Evaluation of Clinical Usefulness of PREG-Q™ as a Screening Test for Pregnancy

Background: Among the many methods estimating the quantity of β-hCG for pregnancy testing in urine, immunochromatography is one of most widely used semi-quantitative detection method for its convenience to use and also for its rapid result reporting system. PREG-Q™ is a newly introduced semi-quantitative immunochromatography method for detecting b-hCG. Clinical usefulness of PREG-Q™ was evaluated as a screening test for early pregnancy detection. Methods: Accuracy, detection limit, cross-reactivity with various glycoprotein hormones, interference study, and comparison study using total 100 urine samples from pregnant (50 samples) and non-pregnant women (50 samples) was evaluated. Results: All the 50 urine samples of pregnant women showed positive results, and another 50 urine samples of non-pregnant women showed negative results with PREG-Q™. The lower detection limit of PREG-Q™ was 25 mIU/mL and the result was not affected by addition of glycoprotein hormones tested. Interfering substance causing false negative or false positive results enrolled didn’t affect the test results in this study. Conclusions: We conclude PREG-Q™ is an excellent test kit for pregnancy test, and is valuable especially for detecting early pregnancy.ope

Annual Report on External Quality Assessment of Immunoassay Subcommittee in Korean Clinical Laboratory Survey (2006)

Two trials of external quality assessment were performed in 2006. The first and the second trials assessed by three test categories, i.e. tumor markers, thyroid hormones and immunoproteins, such as Immunoglobulin G (IgG), IgM, IgA, Complement 3(C3) and C4. All of fourteen test items using immunoassay method were surveyed as previous years. The response rate of external quality assessment for Immunoassay Subcommittee were 98.3% and 98.1%. Ten control materials consisted of 8 home-made pooled sera and 2 commercial control sera (LyphoCheck, BioRad, USA) were used. The results are summarized as follows. 1. Laboratories participating in external quality control program of immunoassay were 259 laboratories and the response rate were 98.3% and 98.1% in 2006. 2. Chemiluminiscence immunoassay autoanalyzers were most commonly used for immunoassay testing in the clinical laboratories. 3. Still some test items show big variations of the test results of the same control material according to reagents and autoanalyzers. 4. A workshop about "Standardization of Immunoassay" was held on December 1st, 2006 in cooperation with Immunoserology Subcommittee. The quality of the participating laboratories seems to be thought being continuously improved. And, this year, many laboratories are newly participated, they were 55 clinical laboratories for the Immunoassay Subcommittee. A new surveillance system for the individual laboratory according to its performance by method and analyzer was on scheduling for special analysis and performance-basis control from next-year survey.ope

Annual Report on External Quality Assessment of Immunoassay Subcommittee in Korean Clinical Laboratory Survey (2007)

Two trials of external quality assessment were performed in 2007. The first and the second trials assessed by three test categories, tumor markers, thyroid hormones and immunoproteins(IgG, IgM, IgA, C3 and C4). All of fifteen test items using immunoassay method were surveyed. The response rates of external quality assessment for Immunoassay Subcommittee were 98.3%in first trial and 98.8% in second trial in 2007. Fourteen control materials consisted of 12 home-made pooled sera and 2 commercial control sera (LyphoCheck, BioRad, USA) were used for external survey. The results are summarized as follows. 1. Laboratories participating in external quality control program of immunoassay were 400 laboratories and the response rates were 95.4% and 98.8% in 2007. 2. Recently chemiluminescence immunoassay autoanalyzers were most commonly used for immunoassay testing in the clinical laboratories. 3. Still some test items show big variations of the test results of the same control material according to reagents and autoanalyzers. 4. A workshop for "Quality control practices of Immunoassay" was held on September 7th, 2007 in cooperation with Annual Autumn Academic Conferences of Clinical Laboratory and Quality Control. The quality of the participating laboratories seems to be continuously improved. And, this year, many laboratories are newly participated to Immunoassay Subcommittee. A new surveillance system for the individual laboratory according to its performance by method and analyzer is on scheduling for special performance-based QC.ope

Performance Characteristics of the UniCel DxI 800 Immunoassay for the Maternal Serum Quadruple Test, Including Median Values for Each Week of Gestation, in Korean Women

BACKGROUND: Maternal serum prenatal quadruple screening includes testing for alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG), unconjugated estriol (uE3), and dimeric inhibin A (DIA). We evaluated quadruple screening using an automated platform and looked for any ethnic differences in the median values of each marker. METHODS: We measured the concentrations of each quadruple test analyte using the UniCel DxI 800 system (Beckman Coulter, USA) in 788 Korean mid-trimester maternal serum samples and calculated their median values using Benetech software (Benetech, Canada). We also compared the results with those obtained using the Immulite 2000 assay (Siemens Healthcare Diagnostics, USA) or ELISA (DSL, USA) in 442 samples. RESULTS: We obtained mid-trimester median values for each marker. The following are the comparative results for each test using the Immulite 2000 assay or ELISA (x) and the UniCel DxI 800 immunoassay (y): AFP, y=1.10x+0.01, r=0.925; uE3, y=0.28x+0.24, r=0.885; hCG, y=1.22x-3047.8, r=0.944; and DIA, y=0.86x+15.31, r=0.833. Assay results for each of the four markers showed good correlations. However, significant biases necessitated new median calculations of prenatal risk estimates in all four tests. CONCLUSIONS: We established gestational age-specific second-trimester median values for four markers in Korean samples using the UniCel DxI 800 immunoassay system. Despite significant bias, there were good correlations between the results obtained using the UniCel DxI 800 immunoassay and those obtained using the Immulite 2000 assay.ope

Annual Report on External Quality Assessment of Immunoassay Subcommittee in Korean Clinical Laboratory Survey (2005)

Three trials of external quality assessment were performed in 2005. The first and the second trials were assessed by 14 test items including tumor markers, hormones and immunoproteins and the third trial was intended only for five items of immunoproteins, i.e. Immunoglobulin G (IgG), IgM, IgA, Complement 3 (C3) and C4. Fourteen test items of immunoassay method including 5 tumor markers, 4 hormones and 5 imunoproteins were surveyed. The response rate of external quality assessment for Immunoassay Subcommittee were 94.4% ～ 95.0% in this year. Ten control materials of the first and second trials were consisted of 8 home-made pooled sera and 2 commercial control sera (LyphoCheck, BioRad, USA and Randox, Randox Ltd., UK). And, for the third trial we used the 05-S-4 specimen of the Immunoserology Subcommittee control material. The results are summarized as follows. 1. Laboratories participating in external quality control program of Immunoassay Subcommittee were 305 laboratories and the response rate were 94.4% and 95.0% in 2005. 2. Autoanalyzers based on enhanced or improved enzyme/chemiluminiscence imunoassay were mostly used in the field of immunoassay testing. 3. A new reporting system which uses the internet web site was introduced in this year from the second trial of external quality survey. 4. Some test items show big variations of the test results of the same control material according to autoanalyzer and reagents. The quality of the participating laboratories seems to be improved step by step. And, the new methods of reporting system and statistic analyses introduced this year were considered to get a good reputation from the member institutes for the surveillance systems.ope

Seven Cases of Decreased Serum Valproic Acid Concentration During Concomitant Use ofCarbapenem Antibiotics

Valproic acid (VPA) is a commonly prescribed anticonvulsant drug for the treatment of various forms of epilepsy. Concomitant administration of VPA and carbapenem antibiotics such as panipenem/ betamipron and meropenem has been reported to decrease the serum level of VPA. We observed seven cases which showed a decrease in serum levels of VPA due to concomitant use of VPA and carbapenem from January 2002 to October 2006 in a 750-bed university hospital, the average decrease of 70.4% was observed. Carbapenem antibiotics administrated concomitantly with VPA were panipenem (1 case), meropenem (3 cases), and imipenem (2 cases), and in one other case imipenem and meropenem were used sequentially. We found the VPA serum levels were significantly decreased with meropenem (n=4) more than with other carbapenem antibiotics (n=4, 89.3% vs. 51.5% decrease, P=0.03). Clinicians should be aware of this potential interaction, pay attention to the failure of seizure control due to decreased serum VPA levels with concomitant use of carbapenem antibiotics, and monitor VPA serum levels for those cases.ope

Evaluation of the extraction method for the cytotoxicity testing of latex gloves

In this study, the cytotoxicity of medical latex gloves to cultured L-929 cells was determined using various extraction conditions. According to the extraction time and temperature, three types of extraction conditions were used: 1) 24 h at 37℃; 2) 72 h at 37℃; 3) 72 h at 50℃. Also, four different extraction vehicles were used, namely, distilled water (DW), 9 g/l sodium chloride (saline) in DW, and culture media with or without serum. Under the above-mentioned conditions, the samples were extracted and then 2-fold serially diluted in the concentration range 3.13 - 50%. When extracted with either DW or saline for 24 h or 72 h at 37℃, only 50% diluted samples showed distinct cytotoxicity to L-929 cells. Moreover, no cytotoxic potentials were observed when gloves were extracted with DW or saline at 50℃ for 72 h. Cytotoxicity was markedly greater when gloves were extracted with culture medium, irrespective of the presence of serum in the medium. These results suggest that optimal extraction conditions should be established for the cytotoxicity evaluations of biomaterials and medical devices.ope

Annual Report on External Quality Assessment of Immunoassay Subcommittee in Korean Clinical Laboratory Survey (2004)

Two trials of external quality assessment were performed in 2004 as previous year. Thirteen test items of immunoassay wlth ten control materials were surveyed. The response rate of external quality assessment for immunoassay Subcommittee were 94.4% and 98.6%. Ten control materials were consisted of 8 home-made pooled sera and 2 commercial control sera (LyphoCheck, BioRad, USA). The results are summarized as follows. 1. Laboratories participating in external quality control program of immunoassay were 259 laboratories and the response rate were 94.4% and 98.6% in 2004. 2. Chemiluminiscence immunoassay autoanalyzers were most widely used in the field of immunoassay testing. 3. A new test item CAI25 was introduced in this year from the second trial of external quality survey. 4. Still some test items show big variations of the test results of the same control material according to autoanalyzers. The quality of the participating laboratories seems to be thought being continuously improved. And, some new methods of the statistic analysis and some standardization protocols were considered to be introduced in the surveillance systems.ope

(A) computer diagnostic system based on automated multiphasic screening by SMA 12/60 on korean

의학과/석사[한글] 1763년 Bayes' theorem이 발표된 이래, 많은 학자들이 수학적 확률을 이용하여 갖고 있는 질병의 진단을 알아내는 방법에 대해 연구하여 왔으나, 실제로 이용하기에는 많은 난 문제를 지니고 있어 널리 이용되지 않고 있었다. 그러나 컴퓨터를 이용한 간단한 방법인 SORT(System of Organizing Relevant Tests)를 Reece 및 Hobbie(1971)가 개발하였는데 이 SORT는 자동분석기인 SMA 12/60(Seqential Multiple Analyzer 12/60)에 의한 혈청내 12가지 화학성분의 검사 결과로부터 환자의 성별과 연령군별 정상치와 비교하여 비정상인 결과를 보이는 검사종목을 찾아내고 또 이로부터 예상할 수 있는 진단 명을 찾아내는 방법이다. 저자는 이러한 SOFT를 이용하기 위해 필요한 성별 및 연령군별 한국인의 정상치를 Hoffmann법으로 산출하였고 퇴원시 진단 명이 확실한 환자 100명을 대상으로 SORT를 시험하여 다음과 같은 결론을 얻었다. 1. 성별 및 연령군별 한국인의 SMA 12/60검사의 정상치를 Hoffann법으로 산출하였다. 2. 산출된 정상치는 외국것에 비해 calcium, phosphorus, BUN, uric acid 및 cholesterol은 대체로 낮았고, alkaline phosphatase 와 LDH는 높았으며, total protein, albumin 및 bilirubin은 거의 비슷하였으나 SGOT는 상한치가 비슷한 반면에 하한 치는 낮게 나타 났다. 3. 컴퓨터를 이용하여 얻은 예상 진단명의 적중율은 예상진단을 5개까지 추출하였을 때 24%이었고 10개까지 추출하였을 때는 47%였다. 4. 성별 및 연령 군별 정상치를 산출하기 위한 대상수를 더 늘리고 Hoffmann법이 지닌 단점을 보완하면 그 적중률은 더 높아질 것으로 생각된다. 5. 컴퓨터이용에 드는 비용은 programming에 4만원 정도이고 한 환자 당 20원 정도 들므로 충분히 경제성이 있다고 생각된다. 6. SORT를 통상 이용하면 놓치기 쉬운 질환을 찾아내는 데에 기여할 수가 있다고 생각 된다. [영문] Since the report or Bayes' theorem in 1763, many studies have been made to set various disease patterns using a mathematical probability. However, most of those were too convenient for practical use. Fortunately the recent development of computer system solved some of these problems. Reece and Hobbie (1971) developped the System of Organizing Relevant Tests (SORT). SORT is a kind of approach to find out the most probable disease pattern, delived from 12 different biochemical data of SMA 12/60 interpreted in regard to the sex and age. This study is conducted to apply the SORT on Korean. First, the Korean normal values in regard to the sex & age were calculated by Hoffmann's method. Then a random selection of 100 patients with various discharge diagnosis were selected. On these patients, the SORT was applied. 1. The normal values was obtained by the Hoffmann's method. 2. The normal values of 12 biochemical tests reveal the following characteristics, in general compared with those of the white population. ⅰ) calcium, phosphorus, BUN, uric acid, and cholesterol are relatively low. ⅱ) Alkaline phosphatase and LDH tend to be high. ⅲ) Total protein, albumin and bilirubin are almost the same. ⅳ) SGOT is almost same in upper limit and low in lower limit. 3. When only 5 possible disease entities were taken in consideration, the SORT was inconsistent with the discharge diagnosis in a rate of 34%. If 10 were taken, the consistency rate becomes 47%. 4. It was discussed that the consistency rate will be raised if the inherited disadvantages of Hoffmann's method were supplemented and if the sample sizes were expanded. 5. The SORT expences per patient were about 20 Won, after the computer programming was completed. It was cousidered quite inexpensive for a practical use. 6. The routine application of SORT was considered to be beneficial for both the patient and doctor to make an early diagnosis otherwise might be overlooked.prohibitio