A novel assay for serum creatinine using a creatine kinase cycling reaction

2021 ◽  
Author(s):  
Shigeru Ueda ◽  
Shin-ichi Sakasegawa
Keyword(s):  
Creatine Kinase ◽  
Serum Creatinine ◽  
Reference Interval ◽  
Comparison Study ◽  
Enzymatic Method ◽  
Reliable Measurement ◽  
Enzymatic Cycling ◽  
Accuracy And Precision ◽  
Low Levels ◽  
Effective Sensitivity

Abstract For assaying serum creatinine, the enzymatic method is regarded as accurate. However, reliable measurement of low levels is problematic. We have developed a new method that utilizes an enzymatic cycling reaction involving creatine kinase (CK) in the presence of excess ATP and IDP and implicated the application to serum creatinine assay incorporating with creatininase. Here, we evaluated applying the CK cycling method to a serum creatinine assay. In this study, we focused on assessing whether an accurate measurement could be achieved, especially in the reference interval and the lower concentration range. The effective sensitivity of the assay using 30 U/mL CK was approximately 4-fold greater than that of a commercial reagent. Under these conditions, .19 mg/dL of creatinine was accurately detected. The correlation coefficient of the comparison study with an existing commercial reagent was .995. Moreover, the effect of the increased signal intensity on accuracy and precision was assured.

Creatine measurement in serum and urine with an automated enzymatic method

1993 ◽  
Vol 39 (8) ◽  
pp. 1613-1619 ◽  
Author(s):  
C Beyer
Keyword(s):  
Creatine Kinase ◽  
Lactate Dehydrogenase ◽  
Pyruvate Kinase ◽  
Present Method ◽  
Comparative Method ◽  
Reference Interval ◽  
Enzymatic Method ◽  
Men And Women ◽  
Enzymatic Procedure ◽  
Serum And Urine

Abstract I describe an automated enzymatic procedure to quantitate creatine in both serum and urine. In this assay, which requires no pretreatment of the sample, creatine kinase (CK; EC 2.7.3.2) and pyruvate kinase (EC 2.1.7.40) are used as auxiliary enzymes and lactate dehydrogenase (EC 1.1.1.27) is used in the indicator reaction. CK is also used as the starting reagent. Data obtained with the present method for creatine measurement in serum were compared with those from the Jaffé method and an enzymatic method: y = 1.13x - 7.58, SE = 4.48, and r = 0.925 (Jaffé); and y = 1.17x + 2.73, SE = 5.06, and r = 0.962 (enzymatic); for creatine measurement in urine: y = 0.63x + 39.74, SE = 296.7 and r = 0.719 (Jaffé). The present method provides improved precision: the total CVs for serum, determined by the present and comparative methods, respectively, were 3.5-8.9%, 8.2-43.0%, and 5.3-16%; for urine, the CVs were 3.3-5.1% and 9.6-21.2% for the present and comparative method, respectively. I established the normal reference interval as 13-74 and 13-89 mumol/L for creatine in serum, and as 175-700 and 150-1200 mumol/24 h for creatine in urine for men and women, respectively.

Are the currently used reference intervals for creatine kinase (CK) reflecting the general population? The Tromsø Study

2012 ◽  
Vol 50 (5) ◽  
Author(s):  
Hallvard Lilleng ◽  
Stein Harald Johnsen ◽  
Tom Wilsgaard ◽  
Svein Ivar Bekkelund
Keyword(s):  
Creatine Kinase ◽  
General Population ◽  
Reference Interval ◽  
Reference Intervals ◽  
Control Analysis ◽  
Age Group ◽  
Background Population ◽  
Norwegian Population ◽  
Reference Limits ◽  
Laboratory Reference

AbstractLaboratory reference intervals are not necessarily reflecting the range in the background population. This study compared creatine kinase (CK) reference intervals calculated from a large sample from a Norwegian population with those elaborated by the Nordic Reference Interval Project (NORIP). It also assessed the pattern of CK-normalization after standardized control analyses.New upper reference limits (URL) CK values were calculated after exclusion of individuals with risk of hyperCKemia and including individuals with incidentally detected hyperCKemia after they had completed a standardized control analysis. After exclusion of 5924 individuals with possible causes of hyperCKemia, CK samples were analyzed in 6904 individuals participating in the 6th survey of The Tromsø Study. URL was defined as the 97.5 percentile.New URL in women was 207 U/L. In men <50 years it was 395 U/L and in men ≥50 years 340 U/L. In individuals with elevated CK, normalization grade after control analysis was inversely correlated to the CK level (p<0.04).URL CK values in women and in men <50 years of age were in accordance with URL CK values given by the NORIP. In men ≥50 years, a higher URL was found and the findings suggest an upward adjustment of URL in this age group.

scholarly journals Clinical relevance of glomerular IgM deposition in patients with lupus nephritis

2021 ◽  
Author(s):  
Fengmei Wang ◽  
Jirong Yu ◽  
Lei zhang ◽  
Yan Zhang ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Lupus Nephritis ◽  
Serum Creatinine ◽  
Plasma Levels ◽  
Clinical Relevance ◽  
Alternative Pathway ◽  
Clinicopathological Parameters ◽  
Low Density ◽  
Lower Plasma ◽  
Low Levels

Abstract Background The aim of the study was to investigate the clinical relevance of IgM deposition in patients with LN in a large cohort. Results 217 patients with renal biopsy–proven lupus nephritis were enrolled. The associations between glomerular IgM deposition and clinicopathological parameters were further analyzed. IgM deposition was positively correlated with glomerular C1q and C3 deposition moderately (r = 0.436, P < 0.001; r = 0.408, P < 0.001, respectively), and inversely correlated with plasma levels of C3 and CFH mildly (r=-0.138, P = 0.043; r=-0.147, P = 0.037, respectively). By multivariate analysis, we found that glomerular IgM deposition independently contributes to glomerular C3 deposition in patients with lupus nephritis (OR = 2.002, 95% CI: 1.295–3.094, P = 0.002). In addition, we also found that patients with IgM 0+-2 + had similar plasma CFH levels, but in patients with IgM3+-4+, plasma CFH levels were significantly lower (300.4 ± 155.8µg/ml vs. 429.9 ± 187.5µg/ml, P < 0.001). Furthermore, patients with high density of glomerular IgM and low levels of CFH had heavier proteinuria, higher serum creatinine and lower plasma C3 levels (5.7 ± 3.1g/d vs. 4.7 ± 3.5g/d, P = 0.037;150.1 ± 121.0µmol/L vs. 105.6 ± 97.1µmol/L, P = 0.005; 0.3 ± 0.2µg/L vs. 0.4 ± 0.2µg/L, P = 0.04, respectively), comparing with those with low density of glomerular IgM and low levels of CFH. Conclusions Our results suggested IgM might bind to injury-associated epitopes and be involved in disease progression and provided a possible relevance of CFH and IgM in the process of alternative pathway (AP) activation.

scholarly journals GAMBARAN KADAR KREATININ SERUM PADA PENDERITA DIABETES MELLITUS TIPE 2 DI RUMAH SAKIT UMUM PUSAT SANGLAH DENPASAR

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Ida Arjani
Keyword(s):  
Diabetes Mellitus ◽  
Renal Function ◽  
Serum Creatinine ◽  
Analytical Study ◽  
Sampling Methods ◽  
Chronic Complications ◽  
Low Levels ◽  
End Stage ◽  
Dm Type 2

ABSTRACTBackground Diabetes mellitus (DM) is a metabolic disease which characterized by hyperglycemia due to abnormalities insulin secretions, insulin performance, or both of them. The condition of insulin resistance in DM type 2 causes chronic complications such as diabetic nephropathy. It has become the second leading cause of end-stage kidney disease, and one of the most common and demaging complication of diabetes. The level of creatinine in blood is one of the parameters used to assess renal function, as in the plasma concentration and excretion in the urine within 24 hours. Serum creatinine levels greater than the normal value suggests an impaired renal function. Objective The purpose of this study was to determine serum creatinine levels in patients with DM type 2 in Sanglah General Hospital Denpasar. Methods The method uses an analytical study with description, used accidental sampling methods, involving 30 patients with DM type 2. Blood samples were analyzed for creatinine levels and data are presented as table. The reslts  of this study showed that 60% samples had high levels of serum creatinine, 30% samples had normal levels serum creatinine, and 10% samples had low levels serum creatinine. From the result was concluded, most patients with DM type 2 in Sanglah Genaral Hospital have highly serum creatinine levels.                                                        Keywords: creatinine serum, DM type 2

An Evaluation of the Greiner Selective Analyzer and its Role in the Clinical Laboratory

1975 ◽  
Vol 12 (1-6) ◽  
pp. 182-191 ◽  
Author(s):  
Andrew G. Skinner ◽  
Peter Wilding
Keyword(s):  
Alkaline Phosphatase ◽  
Serum Creatinine ◽  
Total Protein ◽  
Total Bilirubin ◽  
Clinical Laboratory ◽  
Comparison Of Results ◽  
Operation Temperature ◽  
Accuracy And Precision ◽  
Analytical Range

The Greiner Selective Analyzer (GSA II) was evaluated over a period of six months. The evaluation assessed the reliability, accuracy, and precision of the analyser for six determinations. The methods evaluated were for glucose, urea, creatinine, total protein, total bilirubin, and alkaline phosphatase. Comparison of results was also made with those obtained for the same specimens using the Technicon SMA 12/60 Analyzer. Correlation and comparison of results indicate that the Greiner Selective Analyzer performed better for three of the methods but worse for serum creatinine determination. The role of the analyser as a routine tool in the clinical laboratory was also evaluated during analyses of approximately 900 patient specimens. Other features evaluated were analytical range of the six methods under study, the economics of operation, temperature control, and electrical and mechanical safety.

scholarly journals LC-MS/MS Method for Serum Creatinine: Comparison with Enzymatic Method and Jaffe Method

PLoS ONE ◽  
2015 ◽  
Vol 10 (7) ◽  
pp. e0133912 ◽  
Author(s):  
Meixian Ou ◽  
Yunxiao Song ◽  
Shuijun Li ◽  
Gangyi Liu ◽  
Jingying Jia ◽  
...  
Keyword(s):  
Serum Creatinine ◽  
Enzymatic Method

Misleading normal TSH and persistently elevated creatine kinase: clues to the diagnosis of chronic Sheehan’s syndrome

2021 ◽  
Vol 14 (8) ◽  
pp. e243992
Author(s):  
Ayşe Y Demir ◽  
Christine P Oldenburg-Ligtenberg ◽  
Bianca Loredana Toma-Stan ◽  
Albert van de Wiel
Keyword(s):  
Creatine Kinase ◽  
Postpartum Haemorrhage ◽  
Hormone Replacement ◽  
Sella Turcica ◽  
Reference Interval ◽  
Thyroid Stimulating Hormone ◽  
Empty Sella ◽  
Sheehan’S Syndrome ◽  
Elevated Creatine Kinase ◽  
Sheehan's Syndrome

A 53-year-old woman was referred for medical evaluation of therapy-resistant dyslipidaemia accompanied by elevated creatine kinase levels. Because cessation or alteration of her medication did not improve laboratory abnormalities, hypothyroidism was considered, despite the fact that thyroid stimulating hormone levels were within the reference interval. On further evaluation, she was found to have panhypopituitarism and empty sella turcica as shown by MRI. These findings were unexpected since there was no clinical suspicion during detailed evaluation. When supplementary questions were asked, she brought up a history of severe postpartum haemorrhage 30 years ago, for which she underwent a hysterectomy. Based on these findings, the patient was diagnosed with Sheehan’s syndrome. This syndrome is a rare but potentially life-threatening complication of postpartum haemorrhage, characterised by varying degrees of hypopituitarism that are most commonly presented many years after delivery. The patient recovered after adequate hormone replacement therapy.

Kinetic Enzymatic Method for Determining Serum Creatinine

1975 ◽  
Vol 21 (10) ◽  
pp. 1422-1426 ◽  
Author(s):  
Gerald A Moss ◽  
Richard J L Bondar ◽  
Diane M Buzzelli
Keyword(s):  
Serum Creatinine ◽  
Accurate Determination ◽  
Test Subject ◽  
Rate Of Change ◽  
Enzymatic Method ◽  
Inhibitory Effects ◽  
Standard Curve ◽  
Analytical Recovery ◽  
Enzymatic Procedure

Abstract Creatinine amidohydrolase is used to measure serum creatinine in a totally enzymatic procedure. Creatine, produced by hydrolysis, is acted upon by creatine kinase, and then by pyruvate kinase and lactate dehydrogenase, to result in a change in absorbance at 340 nm. The amount of creatinine present is related to the rate of change in A340 and is determined from a standard curve. Absorbance and concentration are linearly related to 100 mg/liter and only 250 µl of serum is required. At 1.0 g/liter, heparin, oxalate, citrate, ethylenediaminetetraacetate, ascorbate, or glucose had no significant effect on the accurate determination of creatinine; higher concentrations (30 g/liter) had inhibitory effects on the test. Analytical recovery of creatinine added to either normal or abnormal sera averaged 102%. When results of this procedure and of the standard direct Jaffé test were compared, the latter were significantly higher. Unlike the Jaffé method, the present method of determining creatinine is rapid (about 10 min per test), subject to few or no interfering substances, and requires no serum deproteinization.

scholarly journals Highly Sensitive Cholesterol Assay with Enzymatic Cycling Applied to Measurement of Remnant Lipoprotein-Cholesterol in Serum

2002 ◽  
Vol 48 (5) ◽  
pp. 737-741 ◽  
Author(s):  
Koji Kishi ◽  
Koji Ochiai ◽  
Yohsuke Ohta ◽  
Yahiro Uemura ◽  
Kazushi Kanatani ◽  
...  
Keyword(s):  
Cholesterol Oxidase ◽  
Lipoprotein Cholesterol ◽  
Cholesterol Concentration ◽  
Separation Procedure ◽  
Enzymatic Method ◽  
Healthy Individuals ◽  
Apo B ◽  
Remnant Lipoprotein ◽  
Enzymatic Cycling ◽  
Highly Sensitive

Abstract Background: Remnant lipoprotein-cholesterol (RLP-C) concentrations in sera of healthy individuals are very low (0.080–0.437 mmol/L), making conventional cholesterol methods poorly suited to this purpose. We have developed a highly sensitive cholesterol assay (CD method) and applied it to the RLP-C assay. Methods: The CD shuttled cholesterol reversibly between reduced and oxidized forms in the presence of thio-NAD and NADH. The production rate of thio-NADH correlated with the cholesterol concentration and was measured by the absorbance at 404/500 nm. This CD method was combined with an immunoaffinity separation procedure with specific monoclonal antibodies to apolipoprotein (apo) A1 and apo B-100 and used for RLP-C assay. Results were compared with a RLP-C method that uses cholesterol oxidase, peroxidase, and chromogenic substrate. Results: The CD method could detect 0.10 × 10−3 mmol/L cholesterol and was at least 5 times more sensitive than the conventional enzymatic method. Within- and between-day imprecision (as CVs) of the RLP-C assay with the CD method was &lt;4%. Regression analysis of RLP-C assays with the new (y) and conventional (x) cholesterol methods yielded: y = 1.02x − 0.008 mmol/L (Sy|x = 0.0065 mmol/L; r = 0.997; n = 297). Conclusions: Serum RLP-C can be measured by the CD method. The CD method may be useful for other assays that require sensitive cholesterol measurements in biological materials.

scholarly journals Effect of Various Diluents on the Activity of Several Enzymes Present in Serum

1973 ◽  
Vol 19 (9) ◽  
pp. 1079-1080
Author(s):  
Ted W Fendley ◽  
Jane M Hochholzer ◽  
Christopher S Frings
Keyword(s):  
Alkaline Phosphatase ◽  
Creatine Kinase ◽  
Enzyme Activity ◽  
Lactate Dehydrogenase ◽  
Confidence Level ◽  
Aspartate Aminotransferase ◽  
Nacl Solution ◽  
Manual Method ◽  
Accuracy And Precision ◽  
Significant Difference

Abstract We have evaluated the effect of diluting serum with water or NaCl solution (8.5 or 9.0 g/liter) before assaying by a manual method for creatine kinase (EC 2.7.3.2), alkaline phosphatase (EC 3.1.3.1), lactate dehydrogenase (EC 1.1.1.27), and aspartate aminotransferase (EC 2.6.1.1) activity. The t test and the F test show no significant difference in the accuracy and precision of the assays at the 95% confidence level when 100 different samples were compared for each enzyme activity after use of the three diluents.

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