Symptoms of immunoglobulin a nephropathy
How does immunoglobulin a nephropathy present?
About 20% to 30% of patients present with recurrent gross hematuria, typically within a few days of an upper respiratory infection.
Classically known as “synpharyngetic hematuria,” this presentation is much more common in children and young adults than in the older population. Dull flank pain and low-grade fever may be present, and this pattern can mimic both urinary tract infection and urolithiasis.
The majority of the remaining patients with IgAN are asymptomatic at presentation and are detected on routine examination of the urine (positive for microscopic hematuria with or without mild proteinuria [<500 mg/day]).
Systemic hypertension may also be found. Nephrotic-range proteinuria or lesser degrees of proteinuria without hematuria are unusual but also occur. In less than 5% of patients, IgAN can present with acute kidney injury. It is felt that the kidney injury is most commonly secondary to tubular obstruction and/or damage by red cell casts, which form in the course of the gross hematuria.
Crescentic GN in IgAN can also produce a similar clinical phenotype and should be considered whenever an acute deterioration of kidney function occurs. Because this is a relatively rare clinical presentation, a kidney biopsy should be obtained to differentiate acute tubular damage from crescentic GN.
This is particularly important given that their outcome and management are so distinctly different.
At least 20% of patients with IgAN present with chronic kidney disease as a result of long-standing but undiagnosed disease.
The clinical phenotype usually includes hypertension, mild to moderate proteinuria, and hematuria of undetermined duration in combination with varying degrees of chronic kidney disease.
