IgAN was thought relatively benign when it was first identified in 1968 by the French doctor, Jean Berger, but gradually researchers realized that in up to 50% of the cases, the disease very slowly progresses to end-stage renal failure, requiring major lifestyle changes, dialysis, and possibly transplantation. IgAN does not immediately interfere with the kidneys’ filtration work — except in acute cases — but it may threaten it ultimately. Damage results as kidney tissue gradually develops irreversible scarring, which ultimately blocks renal capillaries, causing the death of surrounding tissues as these are deprived of blood and nutrients. The slow accumulation of these tiny affected areas can take ten or twenty — or more — years to produce kidney failure, although a small minority of patients, mainly adults, have a rapidly progressive form that results in renal failure within a few years or even months. As individual capillaries become clogged by coagulation excessive cell growth, or infiltration by inflammatory cells, the nephron loses filtering surface. The kidneys’ glomerular filtration rate [GFR], a measure of how efficiently the kidneys filter blood, declines when that loss is enough to overcome the body’s efforts to adapt by increasing pressure throughout the remaining nephrons. As GFR decreases, the kidneys nose their ability to cleanse the blood of toxins and metabolic byproducts. Kidney failure and uremic poisoning result. It is difficult to predict from initial clinical signs and biopsy results just which patients will have which course. Statistical analyses have yielding conflicting results, but some factors do seem linked to a poor prognosis. Unremittingly heavy proteinuria, uncontrolled hypertension, declining glomerular filtration rate, high serum creatinine, and being age 30 or older at the time of apparent onset of the disease are some of the factors tied to a poor prognosis. Severe lesions in the initial biopsy, especially evidence of sclerosis [scarring] or crescent formation are also ominous signs.