Mesangial IgA Glomerulonephritis: Classification

MEST (Oxford) classification of IgA nephropathy (IgAN).

The Oxford classification of IgA nephropathy is based on four histologic (“fine tissue”) parameters (MEST) to be evaluated biopsy. For evaluation, at least 8 glomuerula (singular: Glomerulus; vascular loops located in the renal cortex and inverted into Bowman’s capsule) must be present in the biopsy (tissue sample).

Mesangial hypercellularity
In ≤ 50% of glomeruli M0
In >50% of glomeruli M1
Endocapillary hypercellularity
Absent E0
Available E1
Segmental glomerulosclerosis
Absent S0
Available S1
Tubular atrophy/interstitial fibrosis
0-25% of the area of the renal cortex T0
26-50% of the area of the renal cortex T1
> 50% of the area of the renal cortex T2