WHAT IS IGA NEPHROPATHY

WHAT IS IGA NEPHROPATHY

Diagnosis

The presence of blood and/or protein in the urine may suggest a diagnosis of IgAN. Some kidney specialists may also use microscopic examinations of urine and red blood cell casts to assist in their diagnosis. However, to confirm a diagnosis for IgAN, it is necessary to remove a small piece of tissue from the kidney (renal biopsy) and examine it microscopically for the presence of the characteristic IgA deposits in the glomeruli.

There are a considerable number of glomerule diseases that have similar symptoms to IgAN. Some are more readily treated than IgAN so a good diagnosis can be important.

Causes

The causes of IgA Nephropathy are not known. The disease seems to cluster in certain families and in certain areas of the world. It is rare in blacks. These facts suggest that genetic influences may play a role in the development of the disease. IgA nephropathy is associated with major histocompatibility HLA and certain other genetic markers; HLA-DR4 is detectable in about 50% of patients. There is a building body of evidence that it is an auto immune or immune complex disease. As an autoimmune disease it may be related to a number of other autoimmune disorders.

Treatment

Efforts to slow the progression of kidney damage have until recently had limited success. The most common and perhaps the most important treatment for all kidney problems is control of associated hypertension (high blood pressure). High blood pressure is a disease of considerable consequence to the kidney. If you suffer from it you need to work to ameliorate the condition and its wide ranging effects. Treatments from dietary controls to more vigorous drug intervention are effective to varying degrees in controlling hypertension which in turn can help to preserve kidney function. Treating high blood pressure is a task you can take an active role in with help from your medical advisors.

There are a number of nutritional based supplements that seem to assist in treating high blood pressure these range from herbal remedies to simply reducing salt intake (if you are salt intolerant as many BP patients are.) Buying a blood pressure measuring device and regularly measuring your blood pressure will tell you a lot about how your own lifestyle and habits effect your blood pressure.

Recent studies have shown that fish oil supplements (12 – 1 gm capsules per day containing EPA-180mg DHA 120mg) help to slow the loss of kidney function due to IgA disease, sometimes in a dramatic fashion. Limiting the amount of protein in the diet of kidney patients has been prescribed but research shows this is of limited value. For patients who progress to kidney failure, required treatment will consist of dialysis or a kidney transplant. The success rate of transplants is good in IgA patients.

Even though the IgA deposits reappear in the transplanted kidney in about half the patients within one year after the operation, the signs and symptoms of the disease remain mild. Loss of a transplanted kidney to recurrent IgA Nephropathy is uncommon. The milder form of the disease seen after transplantation may be due to the use of immunosuppresant anti-rejection drugs such as cyclosporine and mycofenalate mofetil, this latter drug is prescribed in some cases before renal failure to good effect.

Outlook

About 20-40 percent of IgAN patients develop end stage kidney failure within 20 years after the disease becomes apparent. Those patients who have an increased level of creatinine in their blood at the time of their diagnosis are more likely to develop chronic kidney failure. It is harder to predict which of the patients who have normal levels of creatinine at the time of diagnosis will develop kidney failure. In general, a poorer prognosis is expected for those patients who have high blood pressure, a loss of more than 2 grams of protein a day in their urine, and a significant amount of damage (especially with “crescents”) present in their biopsy specimen.

Renal Biopsy

The renal biopsy is the most accurate measure for determining the nature and stage of a renal pathologic condition. It involves the removal of kidney tissue for microscopic examination, conducted to establish the diagnosis of a renal disorder and to aid in determining the stage of the disease, the appropriate therapy, and the prognosis. An open biopsy involves an incision, permits better visualization of the kidney, and carries a lower risk of hemorrhage; a closed or needle biopsy performed by aspirating a specimen of tissue with a needle requires a shorter period of recovery and is less likely to cause infection.

Before the biopsy, the procedure is explained and the patient is medically evaluated and tested for bleeding or coagulation time. The patient’s blood is usually typed and cross-matched with two units of donor blood that are held for a possible transfusion until there is no threat of bleeding after the procedure. An open biopsy (an increasing rare procedure) is generally carried out in the operating room, but the standard needle biopsy may be performed in the radiology department or in the patient’s room.

The location of the kidney, determined by a plain ultrasound, x-ray film, dye contrast study, or fluoroscopic examination, is marked on the patient’s skin in ink for a needle biopsy. The patient is then placed prone over a sandbag and soft pillow with the body bent at the level of the diaphragm, the shoulders on the bed, and the spine in straight alignment. A local anesthetic is injected, and the physician inserts the biopsy needle in the lower pole of the kidney, because this area contains the smallest number of large renal vessels. The needle is quickly withdrawn, and, after pressure is applied to the site for 20 minutes, a pressure bandage is applied; the patient is turned and kept supine and motionless for the next 4 hours.

The dressing, blood pressure, and pulse are checked every 15 to 60 minutes for 2 hours, the temperature every 4 hours for up to 24 hours; excessive drainage, decreased blood pressure, tachycardia, or elevated temperature is reported to the physician. Fluids are forced to the maximum allotted for the patient’s condition; the amount and character of urinary output are noted, and the physician is informed if hematuria occurs. The patient is kept in bed for at least 24 hours and is cautioned not to lift any heavy objects for 10 days.

In the needle biopsy performed on me the procedure took about an hour one morning and I spent overnight in the hospital. The next day I was only a little tender in the area and this tenderness lasted for several days. Some medical clinics perform kidney biopsy as an outpatient procedure with the patient released a few hours after the procedure.

A second more scholarly paper on what is IgA Glomerulnephritis

Historical Background on Henoch-Schonlein Purpura and IgA Nephropathy

Prepared especially for the IgAN Page by:
J. Charles Jennette, M.D.
Director, Nephropathology Laboratory
Professor of Pathology and Laboratory Medicine
Professor of Medicine
University of North Carolina School of Medicine
Chapel Hill, NC 27599-7525

IgA nephropathy (IgAN) and Henoch-Schonlein purpura (HSP) are both caused by deposition of large amounts of IgA ( a particular type of antibody) in small blood vessel walls. This results in inflammation, which involves attack on the vessels by white blood cells. In patients with IgA nephropathy (nephro=kidney, pathy=disease) this injury is confined to the small vessels within the filtering structures of the kidney (glomeruli) resulting in glomerulonephritis (glomerulo=glomerulus, itis=inflammation); whereas in patients with Henoch-Schonlein purpura the injury is present in many vessels throughout the body resulting in widespread vasculitis (vasculo=vessel, itis=inflammation). The relatedness of IgA nephropathy and Henoch-Schonlein purpura was not recognized until the late 20th century when the vascular IgA deposits were first detected.

Purpura (which means purple spots on the skin) is a particular type of rash that is caused by small spots of hemorrhage from small vessels in the skin. There are many causes of purpura, one category of which is inflammation of vessels (vasculitis). Henoch-Schonlein purpura is one of many types of vasculitis. Purpura that is caused by vasculitis usually occurs predominantly on the legs and buttocks; and the purple spots are slightly raised so that they can be felt (palpated) when you rub your finger over them (this is therefore called palpable purpura).

In 1837, Johann Schonlein, a German physician, noticed the association of purpura with joint pain (arthralgias and arthritis) (Schonlein JL. Allegemeine und specielle Pathologie und Therapie, ed 3, vol 2, Herisau, Germany, Literatur-Comptoir, 1837;48). In 1868, Eduard Henoch, a German pediatrician decribed the association of purpura with abdominal pain, especially in children (Henoch E. Uber den zusammenhang von purpura und intestinal-stoerungen. Berl Klin Wochenschur 1868;5:517-519). In his 1882 handbook on pediatric diseases (Henoch E. Lectures on diseases of children: a handbook for physicians and students, W Wood & Co, 1882), Henoch described many of the other features of the disease that is now called Henoch-Schonlein purpura. The major features are purpura, abdominal pain and glomerulonephritis, although not all patients have all of these features, and some patients have additional features.

In 1968, Jean Berger, a French pathologist, reported 25 patients with microscopic hematuria (half of whom also had episodes of gross hematuria), moderate proteinuria and usually normal renal function who had extensive glomerular deposits of IgA (Berger J, Hinglais N: Les depots intercapillaires IgA-IgG. J.Urol. 74:694-695,1968). The following year, Berger extended his series to 55 cases, and reported similar pathologic findings in patients with Henoch-Schonlein purpura (Berger J: IgA glomerular deposits in renal disease. Transplan. Proc. 1:939-944, 1969). A synonym for “IgA nephropathy” is “Berger’s disease”, but this is not used very often. The form of glomerulonephritis that Berger identified is now called “IgA nephropathy.”

In 1973, Baart de la Faille-Kuyper, a Dutch dermatologist, demonstrated that there were IgA deposits not only in renal glomeruli but also in skin vessels in patients with Henoch-Schonlein purpura (Baart de la Faille-Kuyper EH, Kater L, Kooiker CJ, Dorhout Mees EJ. IgA-deposits in cutaneous blood vessel walls and mesangium in Henoch-Schšnlein syndrome. Lancet 1973;1:892-893).

Thus, both IgA nephropathy and Henoch-Schonlein purpura share a pathologically identical form of glomerulonephritis, but Henoch-Schonlein purpura has additional features, especially at the time of initial onset of the disease. Henoch-Schonlein purpura is the most common form of vasculitis in children. It is most frequent in children, especially children under 10 years old, although it can begin at any age. The disease usually first begins following an upper respiratory tract infection. Purpura, joint pain (arthralgias) and colicky abdominal pain are the most frequent symptoms. Approximately half of the patients have hematuria and proteinuria but only a few have reduced renal function.

Most patients have only one bout of Henoch-Schonlein purpura that resolves completely, or has one or more minor flares. The major long-term complication is persistent and progressive renal disease that on renal biopsy looks just like IgA nephropathy. Only about 5% of patients with Henoch-Schonlein purpura eventually develop end-stage renal disease (Goldstein AR, White RHR, Akuse R, Chantler C. Long-term follow-up of childhood Henoch-Schonlein nephritis. Lancet 1992;339:280-82).

No specific treatment is given to patients with Henoch-Schonlein purpura when they first develop the disease unless they have unusually severe renal disease, which is usually treated with corticosteroids and immunosuppresssive drugs (e.g., Bergstein J, Leiser J, Andreoli S. Response of crescentic Henoch-Schonlein purpura nephritis to corticosteroids and azathioprine therapy. J Am Soc Nephrol 1996;7:1328-9).

In summary, patients with IgA nephropathy and Henoch-Schonlein purpura have indistinguishable types of glomerular disease, but patients with Henoch-Schonlein purpura have additional features, at least initially, such as purpura, abdominal pain and joint pains.

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