Prognostic value of the MEST-C score in long-term outcomes of immunoglobulin A nephropathy patients: Insights from a developing country

Table 1 Baseline demographic and clinical characteristics of patients with immunoglobulin A nephropathy, n (%)/mean ± SD

	n = 118
Age at biopsy (years)	29.03 ± 10.58
Gender
Male	73 (61.9)
Female	45 (38.1)
Weight (kg)	65.62 ± 15.14
HTN	44 (37.3)
Presence of edema	65 (55.1)
Evidence of recent infection	26 (22)
Asymptomatic	24 (20.3)
Urinary abnormality	14 (11.9)
Abnormal creatinine	5 (4.2)
Newly diagnosed HTN	5 (4.2)
Symptomatic	94 (79.7)
Nephrotic syndrome	26 (22)
Nephritic syndrome	45 (38.1)
Gross hematuria	23 (19.49)
Proteinuria (dipstick)
Trace	5 (4.2)
+1	11 (9.3)
+2	25 (21.2)
+3	59 (50)
+4	18 (15.3)
Microscopic hematuria
Trace	11 (9.3)
+1	20 (16.9)
+2	21 (17.8)
+3	52 (44.1)
+4	14 (11.9)
Serum creatinine (mg/dL), median (IQR)	1.4 (0.85-2.45)
eGFR (mL/minute/1.73 m2)	67.82 ± 44.60
Serum albumin (g/dL)	3.19 ± 0.81
Spot PCR (mg/dL) or 24-hour proteinuria (g/24 hours), median (IQR)	2.13 (1.08-3.74)
Spot PCR (mg/dL) or 24-hour proteinuria (g/24 hours)
Proteinuria < 1 g	5 (4.2)
Proteinuria 1-3 g	95 (80.5)
Proteinuria > 3 g	18 (15.3)
Serum C3 levels
Low (< 0.8 g/L)	7 (5.93)
Normal (> 0.8 g/L)	111 (94.06)
Serum C4 levels
Low (< 0.16 g/L)	3 (2.54)
Normal (> 0.16 g/L)	115 (97.45)
Required KRT (%)	43 (26.4)
Antiproteinuric treatment	102 (86.4)
Immunosuppressive treatment	73 (61.9)
Steroid alone	43 (36.4)
Combination treatment	30 (25.4)

HTN: Hypertension; IQR: Interquartile rang; eGFR: Estimated glomerular filtration rate; PCR: Protein-to-creatinine ratio; C: Crescent formation; KRT: Kidney replacement therapy.

Table 2 Biopsy findings of immunoglobulin A nephropathy patients categorized by MEST-C score, n (%)/mean ± SD

	n = 118
Total glomeruli	14.86 ± 7.02
Globally sclerosed	2.99 ± 3.73
Mesangial hypercellularity
M0	35 (29.7)
M1	83 (70.3)
Endocapillary hypercellularity
E0	104 (88.1)
E1	14 (11.9)
Segmental glomerular sclerosis
S0	66 (55.9)
S1	52 (44.1)
IFTA (T)
T0	50 (42.4)
T1	56 (47.5)
T2	12 (10.2)
Cellular crescents
C0	76 (64.4)
C1	27 (22.9)
C2	15 (12.7)
C3 staining on IF
Negative	32 (27.1)
+1	43 (36.4)
+2	38 (32.2)
+3	4 (4.2)
IgA staining on IF
Alone	42 (35.6)
IgA + IgG co-deposition	14 (11.9)
IgA + IgM co-deposition	62 (52.5)
MEST-C score
1	30 (25.4)
2	31 (26.3)
3	35 (29.7)
4	16 (13.6)
5	5 (4.2)
6	1 (0.80)
7	0

IFTA: Tubular atrophy/interstitial fibrosis; C3: Complement component 3; IF: Immunofluorescence; Ig: Immunoglobulin.

Table 3 Comparison of clinical characteristics at kidney biopsy in correlation with MEST-C scores, n (%)/mean ± SD

	HTN	P value	Proteinuria (g/24 hours)	P value	eGFR (mL/minute/1.73 m2)	P value
Mesangial hypercellularity
M0	15 (42.8)	0.53	2.90 ± 1.78	0.57	63.74 ± 50.09	0.55
M1	29 (34.9)		2.63 ± 2.48		69.56 ± 42.26
Endocapillary hypercellularity
E0	38 (36.5)	0.77	2.46 ± 2.01	0.002	70.61 ± 44.87	0.04
E1	6 (42.8)		4.95 ± 3.37		47.28 ± 37.91
Segmental glomerular sclerosis
S0	21 (31.8)	0.18	2.86 ± 2.85	0.56	65.70 ± 47.36	0.56
S1	23 (44.2)		2.57 ± 1.60		70.46 ± 41.20
IFTA (T)
T0	12 (24)	0.01	2.48 ± 2.24	0.34	92.77 ± 37.34	0.00
T1-T2	32 (47)		2.94 ± 2.33		49.83 ± 40.77
Cellular crescents
C0	31 (40.7)	0.32	2.31 ± 1.96	0.02	81.20 ± 39.56	0.00
C1-C2	13 (30.9)		3.78 ± 2.76		43.92 ± 43.50

HTN: Hypertension; eGFR: Estimated glomerular filtration rate; IFTA: Tubular atrophy/interstitial fibrosis.

Table 4 Comparison of kidney outcomes with MEST-C score of immunoglobulin A nephropathy at 6 months, 1 year, 2 years, 5 years and 10 years, n (%)

	MEST-C score
	Overall (n = 118)	1 (n = 30)	2 (n = 31)	3 (n = 35)	4 (n = 16)	5 (n = 5)	6 (n = 1)	P value
At 6 months
CR	58 (49.1)	27 (90)	17 (54.8)	11 (31.4)	2 (12.5)	1 (20)	0	0.00
PR	36 (30.5)	3 (10)	14 (45.1)	9 (25.7)	6 (37.5)	4 (80)	0
ESKD	24 (20.3)	0	0	15 (42.8)	8 (50)	0	1 (100)
At 1 year
CR	55 (46.6)	26 (86.6)	15 (48.3)	11 (31.4)	2 (12.5)	1 (20)	0	0.00
PR	37 (31.3)	4 (13.3)	15 (48.3)	8 (22.8)	6 (37.5)	4 (80)	0
ESKD	26 (22.0)	0	1	16 (45.7)	8 (50)	0	1 (100)
At 2 years
CR	54 (45.7)	27 (90)	16 (51.6)	9 (25.7)	2 (12.5)	0	0	0.00
PR	37 (31.3)	3 (10)	14 (45.1)	9 (25.7)	6 (37.5)	5 (100)	0
ESKD	27 (22.8)	0	1 (3.2)	17 (48.5)	8 (50)	0	1 (100)
At 3 years
CR	22 (18.6)	8 (26.6)	10 (32.2)	3 (8.5)	1 (6.2)	0	0	0.00
PR	21 (17.7)	1 (3.3)	7 (22.5)	9 (25.7)	3 (18.7)	1 (20)	0
ESKD	36 (30.5)	0	5 (16.1)	17 (48.5)	10 (62.5)	3 (60)	1 (100)
Lost-to-F/U	39 (33.0)	21 (70)	9 (29.0)	6 (17.1)	2 (12.5)	1 (20)	0
At 5 years
CR	17 (14.4)	6 (20)	8 (25.8)	2 (5.7)	1 (6.2)	0	0	0.00
PR	19 (16.1)	2 (6.6)	7 (22.5)	8 (22.8)	1 (6.2)	1 (20)	0
ESKD	37 (31.3)	0	6 (19.3)	17 (48.5)	10 (62.5)	3 (60)	1 (100)
Lost-to-F/U	45 (38.1)	22 (73.3)	10 (32.2)	8 (22.8)	4 (25)	1 (20)	0
At 10 years
CR	8 (6.7)	3 (10)	4 (12.9)	0	1 (6.2)	0	0	0.00
PR	12 (10.1)	3 (10)	4 (12.9)	5 (14.2)	0	0	0
ESKD	40 (33.8)	0	6 (19.3)	18 (51.4)	12 (75)	3 (60)	1 (100)
Lost-to-F/U	58 (49.1)	24 (80)	17 (19.3)	12 (34.2)	3 (18.7)	2 (40)	0

CR: Complete remission; PR: Partial remission; ESKD: End stage kidney disease; F/U: Follow-up.