Onset with fever and back pain, an 81-year-old man had sudden oliguria and progressively elevated serum creatine from normal range to 660 μmol/L within 1 week after receiving contrast agents, various antibiotics, and several nonsteroidal anti-inflammation drugs. Urine output recovered after supportive treatment. However, his serum creatinine level rose again soon after a temporary decline accompanied by gross hematuria with almost normal morphology, nephrotic proteinuria, and hypoalbuminemia. Renal biopsy revealed necrotizing glomerulonephritis. Methylprednisolone was intravenously administrated 500 mg per day for 3 days, followed by oral glucocorticoids and cyclophosphamide. Gradually the patient′s serum creatinine descended to 144 μmol/L.

Objective To evaluate the predictive factors and renal outcomes of idiopathic membranous nephropathy (IMN) in patients with type 2 diabetes (T2DM).Methods In this retrospective study,clinical data of 101 IMN patients with T2DM and 96 patients with diabetic nephropathy (DN) were consecutively collected.Logistic regression was used to assess potential clinical factors indicating IMN and COX regression was employed to analyze risks of IMN in developing to endstage renal disease (ESRD),as compared with that of DN,in patients with T2DM.Results In a multivariate model,age ≥55 years old,presence of nephrotic syndrome,estimated glomerular filtration rate (eGFR) ＞ 60 ml · min-1 · (1.73 m2)-1,duration of diabetes≤5 years and absence of diabetic retinopathy,were associated with IMN,as compared with DN,in patients with T2DM.In T2DM patients presented with nephrotic syndrome,age≥55 years old,eGFR ＞ 60 ml· min1· (1.73 m2)-1,duration of diabetes≤5 years and absence of diabetic retinopathy,were also associated with IMN,as compared with DN.Receiver operating characteristic curve (ROC) showed eGFR 65.5 ml · min-1 · (1.73 m2) 1 was an optimal cutoff in differentiating DN and IMN.DN was associated with 16.8 times as high risk of incident ESRD as compared with IMN in T2DM patients.Conclusions In patients with T2DM,age≥55 years,presence of nephrotic syndrome,early stage of CKD,duration of diabetes≤5 years and absence of retinopathy,may indicate IMN rather than DN.T2DM patients with IMN have much better renal prognosis as compared with DN.

A 43-year-old male patient with onset of edema caused by nephrotic proteinuria and low titer of anti-M type phospholipase-A 2-receptor (PLA 2R) antibody was diagnosed as idiopathic membranous nephropathy by renal biopsy. Administrated with prednisone 40 mg once a day and cyclosporine 100 mg twice a day as front-line regimen, the patient relapsed after transient partial remission. When treatment was combined with cyclophosphamide 100 mg once a day, the 24-hour total urine protein and titer of anti-PLA 2R antibody were even elevated. Therefore, the patient received rituximab 1 g intravenously in April 2019, October 2019 and October 2020 respectively. CD19 positive B lymphocytes in peripheral blood were eliminated from 71/μl to zero. Immunosuppressants and corticosteroids were withdrawn successively. On the last follow-up in November 2020, the anti-PLA 2R antibody was negative, and the 24-hour total urine protein and serum albumin was 4.4 g and 34 g/L, respectively. This case suggested the potential efficacy of rituximab for refractory membranous nephropathy. Further studies should explore whether the titer of anti-PLA 2R antibody indicates the dose of rituximab.