TABLE 2
Oxford Classification of immunoglobulin A nephropathy: MEST-C score
| Histologic feature | Definition15,16 | Prognosis | |
|---|---|---|---|
| Mesangial hypercellularity | ≥ 4 mesangial cells in any mesangial area of a glomerulus M0: < 50 glomeruli M1: ≥ 50 glomeruli | M1 is predictive of worse outcomes vs M015 | Mesangial hypercellularity and endocapillary proliferation (hematoxylin and eosin stain, magnification ×400) |
| Endocapillary proliferation | Increased number of cells in glomerular capillary lumen E0: absent E1: present | E1 is independently associated with worse renal survival in patients who receive no immunosuppression, and does not predict outcomes in studies where patients receive immunosuppression Patients with endocapillary proliferation (E1) are more likely to receive immunosuppression, which is associated with improved outcomes in these patients16 | |
| Segmental glomerulosclerosis | Adhesion or sclerosis that does not involve the entire glomerulus S0: absent S1: present | S1 is predictive of worse outcomes compared with S015 | |
| Tubulointerstitial fibrosis | Percentage of tubular atrophy and interstitial fibrosis of cortical area T0: absent or ≤ 25% of tubules T1: 26%–50% of tubules T2: > 50% tubules | Presence of tubulointerstitial fibrosis (T1 or T2) is strongest predictor of adverse renal outcomes16 | Crescent formation (periodic acid–Schiff stain, magnification ×400) |
| Crescents, cellular or fibrocellular | Extracapillary cell proliferation > 2 cell layers and < 50% of matrix C0: absent C1: 1%–24% of glomeruli C2: > 25% of glomeruli | C1 is not predictive if immunosuppression is used C2 is predictive of worse outcomes regardless of immunosuppression16 |
Images courtesy of Leal Herlitz, MD, Cleveland Clinic Anatomic Pathology.