Random Assay in Radioimmunoassay: Feasibility and Application Compared with Batch Assay

Lee, Jung Min,Lee, Hwan Hee,Park, Sohyun,Kim, Tae Sung,Kim, Seok-Ki The Korea Society of Nuclear Medicine 2016 핵의학 분자영상 Vol.50 No.4

Purpose The batch assay has been conventionally used for radioimmunoassay (RIA) because of its technical robustness and practical convenience. However, it has limitations in terms of the relative lag of report time due to the necessity of multiple assays in a small number of samples compared with the random assay technique. In this study, we aimed to verify whether the random assay technique can be applied in RIA and is feasible in daily practice. Methods The coefficients of variation (CVs) of eight standard curves within a single kit were calculated in a CA-125 immunoradiometric assay (IRMA) for the reference of the practically ideal CV of the CA-125 kit. Ten standard curves of 10 kits from 2 prospectively collected lots (pLot) and 85 standard curves of 85 kits from 3 retrospectively collected lots (Lot) were obtained. Additionally, the raw measurement data of both 170 control references and 1123 patients' sera were collected retrospectively between December 2015 and January 2016. A standard curve of the first kit of each lot was used as a master standard curve for a random assay. The CVs of interkits were analyzed in each lot, respectively. All raw measurements were normalized by decay and radioactivity. The CA-125 values from control samples and patients' sera were compared using the original batch assay and random assay. Results In standard curve analysis, the CVs of inter-kits in pLots and Lots were comparable to those within a single kit. The CVs from the random assay with normalization were similar to those from the batch assay in the control samples (CVs % of low/high concentration; Lot1 2.71/1.91, Lot2 2.35/1.83, Lot3 2.83/2.08 vs. Lot1 2.05/1.21, Lot2 1.66/1.48, Lot3 2.41/2.14). The ICCs between the batch assay and random assay using patients' sera were satisfactory (Lot1 1.00, Lot2 0.999, Lot3 1.00). Conclusion The random assay technique could be successfully applied to the conventional CA-125 IRMA kits. The random assay showed strong agreement with the batch assay. The random assay procedure could increase the flexibility and decrease the turnaround time of the radioimmunoassay technique.

뇌하수체 - 갑상선 축의 평가에 있어 면역방사계수측정법에 의한 혈청 TSH 의 기저치 측정의 의의

서교일(Kyo Il Suh),조보연(Bo Youn Cho),이홍규(Hong Kyu Lee),고창순(Chang Soon Koh),민헌기(Hun Ki Min),이문호(Mun Ho Lee) 대한내과학회 1988 대한내과학회지 Vol.34 No.6

N/A To evaluate whether thyrotropin(TSH) values measured by sensitive immunoradiometric assay(IRMA) can be used as an indicator of pituitary-thyroid status, serum triiodothyronine(T3) and thyroxine(T4) as well as TSH were measured before and after thyrotropinreleasing hormone(TRH) stimulation in 30 normal subjects, 17 patients with hyperthyroidism and 67 patients receiving chronic oral T, therapy for thyroid cancer. IRMA of TSH involves use of two monoclonal antibodies. The detection limit of the assay was 0.04 mU/L and intrassay and interassay variation was less than 5% in TSH concentration of 2.4 and 31.6 mU/L, Over the undetectable to nomal TSH range, an excellent correlation was observed between basal TSH levels and TRH stimulated TSH increment was observed between basal TSH levels and TRH stimulated TSH increment (r=0.94). When the subjects were grouped by their resting free T. index (FT,I), the curve was found to be steeper in high FT4I group (FT4I>9.4) than normal FT4I group (FT4I<9.4) (y=0.82+113x vs y=0.78+1.28x). In 67 patients with thyroid cancer on suppression therapy, 43 had both undetectable basal TSH levels and no TSH response to TRH stimulation while 7 patients had undetectable basal TSH levels but preserved TSH response to TR~H. Measurable TSH response to TRH were found in all patients with detectable basal TSH. Therefore, when basal TSH value of 0.04mU/L was used as a criterion, sensitivity and specificity for prediciting pituitary suppression were 84% and 100% respectively while those were 78% and 72% in case FT4I of 12 was used as a criterion. These findings suggest that the TSH values measured by sensitive IRMA represents status of pitutitarythyroid axis and can be used as a sensitive indicator of pituitary suppression.

면역방사계수측정법의 민감도 향상을 위한 변법의 평가

권원현,강미지,김나경,박지솔,김정인,이경재,Won-Hyun Kwon,Mi-Ji Kang,Ji-Sol Park,Jung-In Kim,Kyung-Jae Lee 대한핵의학기술학회 2023 핵의학 기술 Vol.27 No.1

Purpose The concentration of PSA (Prostate Specific Antigen) after radical prostatectomy in prostate cancer patients is a predictor of biochemical recurrence, and the AUA (American Urological Association) is defined as biochemical recurrence when the concentration of PSA is measured at 0.2 ng/mL or more, and when the concentration is measured at 0.2 ng/mL or more at the retest. This standard is also applied our hospital. In this laboratory, the PSA reagent using IRMA (Immunoradiometric Assay) is used, and the sensitivity at a very low value was not as good as the reagent used in the department of laboratory medicine. This study aims to increase the reliability of the results by improving the precision and sensitivity of very low values. Materials and Methods As a reagent for the study, PSA reagent using IRMA was used. As a method to improve the precision and sensitivity of very low values, a variation method on the serum volume(25 uL, 50 uL, 100 uL, 200 uL) was studied, and variation usefulness evaluation was conducted. The evaluation items were compared the results of precision, analytical sensitivity, recovery rate, dilution test, high-dose hook effect test, parallel test and very low concentration values(n = 20). Results The validation results were displayed in the order of 25 uL, 50 uL, 100 uL, 200 uL. As the serum volume increased, it was confirmed that CV (Coefficient of Variation)(%) improved. Analytical sensitivity(ng/mL) was 0.038, 0.041, 0.017, 0.015 and recovery rate(%) was 101±3, 101±3, 99±2, 97±4. very low concentration values(ng/mL) between each volume(n=20) were 0.135±0.068, 0.076±0.050, 0.048±0.034, 0.046±0.034. and high dose hook effect appeared as the serum volume increased. Conclusion Through the variation usefulness evaluation, it was confirmed that as the serum volume increased, the precision and sensitivity improved at very low concentration values. However, it is necessary to pay special attention to the occurrence of high-dose hook effect as the serum volume increases. In the case of tests that requires very low concentration values, it is thought that the reliability of the result will be increased if the variation method is properly used after the variation usefulness evaluation.

HBV : PE-022 ; Hepatitis B surface antigen quantification across different phases of chronic hepatitis B virus infection using immunoradiometric assay

( Kwang Hyun Chung ),( Ho Young Lee ),( Yong Jin Jung ),( Hwi Young Kim ),( Ji Won Kim ),( Ji Bong Jeong ),( Byeong Gwan Kim ),( Kook Lae Lee ),( Won Kim ) 대한간학회 2012 춘·추계 학술대회 (KASL) Vol.2012 No.-

Background/Aim: Assays for hepatitis B surface antigen (HBsAg) quantification are emerging serologic tests which might determine treatment strategy and monitor treatment responses in chronic hepatitis B (CHB) patients. The aim of our study was to evaluate the dynamic changes in HBsAg titers during the natural course of CHB infection, and identify correlations between HBsAg titers and hepatitis B virus (HBV) DNA concentrations across different phases of CHB measured using novel immunoradiometric assay (IRMA). Methods: Serum HBsAg titers and paired HBV DNA concentrations in the different phases of CHB were retrospectively compared from August 2010 to March 2011 by correlation analysis. Phases of CHB were defined on the basis of HBV DNA concentrations, serum hepatitis B e antigen/ antibody status, and serum alanine aminotransferase levels. Additionally, mean HBsAg titers were compared across the different stages of chronic liver disease. Results: In 629 serum samples, mean HBsAg titers were significantly higher in the immune tolerance (ITO) and immune clearance (ICL) phases than in immune control (ICN) and immune escape (IES) phases. Correlations between HBsAg titers and HBV DNA concentrations varied with the CHB phases. Modest correlation was observed in ITO (n=54, r=0.733, p<0.001) and ICL (n=28, r=0.677, p<0.001), and poor correlation in ICN (n=79, r=0.242, p=0.032); however, no significant correlation was seen in IES (n=86, r=0.015, p= 0.894) and the oral nucleos(t)ide analogues-treated group (n= 252). Additionally, the mean HBsAg titers were significantly higher in patients with liver cirrhosis or hepatocellular carcinoma than in patient without liver cirrhosis or hepatocellular carcinoma (21574.7 vs. 4525.5 IU/mL, p<0.001; 16616.4 vs. 3529.6 IU/mL, p<0.001, repectively) and tended to gradually decrease as the 10-year age stratum increased (P for trend<0.001). Conclusions: HBsAg quantification using the IRMA method might be useful to discriminating patients in different phases of CHB and in different stages of chronic liver disease.

HBV : PE-022 ; Hepatitis B surface antigen quantification across different phases of chronic hepatitis B virus infection using immunoradiometric assay

( Kwang Hyun Chung ),( Ho Young Lee ),( Yong Jin Jung ),( Hwi Young Kim ),( Ji Won Kim ),( Ji Bong Jeong ),( Byeong Gwan Kim ),( Kook Lae Lee ),( Won Kim ) 대한간학회 2012 춘·추계 학술대회 (KASL) Vol.2012 No.1

Background/Aim: Assays for hepatitis B surface antigen (HBsAg) quantification are emerging serologic tests which might determine treatment strategy and monitor treatment responses in chronic hepatitis B (CHB) patients. The aim of our study was to evaluate the dynamic changes in HBsAg titers during the natural course of CHB infection, and identify correlations between HBsAg titers and hepatitis B virus (HBV) DNA concentrations across different phases of CHB measured using novel immunoradiometric assay (IRMA). Methods: Serum HBsAg titers and paired HBV DNA concentrations in the different phases of CHB were retrospectively compared from August 2010 to March 2011 by correlation analysis. Phases of CHB were defined on the basis of HBV DNA concentrations, serum hepatitis B e antigen/ antibody status, and serum alanine aminotransferase levels. Additionally, mean HBsAg titers were compared across the different stages of chronic liver disease. Results: In 629 serum samples, mean HBsAg titers were significantly higher in the immune tolerance (ITO) and immune clearance (ICL) phases than in immune control (ICN) and immune escape (IES) phases. Correlations between HBsAg titers and HBV DNA concentrations varied with the CHB phases. Modest correlation was observed in ITO (n=54, r=0.733, p<0.001) and ICL (n=28, r=0.677, p<0.001), and poor correlation in ICN (n=79, r=0.242, p=0.032); however, no significant correlation was seen in IES (n=86, r=0.015, p= 0.894) and the oral nucleos(t)ide analogues-treated group (n= 252). Additionally, the mean HBsAg titers were significantly higher in patients with liver cirrhosis or hepatocellular carcinoma than in patient without liver cirrhosis or hepatocellular carcinoma (21574.7 vs. 4525.5 IU/mL, p<0.001; 16616.4 vs. 3529.6 IU/mL, p<0.001, repectively) and tended to gradually decrease as the 10-year age stratum increased (P for trend<0.001). Conclusions: HBsAg quantification using the IRMA method might be useful to discriminating patients in different phases of CHB and in different stages of chronic liver disease.

면역방사계수법을 이용한 Thyroglobulin 측정시 항 Thyroglobulin 항체의 존재가 미치는 영향

안병철,배진호,정신영,박호용,김정국,하승우,이재태,김보완,이규보 대한내분비학회 2004 Endocrinology and metabolism Vol.19 No.1

연구배경: 혈청 thyroglobulin (Tg)은 옥소전신스캔과 함께 분화갑상선암환자에서 갑상선암 재발에 대한 추적관찰에 매우 예민하고, 중요한 표지자로 임상에서 널리 이용된다. 그러나 많은 수의 분화갑상선암환자는 Tg 항체인 항 Tg 항체를 가지고 있고, 이는 방사면역검사법 (radioimmunoassay) 및 면역방사계수 검사법(immunoradiometric assay)으로 Tg 측정시 영향을 미칠 수 있다. 이에 연자들은 면역방사계수법으로 Tg를 측정할 경우, 항 Tg항체에 의하여 어떤 영향이 생길수 있는지를 알아보고자 하였다. 방법: 이중위치 고상법 (solid phase two-site)법을 이용하는 ELSA-hTg in vivo test (CIS international, Schering, France) 시약을 이용하여 Tg를 측정하였다. Tg과 항 Tg 항체는 검사시약에 포함된 표준용액을 사용하였으며, Tg는 두 가지 농도 (23.5 ng/mL, 62.5 ng/mL)로, 항 thyroglobulin 항체는 세 가지 농도(25U/mL, 50U/mL, 100U/mL)로 이용하였다. Tg가 높게 나타나는 환자의 혈청에 항 Tg 항체가 높게 나타나는 환자의 혈청을 혼합하여 동일한 방법으로 Tg 검사를 시행하였다. 통계학적 분석은 ANOVA와 Scheffe test 및 Quadratic regression modeling을 시행하였다. 결과: 면역방사계수법을 이용한 Tg 측정시 항 thyroglobulin 항체가 존재하는 경우 그 값이 낮게 측정되었다. Tg 농도가 23.5 ng/mL인 표준용액이 항 Tg 항체의 농도가 0, 25, 50 및 100U/mL 경우, 각각 24.5±1.1, 11.8±0.4, 7.7±0.1 및 4.5±0.4ng/mL로 측정되었으며, Tg 농도가 62.5 ng/mL인 표준용액은 각각 65.9±5.7, 36.3±2.2, 23.7±0.7, 및 14.0±1.0 ng/mL로 측정되었다(ANOVA test, p=0.000). 항 Tg 항체에 의한 Tg 측정값의 저하 정도는 항 Tg 항체의 농도에 비례하는 것으로 나타났다 (Quadratic model regression, SigT=0.000). 결론: 분화갑상선암환자에서 항 Tg 항체의 존재는 면역방사계수법을 이용한 혈청 Tg 측정으로 갑상선암 재발을 파악하는데 방해하는 인자로 작용될 수 있으며, Tg 측정시 항 Tg 항체의 측정이 꼭 필요하며, 항 Tg 항체를 가진 분화갑상선암환자에서 Tg 수치를 해석할 경우 세심한 주의가 요구된다. Background: Serum thyroglobulin (Tg) is a valuable and sensitive tool needed in the follow-up of patients with differentiated thyroid cancer (DTC), but antithyroglobulin antibody (Anti-Tg), common in patients with DTC, can interfere with the assay for Tg. In this study, we evaluated the influence of Anti-Tg on the measurement of Tg using the immunoradiometric assay (IRMA). Methods: In using ELSA-hTg in vivo test (CIS international, Schering, France), a solid phase two-site IRMA was used to measure Tg (23.5 ng/mL, 62.5 ng/mL) under the absence or presence of three concentrations of Anti-Tg (25U/mL, 50U/mL, 100U/mL). We also performed Tg measurement using patients serum that was mixed with patients serum containing high Anti-Tg. ANOVA and Scheffe tests were performed to evaluate the effect of Anti-Tg on Tg IRMA, and an inverse regression was made to calculate the level of Tg from measured Tg and used Anti-Tg levels and also to assess the degree of effect of anti-Tg on Tg IRMA. Results: In measuring Tg using the standard solution, the presence of Anti-Tg resulted in a falsely suppressed Tg value. The IRMAs for 23.5ng/mL of the standard Tg solution resulted in 24.5±1.1 ng/mL under no Anti-Tg, 11.8±0.4 ng/mL under 25U/mL of Anti-Tg, 7.7±0.1 ng/mL under 50U/mL of Anti-Tg, and 4.5±0.4 ng/mL under 100U/mL of Anti-Tg. IRMAs 62.5 ng/mL of the standard Tg solution resulted in 65.9±5.7 ng/mL under no Anti-Tg, 36.3±2.2 ng/mL under 25U/mL of Anti-Tg, 23.7±0.7 ng/mL under 50U/mL of Anti-Tg, and 14.0±1.0 ng/mL under 100U/mL of Anti-Tg. (ANOVA test, p=0.000). The degree of suppression of the measured Tg value was positively correlated with the Anti-Tg level (Quadratic model regression, Sig T=0.000). The presence of Anti-Tg also resulted in a falsely suppressed Tg value for the Tg measurement using patient's serum. 2004). Conclusion: The presence of Anti-Tg could consist of the use of Tg as a tumor, therefore Anti-Tg should be measured in all patients diagnosed with DTC. The interpretation of the Tg level must be performed with extreme caution in patients with Anti-Tg (J Kor Soc Endocrinol 19:42∼47, 2004)

Hepatitis B Surface Antigen Quantification across Different Phases of Chronic Hepatitis B Virus Infection Using an Immunoradiometric Assay

( Kwang Hyun Chung ),( Won Kim ),( Byeong Gwan Kim ),( Ho Young Lee ),( Eunhyo Jin ),( Yuri Cho ),( Ji Yeon Seo ),( Hwi Young Kim ),( Yong Jin Jung ),( Ji Won Kim ),( Ji Bong Jeong ),( Kook Lae Lee ) 대한소화기학회 2015 Gut and Liver Vol.9 No.5

Background/Aims: Quantification of hepatitis B surface antigen (HBsAg) is an emerging serologic test and may be useful for identifying treatment strategies for chronic hepatitis B (CHB). This study aimed to evaluate HBsAg titers during the natural course of CHB and identify correlations between HBsAg titers and hepatitis B virus (HBV) DNA concentrations across different CHB phases measured using an immunoradiometric assay (IRMA). Methods: CHB phases were defined on the basis of HBV DNA concentrations, the presence of hepatitis B e antigen/antibody (HBeAg/Ab) and serum alanine aminotransferase levels. Serum HBsAg titers and paired HBV DNA concentrations in the different phases of CHB were compared using 627 serum samples. Results: Mean HBsAg titers were significantly higher in the immunotolerant (IT) phase and immunoreactive (IR) HBeAg-positive phase than in the low-replicative (LR) and HBeAg-negative CHB (ENH) states. The correlation between HBsAg titers and HBV DNA concentrations was modest in the IT (n=36, r=0.804, p<0.001) and IR (n=48, r=0.773, p<0.001) phases, and it was poor in the LR state (n=116, r=0.289, p=0.002); however, no significant correlation was observed in the ENH state (n=67, r=0.146, p=0.237) or in the oral nucleos(t)ide analogue-treated group (n=267). Conclusions: HBsAg quantification using IRMA might be useful for discriminating different CHB phases and different stages of chronic liver disease. (Gut Liver 2015;9:657-664)

Does 131I Radioactivity Interfere with Thyroglobulin Measurement in Patients Undergoing Radioactive Iodine Therapy with Recombinant Human TSH?

박소현,방지인,이호영,김상은 대한핵의학회 2015 핵의학 분자영상 Vol.49 No.2

Objectives Recombinant human thyroid-stimulating hormone (rhTSH) is widely used in radioactive iodine therapy (RIT) to avoid side effects caused by hypothyroidism during the therapy. Owing to RIT with rhTSH, serum thyroglobulin (Tg) is measured with high 131I concentrations. It is of concern that the relatively high energy of 131I could interfere with Tg measurement using the immunoradiometric assay (IRMA). We investigated the effect of 131I administration on Tg measurement with IRMA after RIT. Methods A total of 67 patients with thyroid cancer were analysed retrospectively. All patients had undergone rhTSH stimulation for RIT. The patients’ sera were sampled 2 days after 131I administration and divided into two portions: for Tg measurements on days 2 and 32 after 131I administration. The count per minute (CPM) of whole serum (200 μl) was also measured at each time point. Student’s paired t-test and Pearson’s correlation analyses were performed for statistical analysis. Results Serum Tg levels were significantly concordant between days 2 and 32, irrespective of the serum CPM. Subgroup analysis was performed by classification based on the 131I dose. No difference was noted between the results of the two groups. Conclusions IRMA using 125I did not show interference from 131I in the serum of patients stimulated by rhTSH.

사람 혈청 트란스페린수용체의 단클론 항체를 이용한 방사면역측정과 철영양상태의 진단

김승렬(Kim Seung Ryul),정천기(Chung Chun Kee),한정호(Han Jung Ho),채범석(Tchai Bum Suk) 韓國營養學會 1996 Journal of Nutrition and Health Vol.29 No.9

고감도 방사면역측정법에 의한 TSH 측정의 임상적 의의

정영란(Young Ran Jeong),김미나(Mi Na Kim),김성운(Sung Woon Kim),양인명(In Myung Yang),김진우(Jin Woo Kim),김영설(Young Seol Kim),최영길(Young Kil Choi) 대한내과학회 1988 대한내과학회지 Vol.35 No.1

N/A A clinical study was undertaken for the evaluation of the difference and correlation between the determination of TSH by classical RIA and highly sensitive RIA (Immunoradiometric assay; IRMA) and to determine whether the use of IRMA to determine TSH can detect patients without remission earlier than classical RIA. We measured the T3, T4, TSH by RIA, TBII by radioreceptor assay and TSH by IR~MA of 21 control subjects and 27 hyperthyroid patients. Another 5 hyperthyroid patients who had been treated with an antithyroid regimen over 6 months were also analysed by the above parameters after discontinuation of the antithyroid drugs. The results were as follows; 1) TSH concentration measured by IRMA (1.1±0.6μu/ml) was significantly lower than that measured by RIA ~(2.2±0.6μu/ml) and it had a good correlation withthat of RIA (r=0.72, p<0.005). 2) IRMA revealed a good delineation between hyperthyroid patients (0.1±0.09μu/ml) and euthyroid individuals (1.1±0.6μu/ml, p<0.005) 3) IRMA could reveal earlier than RIA that a patient had not been in remission.