Influence of the background activity region selection on the measurement of glomerular filtration rate using the Gates method

Background/Aim. The most frequent method for the assessment of glomerular filtration rate GFR) in clinical practice is clearance of creatinine, clearance of chromium-51 radiolabelled ethylene diamine tetraacetic acid (51Cr-EDTA) and clearance of technetium-99m radiolabelled diethylene triamine pentaacetic acid (99mTc-DTPA). The Gates method for glomerular filtration rate assessment is based on distribution of 99mTc-DTPA in the kidney 2-3 minute after its applying. Calculation of GFR is corrected for the background and depth of the kidney and finally expressed as a percentage of the net injected counts. This value of GFR highly correlates with biexponential model as the most accurate method for the assessment of GFR. The aim of this study was to determine the influence of different background sites on GFR rate assessment using the Gates method. Methods. We analysed 50 patients who were divided into two groups: the group of healthy subjects (21 subjects, mean age 47.38 yrs) and the group of subjects with unilateral kidney damage (29 subjects, mean age 39.79 yrs). Three different background activity regions were chosen: a region drawn below the lower pole of each kidney, region drawn by the lateral side of each kidney and region drawn around the whole kidney. Results. Gromerular filtration rate calculated by the use of a region under the lower pole is statistically significantly higher than GFR calculated using a region by the lateral side and around the whole kidney (p < 0.0001). Glomerular filtration rate calculated using the region by the lateral side and region around the whole kidney did not show statistically significant difference (p > 0.05). Conclusion. The selection of background activity region has a significant influence on GFR rate measured by the Gates method. It is recommended to use only one method for choosing the region of background activity.

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Measurement of Glomerular Filtration Rate by Impulse Synthesis: Clinical Validation and Optimization

Nuklearmedizin ◽

10.1055/s-0038-1629446 ◽

1988 ◽

Vol 27 (04) ◽

pp. 147-150

Author(s):

B. Palagi ◽

F. Villa ◽

P. Verga ◽

Angela Broggi ◽

F. Guzzini ◽

...

Keyword(s):

Renal Failure ◽

Glomerular Filtration Rate ◽

Glomerular Filtration ◽

Filtration Rate ◽

The Other ◽

Time Interval ◽

Severe Renal Failure ◽

Other Hand ◽

Significant Difference ◽

51Cr Edta

Impulse synthesis is a technique which relies upon the logic of continuous infusion but extracts the clearance value from single-injection data by shifting and adding them until an asymptotic value is attained. This study has been aimed at validating and optimizing clinically the measurement of glomerular filtration rate by impulse synthesis. A single intravenous injection of 51Cr-EDTA has been made in 32 patients and plasma activity monitored over the next 6 h. Glomerular filtration rate computed by a single-exponential fit method (GFR- SEF) has been shown to be significantly (p <0.001) overestimated when compared with the glomerular filtration rate obtained by the impulse synthesis technique (GFR-IS) in spite of an excellent (r = 0.989) linear correlation between the two sets of data. On the other hand, the comparison between GFR-IS and 24-h creatinine clearance has not shown any significant difference. Moreover, we have found that in patients with severe renal failure GFR-IS is overestimated when the sampling time span is shortened to 3 h. On the other hand, GFR-IS is slightly underestimated in patients with severe renal failure when the convolution time interval is increased over a few minutes.

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Serum Cystatin C as a Potential Marker for Glomerular Filtration Rate in Patients with Cholangiocarcinoma

International Journal of Hematology-Oncology and Stem Cell Research ◽

10.18502/ijhoscr.v14i3.3723 ◽

2020 ◽

Author(s):

Mang Ngaih Ciin ◽

Tanakorn Proungvitaya ◽

Temduang Limpaiboon ◽

Sittiruk Roytrakul ◽

...

Keyword(s):

Glomerular Filtration Rate ◽

Glomerular Filtration ◽

Cystatin C ◽

Filtration Rate ◽

High Sensitivity ◽

Fundamental Aspect ◽

Serum Cystatin C ◽

Term Survival ◽

Serum Cystatin ◽

Significant Difference

Background: Cholangiocarcinoma (CCA) is the second most common primary hepatobiliary cancer. These patients have meager prognosis and short-term survival. Precise assessment of glomerular filtration rate is a fundamental aspect of clinical care in cancer patients. Cystatin C has been proposed to be superior to creatinine, a well-known marker of renal function. This study aimed to evaluate cystatin C as a marker of GFR calculation in CCA patients. Materials and Methods: One hundred thirty serum samples from CCA patients and 32 from controls were included in this study. Serum cystatin C was measured using immunoturbidity assay. Estimated glomerular filtration rate was calculated by three equations established by chronic kidney disease epidemiology collaboration (based on creatinine and/or cystatin C). Results: Serum cystatin C in CCA patients was higher than that of controls (p=0.0002). Cystatin C was positively correlated with BUN in CCA group (p=0.019). eGFR based on cystatin C and based on both cystatin C and creatinine in CCA was low with significantly different from those of control (p<0.001). Although there was no difference in eGFR using three equations in control, creatinine based eGFR was high with significantly different from eGFR based on cystatin C and on both creatinine and cystatin C in CCA (P=0.000). Proportion in each eGFR stage by three equations showed a high sensitivity with significantly different in CCA (p<0.05). Conclusion: There was a high sensitivity of cys C with significant difference between creatinine and/or cystatin C based eGFR in CCA patients. It should be taken into consideration of mild changes in eGFR by cystatin C which is important in managing drug dosage for CCA patients.

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Renal function, complications, and outcomes of a reduction in tumor size after transarterial embolization for renal angiomyolipomas: a meta-analysis

Journal of International Medical Research ◽

10.1177/0300060519834447 ◽

2019 ◽

Vol 47 (4) ◽

pp. 1417-1428

Author(s):

Letao Lin ◽

Xinfei Li ◽

Haitao Guan ◽

Jian Wang ◽

Xiaoqiang Tong ◽

...

Keyword(s):

Renal Function ◽

Glomerular Filtration Rate ◽

Glomerular Filtration ◽

Tumor Size ◽

Filtration Rate ◽

Estimated Glomerular Filtration Rate ◽

Meta Analysis ◽

Transarterial Embolization ◽

Nitrogen Levels ◽

Significant Difference

Objective The present study aimed to evaluate renal function, complications, and changes in tumor size after transarterial embolization for patients with renal angiomyolipomas. Methods We performed a meta-analysis of transarterial embolization in patients with renal angiomyolipomas from January 1994 to April 2018. Endpoints of interest were the estimated glomerular filtration rate, serum creatinine levels, blood urea nitrogen levels, complications, and reduction of tumors. Results A total of 30 studies comprising 653 patients were included. A total of 32.0% of patients were treated by urgent transarterial embolization for spontaneous ruptured renal angiomyolipomas. Other patients sought to relieve symptoms or received embolism prophylactically. The estimated glomerular filtration rate showed no significant difference between before and after embolization. In 363 patients with data on complications, post-embolization syndrome occurred most frequently (54.0%). Only 16 (4.4%) patients had major complications. The diameter of sporadic angiomyolipomas was reduced by a mean of 2.09 cm (95% confidence interval [CI], 0.73–3.45 cm; I2 = 29.3%) and they were reduced in size by 30.0% (95% CI, 16.0%–44.0%; I2 = 27.9%). Conclusions Transarterial embolization of renal angiomyolipomas affects renal function preservation, with a low complication rate. Transarterial embolization is useful for sporadic and tuberous sclerosis complex-related angiomyolipomas.

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P1718COMPARISON OF MEASURED GLOMERULAR FILTRATION RATE USING 24-HOUR URINE CREATININE CLEARANCE WITH 51-CHROMIUM EDTA IN A MALAYSIAN COHORT OF LIVING KIDNEY DONOR CANDIDATES

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfaa142.p1718 ◽

2020 ◽

Vol 35 (Supplement_3) ◽

Author(s):

Chee Keong Thye ◽

Yee Wan Lee ◽

Maisarah Jalalonmuhali ◽

Soo Kun Lim ◽

Kok Peng Ng

Keyword(s):

Glomerular Filtration Rate ◽

Creatinine Clearance ◽

Glomerular Filtration ◽

Filtration Rate ◽

Urine Volume ◽

Kidney Donor ◽

Living Kidney Donor ◽

Kidney Donors ◽

Living Kidney Donors ◽

51Cr Edta

Abstract Background and Aims All living kidney donors undergo assessment of renal function by evaluation of Glomerular Filtration Rate (GFR). 51Cr-EDTA is one of the most widely used marker for measuring GFR but it is hampered by cost and laboriousness as well as not being widely available in Malaysia. Measuring 24-hour urine for creatinine clearance (Ccr) is a common alternative when exogenous filtration markers are not available. Ccr suffers from over/underestimation of measured GFR (mGFR) due to errors in urine collection and tubular secretion of creatinine. This is a study to compare the correlation of Ccr against 51Cr-EDTA in measuring GFR among the living donors in Malaysian population. Method This is a cross-sectional, single-centre study of a cohort of living kidney donor candidates from January 2007 to March 2019. All candidates who had mGFR done with both 51Cr-EDTA and Ccr in University Malaya Medical Centre were enrolled. Special consideration was taken to account for adequate urine sampling for Ccr. Clinical data was analysed for correlation, bias, precision and accuracy between Ccr and 51Cr-EDTA. Results A total of 83 living kidney donors with a mean age of 45.60 ± 11.06 years and body mass index (BMI) of 24.36 ± 4.03 were enrolled. Female comprised 74.7% of the donors while Chinese, Malay and Indian accounted for 67.5%, 20.5% and 7.2% of the donors respectively. The study group had a mean serum creatinine of 63.37 ± 16.00 umol/L with a urine volume of 2.03 ± 0.81 L (range 0.70 – 3.82). mGFR from 51Cr-EDTA was 125.56 ± 27.64 ml/min/1.73m2 (range 77.0 – 194.3) whereas calculated Ccr was 136.05 ± 36.15 ml/min/1.73m2 (range 75.32 – 280.06). The correlation coefficient between Ccr and 51Cr-EDTA is moderate (r = 0.43) (p < 0.01). Mean absolute bias between Ccr and 51Cr-EDTA was 10.59 ± 37.99 ml/min/1.73m2 (p < 0.05). The accuracy of Ccr within 30% of 51Cr-EDTA was 77.11%. Conclusion Our study showed that Ccr significantly overestimates mGFR compared to 51Cr-EDTA. However, there is a significantly moderate positive correlation between Ccr and 51Cr-EDTA. Thus, in the absence of 51Cr-EDTA, Ccr is a clinically acceptable alternative if utilized with care and understanding its limitations.

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