Advances in Alport syndrome / 国际儿科学杂志

Alport syndrome is a rare genetic disorder of specialized basement membranes in the kidney,ear,and eye.Eighty percent of patients have X-linked disease caused by mutations in the COL4A5 gene;autosomal forms of the other Alport syndrome are caused by mutations in COI4A3 and COL4A4 genes.These mutations result in progressive irregular thickening,thinning,and splitting of the GBM,leading to end stage renal failure.During the past two decades,research into this rare disease has focused on the effects of mutations in collagen type Ⅳ α chains and the role of changes in podocytes and the glomerular basement membrane that lead to early kidney fibrosis.In this review,we discuss the latest basic and clinical research on Alport syndrome,focusing on the roles of podocyte pathology and the extracellular matrix.

The expression and signification of kidney injury molecule-1 on renal ischemia reperfusion injury in rat / 中国小儿急救医学

Objective To observe the expression levels of kidney injury molecule-1(KIM-1) in renal tissues of ischemia-reperfusion rats,and to explore the value in the diagnosis of acute kidney injury.Methods Rats were randomly divided into two groups,control(CON) group (n=64) and acute kidney ischemia reperfusion injury (AIKI) group (n=64).Rats were sacrificed following reperfusion 2h,6h,24h,48h,72h,1 week (w),2 w,and 4 w.The changes of morphology were checked on HE staining sections under light microscope.The extent of tubulointerstitial injury was determined by Sayhan classification.The distribution and expression of KIM-1 in renal tissue were observed by immunohistochemistry and Western blotting.Serum samples were collected and serum creatinine measurement was performed at different reperfusion time points.Results (1) Compared with the CON group,the renal tubulointerstitial injury scores of AIKI group were significantly higher at all times after reperfusion (P<0.01).(2) The expression of KIM-1 was consistent with the tubulointerstitial injury.The positive correlation between KIM-1 and the tubulointerstitial injury scores was significant(r=0.887,P=0.003).(3) Compared with the CON group,serum creatinine in AIKI group was significant higher at 2h,6h,24h,48h,72h after reperfusion (P<0.05).Serum creatinine had no correlation with the damage of renal tubulointerstitial.Conclusion The expression of KIM-1 increases significantly in renal ischemia reperfusion injury,and it is consistent with the tubulointerstitial injury.Compared with serum creatinine,KIM-1 may be a more accurate biomarker of renal damage.

Features of clinical phenotype and genotype in Alport syndrome: a monocentric study / 中华儿科杂志

<p><b>OBJECTIVE</b>To analyze the clinical features and gene mutation of Chinese children with Alport syndrome(AS).</p><p><b>METHOD</b>From May 2011 to May 2014, clinical and pathological information gathered from 25 patients was retrospectively analyzed. COL4A5, COL4A4 and COL4A3 genes were analyzed using next-generation sequencing in these patients, and gene mutations of related family members were identified by Sanger method.</p><p><b>RESULT</b>Of these 25 cases, 19(76%) had X-linked Alport syndromes (XL-AS), 6 had autosomal recessive Alport syndromes (AR-AS). Twenty five patients had an onset of hematuria and proteinuria and in 8 cases the disease was induced by upper respiratory tract infections. Hearing loss was present in 2 of 25 (8%) cases and ocular lesions in 1 of 25 (4%). Renal pathology showed that 16 of them had minimal change disease (MCD), 8 mesangial proliferative glomerulonephritis (MsPNG), 1 focal segmental glomerulo-sclerosis (FSGS). Extensive lamination and split of glomerular basement membrane (GBM) dense layers were found in 2 (8%) of 25 patients. Twenty one of 25 patients (84%) showed abnormal renal α-chain distribution. COL4A5, COL4A4 and COL4A3 genes of 25 patients (23 families) were analyzed and 24 pathogenic mutations were identified: 18 in COL4A5, 1 in COL4A3 and 5 in COL4A4. It was observed that 13 patients inherited the mutation from the mother, 3 patients inherited from the father, 2 patients inherited 1 mutation from the mother and another mutation from the father, and 7 patients carried the novel mutations.</p><p><b>CONCLUSION</b>XL is the main inherited type in AS. Most of patients showed MCD and MsPNG in renal biopsy. This research examined 24 mutations and 16 mutations were not reported previously.</p>

Effects of response gene to complement 32 as a new biomarker in children with acute kidney injury / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the new biomarkers of acute kidney injury, as well as to confirm the values of response gene to complement 32 (RGC-32) for early diagnosis of acute kidney injury by comparing the values of serum creatinine (Scr) and cystatin C (CysC) in children who had undergone cardiopulmonary bypass (CPB).</p><p><b>METHOD</b>Sixty-seven patients who had accepted CPB were recruited from the cardiac surgery intensive care unit, Children's Hospital Affiliated to Shanghai Jiao Tong University from March to June 2013 and assigned to acute kidney injury group (group AKI) or non-acute kidney injury group (group non-AKI), on the basis of the definition by the pediatric RIFLE (pRIFLE) criteria. Also 30 healthy control children were recruited. Serum samples were taken regularly from each patient after CPB at 30 min, 2 h, 4 h, 24 h, 48 h and 72 h for RGC-32. Serum samples were tested by enzyme linked immunosorbent assay (ELISA) which was employed to determine the levels of serum RGC-32. Scr and CysC were analyzed by HITACHI 7180 automatic biochemical analyzer. All the data were analyzed by receiver operator characteristic curve (ROC) and area under curve (AUC).</p><p><b>RESULT</b>The incidence of AKI was 34% (23/67), including 15 cases with risk stage AKI, 4 cases with injury stage AKI, 3 cases with failure stage AKI, 1 cases with loss stage AKI. Three out of four subjects with Failure stage AKI and the one case with Loss stage all accepted renal replacement therapy. CPB group had a higher level of serum RGC-32 than that of pre-operation after CPB 30 minute [(2.88 ± 0.68) µg/L vs. (1.39 ± 0.31) µg/L, P < 0.05]. At the same time, comparing with the non-AKI group, the levels of serum RGC-32 were higher than that of controls 30 min, 2 h, 4 h, 24 h and 48 h after CPB (t = 2.560, 2.180, 2.818, 2.226, 3.017; P < 0.05). The values for the AUC were determined for RGC-32 as 0.770, 0.707, 0.768, 0.728,0.723 and 0.770 after CPB 30 min, 2 h, 4 h, 24 h, 48 h and 72 h. The values for sensitivity of serum RGC-32 30 min, 2 h and 4 h after CPB was 0.914, 0.824, 0.824 and the values for specificity of serum RGC-32 was 0.619, 0.667, 0.810, respectively. But the values for sensitivity of CysC was 0.625, 0.813, 0.813, and specificity 0.571, 0.619, 0.571, respectively. The values for sensitivity of Scr was 0.625, 0.625, 0.813 and specificity was 0.571, 0.571, 0.524, respectively.</p><p><b>CONCLUSION</b>The sensitivity of serum RGC-32 for detecting AKI was much higher than that of Scr and serum CysC in children who had accepted CPB, and that RGC-32 may be a new biomarker for early detection of AKI. However, the conclusion needs to be further elucidated.</p>

Combination of urine neutrophil gelatinase lipocalin associated lipocalin, kidney injury molecular-1 and interleukin-18 in the diagnosis of acute kidney injury in children after cardiopulmonary bypass / 临床儿科杂志

Objective To investigate the values of urine neutrophil gelatinase associated lipocalin (NGAL), kidney injury molecular-1 (KIM-1) and interleukin-18 (IL-18) in the diagnosis of acute kidney injury (AKI) in children after cardiopulmonary by-pass (CPB). Methods Sixty-seven patients who had undergone CPB were recruited from March to June 2013 and assigned to acute kidney injury group (AKI group) or non-acute kidney injury group (non-AKI group) according to the pediatric RIFLE (pRIFLE) cri-teria. Serum and urine samples were collected from each patient at 30 min, 2 h, 4 h, 24 h, 48 h and 72 h after CPB for serum and urine creatinine, urine NGAL, KIM-1 and IL-18. All the data were evaluated by receiver operator characteristic curve (ROC) analysis and area under curve (AUC) analysis. Results Twenty-three cases (34.3%) had AKI in 67 children after CPB. Among them 15 cases were risk-stage AKI, 4 cases injury-stage AKI, 3 cases failure-stage AKI and 1 cases loss-stage AKI. The levels of urine NGAL/Ucr were higher in AKI group than those in non-AKI group at 4h, 48h and 72h after CPB (P<0.05). The cut-off value of NGAL/Ucr was 1.200 at 4 h after CPB, the sensitivity and specificity for prediction of AKI were 0.864 and 0.561, and the AUC was 0.671 (95%CI:0.537-0.804). The levels of urine KIM-1/Ucr were higher in AKI group than those in non-AKI group at 48h and 72 h after CPB (P<0.05). The cut-off value of KIM-1/Ucr was 1.162 at 24h after CPB, the sensitivity and specificity for prediction of AKI were 0.773 and 0.512, and the AUC was 0.698 (95%CI:0.563-0.834). The levels of IL-18/Ucr were higher in AKI group than those in non-AKI group at 4 h after CPB (P<0.05). The cut-off value of IL-18/Ucr was 0.04 at 4 h after CPB, the sensitivity and specificity for predici-ton of AKI were 0.773 and 0.561, and the AUC was 0.655 (95%CI:0.510-0.800). Conclusions It is indicated that urine NGAL, KIM-1 and IL-18 may have important clinical values for early prediction of AKI.

Expression of response gene to complement 32 in renal tissue of children with IgA nephropathy and its significance / 中华肾脏病杂志

Objective To examine the expression of response gene to complement 32 (RGC-32) in renal tissue of children with IgA nephropathy (IgAN), and to explore its significance. Methods The subjects were 45 children diagnosed as IgAN by renal biopsy. The expression of RGC-32, α-smooth muscle actin (α-SMA) and transforming growth factor β1 (TGF-β1) was examined by immunohistochemistry staining. The correlation of RGC-32 expression with α-SMA,TGF-β1, degree of renal pathological lesions and clinical index in IgAN was assessed by Spearman correlation analysis. Results RGC-32 protein located in renal tubular epithelial cells in normal and IgAN renal tissues. The positive expression index of RGC-32 in nomal group, IgAN mild group, moderate group and severe group was (18.29±6.22)%, (23.90±9.65)%, (31.23±9.86)%,and (34.52±10.63)% respectively. With more severity of renal pathological lesions, the expression of RGC-32 in IgAN was enhanced. The RGC-32 expression was positively correlated with the score of glomerulus and renal interstitium in children with IgAN (r=0.385, 0.347, P＜0.05), as well as α-SMA, TGF-β1 (r=0.594, 0.521, P＜0.01), but was not correlated with Scr, urinary NAG/Cr,Alb/Cr, IgG/Cr, and α1-M/Cr (r =0.117, -0.115, -0.138, -0.176, -0.028, all P ＞0.05).Conclusions RGC-32 protein locates in renal tubular epithelial cells in normal and IgAN renal tissues. RGC-32 may participate in the course of renal tubulointerstitial lesions in children with IgAN, especially in the course of epithelial-mesenchymal transition (EMT) induced by TGF-β1.

Large sample follow-up of single centre and assessment of pediatric urolithiasis caused by melamine-contaminated milk powder / 中华肾脏病杂志

Objective To assess the prognosis and effect on renal function of pediatric urolithiasis caused by melamine-contaminated milk powder (PUMMP) in a long-term follow-up.Methods One hundred and two of 8335 children (≤ 6-year-old) with history of consuming melamine-contaminated milk powder screened in our hospital were followed up for eighteen months after diagnosis. Urinary system ultrasonography, urinalysis, urinary microprotein profiles [microalbumin (ALBU), immunoglobulin G (IgG), and N-acetyl-β-D-glucosidase (NAG)], urinary melamine and cyanuric acid were examined in the first visit and at the end of follow-up. Results Follow-up was completed in 91 children and the stone was excreted in 82 children (90.1%).Stones less than 5 mm in diameter were most vulnerable to discharge, and stones larger than 10 mm could not be expelled without interventions. At the end of follow-up, no melamine or cyanuric acid was found in the urine samples of 74 patients. Urinalysis showed that incidences of proteinuria, microscopic hematuria and leukocyturia were 0%, 5.1% and 2.0%, which were significant different from those in the first visit (Pproteinutria=0.123, Phemnatuna=0.038 and Pleukocyhuris=0.005).Urinary microprotein profiles revealed that some children whose urinalysis was normal still presented glomerular and renal tubular injury and the abnormal rates were 8.8% and 12.1%respectively. The glomerular injury was mainly related to persistent stone, male and younger.Conclusions 90.1% of children with PUMMP passes urinary stones at the end of follow-up.Stone size is the major risk factor of discharge. No melamine or cyanuric acid is found in the urine of children. After eighteen months, glomerular and renal tubular injury is still found in some patients. Further follow-up is necessary.