NORD gratefully acknowledges Greg Cichon, MD candidate, Creighton School of Medicine and Khalid Bashir, MD, Assistant Professor of Nephrology, Creighton School of Medicine, for the preparation of this report.
Fibrillary glomerulonephritis (GN) is an uncommon kidney disease of the glomerulus, the site where waste is filtered from the body. Unusual fibril proteins plug the glomerulus, causing it to become inflamed. It mostly affects middle-aged adults between 41 and 80 years and can cause blood and protein in the urine (hematuria and proteinuria, respectively), which makes the urine look red or foamy. Other symptoms include decreased kidney function (renal insufficiency), swelling in the legs or feet and high blood pressure (hypertension). It is diagnosed with a kidney biopsy. While the exact cause is unknown, it is often found in patients with a history of other diseases including cancer, autoimmune diseases, hepatitis C, hypertension and diabetes. Treatment is typically aimed at the associated diseases since no treatments have been shown to be effective yet for fibrillary glomerulonephritis. 40-50% of patients with fibrillary glomerulonephritis will progress to end stage renal disease within two to six years, depending on the severity. These patients will eventually require a kidney transplant and dialysis. The disease may return even after a kidney transplant, but it is usually less severe.
Fibrillary glomerulonephritis and immunotactoid glomerulopathy, a similar but rarer condition, are two forms of nonamyloid fibrillary glomerular deposition diseases. Similar to amyloidosis, fibrils deposit in the wall of the glomerulus (in the basement membrane), but these fibrils are made from immunoglobulins rather than amyloid proteins. Under normal conditions, the glomerulus filters the blood to form urine and keeps the fibrils (which are important for cell structure). The word “fibrillary” refers to these protein fibers and “glomerulonephritis” refers to inflammation (“-itis”) of the kidney filters (“glomerulonephr-“). The buildup of these fibril proteins can activate the immune system and lead to inflammation and kidney damage. Scientists do not fully understand why these fibrils begin depositing in the glomerulus, but most suspect that certain underlying diseases play a role. Over time, the damaged glomeruli spill proteins into the urine and eventually lose their ability to filter blood altogether.
The most common symptoms of fibrillary glomerulonephritis include:
The causes of fibrillary glomerulonephritis are currently unknown and are being researched. Antibodies (immunoglobulins) build up in the glomerulus, often in patients with an underlying disease such as cancer (particularly leukemia, lymphoma and multiple myeloma), a monoclonal gammopathy or an autoimmune disease (Crohn’s disease, Graves’ disease, immune thrombocytopenia, etc.).
Patients with a history of cancer (particularly leukemia or multiple myeloma), a monoclonal gammopathy or an autoimmune disease (particularly Crohn’s disease, lupus, Graves’ disease, or immune thrombocytopenia [ITP]) are at risk for fibrillary glomerulonephritis.
A diagnosis is made from a kidney biopsy to look at the fibrils under an electron microscope and immunofluorescence microscope. Routine lab tests may detect the blood and protein in the urine, but a biopsy is the only way to determine which proteins are affecting the glomerulus.
Clinical Testing and Work-up
Abnormal results from routine blood and urine tests are the first line of evidence for kidney damage. Kidney function tests can then detect the severity of kidney damage. After a kidney biopsy confirms the diagnosis of fibrillary glomerulonephritis, a physician will likely order more blood tests and imaging. These tests are important to find any underlying cancer, hepatitis or autoimmune disease which may be associated with the glomerulonephritis. In some patients, finding and treating the underlying condition can decrease the severity of the kidney disease. In the case when an underlying condition is not found, treatment focuses on controlling the hypertension, protein in the urine and progression of the kidney disease.
There is currently no approved therapy to treat fibrillary glomerulonephritis with unknown cause. Many therapies have been tried with little success including steroids, plasmapheresis, cyclophosphamide and cyclosporine. Clinicians will likely focus instead on controlling the symptoms such as hypertension, proteinuria and kidney insufficiency. If an underlying condition is present (see Affected Populations), clinicians will instead focus on treating the underlying condition, which may improve symptoms of fibrillary glomerulonephritis.
Patients who progress to end-stage renal disease will likely need a kidney transplant and/or dialysis, although fibrillary glomerulonephritis can recur after a kidney transplant.
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Nasr SH, Fogo AB. New developments in the diagnosis of fibrillary glomerulonephritis. Kidney Int. 2019; 96:581.
Payan Schober F, Jobson MA, Poulton CJ, et al. Clinical features and outcomes of a racially diverse population with fibrillary glomerulonephritis. Am J Nephrol. 2017; 45:248.
Nasr SH, Valeri AM, Cornell LD, et al. Fibrillary glomerulonephritis: a report of 66 cases from a single institution. Clin J Am Soc Nephrol. 2011; 6:775.
Rosenstock JL, Markowitz GS, Valeri AM, et al. Fibrillary and immunotactoid glomerulonephritis: Distinct entities with different clinical and pathologic features. Kidney Int. 2003; 63:1450.
Brady HR. Fibrillary glomerulopathy. Kidney Int. 1998; 53:1421.
Markowitz GS, Cheng JT, Colvin RB, et al. Hepatitis C viral infection is associated with fibrillary glomerulonephritis and immunotactoid glomerulopathy. J Am Soc Nephrol. 1998; 9:2244.
Pronovost PH, Brady HR, Gunning ME, et al. Clinical features, predictors of disease progression and results of renal transplantation in fibrillary/immunotactoid glomerulopathy. Nephrol Dial Transplant. 1996; 11:837.
Iskandar SS, Falk RJ, Jennette JC. Clinical and pathologic features of fibrillary glomerulonephritis. Kidney Int. 1992; 42:1401.
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