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1.
Article in English | WPRIM | ID: wpr-874190

ABSTRACT

Background@#Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) is increasingly used for immunosuppressive drug tests. However, most LC-MS/MS tests are laboratory-developed and their agreement is unknown in different Korean laboratories.This interlaboratory comparison study evaluated test reproducibility and identified potential error sources. @*Methods@#Test samples containing three concentrations of tacrolimus, sirolimus, everolimus, cyclosporine, and mycophenolic acid were prepared by pooling surplus samples from patients undergoing routine therapeutic drug monitoring and tested in duplicate in the participating 10 clinical laboratories. Reconstitution and storage experiments were conducted for the commonly used commercial calibrator set. The robust estimators of reproducibility parameters were calculated. Spearman’s rank correlation coefficient (rho, ρ) was used to evaluate the correlation between drugs. Multiple linear regression was used to determine whether the experimental conditions alter the calibration curves. @*Results@#The reproducibility coefficient of variation exceeded 10% only for sirolimus concentrations 1 and 2 (10.8% and 12.5%, respectively) and everolimus concentrations 1 and 2 (12.3% and 11.4%, respectively). The percent difference values showed weak correlations between sirolimus and everolimus (ρ = 0.334, P = 0.175). The everolimus calibration curve slope was significantly altered after reconstitution following prolonged 5°C storage (P = 0.015 for 14 days; P = 0.025 for 28 days); the expected differences at 6 ng/mL were 0.598% for 14 days and 0.384% for 28 days. @*Conclusions@#LC-MS/MS test reproducibility for immunosuppressive drugs seems to be good in the Korean clinical laboratories. Continuous efforts are required to achieve test standardization and harmonization, especially for sirolimus and everolimus.

2.
Article in English | WPRIM | ID: wpr-874161

ABSTRACT

Background@#We developed an assay to measure DNA-incorporated 6-thioguanine (DNATG) and validated its clinical applicability in Korean pediatric patients with acute lymphoblastic leukemia (ALL) in order to improve individualized thiopurine treatment and reduce the life-threatening cytotoxicity. @*Methods@#The DNA-TG assay was developed based on liquid chromatography-tandem mass spectrometry, with isotope-labeled TG-d3 and guanine-d3 as internal standards.This method was applied to 257 samples of pediatric ALL patients. The DNA-TG level was compared with erythrocyte TG nucleotide (RBC-TGN) level in relation to the TPMT and NUDT15 genotypes, which affect thiopurine metabolism, using Spearman’s rank test and repeated measure ANOVA. @*Results@#For DNA-TG quantification, a linearity range of 10.0-5,000.0 fmol TG/µg DNA;bias for accuracy of –10.4% –3.5%; coefficient of variation for intra- and inter-day precision of 3.4% and 5.8% at 80 fmol TG/µg DNA and of 4.9% and 5.3% at 800 fmol TG/µg DNA, respectively; and recovery of 85.7%–116.2% were achieved without matrix effects or carry-over. The median DNA-TG level in the 257 samples was 106.0 fmol TG/µg DNA (interquartile range, 75.8–150.9). There was a strong correlation between DNA-TG and RBC-TGN levels (ρ = 0.68,ρ < 0.0001). The DNA-TG/RBC-TGN ratio was significantly higher in NUDT15 intermediate metabolizers (*1/*2 and *1/*3) than in patients with wildtype alleles (ρ < 0.0001). @*Conclusions@#This simple and sensitive method for measuring DNA-TG level can improve therapeutic drug monitoring for thiopurine treatment.

3.
Article in English | WPRIM | ID: wpr-874130

ABSTRACT

Melatonin and cortisol are clinically important for diagnosing sleep and mood disorders.We developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/ MS) assay for simultaneous measurement of salivary melatonin and cortisol concentrations according to the Clinical and Laboratory Standards Institute guidelines. Additionally, we compared the LC-MS/MS assay with immunoassays, ELISA (Direct Salivary Melatonin Elisa EK-DSM, Bühlmann Laboratories AG, Schönenbuch, Switzerland) and electrochemiluminescence immunoassay (Cortisol II, Roche, Mannheim, Germany), using 121 saliva samples. The LC-MS/MS assay exhibited good performance in terms of linearity, precision, accuracy, limit of detection, lower limit of quantification, extraction recovery, carry-over, and matrix effect. The LC-MS/MS assay and immunoassays showed strong correlation (Pearson’s r = 0.910 for melatonin, r = 0.955 for cortisol), but demonstrated a significant mean bias of 23.2% (range 54.0–143.7%) for melatonin and 48.9% (range 59.7–184.7%) for cortisol. Our LC-MS/MS assay provided more sensitive and reliable salivary melatonin and cortisol quantification results compared with immunoassays.

4.
Psychiatry Investigation ; : 471-477, 2021.
Article in English | WPRIM | ID: wpr-903223

ABSTRACT

Objective@#Organic light-emitting diodes (OLEDs) emit less blue light than traditional light-emitting diodes (LEDs), and we previously found that early-night OLED light exposure (LE) delays the melatonin phase by less than LED at a color temperature of 4,000 K. As a follow-up study, we investigated the effects of OLED and LED at a different color temperature (3,000 K) on melatonin profile, sleep, and vigilance. @*Methods@#24 healthy subjects (27.5±5.1 years) were exposed to three light conditions [OLED, LED, and dim light (DL)] from 17:30 to 24:00, in a random order and with a 1-week interval. Saliva samples for melatonin were taken every hour from 18:00 to 24:00. Polysomnography (PSG) and a psychomotor vigilance test (PVT) were performed. @*Results@#Melatonin onset time was significantly delayed under OLED and LED compared with DL, with no significant difference between OLED and LED. The mean melatonin level at 24:00 under LED was lower than that under DL, but there was no significant difference between OLED LE and DL. The percentage of slow wave sleep (N3) in LED was significantly lower than in OLED. @*Conclusion@#Exposure to light in the evening can suppress melatonin secretion late at night and disturb deep sleep, and those effects are slightly worse under LED than OLED.

5.
Article in English | WPRIM | ID: wpr-898227

ABSTRACT

Background@#Pheochromocytoma and paraganglioma (PPGL) is diagnosed through biochemical confirmation of excessive catecholamines in urine and plasma. Recent technological developments have allowed us to measure urinary free metanephrines; however, the diagnostic accuracy of these new methods and the diagnostic cutoff values have not been evaluated. @*Methods@#This is a retrospective study of 595 subjects, including 71 PPGL cases and 524 controls. PPGL was based on pathological confirmation. Subjects with no evidence of PPGL over 2 years were included in the control group. @*Results@#Urinary free metanephrines yielded similar area under the curve (AUC) to urinary fractionated metanephrines and plasma free metanephrines. However, urinary free normetanephrine yielded a better AUC than did urinary fractionated normetanephrine. The optimal cutoff for urinary free metanephrine and normetanephrine corrected for urinary creatinine yielded 97.2% sensitivity and 98.1% specificity. @*Conclusion@#Urinary free metanephrines are a reliable method for diagnosing PPGL in Asian populations compared with existing biochemical methods.

6.
Psychiatry Investigation ; : 471-477, 2021.
Article in English | WPRIM | ID: wpr-895519

ABSTRACT

Objective@#Organic light-emitting diodes (OLEDs) emit less blue light than traditional light-emitting diodes (LEDs), and we previously found that early-night OLED light exposure (LE) delays the melatonin phase by less than LED at a color temperature of 4,000 K. As a follow-up study, we investigated the effects of OLED and LED at a different color temperature (3,000 K) on melatonin profile, sleep, and vigilance. @*Methods@#24 healthy subjects (27.5±5.1 years) were exposed to three light conditions [OLED, LED, and dim light (DL)] from 17:30 to 24:00, in a random order and with a 1-week interval. Saliva samples for melatonin were taken every hour from 18:00 to 24:00. Polysomnography (PSG) and a psychomotor vigilance test (PVT) were performed. @*Results@#Melatonin onset time was significantly delayed under OLED and LED compared with DL, with no significant difference between OLED and LED. The mean melatonin level at 24:00 under LED was lower than that under DL, but there was no significant difference between OLED LE and DL. The percentage of slow wave sleep (N3) in LED was significantly lower than in OLED. @*Conclusion@#Exposure to light in the evening can suppress melatonin secretion late at night and disturb deep sleep, and those effects are slightly worse under LED than OLED.

7.
Article in English | WPRIM | ID: wpr-890523

ABSTRACT

Background@#Pheochromocytoma and paraganglioma (PPGL) is diagnosed through biochemical confirmation of excessive catecholamines in urine and plasma. Recent technological developments have allowed us to measure urinary free metanephrines; however, the diagnostic accuracy of these new methods and the diagnostic cutoff values have not been evaluated. @*Methods@#This is a retrospective study of 595 subjects, including 71 PPGL cases and 524 controls. PPGL was based on pathological confirmation. Subjects with no evidence of PPGL over 2 years were included in the control group. @*Results@#Urinary free metanephrines yielded similar area under the curve (AUC) to urinary fractionated metanephrines and plasma free metanephrines. However, urinary free normetanephrine yielded a better AUC than did urinary fractionated normetanephrine. The optimal cutoff for urinary free metanephrine and normetanephrine corrected for urinary creatinine yielded 97.2% sensitivity and 98.1% specificity. @*Conclusion@#Urinary free metanephrines are a reliable method for diagnosing PPGL in Asian populations compared with existing biochemical methods.

8.
Article in English | WPRIM | ID: wpr-785398

ABSTRACT

BACKGROUND: Differences in the performance of suggested warfarin dosing algorithms among different ethnicities and genotypes have been reported; this necessitates the development of an algorithm with enhanced performance for specific population groups. Previous warfarin dosing algorithms underestimated warfarin doses in VKORC1 1173C carriers. We aimed to develop and validate a new warfarin dosing algorithm for Korean patients with VKORC1 1173C.METHODS: A total of 109 patients carrying VKORC1 1173CT (N=105) or 1173CC (N=4) were included in this study. Multiple regression analysis was performed to deduce a new dosing algorithm. Following literature searches for genotype-guided warfarin dosing algorithms, 21 algorithms were selected and evaluated using the correlation coefficient (ρ) of actual dose and estimated dose, mean error, and root mean square error.RESULTS: The developed algorithm is as follows: maintenance dose (mg/week)=exp [3.223−0.009×(age)+0.577×(body surface area [BSA])+0.178×(sex)−0.481×(CYP2C9 genotype)+0.227×(VKORC1 genotype)]. Integrated variables explained 44% of the variance in the maintenance dose. The predicted and actual doses showed moderate correlation (ρ=0.641) with the best performance with a mean error of −1.30 mg/week. The proportion of underestimated groups was 17%, which was lower than with the other algorithms.CONCLUSIONS: This is the first study to develop and validate a warfarin dosing algorithm based on data from VKORC1 1173C carriers; it showed superior predictive performance compared with previously published algorithms.


Subject(s)
Genotype , Humans , Korea , Population Groups , Warfarin
11.
Laboratory Medicine Online ; : 265-275, 2020.
Article in English | WPRIM | ID: wpr-902682

ABSTRACT

Background@#Therapeutic drug monitoring (TDM) is clinically recommended for vancomycin and aminoglycoside antibiotics owing to their narrow therapeutic range and nephrotoxicity at high concentrations in the blood. This study was conducted to investigate the current status of TDM of vancomycin and aminoglycosides in Korean clinical laboratories. @*Methods@#Ten organizations participated in this survey. Vancomycin, amikacin, gentamicin, and tobramycin were prepared in three samples of five or six different concentrations. Data from each institution were calculated for the mean, standard deviation, within-day, between-day, and within-laboratory precision. The results from each institution were compared in various ways. @*Results@#Six instruments from three manufacturers were used. Samples with the lowest drug concentration were reported as below the lower limit of quantitation in most laboratories. Coefficients of variation for within-laboratory values ranged from 1.1% to 10.9% for vancomycin, 0.8% to 18.2% for amikacin, 1.2% to 7.8% for gentamicin, and 1.3% to 6.1% for tobramycin. Based on the overall results of the participants, only one institution’s vancomycin samples standard deviation index exceeded 3, with all other values below 2. The College of American Pathologist criteria were met by all institutions; however, measurement of vancomycin in one laboratory and of gentamycin in three laboratories failed to meet the Royal College of Pathologists of Australasia acceptance criteria. @*Conclusions@#Although the precision of the antibiotic test in individual institutions was excellent, there was a difference in the measured values between laboratories. Harmonization of antibiotic TDM is needed to reduce inconsistencies in results.

12.
Laboratory Medicine Online ; : 265-275, 2020.
Article in English | WPRIM | ID: wpr-894978

ABSTRACT

Background@#Therapeutic drug monitoring (TDM) is clinically recommended for vancomycin and aminoglycoside antibiotics owing to their narrow therapeutic range and nephrotoxicity at high concentrations in the blood. This study was conducted to investigate the current status of TDM of vancomycin and aminoglycosides in Korean clinical laboratories. @*Methods@#Ten organizations participated in this survey. Vancomycin, amikacin, gentamicin, and tobramycin were prepared in three samples of five or six different concentrations. Data from each institution were calculated for the mean, standard deviation, within-day, between-day, and within-laboratory precision. The results from each institution were compared in various ways. @*Results@#Six instruments from three manufacturers were used. Samples with the lowest drug concentration were reported as below the lower limit of quantitation in most laboratories. Coefficients of variation for within-laboratory values ranged from 1.1% to 10.9% for vancomycin, 0.8% to 18.2% for amikacin, 1.2% to 7.8% for gentamicin, and 1.3% to 6.1% for tobramycin. Based on the overall results of the participants, only one institution’s vancomycin samples standard deviation index exceeded 3, with all other values below 2. The College of American Pathologist criteria were met by all institutions; however, measurement of vancomycin in one laboratory and of gentamycin in three laboratories failed to meet the Royal College of Pathologists of Australasia acceptance criteria. @*Conclusions@#Although the precision of the antibiotic test in individual institutions was excellent, there was a difference in the measured values between laboratories. Harmonization of antibiotic TDM is needed to reduce inconsistencies in results.

13.
Laboratory Medicine Online ; : 185-196, 2020.
Article | WPRIM | ID: wpr-836926

ABSTRACT

The use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) in clinical laboratories is increasing and is likely to expand into even more clinical venues in the future. Mass spectrometry is the standard method for analyte identification in the clinical chemistry field; however, differences in mass spectrometry protocols and handling affect the accuracy and reliability of these tests and prevent direct comparisons of results between laboratories. For example, the results of laboratories using LC-MS/MS methods are less likely to be reproducible than those of laboratories using conventional, automated methods. This is due to inadequate handling of the equipment and/or poor quality control after the implementation of the method, which may result in unnecessary medical expenditures or even adverse outcomes for the patients. Unfortunately, guidelines to monitor the accuracy of LC-MS/MS-based clinical tests are still lacking. In general, the quality control methods used in conventional clinical tests could also be applied to LC-MS/MS. However, additional quality control methods specific to LC-MS/MS techniques must be continuously employed to maintain the same quality level achieved during method development and verification. This report is intended to help clinical laboratories that operate LC-MS/MS improve the accuracy and reliability of their testing by providing guidance for quality assurance and improvement, based on a collection of existing guidelines and expert opinions from the literature.

14.
Article | WPRIM | ID: wpr-836060

ABSTRACT

External quality assessment (EQA) trials of conventional newborn screeningtests for phenylketonuria, galactosemia, congenital adrenal hyperplasia,maple syrup urine disease, homocystinuria, and congenital hypothyroidism,as well as extended newborn screening tests using tandem massspectrometry, were performed twice in 2018 and 2019. A total of 44 driedblood spot specimens were analyzed in each trial in 14–16 laboratories.Median, mean, standard deviation, minimum and maximum values, andcut-off values were evaluated for each analyte in the newborn screeningtests. The proportion of correct answers was 95%–100%. EQA trials for theanalyses of methylmalonic acid, vanillylmandelic acid, catecholamines,metanephrines, organic acids, and amino acids were also performedusing two or three specimens per trial. A well-designed EQA program andcontinuous education can help improve the performance of metabolitetesting.

15.
Article in English | WPRIM | ID: wpr-831570

ABSTRACT

Background@#Teicoplanin is used to treat serious gram-positive infections. Optimal teicoplanin trough levels are considered to be ≥ 10 μg/mL. Despite its wide use in various clinical settings, data on teicoplanin trough level in pediatric patients are limited. Therefore, the aim of this study was to investigate the therapeutic drug level monitoring of teicoplanin in Korean pediatric patients, including those with impaired renal function. @*Methods@#A retrospective study was performed in pediatric patients (age ≤ 18 years old) who received teicoplanin from September 2014 to April 2018. The regimen included a loading dose of 10 mg/kg/dose at 12 hours' interval three times in a row, and a maintenance dose of 10 mg/kg/dose commenced at 24 hours of interval after the loading dose, with a maximum of 400 mg/dose, respectively. The first therapeutic drug levels were measured. Distribution and characteristics of trough levels in patients with decreased renal function and those with bacteremia were also assessed. @*Results@#A total of 187 trough levels were collected from 143 patients. Hematologic and oncologic diseases were the most common underlying diseases (83.2%, n = 119). One hundred eighty trough levels were first measured, and their median value was 16.2 μg/mL (range, 2.3–100 μg/mL) and the median interval between initial teicoplanin injection and 1st trough level was 96.5 hours (range 47.6–179.3 hours). Lower steady-state levels were observed in younger age group (median, 13.5 vs. 18.0 μg/mL, P = 0.038). Median trough levels were higher in patients with decreased renal functions (P < 0.001). In addition, among eight with gram-positive bacteremia, seven of them had a favorable outcome. @*Conclusion@#This study provides additive information on trough level monitoring of teicoplanin in children with impaired renal function and treatment effect in patients with gram-positive bacteremia. Careful monitoring for steady state trough levels of teicoplanin is warranted.

16.
Yonsei Medical Journal ; : 816-823, 2019.
Article in English | WPRIM | ID: wpr-762125

ABSTRACT

PURPOSE: The present study aimed to investigate the prevalence, characteristics, and clinical significance of concomitant specific cardiomyopathies in subjects with bicuspid aortic valves (BAVs). MATERIALS AND METHODS: A total of 1186 adults with BAV (850 males, mean age 56±14 years) at a single tertiary center were comprehensively reviewed. Left ventricular non-compaction, hypertrophic cardiomyopathy, and idiopathic dilated cardiomyopathy were confirmed when patients fulfilled current clinical and echocardiographic criteria. Clinical and echocardiographic characteristics, including comorbidities, heart failure presentation, BAV morphology, function, and aorta phenotypes, in BAV subjects with or without specific cardiomyopathies were compared. RESULTS: Overall, 67 subjects (5.6%) had concomitant cardiomyopathies: 40 (3.4%) patients with left ventricular non-compaction, 17 (1.4%) with hypertrophic cardiomyopathy, and 10 (0.8%) with dilated cardiomyopathy. BAV subjects with hypertrophic cardiomyopathy had higher prevalences of diabetes mellitus and heart failure with preserved ejection fraction, and tended to have type 0 phenotype, while BAV subjects with dilated cardiomyopathy showed higher prevalences of chronic kidney disease and heart failure with reduced ejection fraction. BAV subjects with left ventricular non-compaction were significantly younger and predominantly male, and had greater BAV dysfunction and a higher prevalence of normal aorta shape. In multiple regression analysis, cardiomyopathy was independently associated with heart failure (odds ratio 2.795, 95% confidential interval 1.603–4.873, p<0.001) after controlling for confounding factors. CONCLUSION: Concomitant cardiomyopathies were observed in 5.6% of subjects with BAV. A few different clinical and echocardiographic characteristics were found. The presence of cardiomyopathy was independently associated with heart failure.


Subject(s)
Adult , Aorta , Aortic Valve , Bicuspid , Cardiomyopathies , Cardiomyopathy, Dilated , Cardiomyopathy, Hypertrophic , Comorbidity , Diabetes Mellitus , Echocardiography , Heart Failure , Humans , Male , Phenotype , Prevalence , Renal Insufficiency, Chronic
17.
Laboratory Medicine Online ; : 161-165, 2019.
Article in Korean | WPRIM | ID: wpr-760500

ABSTRACT

The Clinical Mass Spectrometry Research Committee (CMSRC), in affiliation with the Korean Society of Clinical Chemistry (KSCC), conducted a questionnaire survey on opinions about the general status of clinical mass spectrometric analysis in Korea. As a result, we understand that this field has passed through the introductory stage and is settled as a field of clinical laboratory testing in Korea, with the number of new laboratories performing mass spectrometric analysis being low. In spite of the many difficulties in introducing and operating clinical mass spectrometric analysis, there is a strong interest in this field, and even though further expansion is expected, there are still many issues to be resolved. In the future, it will be necessary to make concrete and thorough efforts to further develop the laboratory tests using clinical mass spectrometric analysis in Korea, centering on the CMSRC affiliated with the KSCC.


Subject(s)
Chemistry, Clinical , Korea , Mass Spectrometry
18.
Article in English | WPRIM | ID: wpr-717642

ABSTRACT

BACKGROUND: To evaluate the value of random urinary vanillylmandelic acid (VMA) as a surrogate marker for monitoring tumor response and predicting outcome in patients with neuroblastoma (NB). METHODS: Medical records of 91 patients newly diagnosed with NB at the Samsung Medical Center between June 2014 and August 2017 were reviewed. Clinical associations and other prognostic factors, including age at diagnosis, stage, pathologic subtype, MYCN amplification, and other cytogenetic aberrations, were analyzed. Furthermore, the significance of random urinary VMA level in predicting outcome and tumor response was also evaluated. RESULTS: The median random urinary VMA level at diagnosis was 27.9 (range: 1.7–600) mg/g creatinine. Abdominal primary site, male sex, advanced stage, less differentiated pathology (poorly differentiated, undifferentiated), 11q deletion, and high-risk tumor were associated with a higher VMA level at diagnosis. The VMA level decreased during chemotherapy (28.4%, 16.9%, and 9.6% of the VMA level at diagnosis after 3, 6, and 9 cycles of chemotherapy, respectively). A higher VMA level at diagnosis tends to be associated with a better overall survival in high-risk patients with borderline significance (58.3±18.6% vs. 76.5±13.4%, P=0.050). However, in the multivariate analysis, the VMA level was not a significant predictor of survival. A slower reduction in VMA level during chemotherapy was not associated with a worse overall survival. However, event free survival was significantly better in the rapid responder group. CONCLUSION: A higher VMA level was associated with high-risk features at diagnosis of NB. Random urinary VMA is a valuable marker for monitoring NB response during chemotherapy.


Subject(s)
Biomarkers , Chromosome Aberrations , Creatinine , Diagnosis , Disease-Free Survival , Drug Therapy , Humans , Male , Medical Records , Multivariate Analysis , Neuroblastoma , Pathology , Prognosis , Vanilmandelic Acid
19.
Article in Korean | WPRIM | ID: wpr-717164

ABSTRACT

External quality assessment (EQA) trials of conventional newborn screening tests for phenylketonuria, galactosemia, congenital adrenal hyperplasia, maple syrup urine disease, homocystinuria, and congenital hypothyroidism, as well as extended newborn screening tests using tandem mass spectrometry, were performed twice in 2016 and 2017. A total of 44 specimens in the form of dried blood spots were distributed in each trial to 16 laboratories. The response rate of these laboratories was 100%. The mean, standard deviation, coefficient of variation, median, and cut-offs were evaluated for each analyte in the newborn screening tests. EQA trials for the analyses of methylmalonic acid, vanillylmandelic acid, catecholamines, metanephrines, organic acids, and amino acids were also performed. A well-designed EQA program and continuous education would improve the performance of metabolite testing.


Subject(s)
Adrenal Hyperplasia, Congenital , Amino Acids , Catecholamines , Congenital Hypothyroidism , Education , Galactosemias , Homocystinuria , Humans , Infant, Newborn , Korea , Maple Syrup Urine Disease , Mass Screening , Methylmalonic Acid , Phenylketonurias , Tandem Mass Spectrometry , Vanilmandelic Acid
20.
Article in English | WPRIM | ID: wpr-714637

ABSTRACT

BACKGROUND/AIMS: Maternal thyroid dysfunction has been associated with adverse pregnancy outcomes. The purpose of our study was to establish trimester-specific reference intervals for thyroid hormones in pregnant women in Korea, where iodine intake is more than adequate and to examine pregnancy and perinatal outcomes in their offspring. METHODS: Among 459 healthy pregnant women who were screened, we enrolled 417 subjects who had negative results for thyroid autoantibodies. Serum thyroid stimulating hormone (TSH) and free thyroxine were measured using an immunoradiometric assay. Urine iodine concentration was measured using inductively coupled plasma-mass spectrometry in 275 women. Reference ranges of thyroid hormones were determined according to the guidelines of the National Academy of Clinical Biochemistry. Pregnancy and perinatal outcomes were compared according to maternal thyroid function. RESULTS: The reference ranges of serum TSH were 0.03 to 4.24 mIU/L in the first trimester, 0.13 to 4.84 mIU/L in the second trimester, and 0.30 to 5.57 mIU/L in the third trimester. Pregnancy and perinatal outcomes did not vary in mothers with subtle changes in thyroid function. CONCLUSIONS: Trimester-specific thyroid hormone reference intervals in Korean pregnant women differ from those of other countries with different iodine nutrition status and ethnicity. The establishment of population-based, reliable trimester-specific reference intervals is critical for the interpretation of thyroid function in pregnant women to avoid unnecessary tests and treatments.


Subject(s)
Autoantibodies , Biochemistry , Female , Humans , Immunoradiometric Assay , Iodine , Korea , Mothers , Nutritional Status , Pregnancy Outcome , Pregnancy Trimester, First , Pregnancy Trimester, Second , Pregnancy Trimester, Third , Pregnancy , Pregnant Women , Reference Values , Republic of Korea , Spectrum Analysis , Thyroid Gland , Thyroid Hormones , Thyrotropin , Thyroxine
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