Total Number Of Glomeruli Research Articles

Relationship of body mass index and kidney outcomes in patients with primary glomerulonephritis: A systematic review and meta-analysis.

Primary glomerulonephritis, is a major contributor to the development of chronic kidney disease and end-stage renal disease. Previous studies on the relationship between overweight/obesity with primary glomerulonephritis in the chronic kidney disease was inconsistent. This study aimed to systematically review and meta-analyze the relationship between body mass index and adverse kidney outcomes in patients with primary glomerulonephritis. PubMed, Embase, the Cochrane Library, and the China National Knowledge Infrastructure were searched. Patients were divided into an overweight/obesity group (group O) and a non-overweight/obesity group (group N) according to their body mass index values. Twenty-six studies with 11,038 patients were selected. Patients in group O had deteriorated baseline characteristics, including worse baseline estimated glomerular filtration rate (weighted mean differences [WMD] = -5.99), higher Scr (WMD = 7.34), uric acid (WMD = 47.53), 24-hour proteinuria (WMD = 0.40), and a higher prevalence rate of hypertension (odds ratio, OR = 2.70) and diabetes mellitus (OR = 2.644). On the histopathologic level, patients in group O had a significantly lower total glomerular number (WMD = -2.30); however, no difference was observed in mesangial cell proliferation, endocapillary hypercellularity, crescents, sclerosis, and tubular atrophy/interstitial fibrosis between the 2 groups. The incidence of adverse renal outcomes in the 2 groups was similar (OR = 0.96). The meta-analysis of hazard ratios from Cox regressions indicated a strong association between overweight/obesity and poor renal outcomes in glomerulonephritis (HR = 1.17). Overweight/obesity glomerulonephritis patients had remarkably poor baseline clinicopathological characteristics. Being overweight or obesity would likely impact the progression of primary glomerulonephritis but not serious enough to contribute to significant poor renal outcomes, which could be prevented by aggressive therapy.

#439 Nephron number determination in whole slide mice kidney specimens using a deep learning assisted disector/fractionator approach

Abstract Background and Aims Nephron number highly varies between different species and within species, ranging in humans from 200 000 to 2 000 000 nephrons per kidney. Low nephron numbers can promote early onset of end-stage kidney disease. Nephron assessment is highly needed for better diagnosis and more targeted treatment. However, its assessment in vivo is not established in clinical practice yet. Pioneer studies suggest nephron number estimation in vivo through a combination of glomerular densities in kidney biopsies together with medical imaging. In contrast, post-mortem nephron assessment either using optical clearing or by exhaustive kidney sectioning is well studied but remains laborious. Here, we propose a new semi-automated nephron counting approach using serial PAS-stained whole slide kidney sections, deep learning segmentation and slide registration. Method Mice were sacrificed, kidneys harvested, measured, halved in the coronary plane and then opposingly embedded in paraffin. Subsequently, the entire kidney was sectioned with 10 µm thickness per slide. Tissue was stained with PAS and slides were digitalized using Aperio GT 450 DX scanner (Leica, Wetzlar, Germany) (Fig. a). Deep learning segmentation of glomeruli was performed in the first and every 10th (reference) section and subsequent (look-up) section using Tensorflow. Obtained segmentation results were manually quality controlled and adjusted, if necessary, in QuPath (Fig. b). Final segmentations of the look-up slides were registered to the reference slides in ImageJ using manual landmarks with the ImageJ BigWarp plugin (Fig. c). Glomeruli being present either in the look-up slide, or in the reference slide were counted as disector particles (Q-). Kidney areas on every examined slide were measured. Total number of glomeruli and total kidney area were determined as previously described (Fig. d). Results A kidney from a 12-week-old mouse suffering chronic kidney disease (mouse line Alb-creERT2 (ki/ki); Glut9 (fl/fl)) was used. Kidney weight was 162 mg, length 11 mm, width 6 mm, depth 4 mm and kidney volume 260 mm³. In total the kidney was sectioned in 95 slices. 20 reference sections and its respective look-up sections were stained and digitalized. In total 5981 glomeruli were segmented in 40 kidney slices using the deep learning algorithm. Glomerular segmentation quality was verified by two independent observers (mean dice score 0.79). Inaccuracies, if any, where manually corrected. For image registration in average 18.1 landmarks per slide were created within the ImageJ BigWarp plugin. Registration took in average 5 minutes per slide. Glomeruli without match (disector particles, Q-) were automatically counted. Number of disector particles (Q-) ranged from 32 to 244 per slide. Total nephron number was 11.085 and kidney area 210 mm³. The differences to the manual measured volume (260 mm³) might be explained by discard of small kidney fractions for the used sectioning technique. Conclusion We report, to our knowledge, the first deep learning assisted disector/fractionator approach to determine nephron number in whole slide kidney specimens. This method requires no physical disector setup, is scalable, cheap, time efficient, and unbiased. The method was so far validated in a mouse model of chronic kidney disease. The method will further be validated on different animal models. Additionally, occurrence of atubular glomeruli will be considered in nephron number determination. Furthermore, the integration of GFR measurements might allow the calculation of mean single nephron GFR and might together with automated glomerular area measurements unravel pathophysiologic processes in kidney ageing and disease.

Three-dimensional morphometry of kidney in New Zealand rabbit using unbiased design-based stereology.

The rabbit is widely used as a laboratory animal in experimental models of kidney diseases. This species is also important from a veterinary perspective as a companion animal. Stereology has been accepted as an accurate approach to kidney morphometry. The objective of the present project was to provide normal quantitative stereological parameters for adult rabbit kidneys. The left kidneys of five adult male New Zealand rabbits were used. Isotropic sections were obtained using the orientation method. Total kidney volume was calculated by the Cavalieri principle. The volume fraction of the renal structures was estimated using the point counting system. The lengths of the proximal convoluted tubule (PCT) and distal convoluted tubule (DCT) were calculated using counting frames. The total glomerular number was accounted for using the physical/fractionator technique. The mean glomerular volume was obtained by dividing the total volume of glomeruli by their total number. The total volume of rabbit kidneys calculated was 10.39 ± 1.98 cm3. The fractional volume of the kidney cortex and medulla accounted for 57.79 ± 0.65% and 42.2 ± 0.65%, respectively. The total glomerular volume was 2.18 ± 0.32% of the whole kidney. The total number of glomeruli in the rabbit kidney was estimated as 204.68 ± 12 × 103. The mean glomerular volume measured 1.07 ± 0.12 × 106 μm3. The total length of PCT and DCT was 2.96 ± 0.29 km and 1.38 ± 0.24 km, respectively. These findings can be used as a reference in experimental nephrology research and may help to expand the knowledge of nephrology in mammals by comparing with available data on humans and other species. RESEARCH HIGHLIGHTS: Three-dimensional morphometry of adult rabbit kidney structures was analyzed using quantitative stereology. Total volume of kidney, fractional volume of cortex and medulla, length of renal tubules and number of nephrons were estimated. These three-dimensional morphometrical data can be used as a reference in experimental nephrology research and may help to expand the knowledge of nephrology in mammals.

Abstract P224: The Role Of Gata3 In Renin Cell Identity

Renin cells act as precursors cells of the kidney vasculature and show high plasticity in postnatal life in response to challenges to homeostasis. Our scRNA-seq studies revealed that the dual-zinc finger transcription factor Gata3, important for cell lineage commitment and differentiation inseveral tissues, is expressed in mouse renin cells. We found an enhancer associated with Gata3 in renin cells leading us to hypothesize that GATA3 is important for renin cell identity. We studied 60 and 120-day-old mice carrying a conditional deletion of Gata3 in renin cells: Gata3 fl/fl ;Ren1 dCre/+ ( Gata3-cKO ) and control Gata3 fl/fl ;Ren1 d+/+ . BUN and plasma renin levels were measured from blood samples collected by cardiac puncture. Ren1, Acta2, and Gata3 were visualized in kidney sections by immunostaining. Histological analysis was performed with H&E, PAS, or Masson’s Trichrome chemical reactions. The juxtaglomerular area (JGA) index was calculated as a ratio of renin-positive JGAs per the total number of glomeruli. Gata3-cKO mice have: 1) a marked reduction in Gata3 staining; 2) a marked reduction of Ren1 (1.78 ± 0.51 (n=5) vs. 12.96 ± 2.29 (n=6), p=.0006) and Akr1b7 (2.12 ± 0.35 (n=5) vs. 19.75 ± 5.43 (n=7), p<0.0001) mRNAs compared to controls under threat; 3) a significant decrease in circulating plasma renin compared to controls under basal conditions (15609 ± 14281 pg/ml (n=5) vs. 78778 ± 33925 pg/ml (n=7), p=.0039) and physiological threat (265981 ± 79431 vs. 62347 ± 75631 pg/ml (n=5), p=.0032); 4) a significantly reduced JGA index (28.47 ± 2.32 (n=5) vs. 44.42 ± 2.72 (n=5), p=.0001); 5) flattened JG cells with misplaced renin staining in the Bowman’s capsule; 6) renal abnormalities with evidence of glomerular sclerosis/fibrosis, hemorrhage with aneurysms, and evidence of inflammatory cell infiltration; 7) misplaced Acta2 staining in the intraglomerular mesangium, interstitium, and Bowman’s capsule. Our results suggest a role of Gata3 in the identity of cells of the renin lineage.

Abstract 026: Three-dimensional Visualization And Evaluation Of Differences In Renin Expression In Kidneys Exposed In Vivo To Either Low Or High Arterial Pressure

Background: Renin cells are essential for the regulation of blood pressure (BP). In adult mammals, renin cells are present in small numbers in the juxtaglomerular area, but when homeostasis is threatened, such as by hypotension, additional cells along the renal arterioles are recruited to synthesize and release renin. However, there have been no studies to date that have shown changes in the distribution of renin cells in response to changes in BP by three-dimensional (3D) imaging. Objective: Establish a method to visualize and measure renin cells, and comparison of renin expression differences in kidneys exposed to hypo- or hypertension in 3D. Methods: We used our new mouse model ( Ren1 c-tdTomato ) that expresses renin and the fluorescent tdTomato under the control of the endogenous renin gene environment. To test whether we could detect differences in the distribution of renin in response to changes in BP, we subjected Ren1 c-tdTomato mice to aortic coarctation at 3 months of life. The right and left kidneys (RK, LK) are exposed to high and low BPs, respectively. We harvested kidneys after 72 hours and performed tissue-clearing. We used light sheet microscopy for imaging and the Imaris software for 3D reconstruction and data analysis. We defined the 3D renin cell index (3D-RI) as total volume of renin cells (μm 3 ) divided by total number of glomeruli. We extracted 10 cubes of 500 μm square each from the L and R renal cortex, calculated their individual 3D-RI and compared them. Results: With tissue-clearing-based 3D imaging, renin cells were clearly visualized, allowing observation of their distribution and appearance at a one-cell resolution. In the LK exposed to hypotension, several afferent arterioles were identified where renin cells extended close to their branching point. Further, the average value of the 3D-RI was significantly higher in LK (21460 ±6303) than in RK (12838 ± 4632; p = 0.003). Conclusion: Using our new Ren1 c-tdTomato mouse and 3D imaging technology we detected differences in renin cells appearance and distribution in kidneys exposed to hypo- or hypertension. Combined with spatial single cell multiomics, 3D visualization of renin cells will open new avenues for understanding how vascular cells acquire their positional identity in health and disease.

#5127 COMBINED ACTIVITY AND CHRONICITY SCORE FOR PROGNOSTIC ASSESSMENT IN ANCA-ASSOCIATED VASCULITIS WITH GLOMERULONEPHRITIS

Abstract Background and Aims Previous studies have shown that chronic changes on kidney biopsy are useful for stratifying the risk of kidney failure in patients with AAV-GN. We aimed to evaluate the impact of inflammatory activity for the prediction of renal outcomes. Method A retrospective cohort study of MPO- or PR3-ANCA positive patients with AAV and active renal disease. Inflammatory activity was assessed by the Activity Index (AI): a ratio between the number of crescents and/or necrosis and the total number of glomeruli (in percent). We calculated the AI score: 0-5 = 0; 6-10 = 1; 11-15 = 2; 16-20 = 3; 21-25 = 4; 26-37.5 = 5; 37.6-50 = 6; 51-65 = 7; 66-80 = 8; 80-90 = 9; 90-100 = 10. Chronicity was evaluated with the Mayo Clinic Chronicity Score (MCCS). For the combined score, we summed the MCCS and the AI. Results Results. We analyzed 326 patients with kidney biopsies available to score. The biopsies had in median (IQR), 13 glomeruli (9-20), 4 crescents (2-6) and an AI of 28.6% (15.3-47.6). The population was classified according with the risk of progression to kidney failure (KF) in 3 classes as (i) low (0-6) – 114 (35.0%), (ii) intermediate (7-11) – 152 (46.6%), and (iii) high (≥12) – 60 (18.4%). Median eGFR at baseline correlated with the overall risk categories: 42.2 vs. 22.1 vs. 13.4 mL/min/1.73 m2, p<0.0001. The proportion of patients with eGFR< 30 mL/min/1.73 m2 was increased in patients classified as high: 88.3% vs. 66.4% vs. 36.0%, p<0.0001. Renal recovery was more frequent in patients at low risk of progression: 87.7% vs. 64.6% vs. 36.6%, p<0.0001, whereas kidney failure at 12 months and dialysis were more frequent in patients at higher risk (36.7% vs. 12.4% vs. 3.8%, p<0.0001; 35.6% vs. 13.0% vs. 2.9%, p<0.0001, respectively). The combination of AI with MCCS independently predicted the risk of KF at 12 months (HR 1.916, 95%CI 1.210 - 3.033, p = 0.006), particularly increased in patients classified as high risk (HR 3.124, 95%CI 1.224 – 7.970, p = 0.017) and in patients with PR3-ANCA (HR 1.896, 95%CI 1.012 - 3.551, p = 0.046) independently of eGFR at AAV-GN diagnosis and adjusted for severity of renal involvement and age. Conclusion The combined assessment of acute inflammatory activity and chronic changes on kidney histology independently predicted renal outcomes in patients with AAV-GN. The impact of the inflammatory activity is cumulative to the chronic changes.

Protective potential of misoprostol against kidney alteration via alleviating oxidative stress in rat following exposure to paclitaxel

The present study investigated the protective effect of misoprostol (MSP) (0.2 mg/kg, oral) against kidney injury caused by paclitaxel (PLX) (2 mg/kg, intraperitoneal) in female Sprague Dawley rats. Twenty-eight 8-week-old rats were used and divided randomly into four equal groups (n = 7): control, MSP, PLX, and PLX+MSP. Malondialdehyde (MDA) level, serum creatinine (Cr), and blood urea nitrogen (BUN) were significantly increased in the PLX group compared to the control group (p < 0.05), while superoxide dismutase (SOD), glutathione (GSH), and catalase (CAT) were decreased (p < 0.05). In the PLX+MSP group, levels of serum Cr, and BUN were significantly decreased than the MSP group (p < 0.05). Further, lower level of MDA, and higher activity of GSH, SOD, and CAT was detected in the PLX+MSP than the PLX group (p < 0.05). In the PLX group, we also found a significant decrease in the total number of glomeruli and the mean volumes of cortex, medulla, and kidney compared to the control group (p < 0.05). Besides, these stereological parameters were improved in the PLX+MSP group than the PLX group (p < 0.05). We speculated that administration of MSP attenuated the toxic effect of PLX on kidney tissue due to its antioxidative and anti-apoptotic efficacy of MSP.

Administration of retinoic acid to pregnant mice increases the number of fetal mouse glomeruli

The prevalence of chronic kidney disease (CKD) is increasing worldwide, and CKD is a serious global health problem. Low glomerular number is one of the risk factors for CKD; therefore, the glomerular number is associated with the risk of CKD. Increasing the glomerular number above normal levels may reduce the risk of CKD. It has been reported that, in vitro, the addition of retinoic acid (RA) to the culture medium increases the glomerular number. However, there is no report of an increase in glomerular number above normal levels with the addition of RA in vivo. In this study, RA (20 mg/kg) was administered intraperitoneally to pregnant mice once at embryonic day (E) 10.5, E12.5, E14.5, or E16.5. The fetuses were harvested at E18.5 and fetal mouse kidneys were evaluated. Fetal kidney volume and weight were significantly increased in the E16.5 group compared to the control group. The total glomerular number in the E16.5 group was also approximately 1.46 times higher than that in the control group. In summary, we established a method to increase the glomerular number in the fetal kidney by administration of RA to pregnant mice at E16.5. These results will facilitate the investigation of whether CKD risk is reduced when the glomerular number increases above normal.

Antennal lobe organisation in ant, Oecophylla smaragdina: A Golgi study

Antennal lobes (AL) are the primary olfactory centres of the insect brain, the organisation of which reflects the chemosensory repertoire of the insect. The sensory neurons from the antenna, local neurons (LNs), and projection neurons (PNs) constitute the neuropilar organisation of the AL, which often varies according to the ecology and behaviour of the insects. We explored the organisation of the AL in the ant Oecophylla smaragdina through Golgi analysis and other standard histological procedures. Six topographically distinct glomerular clusters were noticed in the AL. AL volume, total number of glomeruli and its spatial organisation were different in the castes of Oecophylla smaragdina. We could count 220 glomeruli in the AL of the major worker, whereas only 140 glomeruli were located in AL of minor workers. LNs with their cell body located on the dorsal, dorso-lateral, ventral, ventro-lateral, and medial position of the AL were characterised. Most of the LNs are oligoglomerular. Uniglomerular and multiglomerular PNs were also identified. The results underline a caste specific organisation of the AL in Oecophylla smaragdina. The characterised LNs and PNs further reveals the complex neural circuitry involved in the processing of important chemical cues related to the lifestyle of the ant.

Stereological study of the kidney during prenatal development in sheep.

The development of metanephros is a complex and gradual process. The number, size and distribution of nephrons provide important information about the organization of the kidney. Stereology is the current gold-standard technique for the morphometrical evaluation of kidney structures. This study describes morphometric features of the kidney development in sheep using design-based stereological techniques aimed to introduce the sheep as a translational model in human nephrogenesis. Left kidneys of 16 sheep fetuses in four groups at 9-11, 12-14, 15-17, and 18-20 weeks of gestation were used in the present study. Systematic uniform random sections were obtained. The kidney volume, volume fraction of nephrogenic zone, cortex and medulla, and glomerular volume were estimated using point counting and Cavalieri's estimator. The total glomerular number was estimated using a physical disector/fractionator technique. The kidney and its compartments presented gradual changes with aging, with differences found in the last fetal ages. The kidney volume increased from 0.94 ± 0.22 cm3 to 8.6 ± 0.88 cm3 during development. The volume of cortex increased from 406 ± 85 mm3 to 5,151 ± 309 mm3 and the volume of medulla showed increase from 301 ± 91 mm3 to 3,426 ± 599 mm3 . The total glomerular volume increased from 13.8 ± 1.6 mm3 to 235 ± 44 mm3 . The total glomerular number increased from 4,683 ± 757 to 639 × 103 ± 11.6 × 103 . Our data might contribute to the knowledge of embryological urology and promote future experimental investigations in this field.

Influence of Withania somnifera(L) Dunal Root Extract on Rat Kidney Exposed to Electromagnetic Waves from Mobile Phone: A Histopathological and Antioxidant Analysis

This study is about to discover the consequences of 4G mobile phone emission on MDA, anti-oxidants, antioxidant marker, and histo-pathological variations in the kidney of rats.144 male rats were separated into four groups. The Group I is considered as the control group, Group II was subjected to mobile radiation 2400 MHz frequency range for 3 hours/day for the period of 6 months, Group III was as same as Group II but treated with 250 mg/kg aqueous extract of Withania somnifera root (Aq-Wsr) orally for 6 months. Group IV was given 250 mg/kg Aq-Wsr alone for 6 months. The animals were euthanized and the kidneys cells have been evaluated for antioxidant and histo-pathological parameters. Results of the study demonstrated that the LPO were significantly raised (p &lt; 0.05) while SOD, CAT, GSH and GPx were significantly lowered (p &lt; 0.05) in the EMR exposed group when compared to the Group I and Group III. In histo-pathological observation, intertubular congestion, haemorrhage, necrotic changes in cortex and medulla, cast formation within the proximal and distal tubules have elevated significantly inside the EMR group compared to the control group (p &lt;.05). Contrarily, the total number of glomeruli in the cortex of EMR group of subjects decreased compared to the Control group (p&lt; 0.05). The defensive effects of Aq-Wsr were witnessed within the kidney of Group III rats. From the study, it is very significant to raise open awareness of promising harmful consequences of cell phone radiofrequency EMR exposure.

393-P: Combination Treatment with Lisinopril and Empagliflozin Improves Urine and Histological Markers of Diabetic Kidney Disease in Female Renin-AAV UNx db/db Mice

Introduction: Emerging treatments of diabetic kidney disease (DKD) include SGLT2 inhibitors and GLP-1 receptor agonists that are nephroprotective beyond their blood glucose lowering effects. To confirm the translatability of a mouse model for drug discovery in DKD, we tested the efficacy of an ACE inhibitor and a SGLT2 inhibitor in the reninAAV UNx db/db mouse model. Methods: Female db/db mice were injected with a renin-encoding adeno-associated virus construct (reninAAV) to induce hypertension and uninephrectomized (UNx). At 12 weeks of age, dosing with vehicle, lisinopril, empagliflozin, or the combination (combo) was initiated. Plasma and urine markers were measured after 12 weeks of dosing and terminal kidney samples were collected for 3D light sheet microscopy and 2D histology. Results: In reninAAV UNx db/db mice, treatment with empagliflozin and combo reduced fed BG and HbA1c compared to vehicle. Treatment with lisinopril and combo reduced urine ACR and KIM1-to-creatinine compared to vehicle, while treatment with empagliflozin alone worsened urine ACR. Glomerular hypertrophy as assessed by 3D imaging was reduced in combo treated reninAAV UNx db/db mice compared to vehicle, while treatment with empagliflozin alone worsened glomerular hypertrophy. The total number of glomeruli per kidney was unaffected by treatments. Compared to vehicle treatment, lisinopril and combo treatment reduced the fraction of score 3+4 glomeruli, and glomerulosclerosis index (GSI) was reduced by with lisinopril and combo treatment. Treatment with empagliflozin alone worsened GSI. Morphometric analyses showed that lisinopril and combo treatment reduced kidney CD11b and KIM1 load. Conclusion: Responses to the combination treatment with lisinopril and empagliflozin showed improvement of urine and histological markers of DKD. Together, these data confirm the translatability of the reninAAV UNx db/db mouse model of DKD. Disclosure M. V. Østergaard: None. M. Christensen: None. T. Secher: Employee; Self; Gubra, Employee; Spouse/Partner; Novo Nordisk, Stock/Shareholder; Self; Gubra, Stock/Shareholder; Spouse/Partner; Novo Nordisk. J. L. Skytte: None. U. Roostalu: Employee; Self; Gubra. C. G. Salinas: Employee; Self; Gubra, Employee; Spouse/Partner; Novo Nordisk, Stock/Shareholder; Spouse/Partner; Novo Nordisk. F. E. Sembach: None. L. N. Fink: Employee; Self; Gubra, Stock/Shareholder; Self; Novo Nordisk A/S. N. Vrang: Board Member; Self; Gubra, Employee; Self; Gubra, Stock/Shareholder; Self; Gubra.

MO624COMBINATION TREATMENT WITH LISINOPRIL AND EMPAGLIFLOZIN IMPROVES BIOCHEMICAL AND HISTOLOGICAL MARKERS OF DIABETIC NEPHROPATHY IN HYPERTENSIVE UNINEPHRECTOMIZED DB/DB MICE

Abstract Background and Aims Emerging treatments of diabetic kidney disease (DKD) include SGLT2 inhibitors and GLP-1 receptor agonists that are nephroprotective beyond their blood glucose lowering effects. Despite this progress, patients with diabetes are still at risk of developing DKD, and drug discovery remains impeded by the lack of reproducible rodent models exhibiting features of human DKD. To confirm the translatability of an advanced mouse model, we tested standard of care in the setting of type 2 diabetes and hypertension. Method Female db/db mice were injected with a renin-encoding adeno-associated virus construct (reninAAV) to induce hypertension and uninephrectomized (UNx) at 7-8 weeks of age. At 12 weeks of age, daily dosing with vehicle, lisinopril, empagliflozin, or the combination (combo) was initiated. Blood glucose (BG) was measured every third week, while urine albumin-to-creatinine (ACR) and KIM1 were measured in spot urine samples collected before termination at 24 weeks of age. Cystatin C was measured in terminal plasma, while terminal kidney samples were collected for 3D light sheet microscopy and 2D histology: Glomerulosclerosis scoring was performed by AI-assisted automized scoring, whereby glomeruli were given scores from 0 (normal glomerulus) to 4 (glomerulus with global glomerulosclerosis), and morphometric quantification of kidney collagen 3, CD11b, and KIM1 load was performed. Results In reninAAV UNx db/db mice, 12 weeks treatment with empagliflozin and combo reduced fed BG (12.3±1.5 and 13.1±0.9 mM, vehicle: 18.0±1.9 mM) and HbA1c (5.5±0.2 and 5.8±0.2%, vehicle: 7.4±0.03%). Treatment with lisinopril and combo reduced urine ACR (8110±1320 and 2508±346 µg/mg, vehicle: 26,138±1820 µg/mg) and KIM1-to-creatinine (7.5±1.1 and 3.9±0.6 ng/mg, vehicle: 24.8±3.2 ng/mg), while treatment with empagliflozin alone worsened urine ACR (41,523±4670 µg/mg). Glomerular hypertrophy as assessed by 3D imaging was reduced in reninAAV UNx db/db mice combo treated animals compared to vehicle (glomerular volume: 1.46*105±4.3*103 and 1.65*105±4.3*103 µm3), while treatment with empagliflozin alone worsened glomerular hypertrophy (1.83*105 µm3). The total number of glomeruli per kidney was not affected by treatments. Compared to vehicle treatment, lisinopril and combo treatment reduced the fraction of score 3 + 4 glomeruli (% GS 3 + 4 glomeruli: 0.38±0.06 and 0.27±0.03%, vehicle: 0.54±0.05%) Glomerulosclerosis index (GSI) was also reduced by lisinopril and combo treatment (GSI: 2.29±0.10 and 2.04±0.05, vehicle: 2.62±0.09). Treatment with empagliflozin alone worsened GSI (2.95±0.11). Whereas treatments did not significantly affect collagen 3, lisinopril and combo treatment reduced CD11b (total CD11b mass: 0.25±0.03 and 0.24±0.04 mg, vehicle: 0.57±0.07 mg) and KIM1 (total KIM1 mass: 0.25±0.06 and 0.17±0.09 mg, vehicle: 2.01±0.37 mg), whereas empagliflozin did not affect CD11b and KIM1. Conclusion Responses to the combination treatment with lisinopril and empagliflozin showed improvement of urine and histological markers of DKD. Together, these data confirm the translatability of the ReninAAV UNx db/db mouse model of DKD in type 2 diabetes.

MO279DETERMINANTS TO CONSIDER THERAPEUTIC PLASMA EXCHANGE FOR TREATMENT OF SEVERE ANCA-ASSOCIATED VASCULITIS: A RETROSPECTIVE STUDY FROM A SINGLE CENTER

Abstract Background and Aims Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a systemic vasculitis, most frequently presenting as microscopic polyangiitis (MPA) or granulomatosis with polyangiitis (GPA). Pathogenic ANCAs trigger a deleterious immune response resulting in pauci-immune necrotizing and crescentic glomerulonephritis (GN). Standard therapeutical regimens include aggressive immunosuppressive therapy. Since some patients require RRT despite intensive immunosuppressive therapy, additional therapeutic plasma exchange (PEX) to deplete pathogenic ANCAs has been recommended but its value has recently been questioned. Because therapeutic decision making is crucial in these critically ill patients, we here aimed to identify determinants for PEX consideration in a retrospective study from a single center tertiary hospital in a real-world population of 46 patients with severe AAV requiring intensive care treatment. Method A total number of 46 patients with biopsy-proven AAV at the University Medical Center Göttingen were retrospectively included between 2015 till 2020. While no formal approval was required for the use of routine clinical data, a favorable ethical opinion was granted by the local Ethics committee. Medical records were used to obtain data on age, sex, diagnosis (MPO or PR3) and laboratory results (serum creatinine, C-reactive protein/CRP, urinary albumin/creatinine ration). The estimated glomerular filtration rate (GFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. A renal pathologist (SH) evaluated all biopsies. Within a renal biopsy specimen, each glomerulus was scored separately for the presence of necrosis, crescents and global sclerosis. Consequently, the percentage of glomeruli with any of these features was calculated as a fraction of the total number of glomeruli in each renal biopsy. Apart from these categories, the degree of interstitial fibrosis/tubular atrophy (IF/TA) was quantified. Based on these scorings, histopathological subgrouping according to Berden et al (focal, crescentic, mixed or sclerotic class) and ARRS according to Brix et al (low, medium or high risk) were performed. Results The decision to consider PEX was more likely in patients with need for intensive care treatment and severe renal dysfunction. In contrast, short-term outcomes did not depend on clinical or laboratory characteristics assessed at admission. Histopathological analysis confirmed active disease reflected by increased glomerular necrosis and crescents, but these histopathological findings did not associate with short-term outcome either. Interestingly, only increased global glomerular sclerosis in renal biopsies associated with a detrimental short-term outcome. Conclusion In conclusion, our study investigated determinants for the consideration of therapeutic PEX in patients with severe AAV requiring intensive care treatment. This aspect underscores the need for renal biopsy and requires further investigation in a prospective controlled setting for therapeutic decision making especially in patients with severe AAV requiring intensive care treatment, especially important for treating intensivists.

P1620PROGNOSTIC VALUE OF RENAL BIOPSY QUANTITATIVE HISTOLOGY IN LIVING KIDNEY DONORS AND RECIPIENTS OF KIDNEYS FROM LIVING DONORS

Abstract Background and Aims Living kidney donors (LKD) have an increased risk of chronic kidney disease. Likewise, renal transplant recipients may experience early or unexplained loss of graft function. We examined the predictive value of stereology based on a CT-scan and a biopsy from the transplanted kidney in relation to renal function outcome in both LKD and recipients of kidneys from living donors. Method A pre-transplantation contrast-enhanced CT-scan was used to obtain cortical volume of both kidneys using the Cavalieri estimator. Glomerular number density in a baseline biopsy from the transplanted kidney (taken at the time of transplantation) was estimated by a model-based method and multiplied with cortex volume to estimate the total number of glomeruli in the donated kidney. Glomerular volume was estimated by the 2D nucleator (1). In addition, kidney fibrosis (point-counting), glomerular sclerosis, and arteriole dimensions (2D nucleator) were also calculated. Pre-donation single kidney glomerular filtration rate (GFR) was determined using 51chrome EDTA clearance together with a renography and the GFR measurement was repeated one year after transplantation in both donors and recipients. We examined the association between GFR at one-year follow-up and cortex volume and various histology parameters from the baseline biopsy after adjustment of age, sex, body mass index, smoking status, 24-hour mean blood pressure and single-kidney GFR before transplantation. Results CT-scans, GFR measurements and kidney histology from 49 LKD and 38 recipients of kidneys from living donors were available for analysis. Mean age of donors was 50±12 years (55% women) and of recipients 46±13 years (26% women). In donors, GFR decreased from 113±24 to 71±16 ml/min while in recipients GFR was 61±18 ml/min at one-year follow-up (all with a functioning graft). In donors, GFR at follow-up of the remaining kidney had increased by 28% as compared to baseline. Follow-up GFR correlated to cortex volume (P&amp;lt;0.001), but not to any of the histological parameters (total glomerular number, glomerular volume, % sclerosed glomeruli, % kidney fibrosis or arteriolar dimensions). In recipients, GFR at follow-up had increased by 8% as compared to single-kidney GFR before donation. Follow-up GFR correlated to % kidney fibrosis (P=0.02) and % sclerosed glomeruli (P=0.05), but not any of the other histological parameters or cortex volume. Conclusion When adjusted for relevant clinical confounders the estimation of cortex volume had predictive value for renal function outcome in LKD while % kidney fibrosis and % sclerosed glomeruli had predictive value in recipients of kidneys from living donors.

P0501THE EPIDEMIOLOGICAL FEATURES OF PIRMARY GLOMERULAR DISEASES IN TURKEY: THE MULTICENTER STUDY OF TURKISH SOCIETY OF NEPHROLOGY GLOMERULAR DISEASES (TSN-GOLD) WORKING GROUP

Abstract Background and Aims The largest data on the epidemiology of primary glomerular diseases (PGD) are obtained from the databases of countries or centers. Here, we presented the extended results of the Primary Glomerular Diseases Study of the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD)Working Group. Method The data of patients who underwent renal biopsy and diagnosed as primary glomerular disease were recorded in the database prepared for the study. Between May 2009 and May 2019, a total of 4399 patients from 47 centers were evaluated. Basal data of 3875 patients were analyzed after exclusion of those lacking light microscopy and immunofluorescence findings. Results The mean age was 41.5 ± 14.9 years. Of the patients, 1690 were female (43.6%) and 2180 (56.3%) were male. Nephrotic syndrome was the most common biopsy indication (51.7%). This was followed by asymptomatic urinary abnormalities (18.3%) and nephritic syndrome (17.8%). The most common PGH was IgA nephropathy (25.7%), followed by membranous nephropathy (25.6%) and FSGS (21.9%). The mean total number of glomeruli per biopsy was 17 ± 10. Mean baseline systolic blood pressure was 130 ± 20 mmHg and diastolic blood pressure was 81 ± 12 mmHg. Median proteinuria was 3300 (IQR: 1467-6307) mg / day, mean serum creatinine, estimated GFR and albumin values were 1.4 ± 1.5 mg / dl, 80.7 ± 39.1 ml / min and 3.2 ± 0.9 g / dl, respectively. Conclusion In Turkey, the incidence of IgA nephropathy patients have become more common than membranous nephropathy among PGD patients diagnosed with renal biopsy.

Moderate prenatal ethanol exposure in the rat promotes kidney cell apoptosis, nephron deficits, and sex-specific kidney dysfunction in adult offspring.

Alcohol during pregnancy can impair fetal development and result in offspring with neurodevelopmental deficits. Less is known about how low to moderate alcohol exposure can affect other organs, such as the kidney. Here, the effects of moderate ethanol exposure throughout pregnancy on kidney development were examined using a rat model. Rats were fed a liquid diet containing 6% ethanol (vol/vol) or control (0% ethanol) throughout pregnancy. Kidneys were collected at embryonic day (E) 20 or postnatal day (PN) 30 and total glomerular (nephron) number determined using unbiased stereology. Kidney function was examined in offspring at 8 and 19 months. At E20, fetuses exposed to ethanol had fewer nephrons with increased apoptosis. Alcohol exposure caused kidney dysregulation of pro- (Bax) and anti- (Bcl-2) apoptotic factors, and reduced expression of the cell proliferation marker, Ki67. Prenatal alcohol decreased expression of Gdnf and Tgfb1, important regulators of branching morphogenesis, in male fetuses. At PN30, kidney volume and nephron number were lower in offspring exposed to prenatal alcohol. Urine flow and osmolality were normal in offspring exposed to alcohol however sodium excretion tended to be lower in females prenatally exposed to alcohol. Findings suggest exposure to moderate levels of alcohol during pregnancy results in impaired kidney development and leads to a permanent nephron deficit. Although the impact on adult kidney function was relatively minor, these data highlight that even at moderate levels, alcohol consumption during pregnancy can have deleterious long-term outcomes and should be avoided.

A practical guide to the stereological assessment of glomerular number, size, and cellular composition.

The evaluation of a range of measures in the kidneys, such as developmental stage, rate and success, injury, and disease processes, relies on obtaining information on the three-dimensional structure of the renal corpuscles, and in particular the glomerular capillary tufts. To do this in the most accurate, comprehensive, and unbiased manner depends on a knowledge of stereological methods. In this article, we provide a practical guide for researchers on how to quantitate a number of structures in the kidneys, including the estimation of total glomerular number, glomerular capillary length and filtration surface area, and the cellular composition of individual glomeruli. Guidance is also provided on how to apply these methods to kidneys at different sizes and levels of maturity.

The morphology of the antennal lobe of Ambrostoma quadriimpressum (Coleoptera: Chrysomelidae)

The structure of the primary olfactory brain center was studied in male and female adult Ambrostoma quadriimpressum by means of a series of histological sections labeled using the reduced-silver-stain technique. The antennal lobe was elliptical, and the total number of glomeruli was approximately 50 in the antennal lobe in both sexes. There was no sexual dimorphism with respect to the size of the antennal lobe or the number and shape of glomeruli.

493-P: Synchrotron Radiation Micro-CT Reveals Glomerular Loss without Glomerular or Renal Hypertrophy in Streptozotocin-Induced Type 1 Diabetic Mice

The glomerular number and size are major factors in predicting outcomes in renal disease. We have recently established synchrotron radiation microcomputed tomography (SRµCT) imaging of the glomeruli in perfused kidneys, and reported the glomerular and renal hypertrophy, but not glomerular loss in obese type 2 diabetic db/db mice. To visualize pathophysiological basis of diabetic kidney of type 1 diabetes, we here explored SRµCT imaging of the glomeruli in streptozotocin-induced type 1 diabetic male mice (STZ mice) and of control male C57BL/6J mice (control mice). STZ mice at the age of 22 weeks significantly showed hyperglycemia and elevated urinary albumin excretion, but not hypertension or body weight changes compared to control mice. There was approximately 22% loss of the total glomerular number (Nglom) of STZ mice compared to that of control mice (p&amp;lt;0.001). STZ mice had fewer glomerular number in all renal cortical zone of the whole kidney than control mice (p=0.003). However, type 1 diabetes had no impact on the mean glomerular volume (Vglom), coefficient of variation (CV; SD/mean) of glomerular volume, and renal volume (Vkidney) (Vglom, p=0.149; CV, p=0.591; Vkidney, p=0.093 vs. control mice, respectively). Nglom was significantly correlated with body weight (r=0.458, p=0.032), blood glucose levels (r=-0.623, p=0.002) or HbA1c (r=-0.530, p=0.011). Vglom was correlated with Vkidney (r=0.622, p=0.002) by each other. Multivariate regression analysis with the stepwise forward method identified blood glucose (β=-0.665, p&amp;lt;0.001) and systolic blood pressure (β=-0.499, p=0.001) as significant independent determinants of Nglom. Our study, for the first time, demonstrated a significant reduction of the total glomerular number in STZ mice, without affecting the glomerular volume or renal volume. These results indicate the glomerular pathology markedly differs between type 1 and type 2 diabetes. Disclosure Y. Takiyama: None. T. Sera: None. M. Nakamura: None. R. Bessho: None. T. Takiyama: None. T. Ota: None. M. Haneda: None.