IgA nephropathy

Question 1

Proposed (most accepted) pathogenesis of IgA nephropathy

Answer 1

We have proposed that the glomerular IgA represents deposits of circulating complexes composed of Gd-IgA1 bound
by autoantibody (IgG or IgA) specific for Gd-IgA1 hinge-region O-linked glycans
An alternative hypothesis postulates that latent mesangial deposits of Gd-IgA1 may be bound by autoantibodies from the circulation, forming immune complexes in situ.
Although mesangial cells can degrade
immunodeposits, it is possible that, when this system is “overwhelmed,” alternative processes cause pathologic cellular
activation and tissue injury.
(manish saha - secondary iga nephropathy review)

Question 2

You need what key finding to diagnose IgA nephropathy?

Answer 2

1) Renal Biopsy
2) IF showing dominant or at least co-dominant IgA staining with the predominance of staining in the mesangium
3) no C1q or very little C1q (any C1q is worth thinking lupus)
4) EM confirming immune complex deposition

Question 3

What disease state is most associated with secondary IgA nephropathy?

Answer 3

Liver disease is the leading cause of secondary IgAN

Question 4

What disease state is most associated with secondary IgA nephropathy?

Answer 4

Liver disease is the leading cause of secondary IgAN

Question 4

what is the single most important clinical laboratory finding that is prognostic for IgAN outcomes?

Answer 4

proteinuria
*treatment paradigm is first guided by proteinuria and RAAS blockade is used with proteinuria as a treatment outcome parameter