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What is Fibrillary GN?
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Who gets FIBRILLARY GN?
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What are the Symptoms?
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What Types of Tests Detect FIBRILLARY GN?
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How is it Treated?
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Clinical Trials
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Fibrillary GN Patient Education Podcasts
What is Fibrillary GN?
Fibrillary GN is a disease which affects the millions of filtering units that make up the kidney. These filtering units are called glomeruli. Each individual glomerulus is composed of multiple layers of straining material (endothelium, basement membrane, popdocyte foot processes) which assure only select components of the blood pass from the blood vessel walls (capillary lumen) into the urine. In this condition, for unknown reasons, the body produces a large volume of unusual proteins. These proteins enter the glomeruli (or they may be produced within the glomeruli), but because of their unusual nature become trapped in the straining layers, disrupting filtration. In some instances these proteins activate the immune system causing inflammation in these delicate structures. Over time the inflammation can damage the layers of the filters, as well as adjacent structures, allowing large amounts of proteins to spill into the urine. As the inflammation progresses filtering units are damaged beyond repair and replaced by scar tissue. Ultimately, with the loss of enough glomeruli, the kidneys loose the ability to filter the blood, a condition known as end-stage kidney disease.
Who gets Fibrillary GN?
Fibrillary GN has been reported in those age 10 to 89 and appears to affects Caucasions and a slightly higher rate. Because we do not know exactly what causes the disease, we can not predict who will develop it. Based on published reports, it appears there may be an association of this disease with conditions of immune system dysfunction, such as lupus, or those causing chronic immune system activation, such as Hepatitis C.
What are the symptoms?
Early on Fibrillary GN primarily affects the individual filtering units of the kidney. The symptoms that develop are linked to this initial sight of damage, and the subsequent passage of blood components into the urine. People commonly present with swelling in their legs or feet and foamy urine,due to a significant loss of protein in the urine (proteinuria). However, patients often develop proteinuria without swelling, and first become aware of their condition with the detection of proteinuria on routine urinalysis performed by their primary care doctor. Red blood cells may pass through the filters into the urine as well, though they are usually too few in number to be seen by the naked eye (microscopic hematuria). Blood identified by urinalysis should be confirmed by microscopic evaluation of the urine by a physician to be certain the blood identified is not from another source (ex. the bladder).
As damage to the kidney progresses, individual filtering units are lost, and as a consequence many patients develop high blood pressure, commonly requiring multiple medications for control. Patients may have difficulty managing their phosphorus balance (phosphorus is excreted by the kidney) and often suffer from anemia. This occurs as the kidney can no longer secrete a substance called erythropoietin, a hormone responsible for stimulating bone marrow production of red blood cells. Unfortunately, Fibrillary GN tends to be a progressive disease ultimately leading to loss of kidney function and the need for dialysis or kidney transplant. Symptoms of advanced kidney failure include nausea, fatigue, confusion, loss of appetite, funny taste in the mouth, itching, shortness of breath, or heart palpitations. The rate of decline is variable ranging from months to several years and should be followed closely by your doctor.
What Types of Tests Detect Fibrillary GN?
Early evidence of kidney damage from Fibrillary GN may be detected on routine lab tests. For example, urinalysis may identify protein or blood loss in the urine. Microscopic exam of the urine can identify other evidence of kidney involvement such as red blood cells that have passed through the kidney filters (glomeruli). Later in the course of the disease serum creatinine, a marker of kidney function, can elevate indicating loss of functioning glomeruli. However, as there are many conditions that can damage the glomeruli, the above findings are non-specific for Fibrillary GN. Ultimately, a definitive diagnosis of Fibrillary GN must be made by microscopic examination of kidney tissue obtained by kidney biopsy. Examination of the tissue by light-microscopy may show evidence of protein build up in the glomeruli, but electron-microscopy is ultimately needed to determine the precise nature of the captured proteins. As part of the evaluation a number of blood tests are often done to evaluate for other renal diseases (ex. HIV or Multiple Myeloma) or conditions associated with Fibrillary GN (ex. LUPUS or Hepatitis C).
What are the Treatment Options?
There is no proven effective therapy for Fibrillary GN at present, though many therapies have been attempted with limited success. Treatments used in the past have included immune modulating agents, alone or in combination, such as steroids, cyclophosphamide, and cyclosporine. In very specific cases, physicians have also tried plasmapheresis, a procedure in which the blood is filtered outside the body (like dialysis) in an attempt to remove proteins.The treatment course must ultimately be determined after testing for associated conditions, such as Lupus or Hepatitis, evaluation of kidney function, and a detailed review of the kidney biopsy findings. Use of immunomodulating agents must weigh the potential benefit of disease response versus the known risks of immune suppression, such as susceptibility to infection.
Clinical Trials
