Immunoglobulin A glomerulonephropathy: A review

Table 1 Adapted from the Oxford classification[6]

Variables	Description
Mesangial hypercellularity	Zero: Less than four mesangial cells are present per mesangial area
	One: Four to five mesangial cells are present per mesangial area
	Two: Six to seven mesangial cells are present per mesangial area
	Three: ≥ eight mesangial cells are present per mesangial area
	The scores obtained for each glomerulus are averaged. If the resulting mean score is less than 0.5, the assigned hypercellularity score is M0. If the mean score is greater than 0.5, the assigned hypercellularity score is M1
Endocapillary hypercellularity	E1: If hypercellularity is present within glomerular
	E0: If no hypercellularity is present within lumens
Segmental glomerulosclerosis	S1: If any part of the glomerular tuft is involved in sclerosis
	S0: If no segmental glomerulosclerosis is present
Tubular atrophy/interstitial fibrosis	T0: Involved cortical area 0% to 25%
	T1: Involved cortical area 26% to 50%
	T2: Involved cortical area > 50%
Crescents	The presence of cellular and/or fibrocellular crescents
	C1: Present in at least one glomerulus
	C2: Present in > 25% of glomeruli
	C0: Absent

Biopsies with fewer than eight glomeruli have a low prognostic yield.

Table 2 Risk factors of progressive renal disease

Risk factors	Description
Proteinuria > 1 g/d	In a study of 542 patients with biopsy-proven disease, the authors show that the rate of renal function decline increased with the amount of proteinuria. Those with proteinuria greater than three g/d experienced a 25-fold faster decline in renal function than those with less than 1 g/d[23] (14)
Hypertension	In a study of 332 patients with IgAN, those with hypertension (defined as > 140/90 mmHg) at disease discovery had a higher incidence of dialysis or death compared to those without hypertension[24]
Reduced GFR	Patients with lower GFR at the time of diagnosis had worse outcomes[25]
Hematuria	In a 14-year follow-up study, patients with persistent hematuria had a higher risk of progressing to end-stage kidney disease[26]
Histologic features	Markers of severe inflammatory disease (crescent formation, immune deposits in the capillary loops, mesangial deposits)
	Markers of chronic fibrotic disease (glomerulosclerosis, tubular atrophy, interstitial fibrosis)

Biopsies with fewer than eight glomeruli should be considered of uncertain value for prognosis. GFR: Glomerular filtration rate; IgAN: Immunoglobulin A nephropathy.

Table 3 Renal function and proteinuria before and after treatment

	Time	GTG	ITG	P value
24-h urinary protein quantification (g)	9 months after treatment	1.09 +/- 0.61	0.89 +/- 0.5	0.049
	12 months after treatment	0.68 +/- 0.38	0.39 +/- 0.42	< 0.001
Serum creatinine level (μmol/L)	9 months after treatment	96.81 +/- 34.60	82.23 +/- 31.41	0.016
	12 months after treatment	80.3 +/- 7.45	64.76 +/- 18.32	< 0.01

GTG: Glucocorticoid therapy group; ITG: Immunosuppressive therapy group.