Evaluation of the TSH, Free Triiodothyronine, Free Thyroxine and Estradiol Test of the Vitros ECi(R) Immunodiagnostic System / 대한임상병리학회지

BACKGROUND: The analytical performance of the Vitros ECi(R) Immunodiagnostic System on the thyroid stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4) and estradiol (E2) assays, which are based on electrochemical luminescence to replace the radioimmunoassay was evaluated. METHODS: The precision as measured by the NCCLS protocol and a comparison of the method were done for each TSH, FT3, FT4, and E2 assay. The functional sensitivity and linearity tests were performed for both TSH and E2. The free hormone validity test was performed for both the FT3 and FT4. RESULTS: All four analytes showed an acceptable precision. The functional sensitivities of TSH and E2 were 0.007 mIU/L, and 87 pmol/L, respectively. TSH and E2 showed excellent linearity up to 78 mIU/mL, and up to 7,700 pmol/L, respectively. The free hormone validity test showed acceptable results demonstrating accurate free hormone determination. The E2 showed a significant proportion-al bias requiring an adjustment of the reference range, However, the other analytes showed good agreement with a slight proportional bias. CONCLUSIONS: The TSH, FT3, FT4, and E2 assay by Vitros ECi(R) exhibited excellent performance overcoming the drawbacks of a conventional radioimmunoassay.

Detection of Vancomycin Heteroresistant Staphylococcus aureus Using Mu-3 Agar / 감염

BACKGROUND: The aim of the study was to determine prevalence of potential heterogeneous vancomycin-resistant Staphylococcus aureus (h-VRSA) among methicillin-resistant S. aureus (MRSA) isolated in Korea by using Mu-3 agar and to determine the effect of in vitro vancomycin exposure on the resistance. METHODS: MRSAs isolated in 1980-1999 were screened for the presence of VISA or h-VRSA using Mu-3 agar. MIC of vancomycin was tested by NCCLS agar dilution and broth microdilution tests. Suspected h-VRSA were selected by vancomycin-containing media and change of resistance was determined by population analysis. A strain with Mu50 type growth was serially exposed to 8 pg/ml of vancomycin containing media and change of the vancomycin resistance was determined. RESULTS: Among the 455 MRSA isolates, 18 (3.9 %) grew on selective brain heart infusion agar (BHIA), and 354 (77,8%) on Mu-3 agar, 66 (14.5%) with Mu3 type growth and 78 (17.1%) with Mu50 type growth. MIC of vancomycin was 11 pg/ml for some of the isolates when inocula were approximately 10' CFU, but VISA was not present when tested by NCCLS broth microdilution test. Exposure of the isolates to van-cornycin raised the MIC. Serial exposure once to 8 pg/ml of vancomycin resulted in significant decrease of cells susceptible to 8-12 pg/ml of vancomycin. CONCLUSION: VISA was not present among the test isolates, but 34.2% were suspected to be potential h-VRSAs, suggesting possible emergence of VISA if vancomycin was administered prolonged period. It is considered that suitable screening media are vancomycin containing BHIA for VISA and Mu-3 agar for h-VRSA. The isolates showing Mu50 type growth on Mu-3 agar are not always VISA, but rather h-VRSA.

Evaluation of the Collection Efficiency of the Granulocyte in Leukapheresis Using 10% Pentastarch / 대한임상병리학회지

BACKGROUND: To collect high concentration of granulocytes for transfusion to neutropenic cancer patients with infections, we investigated the effect of G-CSF or dexamethasone as granulocyte mobilizers and 10% pentastarch (PS) as the sedimentation agent in granulocyte collection by leukapheresis. Subsequently, the therapeutic effect of the granulocyte transfusions was assessed. METHODS: Forty five leukapheresis were performed with CS-3000Plus (Baxter, Deerfield, IL, USA) using 10% pentastarch. The donors were classified into three groups according to their premedication drugs and the interface detector offset; group 1 used dexamethasone with offset 15 (n=16), group 2 used dexamethasone with offset 33 (n=16), and group 3 used G-CSF with offset 33 (n=10). We compared total collected granulocyte counts and granulocyte collection efficiency (GCE). RESULTS: The mean counts of total granulocytes collected and GCE were as follows; 0.9 0.5 x 1010 and 31.6 14.3% in group 1, 1.3 0.6 x 1010 and 39.0 14.2% in group 2, and 1.6 0.9 x 1010 and 63.9 32.2% in group 3, respectively. The counts of granulocytes collected in group 3 was significantly higher than that in group 1 (P<0.05). The GCE of group 3 was significantly higher than that of group 1 and group 2 (P<0.05). Sixteen granulocyte transfusions were performed to 11 patients. We observed successful therapeutic effects in 10 out of 16 transfusions (63%). CONCLUSIONS: G-CSF indicates greater potency than dexamethasone although its high cost is limitation of routine use as mobilizing agents and PS was an excellent red cell sedimenting agent in granulocyte collection. Large volume granulocyte transfusions allow high therapeutic effects in neutropenic patients with marrows of sufficient regenerating capacity.

Platelet transfusion support for splenectomy in patients with chronic immune thrombocytopenic purpura / 대한수혈학회지

BACKGROUND: Splenectomy is often performed for the patients with refractory chronic immune thrombocytopenic purpura (ITP). Still, there are no generally accepted guidelines for the minimum level of platelet count and the average requirement of platelet transfusion so that the patients can safely undergo splenectomy. We evaluated the changes of platelet count and transfusion requirements around the splenectomy in patients with chronic ITP. METHODS: We reviewed the medical records of 25 patients with chronic ITP. We compared the platelet counts at admission, immediately pre-op and several post-op days. We also investigated the number of platelet concentrates transfused around splenectomy. We determined the effect of splenectomy according to Difino's classification. RESULTS: The median platelet counts of the patients was 18x109/L (7-238x109/L) on admission and recovered to 108x109/L (22-460x109/L) on preoperation day by platelet transfusion and immunosuppressive treatment. The platelet counts were rapidly recovered after splenectomy from the day of operation. Only 3 patients needed platelet transfusion after splenectomy. Thirteen among twenty five patients (52%) underwent operation without platelet transfusion support. Most transfusions were done before the surgery and 80% (12/15) of the patients required transfusion of more than 10 units of random donor platelet concentrate. Twenty one patients (84%) showed the complete remission after splenectomy. CONCLUSION: Splenectomy can lead to rapid remission even in most cases of refractory chronic ITP. Many cases can undergo the operation only with treatment modalities other than transfusion such as immunosuppressive agents and/or immunoglobulin. The minimum level of platelet counts for splenectomy may be safe over 50x109/L and about 10 units of platelet concentrate may be enough for preparation of splenectomy.