Intimal Fibrosis Research Articles

Deciphering the complex mechanics of atherosclerotic plaques: A hybrid hierarchical theory-microrheology approach

Understanding the viscoelastic properties of atherosclerotic plaques at rupture-prone scales is crucial for assessing their vulnerability. Here, we develop a Hybrid Hierarchical theory-Microrheology (HHM) approach, enabling the analysis of multiscale mechanical variations and distribution changes in regional tissue viscoelasticity within plaques across different spatial scales. We disclose a universal two-stage power-law rheology in plaques, characterized by distinct power-law exponents (αshort and αlong), which serve as mechanical indexes for plaque components and assessing mechanical gradients. We further propose a self-similar hierarchical theory that effectively delineates plaque heterogeneity from the cytoplasm, cell, to tissue levels. Moreover, our proposed multi-layer perceptron model addresses the viscoelastic heterogeneity and gradients within plaques, offering a promising diagnostic strategy for identifying unstable plaques. These findings not only advance our understanding of plaque mechanics but also pave the way for innovative diagnostic approaches in cardiovascular disease management. Statement of significanceOur study pioneers a Hybrid Hierarchical theory-Microrheology (HHM) approach to dissect the intricate viscoelasticity of atherosclerotic plaques, focusing on distinct components including cap fibrosis, lipid pools, and intimal fibrosis. We unveil a universal two-stage power-law rheology capturing mechanical variations across plaque structures. The proposed hierarchical model adeptly captures viscoelasticity changes from cytoplasm, cell to tissue levels. Based on the newly proposed markers, we further develop a machine learning (ML) diagnostic model that sets precise criteria for evaluating plaque components and heterogeneity. This work not only reveals the comprehensive mechanical heterogeneity within plaques but also introduces a mechanical marker-based ML strategy for assessing plaque conditions, offering a significant leap towards understanding and diagnosing atherosclerotic risks.

GSDMD-Dependent Neutrophil Extracellular Traps Mediate Portal Vein Thrombosis and Associated Fibrosis in Cirrhosis.

Portal vein thrombosis (PVT) is a challenging and controversial complication of cirrhosis. Experimental models that reproduce cirrhotic PVT and effective pharmacological therapies are limited. We aimed to investigate the nature course and mechanisms of PVT in cirrhosis. A novel PVT model was developed via two-step total portal vein ligation in healthy and thioacetamide (TAA)-cirrhotic rats. Circulating and liver-infiltrating neutrophils were isolated from individuals with cirrhosis to examine neutrophil extracellular traps (NETs) and explore their unique characteristics and implications in PVT-associated fibrosis in cirrhosis. We further validated macrophage-myofibroblast transition (MMT) via multiplex immunofluorescence and single-cell sequencing. In the experimental model, cirrhosis promoted PVT development and portal vein intimal thickening. Interestingly, cirrhosis promoted spontaneous resolution of PVT due to instability of thrombus structure, along with pulmonary and intrahepatic clots. NETs-MMT mediate cirrhotic PVT and PVT-associated fibrosis, including fibrotic thrombus remodeling and increased hepatic collagen deposition. Mechanistically, caspase-4-dependent activation of neutrophils and GSDMD mediated the formation of NETs. The extracellular DNA of NETs promoted TGF-β1/Smad3-driven MMT. Inhibiting GSDMD with disulfiram suppressed cirrhotic PVT and prevented associated fibrosis. The cirrhotic PVT model reflected the following three main characteristics of cirrhotic PVT: spontaneous resolution, immunothrombosis, and intimal fibrosis. Targeting NETs with GSDMD inhibitors may serve as a new therapeutic concept to treat cirrhotic PVT.

Safety and effectiveness of the sutureless integrated stented graft prosthesis in an animal model

BackgroundProlonged circulatory arrest time is an independent risk factor for postoperative adverse events of type A aortic dissection (TAAD) surgery. Further reduction of the circulatory arrest time is essential to improve surgical outcomes. This study aimed to evaluate the safety and effectiveness of the novel Sutureless Integrated Stented (SIS) graft prosthesis in an animal experiment. Materials and methodsStraight type of the SIS graft prosthesis was implanted into the descending aorta of 10 adult male sheep, and the use of the device was scored on a scale of 1–10. Aortic digital subtraction angiography (DSA) was performed at 4, 14, and 26 weeks to investigate the prostheses. After 26 weeks, the animals were sacrificed for histological analysis. ResultsThe immediate success rate of the surgery was 100 %, and the overall mean score of the use of the device was 9.65 ± 0.99. Three animals died from non-device-related causes during follow-up. Aortic DSA showed filling defects in 5 animals. Histological analysis revealed that all prostheses were intact. Except for 2 early deaths, the other 8 prostheses were endothelialized with mild inflammation, foreign body reactions, and intimal fibrosis. The mean cross-sectional area of the sutureless region was reduced by 26.4 % (range, 1.3–39.1 %). ConclusionsThe safety and effectiveness of the novel SIS graft prosthesis were acceptable, and the delivery system exhibited a promising performance. Using the SIS graft prosthesis in TAAD surgery was expected to simplify the procedures and shorten the circulatory arrest time. Further large-scale clinical trials are required to verify these findings.

Clinical-imaging-pathological correlation in pulmonary hypertension associated with left heart disease.

Pulmonary hypertension (PH) is highly prevalent in patients with left heart disease (LHD) and negatively impacts prognosis. The most common causes of PH associated with LHD (PH-LHD) are left heart failure and valvular heart disease. In LHD, passive backward transmission of increased left-sided filling pressures leads to isolated post-capillary PH. Additional pulmonary vasoconstriction and remodelling lead to a higher vascular load and combined pre- and post-capillary PH. The increased afterload leads to right ventricular dysfunction and failure. Multimodality imaging of the heart plays a central role in the diagnostic work-up and follow-up of patients with PH-LHD. Echocardiography provides information about the estimated pulmonary artery pressure, morphology and function of the left and right side of the heart, and valvular abnormalities. Cardiac magnetic resonance imaging is the gold standard for volumetric measurements and provides myocardial tissue characterisation. Computed tomography of the thorax may show general features of PH and/or LHD and is helpful in excluding other PH causes. Histopathology reveals a spectrum of pre- and post-capillary vasculopathy, including intimal fibrosis, media smooth muscle cell hyperplasia, adventitial fibrosis and capillary congestion. In this paper, we provide an overview of clinical, imaging and histopathological findings in PH-LHD based on three clinical cases.

Unilateral Lung Removal in Combination with Monocrotaline or SU5416 in Rodents: A Reliable Model to Mimic the Pathology of the Human Pulmonary Hypertension.

Pulmonary hypertension (PH) is a chronic and progressive disorder characterized by elevated mean pulmonary arterial pressure, pulmonary vascular remodeling, and the development of concentric laminar intimal fibrosis with plexiform lesions. While rodent models have been developed to study PH, they have certain deficiencies and do not entirely replicate the human disease due to the heterogeneity of PH pathology. Therefore, combined models are necessary to study PH. Recent studies have shown that altered pulmonary blood flow is a significant trigger in the development of vascular remodeling and neointimal lesions. One of the most promising rodent models for increased pulmonary flow is the combination of unilateral left pneumonectomy with a "second hit" of monocrotaline (MCT) or SU5416. The removal of one lung in this model forces blood to circulate only in the other lung and induces increased and turbulent pulmonary blood flow. This increased vascular flow leads to progressive remodeling and occlusion of small pulmonary arteries. The second hit by MCT or SU5416 leads to endothelial cell dysfunction, resulting in severe PH and the development of plexiform arteriopathy.

Retrospective analysis of confirmed cases of pulmonary veno-occlusive disease: a single tertiary referral center study

Abstract Background Pulmonary veno-occlusive disease (PVOD) is a rare cause of pulmonary hypertension that primarily results in intimal fibrosis of the pulmonary venules and veins, the venous lesions are often associated with changes in interlobular septa, lung parenchyma, and pulmonary arterioles and arteries. Purpose We sought to study the clinical characteristics of patients with confirmed PVOD at a single large referral center. Methods We retrospectively reviewed data from a total of 675 patients with pulmonary hypertension (identified by ICD codes or search of text) from 2017 and 2022 from a database obtained from electronic medical records at our institution. Patients with group 2 pulmonary hypertension were excluded. Only 29 cases were confirmed by histology or genetic testing. Results Out of the 29 patients confirmed with PVOD, 28 (96.5%) had a characteristic histology (lung biopsy (55.1%), explanted lung for transplant (27.5%) and autopsy (13.7%)) and 1 (3.4%) had a positive genetic test for EIF2AK4 biallelic mutation. The age at diagnosis was 53±16 years, 14 (48.2%) were men, 2 (6.8%) had systemic scleroderma, 2 (6.8%) had psoriasis, 2 (6.8%) were exposed to cytotoxic agents, 16 (55.1%) were smokers and 2 (6.8%) had a family history of pulmonary hypertension. All patients had computed tomography of the chest but only 12 (41.3%) had all 3 typical features found in PVOD (ground glass opacities, interlobular septal thickening, and lymphadenopathy). The most common feature was interlobular septal thickening in 26 (89.6%), followed by ground glass opacities present in 25 (86.2%) and lymphadenopathy in 12 (41.3%) of the patients. At diagnosis, mean pulmonary artery pressure was 45±15 mmHg and pulmonary vascular resistance was 9±6 WU. The median DLCO was 41 (34-58) %. On echocardiogram, 14 (48.2%) had severely enlarged right ventricle (RV), RV function was ≥moderately reduced in 17 (58.6%), RV systolic pressure was 63±20 mmHg and 6 (20.6%) had pericardial effusion. Out of 21 (72.4%) patients who received pulmonary vasodilators, 4 (13.7%) received single agent. 10 (34.4%) received 2 agents, 6 (20.6%) 3 agents, and 1 (3.4%) received 4 agents. 35.7% of these treated patients reported an improvement or initial worsening of symptoms with subsequent improvement afterwards. 18 (62%) patients with PVOD died, 12 (41.3%) had a lung transplant and 6 (20.6%) were still alive without the transplant until the day data was collected. Mean duration from diagnosis to death and lung transplantation was 446 ± 405 days and 274±479 days respectively. Conclusion PVOD is a rare and lethal cause of pulmonary hypertension. When suspected, a trial of medical therapy should be initiated carefully. The evaluation for lung transplant should be considered early given its high mortality.

A large-scale retrospective study enabled deep-learning based pathological assessment of frozen procurement kidney biopsies to predict graft loss and guide organ utilization

Lesion scores on procurement donor biopsies are commonly used to guide organ utilization for deceased-donor kidneys. However, frozen sections present challenges for histological scoring, leading to inter- and intra-observer variability and inappropriate discard. Therefore, we constructed deep-learning based models to recognize kidney tissue compartments in hematoxylin &eosin-stained sections from procurement needle biopsies performed nationwide in years 2011-2020. To do this, we extracted whole-slide abnormality features from 2431 kidneys, and correlated with pathologists’ scores and transplant outcomes. A Kidney Donor Quality Score (KDQS) was derived and used in combination with recipient demographic and peri-transplant characteristics to predict graft loss or assist organ utilization. The performance on wedge biopsies was additionally evaluated. Our model identified 96% and 91% of normal/sclerotic glomeruli respectively; 94% of arteries/arterial intimal fibrosis; 90% of tubules. Whole-slide features of Sclerotic Glomeruli (GS)%, Arterial Intimal Fibrosis (AIF)%, and Interstitial Space Abnormality (ISA)% demonstrated strong correlations with corresponding pathologists’ scores of all 2431 kidneys, but had superior associations with post-transplant estimated glomerular filtration rates in 2033 and graft loss in 1560 kidneys. The combination of KDQS and other factors predicted one- and four-year graft loss in a discovery set of 520 kidneys and a validation set of 1040 kidneys. By using the composite KDQS of 398 discarded kidneys due to “biopsy findings”, we suggest that if transplanted, 110 discarded kidneys could have had similar survival to that of other transplanted kidneys. Thus, our composite KDQS and survival prediction models may facilitate risk stratification and organ utilization while potentially reducing unnecessary organ discard.

Contrast-enhanced ultrasonography for identifying acute kidney injury in brain-dead donors.

Acute kidney injury (AKI) is frequently found in deceased donors; however, few studies have reported the use of imaging to detect and identify this phenomenon. The purpose of this study was to detect renal microcirculatory perfusion in brain-dead donors using contrast-enhanced ultrasonography (CEUS), investigate the value of CEUS in identifying AKI, and analyze the correlation between CEUS and preimplantation biopsy results and early post-transplant renal function of grafts. This prospective study recruited 94 kidneys from brain-dead donors (AKI =44, non-AKI =50) from August 2020 to November 2022. The inclusion criteria were age ≥18 years and brain death. The exclusion criteria encompassed donors maintained with extracorporeal membrane oxygenation (ECMO) and the presence of irregular kidney anatomy. The mean age of the donors was 45.1±10.4 [standard deviation (SD)] years, and the majority were male (86.2%). CEUS was performed prior to organ procurement, and time-intensity curves (TICs) were constructed. The time to peak (TTP) and peak intensity (PI) of kidney segmental artery (KA), kidney cortex (KC), and kidney medulla (KM) were calculated using TIC analysis. Arrival time (AT) of KA (P<0.001) and TTP of kidney cortex (TTPKC) (P<0.001) of the non-AKI group were significantly shorter than those of the AKI group. The PI of the KA (P=0.003), KM (P=0.005), and kidney cortex (PIKC; P<0.001) of the non-AKI group were significantly higher than those of the AKI group. Multivariable logistic regression analysis showed that serum creatinine [odds ratio (OR) =1.06; 95% CI: 1.03-1.1; P<0.001], TTPKC (OR =1.38; 95% CI: 1.03-1.84; P=0.03), and PIKC (OR =0.95; 95% CI: 0.91-1; P=0.046) were the independent factors of AKI. The area under the receiver operating characteristic curve (AUC) for identifying AKI for TTPKC and PIKC was 0.73 and 0.71, respectively. TTPKC showed a weak correlation with interstitial fibrosis (r=0.23; P=0.03), PIKC showed a weak correlation with arterial intimal fibrosis ((r=-0.29; P=0.004) and arteriolar hyalinosis (r=-0.27; P=0.008), and PIKC showed the strongest correlation with eGFR on postoperative day 7 (r=-0.46; P=0.046) in the donor kidneys with AKI. CEUS can be used to identify AKI in brain-dead donors. Furthermore, there is a correlation between CEUS-derived parameters and pretransplant biopsy results and early preimplantation renal function of grafts.

Myth-Busting the Zone-of-Injury Concept: A Prospective Study on the Vascular Response to High-Energy Lower Extremity Trauma.

Although the zone-of-injury concept is widely accepted, no histologic studies of vessel wall changes causing the phenomenon have been reported. In this prospective study, the vascular response to high-energy lower extremity trauma was investigated to evaluate the validity of the zone-of-injury concept. The histologic appearance of arterial and venous walls in the zone of injury was studied in 19 patients (median age, 46 years; interquartile range, 29.5 to 62.5 years) who underwent osteosynthesis and free flap reconstruction after high-energy lower extremity open fracture. Vascular samples were harvested from the injured extremity, and control samples were harvested from the free flap donor site. Histologic and morphometric characteristics of the vessels were analyzed microscopically and using digital pathology QuPath software. Vascular samples were harvested on postinjury days 1 through 11. Intimal thickness was more than 3 times greater in arteries harvested from the zone of injury than in control samples ( P < 0.01), and the intima/media ratio was 2-fold that in control samples ( P = 0.01). Arterial intimal fibrosis was more evident in vessels harvested from the zone of injury ( P < 0.01), but medial fibrosis and medial thickness did not differ significantly between groups. Venous intimal thickening ( P < 0.01) and the intima/media ratio ( P = 0.02) were greater in samples from the zone of injury. Fibrosis-related changes did not differ between groups ( P = 0.45). These findings support the validity of the zone-of-injury concept by providing a novel histologic basis for this phenomenon. Intimal thickening and arterial intimal fibrosis are prominent histologic features of vessels affected by major lower extremity trauma.

Clinicopathological characteristics, risk factors and prognostic value of intrarenal vascular lesions in IgA nephropathy

BackgroundThe aim was to study clinicopathological characteristics, risk factors and renal outcome in IgA nephropathy (IgAN) patients with vascular lesions. MethodsWe enrolled a Chinese cohort with 458 biopsy-confirmed primary IgAN patients for a retrospective analysis. They were divided into three groups according to vascular lesions: no vascular lesions (n = 239), arterio-/arteriolosclerosis (n = 181) and microangiopathic lesions (n = 38). The clinicopathological features and renal outcome were recorded. In univariate and multivariate models, association between vascular lesions and renal outcome and vascular lesions associated clinical factors were analyzed. ResultsPatients with vascular lesions presented worse clinical characteristics with regard to blood pressure and kidney function, and segmental glomerulosclerosis (S1), tubular atrophy/interstitial fibrosis (T1/2) and lymphocytes and monocytes infiltration were more common. Furthermore, older age, hyperuricemia, proteinuria, global glomerulosclerosis and endocapillary hypercellularity (E1) were more severe in patients with simple arterio-/arteriolosclerosis. By multivariate logistic regression, age, MAP and eGFR were significantly associated with vascular lesions. Vascular lesions, especially arterio-/arteriolosclerosis, were significantly associated with poorer renal survival in IgAN patients, and renal survival was similar whether patients with arterio-/arteriolosclerosis received immunosuppressive therapy. In addition to eGFR, arterio-/arteriolosclerosis, along with arterial intimal fibrosis, was an independent predictor for renal survival in multivariate Cox analyses. ConclusionIgAN patients with vascular lesions, especially with arterio-/arteriolosclerosis, presented more severe clinicopathological features. Renal function, blood pressure and age contributed to distinguishing patients with vascular lesions. Arterio-/arteriolosclerosis lesions were associated with poorer renal survival.

#5132 POST-COVID-19 ANTI-GLOMERULAR BASEMENT MEMBRANE DISEASE: TWO CLINICAL CASES

Abstract Background and Aims Acute kidney injury is a common complication in patients hospitalized with COVID-19, has multiple aetiologies, and is usually multifactorial. We present two cases of anti-glomerular basement membrane (anti-GBM) disease diagnosed after SARS-CoV-2 infection, suggesting a causal correlation. Case Reports A 76-year-old female, with chronic kidney disease (serum creatinine 1.5mg/dL), hypertension, weight loss (16 Kg/6 months) and a pancreatic nodule under surveillance, presented to the emergency department with 1 week of nausea, vomits, diarrhoea and oliguria, as well as a history of mild SARS-CoV-2 infection 2 weeks before presentation. Lab work revealed severe anaemia (7.4 g/dL), inflammatory markers elevation, nephrotic proteinuria (proteinuria/creatininuria ratio 30 g/g), leucoerythrocyturia, serum creatinine of 19.3 mg/dL, hyperkalaemia and metabolic acidosis requiring dialysis induction. Renal ultrasound showed signs of chronicity and several cysts. Aetiological study disclosed positive anti-GBM antibody (1800 U/L) and negative ANCA. Complementary study failed to identify pulmonary involvement or neoplasms. Given the severity of the renal dysfunction along with the absence of alveolar haemorrhage, immunosuppression and plasmapheresis were not initiated. Patient was discharged and remains dialysis dependent. A 65-year-old male smoker with type 2 diabetes and combined pulmonary fibrosis and emphysema, presented in the emergency department with 2 months of asthenia, weight loss and anaemia, in addition to dyspnoea and haemoptysis in the past 3 days. Lab work exposed moderate anaemia (9.7 g/dL), elevated inflammatory markers, serum creatinine of 1.18 mg/dL (previously 0.8 mg/dL), leucoerythrocyturia and positive SARS-CoV-2 test. Angio-Computed Tomography exhibited known pulmonary fibrosis and possible bacterial superinfection. Despite antibiotic therapy (10 days of levofloxacin), haemoptysis remained and kidney function continuously worsened (serum creatinine 2.1 mg/dL). Complementary study showed positive ANCA-MPO (1125.4 U/L) and anti-GBM antibody (460.8U/L). Renal ultrasound was innocent. Kidney biopsy revealed: 6 glomeruli with cellular crescents with segmental necrosis, 3 with focal Bowman's capsule rupture; erythrocyte casts; intimal arterial fibrosis; moderate tubular atrophy; diffuse linear deposits of IgG. Immunosuppression was initiated with prednisolone (1 mg/Kg/day), cyclophosphamide (3x 12.5mg/Kg-750 mg, 2x 500 mg), rituximab (2x 1g), immunoglobulin (1x 2 g/Kg) and plasmapheresis (15 sessions). Kidney function continued to deteriorate (maximum serum urea 306 mg/dL, maximum serum creatinine 6.92 mg/dL) requiring dialysis induction 3 weeks after the beginning of immunosuppression. Even though haemoptysis ceased, the patient remains dialysis dependent 8 months after. Conclusion Literature reports an increase of Anti-GBM disease since the beginning of the pandemic. The presented cases support the apparent correlation, suggesting SARS-CoV-2 as a precipitant of this disease by endothelial injury with basal membrane exposure and autoantibody development. In the second case, the authors assume a subacute ANCA-MPO vasculitis with superimposed anti-GBM (eventually precipitated by COVID-19). Even though the causal association is not established, we highlight the importance of clinical suspicion of this rare aetiology in cases of acute kidney injury after SARS-CoV-2 infection.

Functional state of coronary shunts from the radial artery in the presence of morphological changes in its wall

The OBJECTIVE of the research was to study the patency of coronary shunts from the radial artery in the presence of morphological changes in its wall in the period from 40 to 52 months after surgery.METHODS AND MATERIALS. Fragments of 110 radial arteries taken from 103 patients for coronary artery bypass grafting in the period from 2018 to 2021 were subjected to histological examination. To assess the functional state of the shunts in the period from 40 to 52 months after surgery, computed tomography of the coronary arteries (CTCA) with contrast was performed in 66 patients.RESULTS. Histological examination revealed such changes in the radial artery wall as edema of one layer of the artery or all three layers, proliferation of the subendothelial layer of the inner coat, intimal fibrosis, partial obstruction of the artery lumen by a massive accumulation of agglutinated erythrocytes, as well as occlusion of the radial artery. Occlusion of the shunt from the radial artery in the period of 41–42 months was detected in 2 patients who underwent computed tomography of the coronary arteries.CONCLUSION. Statistical analysis of the obtained results revealed that the presence of such morphological changes in the radial artery wall as alteration, exudation and proliferation does not statistically significantly affect the timing of adequate functioning of the shunt.

P394 PULMONARY HYPERTENSION IN SEARCH OF GROUP

Abstract Episode of haemoptysis in a 25–year–old woman with the following medical history: surgical closure of Botallo‘s duct at the age of 5 months, coeliac disease, growth retardation, polycystic ovary, visus alterations. In the emergency room CT angiography of the chest showed the presence of subpleural parenchymal consolidation in the right lower lobe, with associated ground–glass opacities, cardiomegaly, severe pulmonary artery dilatation and hepatomegaly with intrathoracic involvement by a hernia of Morgagni on the right side. A porto–systemic shunt with an intrahepatic course was also noted in the duct at the VIII segment with an autonomic outlet in the right atrium. The patient was transferred to the Internal Medicine ward. Objective examination revealed an elf facies with hypertelorism, short stature, bradypsychism. On interview she reported dyspnoea on light exertion and frequent lipohymic episodes. Haematochemical examinations showed increased of bilirubinemia mainly indirect, Transaminases and of NTproBNP and normal ammonium levels. Blood gas analysis showed a tendency to respiratory alkalosis with oxyaemia at lower limits. Because of the suspicion of a syndromic picture, a genetic examination was performed. Cardiological evaluation showed a high ultrasound probability of pulmonary hypertension (PH). Transferred to cardiology, catheterisation confirmed pulmonary arterial hypertension (mPAP 64mmHg) precapillary (wedge 4mmHg) with high PVR (11 Wood Units) not responsive to nitric oxide. In addition, there was a superior vena cava protruding into the coronary sinus and an extrahepatic shunt with an isolated outlet in the RA without gradient. The hepatobiliary surgery consultation concluded for Abernethy syndrome, which is a rare congenital syndrome characterised by an extrahepatic portosystemic shunt in which the blood from the splanchnic and lienal circulation bypasses the portal vein and the liver, draining into the systemic circulation via an abnormal conduit. PH is a rare complication of this syndrome, maintained by hyperafflux, vasoactive mediators and the formation of microthrombi and intimal fibrosis in the pulmonary circulation. An HR–CT excluded venulo–capillary plexiform disease. Macitentan 10 mg/day was introduced, then continued at home for the benefit shown and follow–up at the Pulmonary Work Group was initiated. This PH, due to its association with an extremely rare pathology, required the collaboration of a diverse group of specialists.

Oxalate Nephropathy.

Oxalate Nephropathy.

Vein morphometry in end-stage kidney disease: Teasing out the contribution of age, comorbidities, and vintage to chronic wall remodeling.

Chronic kidney disease (CKD) is a highly comorbid condition with significant effects on vascular health and remodeling. Upper extremity veins are important in end-stage kidney disease (ESKD) due to their potential use to create vascular accesses. However, unlike arteries, the contribution of CKD-associated factors to the chronic remodeling of veins has been barely studied. We measured morphometric parameters in 315 upper extremity veins, 131 (85% basilic) from stage 5 CKD/ESKD patients and 184 (89% basilic) from non-CKD organ donors. Associations of demographic and clinical characteristics with intimal hyperplasia (IH) and medial fibrosis were evaluated using multivariate regression models. The study cohort included 33% females, 30% blacks, 32% Hispanics, and 37% whites. Over 60% had hypertension, and 25% had diabetes independent of CKD status. Among kidney disease participants, 26% had stage 5 CKD, while 22 and 52% had ESKD with and without history of a previous arteriovenous fistula/graft (AVF/AVG), respectively. Intimal hyperplasia was associated with older age (β = 0.13 per year, confidence interval [CI] = 0.002-0.26), dialysis vintage > 12 months (β = 0.22, CI = 0.09-0.35), and previous AVF/AVG creation (β = 0.19, CI = 0.06-0.32). Upper quartile values of IH were significantly associated with diabetes (odds ratio [OR] = 2.02, CI = 1.08-3.80), which demonstrated an additive effect with previous AVF/AVG history and longer vintage in exacerbating IH. Medial fibrosis also increased as a function of age (β = 0.17, CI = 0.04-0.30) and among patients with diabetes (β = 0.15, CI = 0.03-0.28). Age was the predominant factor predicting upper quartile values of fibrosis (OR = 1.03 per year, CI = 1.01-1.05) independent of other comorbidities. Age and diabetes are the most important risk factors for chronic development of venous IH and fibrosis independent of CKD status. Among kidney disease patients, longer dialysis vintage, and history of a previous AVF/AVG are strong predictors of IH.

The Relationship Between Klotho and SIRT1 Expression in Renal Aging Related Disease.

BackgroundThis study focused on renal arteriosclerosis and aimed to explore the relationship between Klotho and SIRT1 by morphological staining, which will help to provide new ideas for the treatment of renal-aging-related diseases and a theoretical basis for the development of new drugs.MethodsKidney tissue samples were collected from patients who underwent nephrectomy. HK-2 cells were cultured. The Hematoxylin-eosin (HE) staining, Periodic Acid-Schiff (PAS) staining, Masson’s Trichrome staining, Immunohistochemistry (IHC) staining, Immunofluorescence (ICC) and bioinformatics means were used for this study.ResultsHE staining showed that glomerulosclerosis was atrophic and cast was significantly increased luminal narrowing of renal arterioles in aging group. PAS staining showed that the number of podocytes was reduced, the mesangial matrix expansion and the intimal fibrosis of renal arterioles. Masson’s trichrome staining showed that there was massive collagen proliferation in the tubulointerstitial in aging group, as well as intimal thickening and fibrin deposition in the tubular walls of arterioles. IHC staining showed that the expression of Klotho and SIRT1 protein was downregulated in aging group and the trend of the two was positively correlated (P < 0.01). Klotho and SIRT1 co-localized in HK-2 cells and kidney tissue. The GEPIA database analysis showed a significant positive correlation between Klotho and SIRT1 in multiple human tissues and tumors.ConclusionGlomerulosclerosis in aging group is accompanied by low expression of Klotho and SIRT1 in renal tissue, and Klotho is positively correlated with SIRT1. Klotho-SIRT1 pathway may be involved in the occurrence and development of renal-aging-related diseases.

235.3: Allograft Vasculopathy in Kidney Transplant Patients: Clinical and Histological Associated Factors

Introduction: Allograft vasculopathy (AV) defined by arterial intimal fibrosis with mononuclear cell inflammation in fibrosis and formation of neointima is one of the main limiting factors in renal graft survival. The etiopathogenesis is multifactorial, including immune mediated mechanism (chronic active or chronic ABMR or mixed ABMR/TCMR), inmune independent factors (e.g.,donnor age) and the endothelial to mesenchymal transition (ETM).The aim of this study is to evaluate the presence of transplant vasculopathy in kidney transplant biopsies, and the risk factors associated. Methods: This retrospective study included 400 allograft biopsies for cause in 294 kidney transplant recipient from 2014 to 2018. All biopsies, with and without transplant vasculopathy, donor, recipient and transplant variables were analyzed. We classified the biopsies in Early (< 3 months) and late(> 3 months).Clinical variables of the recipient were analyzed: age, antiHLA sensitization; from the donor: age, alive -deceased; optimal-marginal and transplant process: TIF, mismatch, delayed graft function (DGF); histological features: rejections, microcirculation injury, C4d. Statistical analysis: Categorical variables are reported as percentages and continuous variables as mean ± standard deviation, median or interquartile range, according to distribution. Chi square test was used to compare categorical variables and T test for continuous variables. Logistic regression models were applied to determine the association of clinical and histological factors with vasculopathy. Odds ratios (OR) with 95% CI were estimated. A p <0.05 was considered significant. The statistical package Medcalc 3.0 was used. Results: Transplant vasculopathy was found in 51,7 % (207/400) sample biopsies, 40% in the early and 60 % in the late transplant biopsies. Recipient age 46(18-76) years, 57 % men, 11,1 % sensitized and 12,2 % hypersensitized. 19,3 % had unacceptable antigens and 16,6%(49/294) developed DSA. All patients received induction and triple immunosuppression therapy. Donor age was 46 (10-73) years, 51 % males, 54,4 % deceased donors and 16, 6%(49) met expanded criteria. Mean Ischemic time was 16,7 ± hours, MM 3.5(1.4), DGF 62,3 %. Vasculopathy in early biopsies was associated with ABMR in patients with DSA. In univariate analysis transplant vasculopathy was correlated with male recipient gender (p=0,0354), staining c4d +(p=0,029) and chronic glomerulopathy (p=0,0116). Late vasculopathy was associated with c4d + p=0,0048; MVI p=0,0018; late rejection p<0.0001 and cellular rejection p=0.03. In multivariate analysis recipient gender (p=0,04) and time of rejection(p=0,03) were statistically significant. Conclusion: Transplant vasculopathy was correlated with male recipient gender, staining c4d +, and chronic glomerulopathy. Late vasculopathy was associated with c4d +, MVI, late and cellular rejection.

Osseous Microanatomy and Histochemical Characterization in Species, Gender Determination and Age Estimation

Background: Bone is a tissue of particular interest, because the hard tissue of the skeleton is normally well preserved and details of microscopic structure can be seen in specimens many centuries old. The microscopic structure of bone can be utilized for identification of unknown bone samples in forensic odontology. Physical anthropologists may encounter complete or fragmentary specimens of bone in which standard anthropometric methods provide inconclusive or questionable information. If the histological structure of such material could reveal, with reasonable accuracy, details of species, age, and gender, it would be a useful and valuable laboratory tool. Materials and Methods: A cross-sectional analysis of formalin fixed paraffin embedded sections from biopsied lesions (5 cases each of goat bone, 5 cases of chicken bone specimen, 5 cases of human male bone specimen, 5 cases of human female bone specimen) was done. The variation of the trabeculae by measuring the average width of trabeculae, the average marrow space, and the ratio of the above two through morphometric analysis was assessed. The observational percentage variation amongst the species by number of osteons, osteocytes shape i.e., -spindle, elliptical and round, presence of inflammation was noted. The stroma and hard tissue for Collagen characterization (Special stains)Type, orientation and maturity using Picrosirus stain, Sub intimal fibrosis surrounding the bone using Van Gieson, Percentage of mature and immature bone pattern using Azan stain was analyzed. Result: Chicken bone shows absence of osteons in comparison to human bone with increased number of osteocytes. Goat bone shows plexiform pattern with scattered haversian canals more comparable to human bone architecture. Average human Haversian canal diameter was greater than non-human mammalian species. Azan staining helped in differentiation of mature from immature bone. Picrosirus staining helped in establishing collagen type, orientation and thickness. Sub intimal fibrosis surrounding the bone was checked using Van Gieson staining. Discussion: The complexities of bone tissue and its growth processes are such that misinterpretations of a critical nature can be made if the observer is not well informed on the multitude of basic details dealing with Osteogenesis, remodelling, and comparative histology. Conclusion: Bone histomorphological assessment is an effective method for species identification, gender determination and age estimation by fragmentary osseous remains.

Clinicopathological characteristics of high-altitude polycythemia-related kidney disease in Tibetan inhabitants

High-altitude polycythemia (HAPC) is a clinical syndrome that occurs in native inhabitants or long-term residents living at altitude. The kidney is one of the most affected organs. However, the clinical and kidney histopathological profiles of HAPC-related kidney disease have rarely been reported. Here, we report kidney biopsy-based clinicopathological study on this disease. HAPC was defined as excessive erythrocytosis [females, hemoglobin 190 g/L or more; males, 210 g/L or more] in patients living above an altitude of 2500 m for more than ten years. A total of 416 Tibetan patients underwent kidney biopsy between January 1, 2016, and November 31, 2020. Of these patients 17 met the diagnostic criteria for HAPC-related kidney disease. Clinically, these patients had a median urinary protein level of 2.5 g/24-hour (range 1.81-6.85). Twelve patients had hyperuricemia, nine had hypertension, and three had kidney insufficiency. On histopathology, glomerular hypertrophy, glomerular basement membrane thickening, podocyte foot process effacement, segmental glomerulosclerosis and global glomerulosclerosis were the main features. Extraglomerular arterial/arteriolar lesions were common, presenting as intimal fibrosis, hyalinosis and endothelial cell swelling/subintimal edema. Expansion of the arterial/arteriolar medial wall area characterized by smooth muscle cell proliferation was clearly observed, potentially indicating vascular remodeling. Hypoxia-inducible factor 2α was expressed in the kidney tissues of these patients. Thus, the pathological changes of HAPC-related kidney disease encompassed both glomerular and extraglomerular vascular lesions, suggesting a key role of both chronic hypoxia itself and secondary hemodynamic changes in the pathogenesis of this disease.

Abnormal time-zero histology is predictive of kidney transplant outcomes.

Time-zero biopsies can detect donor-derived lesions at the time of kidney transplantation, but their utility in predicting long-term outcomes is unclear under the updated Kidney Allocation System. We conducted a single-center retrospective cohort study of 272 consecutive post-reperfusion time-zero biopsies. We tested the hypothesis that abnormal time-zero histology is a strong indicator of donor quality that increases the precision of the kidney donor profile index (KDPI) score to predict long-term outcomes. We detected abnormal biopsies in 42% of the cohort, which were independently associated with a 1.2-fold increased hazard for a composite of acute rejection, allograft failure, and death after adjusting for clinical characteristics including KDPI. By Kaplan-Meier analysis, the relationship between abnormal time-zero histology and the composite endpoint was only significant in the subgroup of deceased donor kidney transplants with KDPI scores >35. Abnormal time-zero histology, particularly vascular intimal fibrosis and arteriolar hyalinosis scores, was independently associated with lower 12-month estimated GFR. In conclusion, abnormal time-zero histology is relatively common and identifies a group of kidney recipients at increased risk for worse long-term outcomes. Further studies are needed to determine the optimal patient population in which to deploy time-zero biopsies as an additional surveillance tool.