Renal Unit, First Department of Paediatrics, National and Kapodistrian University of Athens, Aghia Sophia Children's Hospital, Athens, Greece.
Renal Unit, Great Ormond Street Hospital, London, UK.
BMC Nephrol. 2023 May 3;24(1):124. doi: 10.1186/s12882-023-03179-1.
IgA nephropathy (IgAN) is universally recognized as one of the most common primary glomerular diseases in all ages. Cyclic neutropenia (CN) is a rare haematologic disorder that is associated with mutations of the ELANE gene. The co-occurrence of IgAN and CN is extremely rare. This is the first case report of a patient with IgAN and genetically confirmed CN.
We report a case of a 10-year-old boy who presented with recurrent viral upper respiratory tract infections accompanied by several episodes of febrile neutropenia, haematuria, proteinuria and acute kidney injury. Upon first admission, his physical examination was unremarkable. His kidney function was impaired, whereas his urine microscopy showed evidence of macroscopic haematuria and proteinuria. Further workup showed elevated IgA. The renal histology was consistent with mesangial and endocapillary hypercellularity with mild crescentic lesions, while immunofluorescence microscopy showed IgA-positive staining, which was characteristic of IgAN. Moreover, genetic testing confirmed the clinical diagnosis of CN, therefore Granulocyte colony-stimulating factor (G-CSF) was initiated to stabilize the neutrophil count. Regarding proteinuria control, the patient was initially treated with an Angiotensin-converting-enzyme inhibitor for approximately 28 months. However, due to progressive proteinuria (> 1 g/24 h), Corticosteroids (CS) were added for a period of 6 months according to the revised 2021 KDIGO guidelines with favorable outcome.
Patients with CN are more susceptible to recurrent viral infections, which can trigger IgAN attacks. In our case CS induced remarkable proteinuria remission. The use of G-CSF contributed to the resolution of severe neutropenic episodes, viral infections and concomitant AKI episodes, contributing to better prognosis of IgAN. Further studies are mandatory to determine whether there is a genetical predisposition for IgAN in children with CN.
IgA 肾病（IgAN）是一种普遍存在于各年龄段的最常见的原发性肾小球疾病。周期性中性粒细胞减少症（CN）是一种罕见的血液疾病，与 ELANE 基因突变有关。IgAN 和 CN 同时发生的情况极为罕见。这是首例 IgAN 伴基因确诊 CN 的病例报告。
我们报告了一例 10 岁男孩的病例，他因反复发作的病毒性上呼吸道感染，伴有几次发热性中性粒细胞减少症、血尿、蛋白尿和急性肾损伤而就诊。首次入院时，他的体检无明显异常。他的肾功能受损，而尿液显微镜检查显示有大量血尿和蛋白尿。进一步检查显示 IgA 升高。肾组织学表现为系膜和内皮下细胞增多伴轻度新月体病变，免疫荧光显微镜检查显示 IgA 阳性染色，符合 IgAN 的特征。此外，基因检测证实了 CN 的临床诊断，因此开始使用粒细胞集落刺激因子（G-CSF）来稳定中性粒细胞计数。关于蛋白尿的控制，患者最初接受血管紧张素转换酶抑制剂治疗约 28 个月。然而，由于蛋白尿逐渐增加（>1g/24h），根据 2021 年 KDIGO 指南修订版，加用皮质类固醇（CS）治疗 6 个月，结果良好。
CN 患者更容易受到复发性病毒感染的影响，这可能引发 IgAN 发作。在我们的病例中，CS 诱导显著的蛋白尿缓解。G-CSF 的使用有助于解决严重的中性粒细胞减少症发作、病毒感染和并发 AKI 发作，有助于改善 IgAN 的预后。需要进一步的研究来确定 CN 儿童是否存在 IgAN 的遗传易感性。
