IgG4相关慢性间质性肾炎并肾包膜纤维化一例报告暨文献复习

Perirenal capsule involvement in IgG4-related chronic interstitial nephritis:a case report and literature review

目的 通过报道1例IgG4相关慢性间质性肾炎合并肾包膜纤维化的病例,结合文献复习,探讨本病的临床病理特点及肾活检注意事项,以提高临床医生对该病的认识.方法 描述患者发病及诊治经过,系统回顾相关文献,总结临床病理特点及肾活检操作注意事项.结果 本例患者尿比重1.011、尿蛋白±、尿糖3+,血红蛋白53 g/L,血肌酐1665μmol/L,IgG49.39 g/L,CT示双肾体积稍增大,双肾密度降低,肾周见低密度影环绕,增强扫描双肾见不规则低密度强化区,边界不清.第1次肾活检取出2条组织未见肾实质,主要为玻璃样变性的胶原纤维组织,重复肾活检取出3条组织示慢性间质性肾炎,IgG4阳性浆细胞热点区约60个/HPF,IgG4阳性浆细胞/IgG阳性浆细胞>40%,明确诊断IgG4相关慢性间质性肾炎.经足量激素治疗,患者摆脱透析,血肌酐降至502μmol/L.结论 IgG4相关疾病引起肾脏损害表现各异,需留意其累及肾周组织的情况,对肾包膜增厚的患者行肾活检时需权衡出血与取材不佳的风险.

Objective To explore the clinicopathological features and the renal biopsy process of a case of IgG4-related chronic interstitial nephritis with perirenal capsule involved and review associated literature to improve the clinician's understanding for this disease and to perform a better renal biopsy.Methods The onset,diagnosis and treatment course of the disease were described and associated literature were reviewed to summary the clinicopathologic features and key points in renal biopsy.Results The data of the patient showed that the urine specific gravity was 1.011,with urine protein±and urine sugar 3+.The concentration of hemoglobin was 53 g/L,serum creatinine was 1665μmol/L,and IgG4 was 9.39 g/L.Computed tomography showed that both kidneys enlarged slightly with decreased density and low density shadow around the kidneys.On contrast-enhanced scan,irregular low-density enhancement areas were found in both kidneys,and the edge of the boundary was not clear.For the first renal biopsy,no renal parenchyma was found except mainly hyaline collagen fibrils.At the second time,3 pieces of tissues were obtained,which showed chronic interstitial glomerulonephritis.The IgG4 positive plasma cells were about 60/HPF and the IgG4+/IgG+cells ratio was more than 40%.The diagnosis of IgG4-related chronic interstitial glomerulonephritis was confirmed.After corticosteroid treatment,the serum creatinine decreased to 502μmol/L after the patient got rid of dialysis.Conclusions There are various manifestations of renal damage caused by IgG4-related disease.It is necessary to pay attention to the involvement of the perirenal capsule,and to balance the risk of bleeding and poor sampling in renal biopsy.