ABSTRACT
Objective:
To investigate the expression and significance of
Toll-like receptor 4 (TLR4) in renal
tissue and peripheral
blood of
children with idiopathic
nephrotic syndrome(INS).
Methods:
The renal
biopsy tissues of 78
children with INS diagnosed in the First Affiliated
Hospital of Xinxiang Medical
University from October 2015 to June 2018 and normal renal
tissues of 21
children (
control group 1) were collected, and the expressions of TLR4 in the renal
tissue was detected by using immunohistochemical
method.The expression of TLR4 in different renal pathological types and clinical types of INS was compared, and the correlation of TLR4 with 24-hour urinary
protein and
serum albumin was analyzed.The expression levels of TLR4 in peripheral
blood of
children with INS before and
after treatment (active stage and remission stage) and 23 healthy
children (
control group 2) were detected by
enzyme linked immunosorbent assay(
ELISA). The
serum expression levels of TLR4 in different renal pathological types and clinical types of INS were compared, and the correlation of TLR4 with 24-hour urinary
protein and
serum albumin was analyzed; The correlation between TLR4 expression in renal tubules and in the
serum of
children with INS was also analyzed.
Results:
(1)Compared with the expression of TLR4 in normal renal
tissues[(0.93±0.26)%], the expression of TLR4 in glomeruli and interstitium of all pathological types of INS [mesangial proliferative
glomerulonephritis (MsPGN) (0.93 ± 0.21)%,
focal segmental glomerulosclerosis (FSGS) (1.02±0.25)%,
membranous glomerulonephritis(MN) (1.03±0.09)%,
minimal change disease(MCD) (1.02±0.27)%]was not significantly different ( F=0.741, P=0.562), but the expression of TLR4 in renal tubules[MCD (82.94±4.62)%, MN (63.54±1.98)%, MsPGN(42.32±2.97)%, FSGS (22.60±2.07)%] was significantly increased ( F=1 929.842, P<0.01), Especially, the expression of TLR4 in renal tubules of MCD type INS was significantly higher than that of MN, MsPG N and FSGS [MCD (82.94±4.62)%, MN (63.54±1.98)%, MsPGN (42.32±2.97)%, FSGS (22.60±2.07)%], and the differences were statistically significant(all P<0.01). TLR4 expression in renal tubules was the highest in
steroid-sensitive nephrotic syndrome (SSNS) type and the lowest in INS
patients with
steroid-resistant nephrotic syndrome (SRNS) type, and the differences were statistically significant( F=220.951, P<0.01). (2)The expression of
serum TLR4 in INS
children at the active stage [MsPNG (143.36±12.99) ng/L, FSGS(75.94±7.29) ng/L, MN(210.22±14.66) ng/L, MCD(283.93±21.58) ng/L]was significantly higher than that in INS
children at remission stage [MsPNG (29.51±4.93) ng/L, FSGS(15.66±3.78) ng/L, MN(45.40±5.73) ng/L, MCD(62.29±7.90) ng/L]and
control group 2[(0.69 ± 0.33) ng/L], and the differences were statistically significant(all P<0.01); the expression of
serum TLR4 in INS
children at remission stage was significantly higher than that in the
control group 2 ( F=286.287, P<0.01). TLR4 had the highest expression level in
serum of MCD type INS
children at active and remission stages, followed by MN and FSGS successively.The expression of
serum TLR4 was highest in SSNS and lowest in SRNS, and the differences were statistically significant ( F=147.438, P<0.01). (3)The expression of TLR4 in renal tubules of
children with INS[(62.82 ±20.94)%]was positively correlated with the expression of TLR4 in
serum[(213.26±73.33) ng/L] ( r=0.852, P< 0.05). The expression levels of TLR4 in renal tubules and
serum of INS
patients at active stage were positively correlated with 24-hour urinary
protein level[(123.05±33.55) mg/kg] ( r=0.401, 0.427, all P<0.05), and negatively correlated with
serum albumin level[(19.54±3.55)g/L] ( r=-0.602, -0.617, all P<0.05).
Conclusions:
The expression of TLR4 in renal tubules and
serum of
children with INS increases, and may be related to different renal pathological types and clinical types of
children with INS, as well as
disease activity.