scholarly journals Assessment of Agreement between Gates Method and Dual Plasma Sample Method for Measurement of Glomerular Filtration Rate

2018 ◽  
Vol 20 (1) ◽  
pp. 19
Author(s):  
Pupree Mutsuddy ◽  
Mohammad Anwar Ul Azim ◽  
Shamim MF Begum ◽  
Raihan Hussain ◽  
Sharmin Farhana ◽  
...  

<p><strong>Objectives:</strong> Glomerular filtration rate (GFR) is generally considered to be the best index of renal function in both healthy and diseased kidneys. Calculation of GFR plays a vital role in the management of patients having renal diseases. Clinicians can make their final decision regarding the potential need for kidney transplantation and also selection of a potential kidney donor. Many methods have been developed in order to obtain more accurate GFR values. The most popular radionuclide method is camera based Gates method using 99mTc DTPA (Diethylene triaminepentaacetic acid). This method can provide immediate calculation of individual kidney function as well as of global renal function. But several sources of errors may reduce the reliability of this method. Measurement of multiple blood samples offers almost real values of GFR, which have become the gold standard in clinical research. The aim of this research work was to study the agreement between Gates method and dual plasma sample method for measurement of GFR.</p><p><strong>Patients and methods:</strong> This cross sectional study was carried out in National Institute of Nuclear Medicine &amp; Allied Sciences (NINMAS), during July 2015 to June 2016. A total of 59 patients were included in this study. GFR was estimated by both the camera based Gates method and dual plasma sample method (DPSM).Statistical analyses were carried out by using the Statistical Package for Social Sciences version 20.0 for Windows (SPSS Inc., Chicago, Illinois, USA). The mean values were calculated for continuous variables. Categorical data were expressed in percentage and number. Pearson correlation and Bland &amp; Altman (B &amp; A) analyses were applied for assessing correlation and agreement between Gates method and DPSM. Degree of relation between the variables is expressed by r (Pearson’s correlation coefficient).</p><p><strong>Results:</strong> The mean GFR evaluated by Gates method was found 82.2 ± 27.4 mL/min/1.73m<sup>2</sup> and mean GFR by DPSM was found 82.8 ± 24.1 mL/min/1.73m<sup>2</sup>. A strong positive correlation (r = 0.833; p = 0.001) was found between the GFR values measured by Gates method and DPSM. With Bland and Altman analysis, it was observed that mean difference of GFR measured by Gates method and DPSM was – 0.6 ± 15.22 mL/min/1.73m<sup>2</sup>. The limit of agreement ranged from – 30.44 mL/min/1.73m<sup>2</sup> to 29.24 mL/min/1.73m<sup>2</sup>.</p><p><strong>Conclusion:</strong> There was strong positive correlation between Gates method and DPSM for measurement of GFR. Mean difference between the methods was small. The bias between the methods was considered not significant. The differences within mean ± 1.96 SD are not clinically important. Hence Gates method and DPSM can reflect GFR almost equally and can be used interchangeably.</p><p>Bangladesh J. Nuclear Med. 20(1): 19-23, January 2017</p>

2019 ◽  
Vol 22 (1) ◽  
pp. 36-40
Author(s):  
Suraya Sarmin ◽  
Sadia Sultana ◽  
Madhuchhanda Hazra Mou ◽  
Naheed Khan ◽  
Pupree Mutsuddy ◽  
...  

Objectives: Glomerular Filtration Rate (GFR) is an important parameter of kidney function. Many methods are used to measure GFR namely: inulin clearance, double plasma sample method (DPSM), Gates’ method, and equation based method. DPSM has become the gold standard in clinical research. Gates’ method is routinely practiced at National Institute of Nuclear Medicine and Allied Sciences. Chronic kidney disease epidemiology collaboration (CKD-EPI ) equation is encouraged as it is simple and reliable. The aim of the study was assesment of agreement between Gates’ method and CKD-EPI equation with plasma sample method for estimation of GFR. Patients and methods: This cross sectional observational study was carried out at NINMAS, during July 2017 to June 2018. A total of 70 subjects referred for 99mTC-DTPA renography along with GFR estimation, were included in this study. Result: The mean GFR value evaluated by DPSM, Gates’ and CKD-EPI  equation were, 81.86 ± 22.42, 86.13 ± 26.70 and 78.48 ± 23.87 mL/min/1.73 m2 respectively. A strong positive correlation (r = 0.922) was found between DPSM and Gates’ method and also between DPSM and CKD-EPI equation (r= 0.930). The Gates’ and CKD-EPI equation also showed strong positive correlation (r = 0.872). The mean difference between DPSM and Gates’, between DPSM and CKD-EPI equation,  between Gates’ and CKD-EPI equation were 4.26 ± 10.45, 3.38 ± 8.78  and  7.64 ± 13.09 mL/min/1.73 m2 respectively. Conclusion: Strong positive correlation and excellent agreement were observed between DPSM and Gates’ and also between DPSM and CKD-EPI equation. Strong correlation was also found in between Gates’ and CKD-EPI equation. So, DPSM, Gates’ method and CKD-EPI equation can reflect GFR almost equally and used interchangeably. Bangladesh J. Nuclear Med. 22(1): 36-40, Jan 2019  


1993 ◽  
Vol 85 (6) ◽  
pp. 733-736 ◽  
Author(s):  
R. Rustom ◽  
J. S. Grime ◽  
P. Maltby ◽  
H. R. Stockdale ◽  
M. J. Jackson ◽  
...  

1. The new method developed to measure renal tubular degradation of small filtered proteins in patients with normal renal function, using radio-labelled aprotinin (Trasylol) (R. Rustom, J. S. Grime, P. Maltby, H. R. Stockdale, M. Critchley, J. M. Bone. Clin Sci 1992; 83, 289–94), was evaluated in patients with chronic renal failure. 2. Aprotinin was labelled with either 99mTc (40 MBq) or 131I (0.1 MBq), and injected intravenously in nine patients, with different renal pathologies. 51Cr-EDTA clearance (corrected for height and weight) was 40 + 5.4 (range 11.2-81) ml min−1 1.73 m−2. Activity in plasma and urine was measured over 24–48 h, and chromatography on Sephadex-G-25-M was used to separate labelled aprotinin from free 99mTcO4− or 131I−. Renal uptake was measured for 99mTc-labelled aprotinin only. 3. The volume of distribution was 20.2 + 2.3 litres. Chromatography showed all plasma activity as undegraded aprotinin, and urine activity only as the free labels (99mTcO4− or 131I−). 4. As in patients with normal renal function, activity in the kidney appeared promptly, with 5.7 + 2.5% of the dose detected even at 5 min. Activity rose rapidly to 9.4 + 1.6% of dose after 1.5 h, then more slowly to 15.0 + 0.5% of dose at 4.5 h, and even more slowly thereafter, reaching 24.1 + 2.8% of dose at 24 h. Extra-renal uptake was again insignificant, and both 99mTcO4− and 131I− appeared promptly in the urine, with similar and uniform rates of excretion over 24 h. 5. Both tubular uptake at 24 h and the rate of tubular metabolism over 24 h were lower than in the patients with normal renal function studied previously, but only the rate of tubular metabolism was directly related to the glomerular filtration rate (r = 0.75, P <0.02). 6. Correction for the reduced glomerular filtration rate yielded values for both tubular uptake (0.67 + 0.14 versus 0.32 + 0.03% of dose/ml of glomerular filtration rate, P <0.005), and tubular metabolism (0.033 + 0.07 versus 0.015 + 0.001% of dose h−1 ml−1 of glomerular filtration rate, P <0.005) that were higher by comparison with those for patients with normal renal function studied previously. 7. Fractional renal degradation of 99mTc-aprotinin (in h−1), derived from the mean rate of urinary excretion of the free isotope over a given interval, divided by the mean cumulative kidney uptake over the same interval, also fell steeply early, and then more slowly to 0.07 + 0.01 h−1 at 14.25 h (between 4.5 and 24 h). 8. It is concluded that the method described previously is also suitable in patients with chronic renal failure, allowing further research into renal disease progression.


Author(s):  
V. E. Syutkin ◽  
A. A. Salienko ◽  
S. V. Zhuravel ◽  
M. S. Novruzbekov

Objective: to compare changes in estimated glomerular filtration rate (eGFR) in liver recipients with initially normal and impaired eGFR within the first year after immunosuppression conversion.Materials and methods. Enrolled in the study were 215 recipients of deceased-donor livers from February 2009 to February 2020, who received everolimus with dose reduction or complete withdrawal of calcineurin inhibitors (immunosuppression conversion, ISxC) for varying periods of time. GFR was measured using the MDRD-4 formula immediately before ISxC, then 3, 6, and 12 months after orthotopic liver transplantation (LTx). One month was considered an acceptable temporary deviation from the corresponding point.Results. At the time of ISxC, 32 (15%) of 215 recipients had normal renal function. Chronic kidney disease (CKD) increased in 60% of the recipients with normal eGFR by the end of the first year following ISxC; the fall in eGFR was particularly pronounced in older recipients. In the group with a baseline eGFR of 60–89 mL/min/1.73 m2, eGFR normalized in 62% of cases within 12 months; 28% of cases had no changes in renal function. In the subgroup with a pronounced decrease in eGFR at the time of ISxC, increased eGFR was observed as early as 1 month after ISxC, and the maximum was recorded after 3–6 months. The mean eGFR relative to baseline by month 3 after eGFR were higher for ISxC that was done in the first 2 months after LTx (19.7 ± 15.7 ml/minute/1.73 m2) than for ISxC done in the long-term period after LTx (10.1 ± 8.7 ml/minute/1.73 m2, p < 0.05).Conclusion. Changes in eGFR in liver recipients receiving EVR plus low-dose calcineurin inhibitor (CNI) depend on baseline eGFR and are multidirectional. The use of ISxC in the early post-LTx period led to a more pronounced improvement in eGFR. Maximal changes in eGFR were observed by 3–6 months after ISxC.


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