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Dumas De La Roque C, Brocheriou I, Mirouse A, Cacoub P, Le Joncour A. [Fibrillary glomerulonephritis]. Rev Med Interne 2024:S0248-8663(24)00567-8. [PMID: 38755072 DOI: 10.1016/j.revmed.2024.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 04/15/2024] [Accepted: 05/02/2024] [Indexed: 05/18/2024]
Abstract
Fibrillary glomerulonephritis (FGN) is a glomerular disease described since 1977, with a prevalence in renal biopsies of less than 1%. It presents as renal failure, proteinuria, haematuria and hypertension in middle-aged adults. It is defined histologically, using light microscopy, which reveals organised deposits of fibrils measuring around 20nm, which are negative for Congo red staining. Electron microscopy, the first gold standard for diagnosis, has now been superseded by immunohistochemistry using the anti-DNAJB9 antibody. The discovery of this molecule has revolutionised the diagnosis of GNF, thanks to its excellent sensitivity and specificity (98% and 99% respectively). The association of GNF with hepatitis C virus, autoimmune diseases, neoplasia or haemopathy is debated. Renal prognosis is guarded, with 50% of patients progressing to end-stage renal failure within 2 to 4years of diagnosis. In the absence of randomised controlled trials, the recommended treatment is based on nephroprotective measures, corticosteroid therapy and possibly a second-line immunosuppressant such as rituximab. After renal transplantation, recovery or recurrence is possible. The pathophysiology of the disease is still poorly understood, and further studies are needed.
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Affiliation(s)
- C Dumas De La Roque
- Département de médecine interne et immunologie clinique, hôpital de la Pitié-Salpêtrière, 75013 Paris, France; Centre de référence maladies auto-immunes systémiques rares, Paris, France; Sorbonne université, Paris, France
| | - I Brocheriou
- Service d'anatomie pathologique, hôpital de la Pitié-Salpêtrière, 75013 Paris, France; Sorbonne université, Paris, France
| | - A Mirouse
- Département de médecine interne et immunologie clinique, hôpital de la Pitié-Salpêtrière, 75013 Paris, France; Centre de référence maladies auto-immunes systémiques rares, Paris, France; Sorbonne université, Paris, France
| | - P Cacoub
- Département de médecine interne et immunologie clinique, hôpital de la Pitié-Salpêtrière, 75013 Paris, France; Centre de référence maladies auto-immunes systémiques rares, Paris, France; Sorbonne université, Paris, France
| | - A Le Joncour
- Département de médecine interne et immunologie clinique, hôpital de la Pitié-Salpêtrière, 75013 Paris, France; Centre de référence maladies auto-immunes systémiques rares, Paris, France; Sorbonne université, Paris, France.
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Gambella A, Pitino C, Barreca A, Nocifora A, Giarin MM, Bertero L, Biancone L, Roccatello D, Papotti M, Cassoni P. DNAJB9 Is a Reliable Immunohistochemical Marker of Fibrillary Glomerulonephritis: Evaluation of Diagnostic Efficacy in a Large Series of Kidney Biopsies. Biomedicines 2022; 10:biomedicines10092102. [PMID: 36140202 PMCID: PMC9495529 DOI: 10.3390/biomedicines10092102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/25/2022] [Accepted: 08/25/2022] [Indexed: 11/21/2022] Open
Abstract
Fibrillary glomerulonephritis (FGN) is a rare glomerular disease characterized by a challenging diagnostic workup requiring ultrastructural identification of 20 nm-thick randomly oriented fibrillar deposits. However, the recent introduction of DNAJB9 as a putative diagnostic marker of FGN could thoroughly improve this diagnostic scenario. This study aims to assess the DNAJB9 immunohistochemical expression in a large series of FGN cases and to eventually confirm its role as a diagnostic marker of FGN. We evaluated the immunohistochemical expression of DNAJB9 (Rabbit Polyclonal, ThermoFisher) in a series of 77 FGN and 128 non-FGN cases diagnosed between January 1992 and June 2022 at the Pathology Unit of the AOU Città della Salute e della Scienza Hospital. DNAJB9 was expressed in 73 of the 74 evaluable FGN cases, mostly showing a strong glomerular positivity (68 cases). Additionally, DNAJB9 resulted positive in all challenging scenarios [early-stage (6), congophilic (4), combined (4), and uncertain (4) cases of FGN)]. DNAJB9 was negative in all non-FGN cases, eventually resulting in a specificity of 100% and sensitivity of 99%. In conclusion, we confirmed the role of DNAJB9 as a diagnostic marker of FGN. Its adoption in the clinical routine will allow a faster, more feasible, and more accurate FGN diagnosis.
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Affiliation(s)
- Alessandro Gambella
- Pathology Unit, Department of Medical Sciences, University of Turin, 10126 Turin, Italy
| | - Chiara Pitino
- Pathology Unit, Department of Medical Sciences, University of Turin, 10126 Turin, Italy
| | - Antonella Barreca
- Pathology Unit, “Città della Salute e della Scienza di Torino” University Hospital, Via Santena 7, 10126 Turin, Italy
- Correspondence:
| | - Alberto Nocifora
- Pathology Unit, “Città della Salute e della Scienza di Torino” University Hospital, Via Santena 7, 10126 Turin, Italy
| | - Manuela Maria Giarin
- Pathology Unit, “Città della Salute e della Scienza di Torino” University Hospital, Via Santena 7, 10126 Turin, Italy
| | - Luca Bertero
- Pathology Unit, Department of Medical Sciences, University of Turin, 10126 Turin, Italy
| | - Luigi Biancone
- Division of Nephrology Dialysis and Transplantation, “Città della Salute e della Scienza di Torino” University Hospital, Department of Medical Sciences, University of Turin, 10126 Turin, Italy
| | - Dario Roccatello
- CMID, Coordinating Center of the Network for Rare Diseases of Piedmont and Aosta Valley, Nephrology and Dialysis Unit (ERK-Net Member), San Giovanni Bosco Hub Hospital, University of Turin, 10144 Turin, Italy
| | - Mauro Papotti
- Pathology Unit, Department of Oncology, University of Turin, 10126 Turin, Italy
| | - Paola Cassoni
- Pathology Unit, Department of Medical Sciences, University of Turin, 10126 Turin, Italy
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The function of the co-chaperone ERdj4 in diverse (patho-)physiological conditions. Cell Mol Life Sci 2021; 79:9. [PMID: 34950970 PMCID: PMC8702508 DOI: 10.1007/s00018-021-04082-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 12/16/2022]
Abstract
Accumulation of misfolded proteins in the endoplasmic reticulum (ER) induces a well-orchestrated cellular response to reduce the protein burden within the ER. This unfolded protein response (UPR) is controlled primarily by three transmembrane proteins, IRE1α, ATF6, and PERK, the activity of which is controlled by BiP, the ER-resident Hsp70 protein. Binding of BiP to co-chaperones via their highly conserved J-domains stimulates the intrinsic ATPase activity of BiP, thereby providing the energy necessary for (re-)folding of proteins, or for targeting of misfolded proteins to the degradation pathway, processes specified and controlled by the respective co-chaperone. In this review, our aim is to elucidate the function of the co-chaperone ERDJ4, also known as MDG1, MDJ7, or DNAJB9. Knockout and knockin experiments clearly point to the central role of ERDJ4 in controlling lipogenesis and protein synthesis by promoting degradation of SREBP1c and the assembly of the protein complex mTORC2. Accumulating data reveal that ERDJ4 controls epithelial-to-mesenchymal transition, a central process during embryogenesis, in wound healing, and tumor development. Overexpression of ERdj4 has been shown to improve engraftment of transplanted human stem cells, possibly due to its ability to promote cellular survival in stressed cells. High ERDJ4-plasma levels are specific for fibrillary glomerulonephritis and serve as a diagnostic marker. As outlined in this review, the functions of ERDJ4 are manifold, depending on the cellular (patho-) physiological state, the cellular protein repertoire, and the subcellular localization of ERDJ4.
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