Acute Glomerulonephritis in children

Acute Glomerulonephritis in Children Submitted to Muktarali kyzy begimai by Riya Patil of Group 32 1. Introduction Acute glomerulonephritis (AGN) is a clinical syndrome characterized by the sudden onset of hematuria, proteinuria, hypertension, and varying degrees of renal dysfunction. It primarily results from inflammation of the glomeruli, the filtering units of the kidney. In children, AGN is a significant cause of acute kidney injury and can result in serious complications if not promptly recognized and managed. The condition is most commonly post-infectious, especially following a streptococcal infection, but may also arise from a variety of other causes, including autoimmune and systemic diseases. The incidence of AGN in children varies globally, influenced by socioeconomic conditions, healthcare access, and infection rates. Early detection, appropriate investigation, and prompt treatment are crucial in ensuring favorable outcomes and preventing long-term renal damage. This article provides a comprehensive overview of acute glomerulonephritis in children, discussing its epidemiology, pathogenesis, clinical features, diagnostic approach, management, and prognosis. 2. Epidemiology Acute glomerulonephritis is more common in children between the ages of 5 and 12 years, with a slight male predominance. Post-streptococcal glomerulonephritis (PSGN) is the most frequent form seen in this age group, particularly in developing countries where streptococcal infections are more prevalent due to overcrowding and limited healthcare access. The incidence of PSGN has declined in developed countries due to improved hygiene and prompt treatment of streptococcal infections. However, other causes of AGN, such as Henoch-Schönlein purpura nephritis and lupus nephritis, remain significant contributors. Seasonal variations are also observed, with a higher incidence of PSGN during colder months, correlating with the increased prevalence of streptococcal infections. 3. Etiology and Risk Factors The etiology of acute glomerulonephritis in children can be broadly categorized into infectious and non-infectious causes: Infectious Causes: - Post-streptococcal (most common) - Other bacterial infections (e.g., staphylococcus, pneumococcus) - Viral infections (e.g., hepatitis B and C, HIV, Epstein-Barr virus) - Parasitic infections (e.g., malaria, schistosomiasis) Non-infectious Causes: - IgA nephropathy - Henoch-Schönlein purpura (now called IgA vasculitis) - Systemic lupus erythematosus - Membranoproliferative glomerulonephritis - Vasculitides (e.g., granulomatosis with polyangiitis) Risk Factors: - Recent history of sore throat or skin infection - Poor socioeconomic conditions - Inadequate treatment of streptococcal infections - Family history of autoimmune diseases - Certain genetic predispositions 4. Pathophysiology The pathophysiology of AGN involves immune-mediated injury to the glomeruli. In post-infectious GN, for instance, streptococcal antigens form immune complexes that deposit in the glomerular basement membrane, triggering complement activation and recruitment of inflammatory cells. This results in glomerular inflammation, proliferation of mesangial and endothelial cells, and damage to the capillary walls, causing leakage of red blood cells and protein into the urine. In diseases like lupus nephritis, autoantibodies target native antigens in the kidney, while in IgA nephropathy and IgA vasculitis, there is deposition of IgA-containing immune complexes. The precise mechanisms may vary, but all forms of AGN share the common endpoint of glomerular inflammation and injury. 5. Clinical Features The clinical presentation of AGN can range from asymptomatic microscopic hematuria to full-blown nephritic syndrome. Common features include: - Hematuria (often cola- or tea-colored urine) - Proteinuria (usually sub-nephrotic) - Edema (especially periorbital and lower extremities) - Hypertension - Oliguria or decreased urine output - General malaise, fatigue, and irritability In severe cases, children may present with signs of acute kidney injury, such as elevated creatinine, fluid overload, and uremic symptoms (e.g., nausea, vomiting, confusion). 6. Diagnosis A thorough history and physical examination are critical. The diagnosis is supported by laboratory and imaging studies: Laboratory Tests: - Urinalysis: hematuria, proteinuria, red blood cell casts - Blood tests: elevated BUN and creatinine, low complement (C3) levels (especially in PSGN) - Antistreptolysin O (ASO) titer or anti-DNase B: evidence of recent streptococcal infection - Complete blood count: may show anemia or leukocytosis - Autoimmune panel: ANA, anti-dsDNA, ANCA (for suspected lupus or vasculitis) Imaging: - Renal ultrasound: may show enlarged kidneys with increased echogenicity Renal Biopsy: - Reserved for atypical cases, rapidly progressive disease, or suspicion of systemic disease - Helps determine exact histopathology and guide treatment 7. Differential Diagnosis The differential diagnosis for AGN includes: - Nephrotic syndrome (primarily proteinuria and edema without hematuria or hypertension) - Hemolytic uremic syndrome - Acute interstitial nephritis - Urinary tract infection - Structural anomalies of the urinary tract 8. Complications Although many children recover fully from AGN, complications can occur: - Acute kidney injury - Hypertensive encephalopathy - Pulmonary edema - Electrolyte imbalances (e.g., hyperkalemia) - Chronic kidney disease (especially with recurrent or severe episodes) - End-stage renal disease (rare but serious) 9. Management and Treatment Management is largely supportive, with treatment tailored to the underlying cause. *General Measures:* - Bed rest during the acute phase - Salt and fluid restriction to manage edema and hypertension - Antihypertensive therapy (e.g., calcium channel blockers, ACE inhibitors) - Diuretics for fluid overload - Antibiotics if an ongoing infection is present (e.g., penicillin for streptococcal infection) *Specific Therapies:* - Corticosteroids: for cases with IgA nephropathy, lupus nephritis, or vasculitis - Immunosuppressive agents (cyclophosphamide, mycophenolate mofetil) for severe autoimmune GN - Plasma exchange in rapidly progressive GN or severe vasculitis - Dialysis in cases of severe acute kidney injury 13. Case Studies or Examples L *Case 1: Post-Streptococcal GN* A 7-year-old boy presents with dark-colored urine, facial swelling, and elevated blood pressure. He had a sore throat 2 weeks prior. Investigations show low C3, elevated ASO titer, and hematuria with red cell casts. He is managed with fluid restriction, antihypertensives, and close monitoring. He recovers completely within 4 weeks. Case 2: Lupus Nephritis A 12-year-old girl presents with fatigue, joint pain, and facial rash. Urinalysis reveals hematuria and proteinuria. ANA and anti-dsDNA are positive. Renal biopsy shows Class IV lupus nephritis. She is treated with corticosteroids and mycophenolate mofetil, with good response. Conclusion Acute glomerulonephritis in children remains an important pediatric condition requiring timely diagnosis and management. While most cases resolve without complications, a subset may progress to chronic kidney disease or require long-term follow-up. Improved understanding of the underlying pathophysiology and advances in treatment have significantly enhanced outcomes. Continued research and public health measures are essential to further reduce the burden of this condition, especially in resource-limited settings. Reference https://my.clevelandclinic.org/health/diseases/16167-glomerulonephritis-gn https://emedicine.medscape.com/article/239278-overview https://www.kidney.org/kidney-topics/glomerulonephritis https://en.wikipedia.org/wiki/Glomerulonephritis https://www.mayoclinic.org/diseases-conditions/glomerulonephritis/symptoms-causes/syc-20355705儿童急性肾小球肾炎 由第32组的Riya Patil提交予Muktarali kyzy begimai 1. 引言 急性肾小球肾炎（Acute Glomerulonephritis, AGN）是一组以起病急骤的血尿、蛋白尿、高血压及不同程度肾功能不全为特征的临床综合征。其核心病理为肾脏滤过单位——肾小球的炎症反应。在儿童群体中，AGN是急性肾损伤的重要诱因，若未及时识别与规范管理，可引发严重并发症。该病最常见类型为感染后性，尤以链球菌感染后最为多见，但也可由多种其他病因引发，包括自身免疫性疾病及全身性疾病。 儿童AGN的全球发病率存在显著差异，受社会经济状况、医疗可及性及感染发生率的共同影响。早期发现、规范检查与及时治疗是保障良好预后、预防远期肾损伤的关键。本文全面综述儿童急性肾小球肾炎，涵盖其流行病学、发病机制、临床表现、诊断思路、治疗方案及预后情况。 2. 流行病学 AGN在5~12岁儿童中更为常见，男性略多于女性。链球菌感染后肾小球肾炎（Post-streptococcal Glomerulonephritis, PSGN）是该年龄段最常见的AGN亚型，在因居住拥挤、医疗资源匮乏导致链球菌感染高发的发展中国家尤为多见。 随着卫生条件改善与链球菌感染及时治疗的普及，发达国家PSGN的发病率已有所下降，但其他类型AGN如过敏性紫癜肾炎、狼疮性肾炎仍占相当比例。此外该病存在季节性特征，寒冷季节PSGN发病率更高，与该时段链球菌感染的流行率升高密切相关。 3. 病因与危险因素 儿童AGN的病因可大致分为感染性与非感染性两类： 感染性病因： - 链球菌感染后（最常见） - 其他细菌感染（如葡萄球菌、肺炎链球菌） - 病毒感染（如乙型肝炎、丙型肝炎、人类免疫缺陷病毒、EB病毒） - 寄生虫感染（如疟疾、血吸虫病） 非感染性病因： - IgA肾病 - 过敏性紫癜（现称为IgA血管炎） - 系统性红斑狼疮 - 膜增生性肾小球肾炎 - 血管炎（如肉芽肿性多血管炎） 危险因素： - 近期咽痛或皮肤感染史 - 社会经济状况不佳 - 链球菌感染治疗不充分 - 自身免疫性疾病家族史 - 特定遗传易感性 4. 病理生理学 AGN的核心发病机制为免疫介导的肾小球损伤。以感染后GN为例，链球菌抗原形成免疫复合物并沉积于肾小球基底膜，触发补体激活与炎症细胞募集，进而引发肾小球炎症、系膜细胞及内皮细胞增殖、毛细血管壁损伤，最终导致红细胞与蛋白漏入尿液中。 在狼疮性肾炎等疾病中，自身抗体靶向肾脏自身抗原；而在IgA肾病及IgA血管炎中，则可见含IgA的免疫复合物沉积。尽管具体机制存在差异，但所有类型AGN的最终共同通路均为肾小球炎症与损伤。 5. 临床表现 AGN的临床表现谱跨度极大，从无症状镜下血尿直至典型肾炎综合征均可见。常见症状包括： - 血尿（常表现为浓茶色或茶色尿） - 蛋白尿（多为非肾病范围） - 水肿（尤以眶周及下肢最为显著） - 高血压 - 少尿或尿量减少 - 全身不适、乏力及烦躁不安 重症患儿可出现急性肾损伤相关表现，如肌酐升高、液体超负荷及尿毒症症状（如恶心、呕吐、意识障碍）。 6. 诊断 详细的病史采集与体格检查是诊断的基础，实验室及影像学检查可进一步佐证诊断： 实验室检查： - 尿液分析：可见血尿、蛋白尿及红细胞管型 - 血液检查：血尿素氮（BUN）及肌酐升高，补体C3水平降低（PSGN患者尤为显著） - 抗链球菌溶血素O（ASO）滴度或抗DNA酶B抗体检测：提示近期链球菌感染 - 全血细胞计数：可出现贫血或白细胞增多 - 自身抗体谱：抗核抗体（ANA）、抗双链DNA（anti-dsDNA）抗体、抗中性粒细胞胞浆抗体（ANCA）（疑诊狼疮或血管炎时） 影像学检查： - 肾脏超声：可见肾脏体积增大、回声增强 肾活检： - 仅用于非典型病例、急进性病变或疑诊全身性疾病的情况 - 有助于明确具体组织病理学类型并指导治疗 7. 鉴别诊断 AGN的鉴别诊断包括： - 肾病综合征（以蛋白尿及水肿为主要表现，无血尿或高血压） - 溶血性尿毒症综合征 - 急性间质性肾炎 - 尿路感染 - 尿路结构异常 8. 并发症 尽管多数患儿可完全康复，但AGN仍可能引发并发症： - 急性肾损伤 - 高血压脑病 - 肺水肿 - 电解质紊乱（如高钾血症） - 慢性肾脏病（反复发作或重症病例尤为常见） - 终末期肾病（罕见但病情危重） 9. 治疗与管理 治疗以支持治疗为主，同时需结合病因制定个体化方案。 *一般措施：* - 急性期卧床休息 - 限盐限液以控制水肿与高血压 - 降压治疗（如钙通道阻滞剂、血管紧张素转换酶抑制剂） - 利尿剂用于液体超负荷的处理 - 活动性感染时予抗生素治疗（如链球菌感染予青霉素） *特殊治疗：* - 糖皮质激素：用于IgA肾病、狼疮性肾炎或血管炎病例 - 免疫抑制剂（环磷酰胺、霉酚酸酯）：用于重症自身免疫性GN - 血浆置换：用于急进性GN或重症血管炎 - 透析：用于重症急性肾损伤病例 13. 案例研究或示例 L *案例1：链球菌感染后GN* 一名7岁男童因尿色加深、面部肿胀及血压升高就诊，2周前曾有咽痛病史。检查显示补体C3降低、ASO滴度升高，血尿伴红细胞管型。予限液、降压治疗及密切监测后，患儿于4周内完全康复。 *案例2：狼疮性肾炎* 一名12岁女童因乏力、关节痛及面部皮疹就诊，尿液分析显示血尿及蛋白尿，ANA与anti-dsDNA抗体均为阳性，肾活检提示IV型狼疮性肾炎。予糖皮质激素及霉酚酸酯治疗后疗效良好。 结论 儿童急性肾小球肾炎仍是一类需要及时诊断与干预的重要儿科疾病。尽管多数病例可无并发症痊愈，但部分患儿可进展为慢性肾脏病或需要长期随访。对发病机制的深入理解与治疗手段的进步已显著改善了该病的预后。持续开展研究与公共卫生干预措施，对于进一步降低该病的疾病负担，尤其是在资源匮乏地区，具有重要意义。 参考文献 https://my.clevelandclinic.org/health/diseases/16167-glomerulonephritis-gn https://emedicine.medscape.com/article/239278-overview https://www.kidney.org/kidney-topics/glomerulonephritis https://en.wikipedia.org/wiki/Glomerulonephritis https://www.mayoclinic.org/diseases-conditions/glomerulonephritis/symptoms-causes/syc-20355705