RESUMO
Type D enterotoxemia, caused by Clostridium perfringens epsilon toxin (ETX), is one of the most economically important clostridial diseases of sheep. Acute type D enterotoxemia is characterized by well-documented lesions in the nervous, cardiocirculatory, and pulmonary systems. However, discrepancies and confusion exist as to whether renal lesions are part of the spectrum of lesions of this condition, which is controversial considering that for many decades it has been colloquially referred to as "pulpy kidney disease." Here, the authors assess renal changes in an experimental model of acute type D enterotoxemia in sheep and evaluate the possible role of ETX in their genesis. Four groups of 6 sheep each were intraduodenally inoculated with either a wild-type virulent C. perfringens type D strain, an etx knockout mutant unable to produce ETX, the etx mutant strain complemented with the wild-type etx gene that regains the ETX toxin production, or sterile culture medium (control group). All sheep were autopsied less than 24 hours after inoculation; none of them developed gross lesions in the kidneys. Ten predefined histologic renal changes were scored in each sheep. The proportion of sheep with microscopic changes and their severity scores did not differ significantly between groups. Mild intratubular medullary hemorrhage was observed in only 2 of the 12 sheep inoculated with the wild-type or etx-complemented bacterial strains, but not in the 12 sheep of the other 2 groups. The authors conclude that no specific gross or histologic renal lesions are observed in sheep with experimental acute type D enterotoxemia.
Assuntos
Infecções por Clostridium , Doenças dos Ovinos , Ovinos , Animais , Clostridium perfringens/genética , Enterotoxemia/microbiologia , Infecções por Clostridium/patologia , Infecções por Clostridium/veterinária , Rim/patologia , Doenças dos Ovinos/patologiaRESUMO
Membranous nephropathy (MN) is a form of kidney disease that is idiopathic in 70%-80% of cases. Glomerular involvement in autoimmune thyroiditis can occur in 10%-30% of patients, and MN manifests in association with Hashimoto thyroiditis in up to 20% of the cases with glomerular involvement. Reports of MN associated with Graves' disease (GD) are extremely rare in the current literature. Herein, we report the case of a 46-year-old man admitted to the hospital with nephrotic syndrome and symptomatic hyperthyroidism due to GD. Kidney biopsy revealed a secondary MN pattern. Immunohistochemical staining for PLA2R was negative, and thyroglobulin showed weak and segmental staining along the glomerular capillary. Anti-thyroid peroxidase (TPO) antibody test was not performed. The patient was treated for GD with methimazole and prednisone, and despite reaching clinical improvement after 8 months, proteinuria remained close to nephrotic levels. In this scenario, the patient was submitted to radioactive iodine, and there was a dramatic reduction in proteinuria levels after treatment. In conclusion, GD association with MN is rare, and when present, diagnosis using PLA2R and immunohistochemistry can be useful in determining association. In addition, radioactive iodine therapy can be an effective treatment modality when preceded with immunosuppressive corticosteroid therapy.
Assuntos
Glomerulonefrite Membranosa , Doença de Graves , Neoplasias da Glândula Tireoide , Glomerulonefrite Membranosa/diagnóstico , Glomerulonefrite Membranosa/tratamento farmacológico , Glomerulonefrite Membranosa/etiologia , Doença de Graves/complicações , Doença de Graves/diagnóstico , Doença de Graves/tratamento farmacológico , Humanos , Radioisótopos do Iodo/uso terapêutico , Masculino , Pessoa de Meia-Idade , ProteinúriaRESUMO
INTRODUCTION: Electron microscopy (EM) has been used in the study of renal biopsies for more than 5 decades; however, it is expensive and the possibility of restricting it to selected cases has been considered. This study aims to reevaluate the necessity for EM in the diagnosis of renal biopsies today. MATERIAL AND METHODS: All renal biopsies taken between 2016 and 2019 with adequate light microscopy (LM), immunofluorescence (IF) and EM studies were included. The initial diagnosis (without EM) and the final diagnosis (with EM) was recorded. EM was considered necessary in cases in which the initial and final diagnoses did not concur, when diagnosis could not be made with LM and IF only or if the EM study revealed further clinically relevant findings. RESULTS: A total of 621 biopsies were included, 498 (80.2%) of native kidneys and 123 (19.8%) of transplanted kidneys. In 115 cases (18.5%) EM had been deemed necessary for diagnosis; it was required more frequently in hereditary diseases (96.8%) and isolated hematuria (88.9%) but less often in nephrotic syndrome (6.7%) and renal transplant biopsy (5.7%) (p < 0.001). CONCLUSIONS: EM was required in less than a fifth of renal biopsies, being more necessary in isolated hematuria and hereditary diseases and less so in nephrotic syndrome and in renal graft biopsies. These findings may prove useful as a guide to case selection protocols in which EM could be considered as a non-mandatory technique.
Assuntos
Nefropatias , Rim , Biópsia , Humanos , Microscopia Eletrônica , NefrectomiaRESUMO
BACKGROUND: With the emergence of the new coronavirus pandemic (COVID-19), distance learning, especially that mediated by information and digital communication technologies, has been adopted in all areas of knowledge and at all levels, including medical education. Imminently practical areas, such as pathology, have made traditional teaching based on conventional microscopy more flexible through the synergies of computational tools and image digitization, not only to improve teaching-learning but also to offer alternatives to repetitive and exhaustive histopathological analyzes. In this context, machine learning algorithms capable of recognizing histological patterns in kidney biopsy slides have been developed and validated with a view to building computational models capable of accurately identifying renal pathologies. In practice, the use of such algorithms can contribute to the universalization of teaching, allowing quality training even in regions where there is a lack of good nephropathologists. The purpose of this work is to describe and test the functionality of SmartPathk, a tool to support teaching of glomerulopathies using machine learning. The training for knowledge acquisition was performed automatically by machine learning methods using the J48 algorithm to create a computational model of an appropriate decision tree. RESULTS: An intelligent system, SmartPathk, was developed as a complementary remote tool in the teaching-learning process for pathology teachers and their students (undergraduate and graduate students), showing 89,47% accuracy using machine learning algorithms based on decision trees. CONCLUSION: This artificial intelligence system can assist in teaching renal pathology to increase the training capacity of new medical professionals in this area.
Assuntos
COVID-19 , Educação a Distância , Inteligência Artificial , Humanos , Aprendizado de Máquina , SARS-CoV-2 , EnsinoRESUMO
BACKGROUND: The prevalence of glomerular disease (GD) varies according to the different socio-demographic characteristics of each population. For the first time we present the prevalence of the different forms of GD among patients from several different areas of Columbia. METHODS: Data from 12,613 renal biopsies studied at our University Hospital between 2003 and 2015 was reviewed. Pathology results were classified according to a list of renal diseases proposed by various authors. RESULTS: Focal segmental glomerulosclerosis was present in 22%, IgA disease in 21%, Lupus nephritis in 17%, membranous glomerulonephritis in 13% and thin basal membrane disease in 9%. CONCLUSIONS: This study confirms that focal segmental glomerulosclerosis and IgA disease are the most prevalent GDs found in Columbian patients. This is the first study to analyze GDs in a Columbian population and we recommend that a national registry system be created to collect comprehensive information from future research.
Assuntos
Glomerulonefrite/epidemiologia , Adulto , Biópsia , Criança , Colômbia/epidemiologia , Feminino , Glomerulonefrite/patologia , Glomerulonefrite por IGA/epidemiologia , Glomerulosclerose Segmentar e Focal/epidemiologia , Humanos , Rim/patologia , Masculino , Prevalência , Sistema de Registros , Estudos RetrospectivosRESUMO
Clinical and histological factors have been identified as predictors of early and late renal outcome in ANCA-associated vasculitides (AAV). The presence and severity of kidney involvement at diagnosis are associated with poor prognosis in both patient and renal survival. Histologic findings remain the gold standard for diagnosing patients with AAV. In order to quantify the extent of the morphological parameters in the renal biopsies and to identify the histopathological lesions that predict renal outcome, several scoring systems have been proposed to systematically assess kidney biopsies in AAV. Renal pathologists from an international working group proposed in 2010 a new histopathological classification. This scheme comprises four general categories, based on the predominance of the glomerular histological lesions: focal (≥50% normal glomeruli); crescentic (≥50% glomeruli with cellular crescents); mixed (<50% normal, <50% crescentic, <50% globally sclerotic glomeruli), and sclerotic (≥50% globally sclerotic glomeruli). This article reviews the background and the main studies that have validated the histopathologic classification of ANCA-associated glomerulonephritis, the conclusions derived from these studies, and the perspectives for the assessment of renal outcome in AAV.
Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/patologia , Glomerulonefrite/classificação , Glomerulonefrite/patologia , Rim/patologia , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/diagnóstico , Anticorpos Anticitoplasma de Neutrófilos/análise , HumanosRESUMO
BACKGROUND: Mesoamerican nephropathy (MeN) is a chronic kidney disease affecting rural inhabitants in Central America. We have previously described the renal morphology in 8 patients from El Salvador. To confirm the renal pathology, we have studied kidney biopsies from patients with MeN in Nicaragua. Follow-up urine and blood samples from both biopsy studies were collected to investigate the natural history. STUDY DESIGN: Case series. SETTINGS & PARTICIPANTS: In the kidney biopsy study, 19 male sugarcane workers in Nicaragua with suspected MeN were investigated with questionnaires, kidney biopsies, and blood and urine analysis. Inclusion criteria were age 20 to 65 years and plasma creatinine level of 1.13 to 2.49mg/dL or estimated glomerular filtration rate (eGFR) of 30 to 80mL/min/1.73m2. Exclusion criteria were proteinuria with protein excretion > 3g/24 h, uncontrolled hypertension, diabetes mellitus, or other known kidney disease. In the follow up-study, blood and urine from the kidney biopsy study in Nicaragua (n=18) and our previous biopsy study of MeN cases in El Salvador (n=7) were collected 1 to 1.5 and 2 to 2.5 years after biopsy, respectively. OUTCOMES: Renal morphology, clinical, and biochemical characteristics, change in eGFR per year. MEASUREMENTS: eGFR was calculated using the CKD-EPI creatinine (eGFRcr), cystatin C (eGFRcys), and creatinine-cystatin C (eGFRcr-cys) equations. RESULTS: In the kidney biopsy study, participants had a mean eGFRcr of 57 (range, 33-96) mL/min/1.73m2. 47% had low plasma sodium and 21% had low plasma potassium levels. 16 kidney biopsies were representative and showed glomerulosclerosis (mean, 38%), glomerular hypertrophy, and signs of chronic glomerular ischemia. Mild to moderate tubulointerstitial damage and mostly mild vascular changes were seen. In the follow up-study, median duration of follow-up was 13 (range, 13-27) months. Mean change in eGFRcr was -4.4±8.4 (range, -27.7 to 10.2) mL/min/1.73m2 per year. Most patients had stopped working with sugarcane cultivation. LIMITATIONS: 3 biopsy specimens had 4 or fewer glomeruli. CONCLUSIONS: This study confirms the renal morphology of MeN: chronic glomerular and tubulointerstitial damage with glomerulosclerosis and chronic glomerular ischemia. Follow-up data show that eGFRs, on average, deteriorated.
Assuntos
Taxa de Filtração Glomerular , Glomérulos Renais/patologia , Insuficiência Renal Crônica/patologia , Injúria Renal Aguda , Adulto , América Central/epidemiologia , Creatinina/metabolismo , Cistatina C/metabolismo , Progressão da Doença , El Salvador , Doenças Endêmicas , Fazendeiros , Seguimentos , Temperatura Alta , Humanos , Hipertrofia , Hipopotassemia/epidemiologia , Hipopotassemia/metabolismo , Hiponatremia/epidemiologia , Hiponatremia/metabolismo , Hipovolemia , Biópsia Guiada por Imagem , Isquemia , Rim/metabolismo , Rim/patologia , Rim/fisiopatologia , Glomérulos Renais/irrigação sanguínea , Glomérulos Renais/metabolismo , Glomérulos Renais/fisiopatologia , Masculino , Pessoa de Meia-Idade , Nicarágua/epidemiologia , Exposição Ocupacional , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/fisiopatologia , População Rural , Saccharum , Esclerose , Ultrassonografia , Desequilíbrio Hidroeletrolítico , Adulto JovemRESUMO
BACKGROUND: The study investigated whether immunohistochemical features of interstitial and glomerular CD56 and CD16 infiltrates - NK cells markers - could be associated with microcirculation injury scores - peritubular capillaritis (ptc) and glomerulitis (g) - and graft survival. METHODS: The research analyzed the immunohistochemical pattern of CD56 and CD16 in interstitial and glomerular compartments of biopsies for-cause biopsies from 59 recipients diagnosed with acute rejection (mean = 135.5 days post-transplant). RESULTS: Interstitial CD56+ cells had an increased expression for glomerulitis (g ≥ 1) (P = 0.02) and peritubular capillaritis (ptc ≥ 2) (P = 0.003) presence. It was noted that interstitial CD56 + cells with mean above 0.56 cells/mm2 had worse allograft survival. CD56+ cells in the interstitial compartment with mean less than or equal to 0.56cells/mm2 was related with absence or mild peritubular capillaritis (P = 0.012) and mean above 0.56 cells/mm2 , respectively, with glomerulitis (P = 0.002) presence. Interstitial CD16 cells showed greater positive results in relation to peritubular capillaritis (P = 0.0001) cases. Similarly, it was observed that glomerular CD16+ cells had higher positive results in glomerulitis (P = 0.009) presence. CONCLUSIONS: The study findings showed that CD56+ cell infiltrated in the interstitial compartment was significantly associated with microcirculation injury scores, especially the glomerulitis, and graft survival.
Assuntos
Antígeno CD56/análise , Rejeição de Enxerto , Sobrevivência de Enxerto , Transplante de Rim/efeitos adversos , Receptores de IgG/análise , Doença Aguda , Adolescente , Adulto , Biópsia , Feminino , Proteínas Ligadas por GPI/análise , Humanos , Masculino , Microcirculação , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
BACKGROUND: An endemic of chronic kidney disease (CKD) of unknown cause among rural inhabitants in Central America has been identified. Young and otherwise healthy men working in plantations are frequently affected. The name Mesoamerican nephropathy (MeN) has been suggested. Clinically, MeN presents with low-grade proteinuria and progressive kidney failure. The renal pathology of this disease has not yet been described. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: 8 male patients with CKD of unknown cause and clinically suspected MeN were recruited from a nephrology unit in El Salvador. All recruited patients had been working on plantations. Kidney biopsies, blood, and urine samples were collected. OUTCOMES & MEASUREMENTS: Renal morphology examined with light microscopy, immunofluorescence, and electron microscopy; clinical and biochemical characteristics. RESULTS: A similar pattern was seen in all 8 biopsy specimens, with extensive glomerulosclerosis (29%-78%) and signs of chronic glomerular ischemia in combination with tubular atrophy and interstitial fibrosis, but only mild vascular lesions. Electron microscopy indicates podocytic injury. Biochemical workup showed reduced estimated glomerular filtration rate (27-79 mL/min/1.73 m(2) with the CKD Epidemiology Collaboration [CKD-EPI] creatinine equation), low-grade albuminuria, and increased levels of tubular injury biomarkers. Hypokalemia was found in 6 of 8 patients. LIMITATIONS: Small number of patients from one country. CONCLUSIONS: This study is the first report of the biochemical and morphologic findings in patients with MeN. Our findings indicate that MeN constitutes a previously unrecognized kidney disease with damage to both glomerular and tubulointerstitial compartments.