Correlation of the Glomerular Filtration Rate Measured With the Use of DTPA-Tc99m in Live Kidney Donors With Equations Based on Creatinine and Cystatin C

BACKGROUND

Renal donation leads to a risk of developing chronic kidney disease, with an incidence of 0.47%. To evaluate for its presence, formulas based on serum creatinine are used, but up to 80% of these formulas underestimate the glomerular filtration rate (GFR) in donors. The aim of this work was to confirm the highest correlation of the GFR as measured with the use of DTPA-Tc99m with the GFR as estimated by means of the formula based on serum cystatin C (CKD-EPI creatinine-cystatin C) in healthy kidney donors.

METHODS

In this observational, analytic, cross-sectional study, the GFR of kidney donors was determined ≥1 year after donation by means of DTPA gammagram and estimation with the use of conventional formulations and with cystatin C.

RESULTS

Of 112 donors, 38 (34%) were included, 20 (60%) were female, with an overall average age of 40 years, 36.5 months after donation, and body mass index of 25.5 kg/m². Correlation with the GFR as measured by means of DTPA gammagram was better with the use of CKD-EPI cystatin C (0.402; P = .020) and CKD-EPI creatinine-cystatin (0.549; P < .001) than the conventional formulas. Linear correlation with serum cystatin C was 0.825 (P < .001; 95% confidence interval, -105.3 to -63.2) for the CKD-EPI cystatin C formula, 0.77 (P < .001; -89.9 to -48.1) for the CKD-EPI creatinine-cystatin formula, and 0.525 (P = .002; -91.1 to -23.2) for DTPA-Tc99m scintigraphy.

CONCLUSIONS

There is a strong correlation between estimate the GFR by equations based on cystatin C and the measurement of the GFR by DTPA-Tc99m gammagram.

Correlation of the Renal Cortex Volume With the Glomerular Filtration Rate in Live Donors for Renal Transplantation

INTRODUCTION

As a pretransplantation evaluation, renal function is determined by the glomerular filtration rate (GFR) with the use of renal scintigraphy (RS) and the estimated glomerular filtration rate (eGFR). To date, there are few studies that correlate renal cortex volume with eGFR determined with renal gammagram (GR) and eGFR by equations (Cockroft-Gault, Modification of Diet in Renal Disease, and Chronic Kidney Disease Epidemiology Collaboration equation) in Latin American living donors.

AIM

This study sought to determine whether there is correlation of the volume of the renal cortex by Herts equation with the GFR determined with renal gammagram (GFR-GR).

PATIENTS AND METHODS

This was an analytical, observational, and cross-sectional study. A review of the donor charts from January 1, 2014, to December 1, 2014, with a complete clinical file, kidney measurements, predonation tomography volume, and eGFR by different formulas and by renal scintigraphy.

RESULTS

Thirty-three donors were included, 51.5% male and 48.5% female. The mean age was 38.58 ± 10 years, with an average volume of 127.83 ± 28.30 mL, with diethylenetriamine-pentaacetate (DTPA) of 54.80 ± 7.13 mL/min/1.73 m² in the donated kidney. Spearman correlation showed the best association with the Herts equation (r = 0.346) reaching significance (P = .049) when comparing the different equations against the GFR with DTPA. Using the Bland-Altman method, the lowest variability and best significance was verified with the same equation compared to the other formulas (P = .0002).

CONCLUSIONS

There is no consensus regarding which is the best formula for calculating the GFR of both kidneys. Of the different formulas, the one that best correlated with the GFR was the Herts method, which uses the volume of the kidney.

Lack of Association Between Elevated Urinary Levels of Interleukin-10 and Interferon Gamma With the Presence of Inflammation in Kidney Transplant Recipients

INTRODUCTION

A lot of evidence has demonstrated the importance of different cytokines in acute renal rejection. Previous studies have examined the presence or absence of interleukin (IL)-10 in related immunopathologic rejection grafts as well as other interleukins. Studies in human transplantation show elevated levels of IL-10 and gamma interferon (INF-γ) in inflammation and rejection.

OBJECTIVE

The objective of this study was to demonstrate the lack of association of elevated urinary levels of IL-10 and IFN in the presence of active inflammation.

METHODS

An observational, descriptive, cross-sectional study conducted in transplant recipients at 12 months of follow-up after renal transplantation. In those who were held biopsy after renal transplantation at one year follow-up, or allograft dysfunction, we also measured IL-10 and INF-γ in the urine. The following were considered as variables: age, body mass index (BMI), gender, transplant type, creatinine, chronic kidney disease epidemiology collaboration equation, (CKD-EPI), modification of diet in renal disease study equation (MDRD), Banff classification, and levels of IL-10 and INF-γ. Statistical analysis was performed calculating a sample size of 25 patients, with an alpha bias of 0.05%, yielding measures of central tendency and determining no association between levels of IL-10 and INF-γ with the presence of rejection using SPSS 21.0 program.

RESULTS

A total of 50 patients, 34 (68%) males, 16 (32%) females, with an average 31.7 ± 9.9 years, weight of 64.91 ± 13.84 kg, size 1.60 ± 0.10 m and 24.97 ± 4.07 BMI were included,39 (78%) living donor and 11 (22%) cadaveric. Twenty-six (52%) showed inflammation in the biopsy and 24 (48%) showed none. Mean creatinine was 1.81 ± 1.5, and the estimated glomerular filtration rate (eGFR) was 55.27 ± 22.46, 65.76 ± 26.7. (MDRD and CKD-EPI, respectively). No statistical difference was found in the levels of IL-10 and IFN-γ using analysis of variance. (ANOVA; P = .467 and P = .063, respectively) Based on Banff, the inflammation on biopsy score was 2.78 ± 2.84. There was statistical significance (P < .05) with respect to the Cr and eGFR by different equations. There were no significant interactions between cytokine levels and more than 1 factor. (as indicated by P < .2).

DISCUSSION AND CONCLUSIONS

No significant differences were observed in the level of interleukins in patients with and without inflammation, denoting an adequate immunosuppression in most of these patients. Determination of inflammatory cytokines in urine could be used as a determinant of a good immunosuppression status, rather than as an early marker of rejection.

Topographic mapping from the retina to the midbrain is controlled by relative but not absolute levels of EphA receptor signaling

Topographic maps are a fundamental feature of sensory representations in nervous systems. The formation of one such map, defined by the connection of ganglion cells in the retina to their targets in the superior colliculus of the midbrain, is thought to depend upon an interaction between complementary gradients of retinal EphA receptors and collicular ephrin-A ligands. We have tested this hypothesis by using gene targeting to elevate EphA receptor expression in a subset of mouse ganglion cells, thereby producing two intermingled ganglion cell populations that express distinct EphA receptor gradients. We find that these two populations form separate maps in the colliculus, which can be predicted as a function of the net EphA receptor level that a given ganglion cell expresses relative to its neighbors.

Rat oligodendroglia express c-met and focal adhesion kinase, protein tyrosine kinases implicated in regulating epithelial cell motility

Oligodendrocytes, the myelinating cells of the central nervous system, arise from a profilerating pool of motile progenitor cells. The proliferation and survival of these cells is dependent on signal transduction via several protein tyrosine kinases (PTKs) including receptors for fibroblast growth factor -2, the platelet-derived growth factor receptors and the neurotrophin receptor, trkC. We hypothesized that additional PTKs could also influence oligodendroglial development. Utilizing RTPCR, we amplified from post-natal day 6 rat oligodendroglia 17 distinct kinase domain sequences, 14 of which were not previously known to be expressed by oligodendroglia. Amongst the sequences identified were the c-met and Fak genes, whose protein products regulate the motility of other epithelial cell types. Utilizing immunohistochemistry, we confirmed that both c-met and Fak are expressed by cultured oligodendroglia, suggesting that these proteins could also be implicated in regulating the motility of these cells.

A transgenic mouse model for human hereditary neuropathy with liability to pressure palsies

Mutations in the gene encoding peripheral myelin protein 22 (PMP22) account for several inherited peripheral neuropathies in humans. We now show that transgenic mice expressing antisense PMP22 RNA exhibit modestly reduced levels of PMP22 together with a phenotype that is reminiscent of hereditary neuropathy with liability to pressure palsies (HNPP), a human disease caused by a 1.5-Mb deletion of a chromosome 17 region that contains the PMP22 gene. Transgenic antisense homozygotes display a striking movement disorder and a slowing of nerve conduction that worsens with age. Morphological analysis of peripheral nerves demonstrates that a subset of axons have thickened myelin sheaths and tomacula in young adults, with significant myelin degeneration detected in older animals. Together with other recent work, these data suggest that dosage of the PMP22 gene alone underlies the pathophysiology observed in HNPP and related disorders.