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Nuclear Medicine and Molecular Imaging Dec 2016The batch assay has been conventionally used for radioimmunoassay (RIA) because of its technical robustness and practical convenience. However, it has limitations in...
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 inter-kits 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.
PubMed: 27994689
DOI: 10.1007/s13139-016-0436-7 -
Postepy Dermatologii I Alergologii Dec 2014Acne and hirsutism are common manifestations of hyperandrogenism.
INTRODUCTION
Acne and hirsutism are common manifestations of hyperandrogenism.
AIM
To investigate whether or not acne is present in women with hirsutism, associated with different clinical, endocrine and ultrasonographic features.
MATERIAL AND METHODS
The prospective study included 135 women with hirsutism, aged 14-46 years. We measured the levels of hormones with radioimmunoassay/immunoradiometric assay methods.
RESULTS
Acne were present in 63 (47.6%) women with hirsutism. Sixty women had mild forms of acne, including: whiteheads, blackheads, papules and pustules. Only 3 women had moderate to severe acne, including nodules. In a group of women with hirsutism and acne, 6 (9.5%) were obese. In our study we found a high prevalence of androgen excess among hirsute women with acne: total testosterone was increased in 79%, free testosterone in 20.6%, androstenedione in 69.8%, dehydroepiandrosterone sulfate (DHEAS) in 30.1%, 17-OH-progesterone 68.2% and sex hormone-binding globulin (SHBG) was decreased in 33.3% of women. Women with hirsutism and acne have received oral contraceptives for a year, without or in a combination with other medication. Thirty-four (53.9%) women have shown improvement in hirsutism and acne.
CONCLUSIONS
In this study we found a high prevalence of acne in hirsute women. The prevalence of acne was higher in polycystic ovarian syndrome. Since these women have associated endocrine changes it is important to correct them with hormonal therapy.
PubMed: 25610349
DOI: 10.5114/pdia.2014.47118 -
Annals of Laboratory Medicine Sep 2016Measurement of postoperative serum thyroglobulin (Tg) is important for detecting persistent or recurrent differentiated thyroid cancer. We evaluated the analytic...
BACKGROUND
Measurement of postoperative serum thyroglobulin (Tg) is important for detecting persistent or recurrent differentiated thyroid cancer. We evaluated the analytic performance of the DxI 800 assay (Beckman Coulter, USA) for serum Tg and anti-thyroglobulin antibodies (TgAbs) in comparison with that of the GAMMA-10 assay (Shinjin Medics Inc., Korea) for serum Tg and RIA-MAT 280 assay (Stratec, Germany) for TgAb.
METHODS
We prospectively collected blood samples from 99 patients thyroidectomized for thyroid cancer. The functional sensitivity was investigated in standards and human serum. Precision and linearity were evaluated according to the guidelines of the Clinical and Laboratory Standards Institute. The correlation between the two assays was assessed in samples with different Tg ranges.
RESULTS
The functional sensitivity of the DxI 800 assay for serum Tg was between 0.0313 and 0.0625 ng/mL. The total CV was 3.9-5.6% for serum Tg and 5.3-6.9% for serum TgAb. The coefficient of determination (R²) was 1.0 and 0.99 for serum Tg and TgAb, respectively. The cut-offs for serum TgAb were 4.0 IU/mL (DxI 800) and 60.0 IU/mL (RIA-MAT 280), and the overall agreement was 68.7%. The correlation between the two assays was excellent; the correlation coefficient was 0.99 and 0.88 for serum Tg and TgAb, respectively.
CONCLUSIONS
The DxI 800 is a sensitive assay for serum Tg and TgAb, and the results correlated well with those from the immunoradiometric assays (IRMA). This assay has several advantages over the IRMA and could be considered an alternative test for Tg measurement.
Topics: Autoantibodies; Humans; Immunoradiometric Assay; Luminescent Measurements; Prospective Studies; Reagent Kits, Diagnostic; Reproducibility of Results; Thyroglobulin; Thyroid Neoplasms
PubMed: 27374705
DOI: 10.3343/alm.2016.36.5.413 -
Clinical Journal of the American... Jul 2014Alge et al. recently reported that urinary renin may be a prognostic biomarker for AKI after cardiac surgery. However, their urinary renin levels far exceeded published... (Comparative Study)
Comparative Study
BACKGROUND AND OBJECTIVES
Alge et al. recently reported that urinary renin may be a prognostic biomarker for AKI after cardiac surgery. However, their urinary renin levels far exceeded published plasma renin levels, whereas normally, urinary renin is <10% of plasma renin. This result raises questions about the specificity of the new Quantikine Renin ELISA Kit used in the work by Alge et al., which is claimed to detect total renin (i.e., renin and prorenin). Therefore, this study tested this assay.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS
Plasma and urine from 30 patients with hypertension, diabetes, or preeclampsia and 10 healthy pregnant women (randomly selected from sample sets obtained earlier to investigate urinary renin-angiotensin system components) were used to compare the ELISA with a validated renin immunoradiometric assay and an in-house enzyme kinetic assay. Measurements were performed before and after in vitro prorenin activation, representing renin and total renin, respectively.
RESULTS
Total renin measurements by ELISA, immunoradiometric assay, and enzyme kinetic assay were highly correlated. However, ELISA results were consistently ≥10-fold higher. The ELISA standard yielded low to undetectable levels in the immunoradiometric assay and enzyme kinetic assay, except after prorenin activation, when the results were ≥10-fold lower than the ELISA results. In plasma, prorenin activation increased ELISA results by 10%-15%. Urine contained no detectable prorenin.
CONCLUSIONS
The ELISA renin kit standard is prorenin, and its immunoreactivity and enzymatic activity after conversion to renin do not match the International Reference Preparation of human renin that has been used to validate previous immunoradiometric assays and enzyme kinetic assays; in fact, they are at least 10-fold lower, and thus, any measurements obtained with this ELISA kit yield levels that are at least 10-fold too high. The ELISA antibodies detect both renin and prorenin, with a preference for the former. Given these inconsistencies, urinary renin levels should be measured by established renin assays.
Topics: Adult; Aged; Biomarkers; Calibration; Case-Control Studies; Diabetic Nephropathies; Enzyme Precursors; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunoradiometric Assay; Kidney Diseases; Male; Middle Aged; Predictive Value of Tests; Pregnancy; Reagent Kits, Diagnostic; Reference Standards; Renin; Reproducibility of Results
PubMed: 24742480
DOI: 10.2215/CJN.12661213 -
The Kaohsiung Journal of Medical... Apr 2020Papillary thyroid carcinoma (PTC) generally has a good prognosis, but disease recurs in 25% to 30% of PTC patients and significantly reduces the survival rate. Lymph... (Review)
Review
Clinical application of the ultrasound-guided fine needle aspiration for thyroglobulin measurement to diagnose lymph node metastasis from differentiated thyroid carcinoma-literature review.
Papillary thyroid carcinoma (PTC) generally has a good prognosis, but disease recurs in 25% to 30% of PTC patients and significantly reduces the survival rate. Lymph node metastasis (LNM) is reported in 20% to 50% of PTC patients, mainly in the neck, and 20% originates from recurrence. LNM of papillary thyroid carcinoma are a plausible prognostic factor to determine disease recurrence. Currently, fine needle lymph node aspiration for cytology (LN-FN-cytology) is the best modality to diagnose LNM but is limited by diagnostic sensitivity and sample error. Fine needle lymph node aspiration for thyroglobulin measurement (LN-FNA-Tg) could offer a reliable and quantitative diagnostic method for LNM. The combination of LN-FNA-cytology and LN-FNA-Tg could achieve almost 100% diagnostic sensitivity and specificity for LNM. Both treatment guidelines of the American Thyroid Association and European Thyroid Association recommend LN-FNA-Tg to diagnose LNM after total thyroidectomy. Diagnostic accuracy of the LN-FNA-Tg depends on optimal equipment, scanning protocol, skill, and experience of operators. Normal saline is mainly used for aspiration needle wash-out and buffer solution. And radioimmunoassay or immunoradiometric assay are widely used for the LN-FNA-Tg measurement. So far, there is no consensus about the diagnostic threshold of LN-FNA-Tg for positive LNM, but high LN-FNA-Tg, especially higher than 10 ng/mL, strongly favors LNM.
Topics: Biopsy, Fine-Needle; Cell Differentiation; Humans; Lymphatic Metastasis; Thyroglobulin; Thyroid Neoplasms; Ultrasonography
PubMed: 31909556
DOI: 10.1002/kjm2.12173 -
Journal of Human Hypertension Jan 2022Determination of plasma aldosterone concentrations (PAC) and plasma active renin concentrations (ARC) is essential for the diagnosis of primary aldosteronism (PA). In...
Determination of plasma aldosterone concentrations (PAC) and plasma active renin concentrations (ARC) is essential for the diagnosis of primary aldosteronism (PA). In Japan, although PAC and ARC are measured by radioimmunoassay and immunoradiometric assay, respectively, non-radioisotopic methods with better detection sensitivity, measurement accuracy, and technical simplicity are needed. We developed two-site sandwich chemiluminescent enzyme immunoassays (CLEIAs) to measure both PAC and ARC using monoclonal antibodies immobilized onto ferrite particles. The results of both assays are obtained simultaneously from a single plasma sample within 30 min using a fully automated system. The novel CLEIAs were validated using plasma samples from patients with PA (n = 52) and essential hypertension (n = 23). The PAC determined by the CLEIA was significantly correlated with that measured by liquid chromatography/mass spectrometry or conventional radioimmunoassay. The ARC determined by the CLEIA was significantly correlated with that measured by immunoradiometric assay. The limits of detection of the CLEIAs for PAC and ARC were 0.1 ng/dl and 0.04 pg/ml, respectively, which were better than those of conventional methods (PAC: 2.5 ng/dl; ARC: 5 pg/ml). The PAC and PAC/ARC ratio (ARR) were significantly higher, and the ARC significantly lower, in patients with PA than in those with essential hypertension. An ARR cut-off of 1.31 ng/dl per pg/ml showed a sensitivity of 96.2% and specificity of 78.3% for PA screening. The newly developed CLEIAs for measuring PAC and ARC could provide a clinically powerful alternative to conventional methods used for hypertension screening in clinical practice.
Topics: Aldosterone; Essential Hypertension; Humans; Hyperaldosteronism; Hypertension; Radioimmunoassay; Renin
PubMed: 33564064
DOI: 10.1038/s41371-020-00465-5 -
Endocrinology and Metabolism (Seoul,... Apr 2021Serum calcitonin measurement contains various clinical and methodological aspects. Its reference level is wide and unclear despite sensitive calcitonin kits are...
BACKGROUND
Serum calcitonin measurement contains various clinical and methodological aspects. Its reference level is wide and unclear despite sensitive calcitonin kits are available. This study aimed to identify the specific reference range in the healthy Korean adults.
METHODS
Subjects were ≥20 years with available calcitonin (measured by a two-site immunoradiometric assay) data by a routine health checkup. Three groups were defined as all eligible subjects (group 1, n=10,566); subjects without self or family history of thyroid disease (group 2, n=5,152); and subjects without chronic kidney disease, autoimmune thyroid disease, medication of proton pump inhibitor/H2 blocker/steroid, or other malignancies (group 3, n=4,638).
RESULTS
This study included 6,341 male and 4,225 female subjects. Males had higher mean calcitonin than females (2.3 pg/mL vs. 1.9 pg/mL, P<0.001) in group 1. This gender difference remained similar in groups 2 and 3. Calcitonin according to age or body mass index was not significant in both genders. Higher calcitonin in smoking than nonsmoking men was observed but not in women. Sixty-nine subjects had calcitonin higher than the upper reference limit (10 pg/mL) and 64 of them had factors associated with hypercalcitoninemia besides medullary thyroid cancer. Our study suggests the reference intervals for men who were non, ex-, current smokers, and women (irrespective of smoking status) as <5.7, <7.1, <7.9, and <3.6 pg/mL, respectively.
CONCLUSION
Specific calcitonin reference range should be provided considering for sex and smoking status. Taking account for several factors known to induce hypercalcitoninemia can help interpret the gray zone of moderately elevated calcitonin.
Topics: Adult; Calcitonin; Carcinoma, Neuroendocrine; Female; Humans; Male; Reference Values; Republic of Korea; Thyroid Neoplasms
PubMed: 33823567
DOI: 10.3803/EnM.2020.939 -
Biochemical and Biophysical Research... May 2017Poly(ADP-ribose) polymerases (PARPs) use nicotinamide adenine dinucleotide (NAD) as a co-substrate to transfer ADP-ribose when it releases nicotinamide as the...
Poly(ADP-ribose) polymerases (PARPs) use nicotinamide adenine dinucleotide (NAD) as a co-substrate to transfer ADP-ribose when it releases nicotinamide as the metabolized product. Enzymes of the PARP family play key roles in detecting and repairing DNA, modifying chromatin, regulating transcription, controlling energy metabolism, and inducing cell death. PARP14, the original member of the PARP family, has been reported to be associated with the development of inflammatory diseases and various cancer types, making it a potential therapeutic target. In this study, we purified the macrodomain-containing PARP14 enzyme and established an assay for detecting the auto-ribosylation activity of PARP14 using RapidFire high-throughput mass spectrometry and immunoradiometric assay using [H]NAD. Subsequently, we performed high-throughput screening using the assays and identified small-molecule hit compounds, which showed NAD-competitive and PARP14-selective inhibitory activities. Co-crystal structures of PARP14 with certain hit compounds revealed that the inhibitors bind to the NAD-binding site. Finally, we confirmed that the hit compounds interacted with intracellular PARP14 by a cell-based protein stabilization assay. Thus, we successfully identified primary candidate compounds for further investigation.
Topics: Amino Acid Motifs; Binding Sites; Cloning, Molecular; Crystallography, X-Ray; Enzyme Inhibitors; Escherichia coli; Gene Expression; High-Throughput Screening Assays; Humans; Kinetics; Models, Molecular; Poly(ADP-ribose) Polymerases; Protein Binding; Protein Domains; Protein Structure, Secondary; Radioimmunoassay; Recombinant Proteins; Small Molecule Libraries; Thermodynamics
PubMed: 28315326
DOI: 10.1016/j.bbrc.2017.03.052 -
Prague Medical Report 2021Determination of renin plasma levels is useful in the diagnosis of hypertension and in the therapeutic follow-up of hypertensive patients. Plasmatic concentration of...
Determination of renin plasma levels is useful in the diagnosis of hypertension and in the therapeutic follow-up of hypertensive patients. Plasmatic concentration of renin decreases in patients with hypertension due to a primary hyperaldosteronism, contrary to renovascular hypertension where concentrations of renin and aldosterone are both elevated. Blood samples (serum, EDTA plasma) were analysed using two different chemiluminiscent methods CLIA LIAISON® and radioimmunoassay for aldosterone (IMMUNOTECH Beckman Coulter) and renin (Cisbio Bioassay) measurements were compared. We used both methods to ascertain the correlation between serum vs. EDTA plasma levels of aldosterone (RIA, CLIA) and renin (IRMA, CLIA) and to compare aldosterone to renin ratios for CLIA and for radioimmunoassay: serum aldosterone to plasma renin and plasma aldosterone to plasma renin. We compared serum aldosterone CLIA vs. RIA (rP=0.933, P<0.001) and plasma renin determined using CLIA vs. IRMA (rP=0.965, P=0.062). Furthermore, we used both methods to establish the correlation between the serum vs. plasma levels of aldosterone: RIA (rP=0.980, P<0.001); CLIA (rP=0.994, P=0.353) and serum vs. plasma levels of renin: IRMA (rP=0.948, P<0.001); CLIA (rP=0.921, P=0.011). Aldosterone (serum, plasma) to plasmatic renin ratios for CLIA (rP=0.999, P=0.286) and for radioimmunoassay (rP=0.992, P=0.025). Our data demonstrate that renin and aldosterone concentrations obtained using CLIA correlate with renin and aldosterone concentrations using radioimmunoassay methods. Correlation coefficients of pair results ranged from 0.921 to 0.994. Aldosterone (serum, EDTA plasma) to plasmatic renin ratios are comparable and any of them can be used with no significant differences found.
Topics: Aldosterone; Humans; Hyperaldosteronism; Luminescence; Radioimmunoassay; Renin
PubMed: 34137684
DOI: 10.14712/23362936.2021.9 -
International Journal of Endocrinology 2020. Parathyroid hormone (PTH) is a linear peptide constituted by 84 amino acids and active in its 1-84 form, but a wide range of PTH forms produced by its...
UNLABELLED
. Parathyroid hormone (PTH) is a linear peptide constituted by 84 amino acids and active in its 1-84 form, but a wide range of PTH forms produced by its post-transcriptional modifications are present in blood. Many assays with different specificities are commercially available. The aim of our study was to compare a 2 and 3 generation in healthy population in order to better define the reference range in the healthy population residing in our region. . 108 subjects (53 females and 55 males) referring to the transfusion donor were enrolled in the study centre in April 2016 and underwent PTH levels measurements with a 3 generation kit (chemiluminescent immunoassay DiaSorin Liaison) and with a 2 generation kit (immunoradiometric assay Total Intact PTH Assay (Coated Tube), Scantibodies). Also calcium, phosphate, creatinine, and 25OHD3 were measured. A questionnaire on lifestyle and dietary habits was obtained.
RESULTS
The median PTH values obtained with the 2 generation assay and the whole 3 generation assay were 20.26 pg/ml and 23.11 pg/ml, respectively. Bland-Altman method showed substantial concordance between the two PTH assays, although with an overestimation of the 3 generation method over the 2 generation method. There was no correlation between 3 generation PTH and 25OHD3 and creatinine. Calcium was negatively correlated with PTH only when measured with 3 generation kit.
CONCLUSIONS
On the basis of our data, obtained from healthy subjects, we can conclude that the reference range used by our laboratory was too narrow and was necessary to reestablish normal ranges according to our population. This is useful to avoid hyperparathyroidism misdiagnosis.
PubMed: 32148482
DOI: 10.1155/2020/1053719