Immunoglobulin A (IgA) nephropathy was first described by Berger and Hinglais in 1968; it is considered the most common glomerular disease in the world. IgA nephropathy is viewed as a chronic disease; clinical remission may be found in approximately one-third of patients several years after renal biopsy, however, disappearance of the IgA has been documented by renal biopsy in only a few patients.
After its 1968 description, IgA nephropathy was assumed to follow an uneventful course and was equated with benign recurrent hematuria. Over the years, loss of renal function was observed in about 40 percent of patients, and approximately half of these patients reached end-stage renal failure after 20 years of known disease. Loss of renal function varies, some patients reach renal failure within months after diagnosis, others demonstrate an indolent course lasting over 20 years. Around 10 percent of patients develop the nephrotic syndrome.
The duration of the disease is difficult to define, since the onset is likely to be unknown; urinary testing may be performed at random intervals, and the disease may be undetected. Duration of the disease can only be measured from the first documented hematuria or proteinuria.
Macroscopic hematuria is found to be more common among pediatric patients and its frequency decreases with age. IgA nephropathy is common in young adults. Safety of pregnancy in women with the disease is a concern; reports describe irreversible decline of renal function associated with worse hypertension in these women.
Clinical features that lead to an unfavorable long-term prognosis include, renal insufficiency at the time of biopsy, and proteinuria in excess of 2 g/day. Hypertension with the absence of a history of an episode of macroscopic hematuria indicate a poor clinical outcome. Serum IgA levels do not appear to correlate with a clinical course. The prognosis of IgA nephropathy may differ among g...