What IgAN is (a summary)

The Foundation for IgA Nephropathy

What IgAN is (a summary)

IgA nephropathy (or Berger's Disease, IgA nephritis) is an immune complex disorder (or immune-system mediated disease) which causes IgA immune complexes to be deposited and trapped in the glomeruli (the filters in the kidneys), where they cause inflammation (called glomerulonephritis), proliferation of cells in the mesangial matrix, and eventual scarring of the glomeruli (called glomerulosclerosis).

Some of the scarring may be caused by inflammation, some simply by the lumen of the glomeruli (the part the blood goes through) gradually and eventually being squeezed and closed-off by the expanding mesangial matrix (the mesangial matrix can be thought of as the structural support for the tiny clump of miniature blood vessel which is a glomerulus). Once blood cannot flow through the lumen of a glomerulus, this glomerulus becomes non-functional, and is from that point on essentially just non-functional scar tissue. There are about one million nephrons in each kidney (each nephron consisting of a glomerulus and other associated parts), and as a person gradually loses functioning glomeruli, overall glomerular kidney function decreases. Glomerular kidney function (or more precisely, glomerular filtration rate, abbreviated as GFR) is what kidney patients commonly know as % kidney function, as in, "I have 30% kidney function". Eventually, the person "progresses" from having mild IgA nephropathy to having chronic renal insufficiency (loosely defined as being a GFR under 50%), and at some point, if and when the GFR reaches down to about 10% kidney function, the person will need to be started on some form of renal replacement therapy (dialysis or kidney transplant).

Is it an autoimmune disease? Well, it depends on how we define autoimmune. It is not an autoimmune disease in the classic sense of that term, but it does involve the immune system. IgA nephropathy is probably most accurately described as a circulating immune complex glomerulonephritis in which there is glomerular trapping of predominantly IgA immune complexes. It is a common misconception that having IgA nephropathy somehow goes hand in hand with a weakened immune system. There is very little evidence to suggest this is the case. IgAN patients who have a particularly "weakened immune system" may have it for other reasons than the IgAN.

IgAN is one of a group of kidney diseases which are sometimes referred to as glomerulonephropathies, or simply, nephropathies - hence the name IgA nephropathy. IgAN is thought to be the most common type of glomerulonephritis. Despite this, IgAN is not the most common cause of end-stage renal disease. According to some estimates, IgAN accounts for about 10% of end-stage renal disease cases. However, in my experience, you can go to many dialysis centres and never encounter another IgAN patient. The majority of dialysis patients seem to be there because of diabetes or hypertension, and the statistics certainly do bear out this observation.

A very variable disease, it can present as an acute or a chronic form of kidney disease, and in some cases it can be rapidly-progressive. The majority of patients have the less aggressive chronic form, which may or may not progress to end-stage renal disease (esrd) over many years (10 to 25 years or more). In the small number of patients who have the rapidly-progressive form, it can lead to esrd within 5 years or less. At present, there is no cure for IgAN. Some people have mild cases which progress very slowly, with long periods of relative stability (which may even be perceived as a "remission"), and some have more aggressive cases which progress to chronic renal insufficiency and to end-stage renal disease more rapidly. Why it is more aggressive in some than others is simply not known, although it is safe to say that, as far as is known, it has nothing to do with what the person eats or doesn't eat, or with anything a person does or doesn't do. This author suspects that adult who has IgA nephropathy would eventually reach end-stage renal failure if the person lived long enough (that is, didn't die of old age or other causes first). However, IgAN in children may be an exception, because it does appear to be relatively benign once the more acute proteinuric phase passes (either on its own, or with medication). There isn't currently much data about what happens to these children later in adulthood.

IgAN is suspected when protein and blood (visible or not) are found in the urine, and is ultimately diagnosed by biopsy. While IgAN can be suspected from the symptoms a person has, many kidney diseases have similar symptoms to varying degrees, and a definitive diagnosis of IgA nephropathy is not currently possible without a kidney biopsy. Sometimes, a firm diagnosis of IgAN is not even possible from a biopsy, if the biopsy is done only when the patient is already in an advanced stage of chronic renal insufficiency.

IgAN can affect people of all ages, but it is most commonly diagnosed from adolescence until about the age of 40, and it is thought to be three times more frequent in males than in females. Pediatric IgAN may appear in childhood to adolescence (and into the early 20's) in its more acute presentation.

If you or your child has been diagnosed with IgA nephropathy, you will find that, as time goes by and the disease progresses (which could easily be a decade or more, if it progresses at all, that is), and enough kidney function is lost such that the patient gradually moves into chronic renal insufficiency, it becomes less and less a matter of having IgAN, and more a matter of having chronic renal insufficiency (also referred to as chronic renal failure). Nephrology is a medical specialty which essentially treats the symptoms of chronic renal insufficiency, and which provides ongoing renal replacement therapy (dialysis, kidney transplant). It is not really involved with other parts of the body, so, don't expect your nephrologist to act as your primary care physician, nor to deal with aches and pains and other problems elsewhere in the body unless they are clearly a symptom of chronic renal insufficiency (such as swelling of the feet due to fluid retention, for example).

It's important to realize that, if a person has chronic renal insufficiency or, eventually, end-stage renal disease, it doesn't really matter much at that point which specific kidney disease caused it to happen. What is being treated then is really the chronic renal failure or the end-stage renal disease. However, it can become relevant again once a person has had a kidney transplant, because it is possible that the IgAN will recur in the transplanted kidney to some extent (although in most cases, the kidney is more likely to be lost due to acute or chronic rejection than because of recurring IgA nephropathy).

IgAN patients have been looking for years for some sort of causal connection they might share with others, a clue as to why or how they or their child developed this disease. The truth is, there doesn't seem to be any particular connection. People have considered allergies, things they may have been exposed to, foods, occupations, blood types, etc. So far, hundreds if not thousands have not been able to identify any such link. Billions of people eat, millions of people have allergies all of all kinds, everyone in the world is exposed to various things, millions are vaccinated, and yet, only a very few develop IgA nephropathy. In the meantime, having IgAN has to be dealt with, perhaps with nothing at all or only blood pressure medications if the IgAN is mild, perhaps with oral steroids if proteinuria is significant, and maybe other immune system suppressing drugs if the IgAN is aggressive enough to warrant the risks. Even people with apparently very mild, very slow IgAN, no troublesome "flare-ups" of visible blood in the urine and only mild proteinuria can and do eventually run out of kidney function due to the on-going progression of this chronic kidney disease - even though this may take decades. This author, the website and its associated email group do not have any magic bullets, no homepathic or naturopathic products, no special diets that can cure IgAN. We only try to inform other patients as best we can, filling in the blanks in the information they receive from their nephrologists, and we help them deal with the real world situation of having this disease without being consumed by it.

More detailed information about various aspects of IgAN can be found in subsequent sections of the website. Please refer to the index at the left of this page.

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