Publications by authors named "Ingeborg M Bajema"

Article Synopsis
  • Recurrent IgA deposition after kidney transplantation is common, but it's unclear if it causes organ damage or is harmless.
  • A study analyzed kidney transplant recipients with native IgA nephropathy undergoing biopsies from 1995 to 2020, revealing that 37% had recurrent IgA deposition, but there were no substantial clinical differences between those with and without it.
  • While recurrent IgA deposition alone didn't lead to graft failure, the presence of the complement factor C4d was linked to higher graft loss risk, indicating its potential pathogenic role in recurrent IgA nephropathy.
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Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis consists of two main diseases, granulomatosis with polyangiitis and microscopic polyangiitis, and remains among the most devastating and potentially lethal forms of autoimmune inflammatory disease. Granulomatosis with polyangiitis and microscopic polyangiitis are characterised by a necrotising vasculitis that can involve almost any organ, and have generally been studied together. The diseases commonly affect the kidneys, lungs, upper respiratory tract, skin, eyes, and peripheral nerves.

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The histopathological lesions, minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) are entities without immune complex deposits which can cause podocyte injury, thus are frequently grouped under the umbrella of podocytopathies. Whether MCD and FSGS may represent a spectrum of the same disease remains a matter of conjecture. Both frequently require repeated high-dose glucocorticoid therapy with alternative immunosuppressive treatments reserved for relapsing or resistant cases and response rates are variable.

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Glomerular fibrillary deposits have occasionally been reported in diabetic nephropathy, but no large-scale, ultrastructural evaluation of these deposits has been reported so far. Here, we report our study of glomerular non-Congophilic, DnaJ homolog subfamily B member 9 negative fibrillary deposits in diabetic nephropathy as characterized by transmission electron microscopy. Clinical data from 55 patients with biopsy-confirmed diabetic nephropathy and 18 healthy living donors were reviewed, and their biopsies were evaluated by light microscopy, immunofluorescence, and electron microscopy.

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Glomerular diseases are common causes of chronic kidney disease in childhood, adolescence, and adulthood. The epidemiology of glomerular diseases differs between different age groups, with minimal change disease being the leading cause of nephrotic syndrome in childhood, while membranous nephropathy and focal segmental glomerulosclerosis are more common in adulthood. IgA vasculitis is also more common in childhood.

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Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, characterized by asthma, eosinophilia and granulomatous or vasculitic involvement of several organs. The diagnosis and management of EGPA are often challenging and require an integrated, multidisciplinary approach. Current practice relies on recommendations and guidelines addressing the management of ANCA-associated vasculitis and not specifically developed for EGPA.

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The first European Vasculitis Society (EUVAS) meeting report was published in 2017. Herein, we report on developments in the past 5 years which were greatly influenced by the pandemic. The adaptability to engage virtually, at this critical time in society, embodies the importance of networks and underscores the role of global collaborations.

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Objectives: We aimed to determine the presence, amount and origin of microchimerism in peripheral blood of pregnant and non-pregnant parous women with systemic lupus erythematosus (SLE) as compared to control subjects.

Methods: We performed a comparative study in which peripheral blood was drawn from eleven female non-pregnant SLE-patients and 22 control subjects, and from six pregnant SLE-patients and eleven control subjects during gestation and up to six months postpartum. Quantitative PCR for insertion-deletion polymorphisms and null alleles was used to detect microchimerism in peripheral blood mononuclear cells and granulocytes.

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Introduction: Lupus nephritis (LN) class III or IV is strongly related to patient mortality and morbidity. The interobserver agreement of endocapillary hypercellularity by routine light microscopy, one of the most important lesions determining whether class III or IV is present, is moderate. In IgA nephropathy (IgAN), the presence of glomerular CD68+ cells was found to be a good surrogate marker for endocapillary hypercellularity.

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Introduction: In 2020, a working group of 13 renal pathologists published consensus definitions for 47 individual glomerular lesions found on light microscopy (LM) and 47 glomerular lesions and 9 normal structures found on electron microscopy (EM).

Methods: To test the impact of these definitions on identification of these lesions and structures, 2 surveys were circulated to all members of the Renal Pathology Society (RPS), each having 32 images (19 LM, 13 EM) and accompanying questions with 5 multiple-choice answers, one being the consensus choice of the working group. The first survey (survey 1 [S1]), answered by 297 RPS members, was sent in September 2020, before publication of the consensus definitions.

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The Coronavirus Disease 2019 (COVID-19) pandemic influenced the management of patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis. A paucity of data exists on outcome of patients with vasculitis following COVID-19, but mortality is higher than in the general population and comparable to patients undergoing haemodialysis or kidney transplant recipients (reported mortality rates of 20-25%). Delays in diagnosis have been reported, which are associated with sequelae such as dialysis-dependency.

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Background: Renal involvement in ANCA-associated vasculitis (AAV) is associated with poor outcomes. The clinical significance of arteritis of the small kidney arteries has not been evaluated in detail.

Methods: In a multicenter cohort of patients with AAV and renal involvement, we sought to describe the clinicopathologic characteristics of patients with AAV who had renal arteritis at diagnosis, and to retrospectively analyze their prognostic value.

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The usage of artificial intelligence to evaluate histological images was recently explored in many different areas of pathology. Studies focusing on nephropathology demonstrated that algorithms could be trained to identify various structures of the kidney, like glomeruli and interstitium, as well as performing a classification task just as good as highly experienced pathologists. It is conceivable that further development of digitalized pathology in combination with all opportunities that artificial intelligence and machine learning have to offer, will rapidly change the work of the clinical pathologist in a substantial way.

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The endothelial glycoprotein thrombomodulin regulates coagulation, inflammation, and apoptosis. In diabetic mice, reduced thrombomodulin function results in diabetic nephropathy (DN). Furthermore, thrombomodulin treatment reduces renal inflammation and fibrosis.

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Over the past 2 decades, scoring systems for multiple glomerular diseases have emerged, as have consortia of pathologists and nephrologists for the study of glomerular diseases, including correlation of pathologic findings with clinical features and outcomes. However, one important limitation faced by members of these consortia and other renal pathologists and nephrologists in both investigative work and routine practice remains a lack of uniformity and precision in clearly defining the morphologic lesions on which the scoring systems are based. In response to this issue, the Renal Pathology Society organized a working group to identify the most frequently identified glomerular lesions observed by light microscopy and electron microscopy, review the literature to capture the published definitions most often used for each, and determine consensus terms and definitions for each lesion in a series of online and in-person meetings.

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Background And Objectives: The histopathologic classification for ANCA-associated GN distinguishes four classes on the basis of patterns of injury. In the original validation study, these classes were ordered by severity of kidney function loss as follows: focal, crescentic, mixed, and sclerotic. Subsequent validation studies disagreed on outcomes in the crescentic and mixed classes.

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Mesenchymal stromal cells (MSC) hold promise as a novel immune-modulatory therapy in organ transplantation. First clinical studies have used autologous MSCs; however, the use of allogeneic "off-the-shelf" MSCs is more sustainable for broad clinical implementation, although with the risk of causing sensitization. We investigated safety and feasibility of allogeneic MSCs in renal transplantation, using a matching strategy that prevented repeated mismatches.

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Malvar et al. report the results of a study on protocolized repeat renal biopsies in 76 patients with class III or IV (± class V) lupus nephritis. They show that managing maintenance therapy in patients with lupus nephritis through protocolized repeat kidney biopsies results in a lower flare rate.

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Complement is a key component of the innate immune defence and in addition forms a bridge to the adaptive immune responses. As such complement is of vital importance for efficient protection against infections. However, the activity of the complement system can also aberrantly be directed against the tissues of the body itself and contribute to organ damage in a variety of diseases.

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