1
|
Said SM, Rocha AB, Royal V, Valeri AM, Larsen CP, Theis JD, Vrana JA, McPhail ED, Bandi L, Safabakhsh S, Barnes C, Cornell LD, Fidler ME, Alexander MP, Leung N, Nasr SH. Immunoglobulin-Negative DNAJB9-Associated Fibrillary Glomerulonephritis: A Report of 9 Cases. Am J Kidney Dis 2020; 77:454-458. [PMID: 32711071 DOI: 10.1053/j.ajkd.2020.04.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 04/22/2020] [Indexed: 11/11/2022]
Abstract
Fibrillary glomerulonephritis (FGN) was previously defined by glomerular deposition of haphazardly oriented fibrils that stain with antisera to immunoglobulins but do not stain with Congo red. We report what is to our knowledge the first series of immunoglobulin-negative FGN, consisting of 9 adults (7 women and 2 men) with a mean age at diagnosis of 66 years. Patients presented with proteinuria (100%; mean protein excretion, 3g/d), hematuria (100%), and elevated serum creatinine level (100%). Comorbid conditions included carcinoma in 3 and hepatitis C virus infection in 2; no patient had hypocomplementemia or monoclonal gammopathy. Histologically, glomeruli were positive for DNAJB9, showed mostly mild mesangial hypercellularity and/or sclerosis, and were negative for immunoglobulins by immunofluorescence on frozen and paraffin tissue. Ultrastructurally, randomly oriented fibrils measuring 13 to 20nm in diameter were seen intermingling with mesangial matrix in all and infiltrating glomerular basement membranes in 5. On follow-up (mean duration, 21 months), 2 had disease remission, 4 had persistently elevated serum creatinine levels and proteinuria, and 3 required kidney replacement therapy. Thus, rare cases of FGN are not associated with glomerular immunoglobulin deposition, and the diagnosis of FGN in these cases can be confirmed by DNAJB9 immunostaining. Pathogenesis remains to be elucidated.
Collapse
Affiliation(s)
- Samar M Said
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN
| | | | - Virginie Royal
- Division of Pathology, Hôpital Maisonneuve-Rosemont, Université de Montréal, Montréal, Canada
| | - Anthony M Valeri
- Division of Nephrology, Columbia University Medical Center, New York, NY
| | | | - Jason D Theis
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN
| | - Julie A Vrana
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN
| | - Ellen D McPhail
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN
| | | | - Saied Safabakhsh
- Micronesian Institute for Disease Prevention & Research, Sinajana, Guam
| | | | - Lynn D Cornell
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN
| | - Mary E Fidler
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN
| | | | - Nelson Leung
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN
| | - Samih H Nasr
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.
| |
Collapse
|