无症状性血尿患儿402例病因分析

目的　分析402例无症状性血尿患儿的病因。 方法　选择2009年1月至2019年12月新乡医学院第一附属医院收治的402例无症状性血尿患儿为研究对象。通过查阅病历资料收集患儿的一般临床资料（性别、年龄、血压、临床表现、家族史）、临床相关检验资料［尿红细胞畸形率、24 h尿蛋白定量、血尿酸、血尿素、血清免疫球蛋白A（IgA）、血清补体C₃、胱抑素C（Cys C）水平］。115例患儿在超声引导下行肾穿刺活检术，其中97例患儿肾组织标本经免疫组织化学法处理后进行光学显微镜、免疫荧光、电子显微镜检查，18例患儿肾组织标本经免疫组织化学法处理后进行光学显微镜、免疫荧光检查（未做电子显微镜检查）。402例无症状血尿患儿中，尿红细胞畸形率>70%为肾小球源性组（n=230），尿红细胞畸形率≤70%为非肾小球源性组（n=172）。97例行光学显微镜、免疫荧光、电子显微镜检查的无症状血尿患儿中，24 h尿蛋白定量≤150 mg为单纯血尿组（n=51），24 h尿蛋白定量>150 mg为血尿＋蛋白尿组（n=46）；经肾组织免疫荧光检查有IgA在肾小球系膜区沉积者为 IgA肾病（IgAN）组（n=42），无IgA在肾小球系膜区沉积者为非IgAN组（n=55）。结果　肾小球源性组中，镜下血尿83例，肉眼血尿147例；病因主要为孤立性血尿（33.5%），IgAN（20.4%），轻微病变（14.3%），急性肾小球肾炎（13.5%）。非肾小球源性组中，镜下血尿63例，肉眼血尿109例；病因主要为感染伴一过性血尿（28.5%）、泌尿道感染（27.3%）、胡桃夹综合征（17.4%）。血尿＋蛋白尿组患儿的血清IgA、Cys C水平显著高于单纯血尿组 (P<0.05)；单纯血尿组与血尿＋蛋白尿组患儿的血尿素、血尿酸及补体C₃水平比较差异无统计学意义 (P>0.05)。IgAN组患儿的血清Cys C、IgA水平显著高于非IgAN组(P<0.05)；IgAN组与非IgAN组患儿的血尿酸、血尿素、补体C₃水平比较差异无统计学意义(P>0.05)。结论　无症状性血尿病因复杂多样，以肾小球源性血尿为主，其早期诊断、治疗及预后评估有赖于肾穿刺活检；血清Cys C和IgA水平可能对肾脏损害程度和IgAN有一定的预测价值。

Etiology analysis of 402 children with asymptomatic hematuria

Objective　To analyze the etiology of 402 children with asymptomatic hematuria.
Methods　A total of 402 children with asymptomatic hematuria admitted to the First Affiliated Hospital of Xinxiang Medical University from January 2009 to December 2019 were selected as the study subjects.The general clinical data (gender,age,blood pressure,clinical manifestations,family history) and clinical related test data ［urinary erythrocyte malformation rate,24-hour urine protein quantification,blood uric acid,blood urea,serum immunoglobulin A (IgA),serum complement C₃,and cystatin C (Cys C) levels］ of the children were collected by consulting the medical records.A total of 115 children underwent kidney puncture biopsy under ultrasound guidance;among them,the renal tissue samples of 97 children were examined by light microscope,immunofluorescence and electron microscope after immunohistochemical treatment,and the renal tissue samples of 18 children were examined by light microscope and immunofluorescence after immunohistochemical treatment (without electron microscope).In 402 children with asymptomatic hematuria,the children with urinary erythrocyte malformation rate>70% were included in the glomerular origin group(n=230),and the children with urinary erythrocyte malformation rate≤70% were included in the non-glomerular origin group (n=172).Among 97 children with asymptomatic hematuria examined by light microscopy,immunofluorescence and electron microscopy,the children with 24 h urine protein ≤150 mg were included in the simple hematuria group (n=51),and the children with 24 h urine protein>150 mg were included in the hematuria+proteinuria group (n=46);the children with IgA deposition in the mesangial area by renal tissue immunofluorescence test were included in the IgA nephropathy (IgAN) group (n=42),and the children without IgA deposition in the mesangial area were included in the non-IgAN group (n=55).
Results　In the glomerulogenic group,83 cases had microscopic hematuria and 147 cases had gross hematuria;the main causes were isolated hematuria (33.5%),IgAN (20.4%),mild lesions (14.3%),and acute glomerulonephritis (13.5%).In the non-glomerular group,63 cases had microscopic hematuria and 109 cases had gross hematuria;the main causes were transient hematuria with infection(28.5%),urinary tract infection (27.3%),and nutcracker syndrome (17.4%).The serum IgA and Cys C levels of children in the hematuria＋proteinuria group was significantly higher than that in the simple hematuria group (P<0.05);there was no significant difference in the levels of blood urea,blood uric acid and complement C₃ of children between the simple hematuria group and the hematuria+proteinuria group (P>0.05).The serum Cys C and IgA levels of children in the IgAN group were significantly higher than those in the non-IgAN group(P<0.05);there was no significant difference in the levels of serum uric acid,blood urea and complement C₃ of children between the IgAN group and non-IgAN group (P>0.05).
Conclusion　The etiology of asymptomatic hematuria is complex and varied,mainly is glomerulus derived hematuria,and its early diagnosis,treatment and prognosis evaluation depended on kidney biopsy.The serum Cys C and IgA levels may have some value in predicting the degree of renal damage and IgAN.