus kit (Waters Corporation, USA). METHODS: The performance of LC-MS/MS for determination of tacrolimus concentration were analyzed using patient samples and MassTrak LC/MS/MS Tacrolimus kit including calibrators, quality controls, internal standard, column and neat solution with respect to linearity, precision, lower limit of detection, lower limit of quantitation, sample carryover and comparison according to CLSI guidelines. The LC-MS/MS using home-brew reagents were performed for comparison test. RESULTS: The LC-MS/MS using MassTrak LC/MS/MS Tacrolimus kit showed a good linearity (R2> or =0.997) and precision (CV or =0.974). CONCLUSIONS: LC-MS/MS using MassTrak LC/MS/MS Tacrolimus kit for determination of tacrolimus concentration showed good performance for linearity, precision, LLOD, LLOQ, carryover and comparison. Introduction of MassTrak LC/MS/MS Tacrolimus kit could be warranted results by manufacturer and useful for management of quality control.

The Effects of Dietary Interventions on mRNA Expression of Peroxisome Proliferator Activated Receptor Isoforms (PPAR Isoforms)in Rat Skeletal Muscle

We determined the effects of dietary manipulations on messenger RNA of peroxisome proliferators activated receptor isoforms (i.e., PPAR alpha, beta/delta, gamma)in red vastus lateralis muscle of rats. Total 16 male Sprague-Dawley rats were used, and animals were divided into one of two dietary conditions :either chow diet group (CHOW ;n =8 )in which animals were fed with standard rodent chow (61.8% carbohydrate, 15.7% fat, 22.5% protein )or high fat diet group (FAT n =8 ) in which animals were fed 24.3% carbohydrate, 52.8% fat, 22.9% protein. At the end of the 8 weeks of experimental pe-riod, red vastus lateralis muscle was dissected out from all animals, and PPAR alpha, beta/delta, gamma mRNA expression was deter-mined. There was no significant difference in body mass (BM )between CHOW and FAT. As expected, blood glucose and free fatty acid (FFA )concentration was higher in FAT than CHOW (p <0.05 ), and lactate concentration was significan-tly lower in FAT compared to CHOW (p <0.05 ). Insulin concentration tended to higher in FAT than CHOW (67.2 +/- 21.9 vs. 27.0 +/-5.2 pmol/L ), but it did not reach to the statistical significance. Gene expression of PPAR alpha was not signifi-cantly different between CHOW and FAT. It was not also significantly different in PPAR beta/delta. Interestingly, expression of mRNA in PPAR gamma however, was markedly depressed in FAT compared to CHOW (approximately 3 fold higher in CHOW ; p <0.05 ). Results obtained from present study implies that PPAR gamma (as compensatory function of PPAR alpha is expressed ) possibly exerts another major tuning roles in fatty acid transport, utilization, as well as biosynthesis in skeletal muscle cells. The situations and conditions that can be postulated for this implication need to be further examined.

Evaluation of IMMUNOTICLES Auto3RPR and Auto3TP for Testing of Syphilis Infection / 임상검사와정도관리

BACKGROUND: The serologic tests for syphilis infection have been performed manually, but the procedures are time-consuming and interpretations may be subjective. Recently, automated assays were developed for rapid and efficient testing for syphilis infection. In this study, we evaluated the performances of IMMUNOTICLES Auto3 RPR and Auto3TP (A&T Corporation, Japan) using latex agglutination turbidimetry method. METHODS: Using 236 serum samples referred for syphilis at Ewha Womans University, Mokdong Hospital, between March 2004 and April 2007, we evaluated precision, linearity, detection limit and compared with the results of manual serologic tests, RPR (RPR card test, ASAN Pharmaceutical, Korea) and TPHA (ASAN-TPHA, ASAN Pharmaceutical). RESULTS: The within-run and between day precisions of Auto3RPR and Auto3TP were from 2.1% to 4.8%. The linearity was good up to 5.0 RU for Auto3RPR and to 250 TU for Auto3TP. Agreement of Auto3RPR with RPR was 65.7% (155/236) and 32.6% of patients (77/236) were RPR positive and Auto3RPR negative. RPR titers were less than 1:8 in 99% of these discrepant samples (76/77) and 65% (50/77) were latent infection and the others were false positive (32%, 27/77). Agreement of Auto3TP with TPHA was 97.1%. CONCLUSIONS: IMMUNOTICLES Auto3RPR and Auto3TP may be useful for rapid and efficient testing for syphilis. However, discrepant results were present in patients with low titer RPR positivity and method of reporting shoud be considered in individual clinical situation. In addition, linear range was not wide and further study is needed for reporting of quantitative results.

Characteristics of Acute Myeloid Leukemia without HLA-DR Expression / 대한진단검사의학회지

BACKGROUND: HLA-DR negativity is known to be useful for distinguishing acute promyelocytic leukemia (APL) from other subtypes of AML, but non-APL cases without HLA-DR antigen expression have been reported. The purpose of this study was to evaluate and compare the characteristics of APL, HLA-DR negative non-APL, and HLA-DR positive non-APL cases. METHODS: A total of 114 cases of AML admitted at Ewha Womans University, Mokdong Hospital between March 1997 and June 2006 were included in this study. A diagnosis of AML was made based on the results of morphology, cytochemistry, immunophenotype, cytogenetics, and/or fluorescence in situ hybridization. RESULTS: Among the 114 AML patients, HLA-DR antigen was not expressed in 39 (34%), including 24 non-APL (62%) and 15 APL patients (38%). The HLA-DR negative non-APL group showed higher leukocyte counts and positive rate of CD19 expression than did APL group (P<0.05). The remaining laboratory findings were not statistically different between the HLA-DR negative non-APL and APL groups. CD34 expression was more frequent in the HLA-DR positive non-APL group than in the HLA-DR negative non-APL group and APL group. Of the 24 patients with HLA-DR negative non-APL, 7 patients had disseminated intravascular coagulation and 2 patients showed morphologic features similar to those of APL. CONCLUSIONS: CD19 expression and leukocyte count may be helpful for differentiating HLA-DR negative non-APL from APL. However, the final diagnosis and classification should be confirmed by cytogenetic or molecular studies.

Incidence and Clinical Significance of Sex Chromosome Losses in Bone Marrow of Patients with Hematologic Diseases / 대한진단검사의학회지

BACKGROUND: Loss of sex chromosomes in bone marrow is observed both in elderly persons as an aging phenomenon and in patients with hematologic malignancies. The purpose of this study was to evaluate the incidence and clinical significance of sex chromosome losses in patients with hematologic diseases, comparing the characteristics between patients with sole and secondary sex chromosome losses in conjunction with other chromosomal abnormalities. METHODS: Study group included 868 patients with hematologic diseases between June 1998 and May 2006. The cells of bone marrow aspirates were processed using unstimulated culture methods such as direct, 24-hr and/or 48-hr culture. Sex chromosome losses were included in the karyotype, when X or Y chromosome loss is observed in more than 2 metaphase cells. RESULTS: The sex chromosome losses in bone marrow were found in 5.1% of the patients and 1.8% showed sex chromosome losses as a sole chromosomal abnormality. According to the disease categories, the incidences of sex chromosome losses were as follows: acute myelogenous leukemia (AML), 9.5%; acute lymphoblastic leukemia, 0%; myelodysplastic syndrome, 6.0%; chronic myelogenous leukemia 3.6%; myeloproliferative disorders, 1.3%; multiple myeloma (MM), 13.0%; chronic lymphocytic leukemia, 0%; malignant lymphoma, 3.8%; and benign hematologic diseases 2.2%. The patients with sex chromosome losses as a sole chromosomal abnormality were all male and median age was higher than that of patients with sex chromosome losses as a secondary abnormality (64 vs. 58 yr, P=0.02). The proportion of metaphase cells with sex chromosome losses was significantly lower in patients with sex chromosome losses as a sole chromosomal abnormality (40% vs. 100%, P<0.0001). The changes of sex chromosome loss were correlated with the disease status of AML and MM. CONCLUSIONS: These results suggest that secondary sex chromosome losses in conjunction with other chromosomal abnormalities seem to be one of the clonal abnormalities, whereas sex chromosome losses as a sole change seem to be an aging phenomenon, but further studies are needed.

A Case of CD45-, CD19- Precursor B Cell Acute Lymphoblastic Leukemia with an Atypical Morphology / 대한진단검사의학회지

The differential diagnosis of acute lymphoblastic leukemia (ALL) from other small round blue cell tumors in children is very important for proper treatment, but sometimes difficult. CD45 is expressed on almost all-human leukocytes and not expressed on other small round blue cell tumors. Moreover, CD19 is expressed on all stages of B lineage cells and loss of this antigen is very rare in precursor B-cell ALL. We report a case of ALL with atypical morphology and immunophenotype. A 6-yr-old girl presented with fever and weight loss. Many abnormal cells with variable sized, high nuclearcytoplasmic ratio and distinct nucleoli were counted 23% in bone marrow. The results of immunophenotyping were negative for CD45, CD19, CD10, CD20, CD3, CD5, CD7, CD56/16, CD13, and CD33 and positive for CD22, TdT, and CD34. The immunohistochemical staining of bone marrow biopsies was positive for CD79a, CD10, TdT and CD99. The cytogenetic study showed normal karyotype but amplification of MLL (myeloid/lymphoid or mixed lineage leukemia) gene was suggestive in the fluorescent in situ hybridization. The patient received the standard chemotherapy for acute lymphoblastic leukemia and reached complete remission.

In Vitro Activity of Antimicrobial Combination against Multidrug-Resistant Pseudomonas aeruginosa, Korea / 대한임상미생물학회지

BACKGROUND: Pseudomonas aeruginosafrequently causes nosocomial infection. Recently, there have been reports of infection with multidrug-resistant P. aeruginosa. The purpose of this study was to evaluate the in vitro effect of antimicrobial combination against multidrug-resistant P. aeruginosa. METHODS: Twenty isolates of imipenem and/or cefepime resistant P. aeruginosa were collected from the microbiology laboratory of Ewha Womans Unversity Mokdong Hospital. Checkerboard titration method was used to assess the activity of ceftazidime or cefepime in combination with amikacin, gentamicin or aztreonam, and colistin in combination with ceftazidime or rifampin. RESULTS: All isolates were resistant to more than 12 antimicrobial agents including imipenem and/or cefepime by broth microdilution method; however, no isolates were resistant to colistin. Most of the isolates showed high level resistance to ceftazidime, cefepime and meropenem, with MIC90 of 128, 512 and 64 microgram/mL, respectively. The MIC90 of colistin was 2 microgram/mL, which is within the su ceptiblerange. Synergistic effect was not detected by the checkerboard titration method with any antimicrobial combinations. However, a partial synergy was observed in 40% of the isolates with the combination of ceftazidime and amikacin, 65% with ceftazidime and gentamicin, 45% with cefepime and amikacin, and 75% with cefepime and gentamicin. Other antimicrobial combinations showed indifference against most strains, and antagonism was not observed. CONCLUSION: Multidrug-resistant P. aeruginosa isolates were all susceptible to colistin. The combined regimens of ceftazidime with amikacin or gentamicin and cefepime with amikacin or gentamicin revealed a partially synergistic effect in 40-75% of the isolates.