In six patients who received bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor (VEGF), proteinuria subsequently developed, and thrombotic microangiopathy was ...shown on renal biopsy. In a murine model, the authors showed that using conditional gene targeting to ablate the VEGF gene from renal podocytes can trigger thrombotic microangiopathy. This finding suggests that glomerular injury from bevacizumab may be due to the direct targeting of VEGF.
In six patients who received bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor (VEGF), proteinuria subsequently developed and thrombotic microangiopathy was shown on renal biopsy. Findings from this study suggest that glomerular injury from bevacizumab may be due to the direct targeting of VEGF.
The discovery that vascular endothelial growth factor (VEGF) is a critical factor in the growth of blood vessels led to the development of VEGF inhibitors, such as bevacizumab, to treat diseases that are characterized by pathologic angiogenesis. The addition of bevacizumab to chemotherapeutic regimens improved survival rates among patients with cancers of the colon, lung, and breast; it is also used as a single agent for renal-cell carcinoma. With the expanding use of bevacizumab, adverse effects have become apparent. Two of the most common are proteinuria (in 21 to 64% of patients) and hypertension (in 3 to 36%).
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Nephrotic-range proteinuria, . . .
There remains a need for robust mouse models of diabetic nephropathy (DN) that mimic key features of advanced human DN. The recently developed mouse strain BTBR with the ob/ob leptin-deficiency ...mutation develops severe type 2 diabetes, hypercholesterolemia, elevated triglycerides, and insulin resistance, but the renal phenotype has not been characterized. Here, we show that these obese, diabetic mice rapidly develop morphologic renal lesions characteristic of both early and advanced human DN. BTBR ob/ob mice developed progressive proteinuria beginning at 4 weeks. Glomerular hypertrophy and accumulation of mesangial matrix, characteristic of early DN, were present by 8 weeks, and glomerular lesions similar to those of advanced human DN were present by 20 weeks. By 22 weeks, we observed an approximately 20% increase in basement membrane thickness and a >50% increase in mesangial matrix. Diffuse mesangial sclerosis (focally approaching nodular glomerulosclerosis), focal arteriolar hyalinosis, mesangiolysis, and focal mild interstitial fibrosis were present. Loss of podocytes was present early and persisted. In summary, BTBR ob/ob mice develop a constellation of abnormalities that closely resemble advanced human DN more rapidly than most other murine models, making this strain particularly attractive for testing therapeutic interventions.
The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into ...three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.1
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Glomerular diseases remain the leading cause of chronic and end-stage kidney disease. Significant advances in our understanding of human glomerular diseases have been enabled by the development and ...better characterization of animal models. Diseases of the glomerular epithelial cells (podocytes) account for the majority of proteinuric diseases. Rodents have been extensively used experimentally to better define mechanisms of disease induction and progression, as well as to identify potential targets and therapies. The development of podocyte-specific genetically modified mice has energized the research field to better understand which animal models are appropriate to study acquired podocyte diseases. In this review we discuss inducible experimental models of acquired nondiabetic podocyte diseases in rodents, namely, passive Heymann nephritis, puromycin aminonucleoside nephrosis, adriamycin nephrosis, liopolysaccharide, crescentic glomerulonephritis, and protein overload nephropathy models. Details are given on the model backgrounds, how to induce each model, the interpretations of the data, and the benefits and shortcomings of each. Genetic rodent models of podocyte injury are excluded.
Fibrillary and immunotactoid glomerulonephritis are infrequent causes of primary nephrotic range proteinuria and are poorly understood. Recent significant developments include the discovery of DNA ...JB9 antigen in fibrillary glomerulonephritis. Here, we present a case of a middle-aged woman who presented with nephrotic range proteinuria, hematuria, and normal renal function. Renal biopsy revealed fibrils that were randomly arranged on electron microscopy. They were of small size and congo red negative similar to the ones found in fibrillary glomerulonephritis, but were also DNA JB 9 negative, and had a hollow core like in immunotactoid glomerulopathy. Though we try to classify these conditions into either immunotactoid glomerulonephropathy (ITGN) or fibrillary glomerulonephritis (FGN), there are scenarios such as this case where it does not fit into either and is probably an overlap or intermediate variant of these two conditions. Pathological features of these glomerulonephrites are discussed together with their clinical implications, treatment choices, and diagnostic importance.
Systemic sclerosis (SSc) is a rare autoimmune disorder that is typically divided into limited cutaneous systemic sclerosis and diffuse cutaneous systemic sclerosis. Scleroderma renal crisis (SRC) is ...a severe complication of SSc and typically presents with new-onset hypertension and a reduction in renal functioning. In patients presenting with typical features of SRC, treatment with an angiotensin-converting enzyme inhibitor along with dialysis as needed is typically initiated empirically. Renal biopsy is not recommended in patients with SSc presenting with typical features of SRC. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare co-occurrence with SSc, in around 2.5% to 9% of patients. AAV is an inflammatory condition that can result in renal failure due to mononuclear cell infiltration and destruction of blood vessels. Treatment of AAV is drastically different from SRC and typically consists of immunosuppressants and dialysis if needed. SRC and AAV can only reliably be distinguished by renal biopsy. We present a rare case of a 70-year-old female with limited cutaneous systemic sclerosis who presented to the emergency department with new-onset renal failure. Her serology was found to be positive for antinuclear antibodies and myeloperoxidase antibodies, resulting in a renal biopsy, which revealed an acute necrotizing vasculitis consistent with AAV. We suggest consideration of a renal biopsy in patients with SSc who present with new-onset renal failure, especially with nonresponse to SRC treatment or positive serology.
Hematopoietic cell transplantation is a common treatment option for a variety of hematopoietic malignancies. As a result of the use of total body irradiation and/or chemotherapeutic agents, renal ...dysfunction often ensues. Many pharmacologic agents, such as cyclosporine and high-intensity conditioning regimens, have been linked with thrombotic microangiopathy. In addition, an association between membranous nephropathy and graft-versus-host disease has been reported in this clinical setting.
A study of autologous and allogeneic hematopoietic cell transplantation patients with renal dysfunction was conducted to document the spectrum of renal manifestations. The pathology files at the University of Washington and University of Chicago Medical Centers were reviewed, and 20 patients with a kidney biopsy after hematopoietic cell transplantation were identified. The histologic findings were correlated with relevant clinical information.
A wide spectrum of renal diseases could be classified into four categories: (1) Complications related to hematopoietic cell transplantation (conditioning regimen, immunosuppression, or posttransplantation complications), (2) podocytopathy, (3) membranous nephropathy, or (4) recurrence or persistence of original hematologic disease. Pathologic diagnoses included thrombotic microangiopathy, polyoma virus nephropathy, acute kidney injury/acute tubular necrosis, acute and chronic interstitial nephritis, minimal-change disease, "tip" variant of focal segmental glomerulosclerosis, membranous nephropathy, amyloidosis, and myeloma cast nephropathy. Membranous nephropathy, minimal-change disease, and amyloidosis were common causes of severe proteinuria. Because of the conditioning regimens, posttransplantation complications, and potential nephrotoxic agents used during hematopoietic cell transplantation, it was difficult to attribute the subsequent renal dysfunction to specific factors.
The renal biopsy remains essential for diagnosing the underlying injury that can affect one or more compartments of the kidney in this unique clinical setting.
Coronavirus disease 2019 (COVID-19), initially appreciated as a respiratory illness, is now known to affect many organs in the human body. Significant data has become available on muscle involvement, ...with creatinine kinase elevations present in a significant percentage of patients. For those with suspected COVID-19-associated myositis, the imaging modality of choice has been gadolinium-enhanced magnetic resonance imaging; however, the use of technitium-99 m bone scan has not been previously reported. Here, we report two cases of COVID-19 patients with severe elevation in creatinine kinase who underwent technitium-99 m bone scan. The resulting images showed diffuse symmetrical muscle involvement. Both patients developed acute renal injury due to rhabdomyolysis. To our knowledge, this is the first report of bone scan as a diagnostic imaging modality for COVID-19-associated myositis.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
ANCA (anti-neutrophil cytoplasmic antibody) vasculitides are systemic autoimmune diseases in which anti-neutrophilic cytoplasmic antibodies activate primed neutrophils, thereby generating an ...inflammatory cascade resulting in the damage of small sized blood vessels in various organs of the body, including the heart. Pleuropericardial involvement is underrecognized as a complication of ANCA vasculitis and is highlighted in this case report of a 51-year-old male who presented with an initial symptomatic presentation of pleuropericardial effusion progressing to pericardial tamponade in the setting of a later renal biopsy proven pauci-immune crescentic glomerulonephritis with high ANA titres along with positive cANCA (cytoplasmic ANCA) and PR3 (proteinase 3) antibodies. He was found to have acute renal failure which progressively got better with cyclophosphamide.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Summary Glomerular injury may occur as a result of immune dysfunction in patients with remote lymphoplasmacytic neoplasms. Glomerular injury concurrent with direct infiltration of the kidney by ...lymphoplasmacytic neoplasms has been reported but is not extensively characterized. We identified 18 patients, all presenting with elevated serum creatinine and many with proteinuria, whose renal biopsies showed direct involvement of kidney by a variety of neoplasms, including chronic leukocytic leukemia/small lymphocytic lymphoma (n = 7), diffuse large B-cell lymphoma (n = 6), multiple myeloma (n = 4), or B-cell lymphoblastic lymphoma (n = 1). In 10 cases (55%), there was coexistent glomerular pathology: 5 of these cases, including glomerulonephritis with membranoproliferative glomerulonephritis–like pattern of injury (n = 4) and membranous nephropathy (n = 1), featured deposition of immune complexes; 2 demonstrated deposition of monoclonal immunoglobulin components: λ light chain amyloidosis (n = 1) and light chain deposition disease (n = 1); 2 showed minimal change disease; and, in 1 case, there was focal crescentic pauci-immune–type glomerulonephritis. In addition, 1 biopsy revealed diabetic nephropathy and 3 showed nonspecific ischemic changes. In the remaining 4 cases, there were no significant glomerular abnormalities. In 11 cases (61%), the diagnosis of lymphoproliferative disease was established following the kidney biopsy. Our study indicates that lymphoplasmacytic neoplasms may be first diagnosed in renal biopsies performed for evaluation of renal dysfunction with or without proteinuria. Concurrent glomerular injury may be a direct result of the lymphoplasmacytic disorder through a paraprotein deposition process resulting in amyloid or monoclonal immunoglobulin deposition disease, or may be caused indirectly through immune-mediated mechanisms, as in the cases of glomerulonephritis with membranoproliferative glomerulonephritis–like pattern of injury, membranous nephropathy, and possibly minimal change disease.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK