IgA Nephropathy And Related Disorders

Question 1

Definition

Answer 1

Mesangial IgA deposition often accompanied by mesangial proliferation
Recurrent visible hematuria-hallmark of disease
Common in asian people, uncommon in african

Question 2

Clinical Presentation

Answer 2

Episodic visible henaturia (usually Brown; cola-colored) 40-50%—> after time microscopic hematuria (30-40%)

Appearing within 24h of the onset of the symptoms of infection (DDx 2-3 week delay in poststreptococcal GN)
Nephrotic Syndrome rare <5%
AKI rare <5%
Hypertension
CKD

Question 3

Oxford classification of IgAN

Answer 3

Mesangial hypercellularity
Endocapillary hypercellularity
Segmental glomerulosclerosis
Tubular atrophy/interstitial fibrosis
Crescents

Question 4

Pathogenesis

Answer 4

Polymeric IgA1 is predominantly found
IgA1 vs IgA2 variable complement of O-linked carbohydrates in the hinge region
—> IgA1 high molecular weight circulating immune complexes —> prone to mesangial deposition

Question 5

Pathophysiology

Answer 5

Exposure to IgA immune complexes triggers mesangial cell acti-vation, proliferation (M), and release of proinflammatory and pro-fibrotic mediators. These mediators, along with the direct effects of exposure to IgA immune complexes, recruit inflammatory cells into the glomerular endothelial space (E); cause podocyte injury, a process fundamental to segmental glomerular scarring (S); and cause proximal tubule cell activation, which drives tubulointersti-tial scarring (T). If unregulated, this inflammatory response in the glomeruli leads to crescent formation (C).

Question 6

Prognosis

Answer 6

<10% complete resolution of urinary abnormalities
25-30% will require kidney transplant within 20-25Y

Question 7

Treatment

Answer 7

Like all chronic glomerulonephritides:
Reduction of proteinuria
Use of renin- angiotensin blockade
Control of hypertension
Reduce cardiovascular risk factors
Weight reduction
Smoking cessation
Healthy diet
Exercise