Renal Fanconi syndrome (FS) is a rare renal manifestation of primary Sjögren's syndrome (pSS). This study aims to analyze the clinical and prognostic characteristics of patients with pSS-associated renal FS (pSS-FS) and provide insights for clinical management.

A 15-year-old boy developed abdominal pain and melena two weeks after COVID-19 infection, which was followed by gross hematuria and proteinuria. Laboratory studies revealed significantly elevated inflammatory markers. Endoscopic examinations showed multiple jejunal and ileal ulcers. Renal biopsy suggested mesangial proliferative glomerulonephritis with crescent formation, necrosis of capillary loops, and mesangial IgA deposits. IgA vasculitis without purpura was considered as a possible diagnosis, and the treatment with prednisone led to remission of both gastrointestinal and renal diseases.

Since the discovery of anti-phospholipase A2 receptor antibodies, the diagnosis of primary membranous nephropathy has evolved from reliance on renal tissue biopsy to the use of serum assays in certain patients, owing to continuously developing and improving methodologies. The advancement of detection methods and the discovery of new antigens are driving primary membranous nephropathy to personalized diagnosis and treatment. This article summarizes the evolution of antigens and antibodies detection techniques related to primary membranous nephropathy, aiming to explore the advantages, disadvantages, and possible future directions of methodology.

A 15-year-old boy developed abdominal pain and melena two weeks after COVID-19 infection, which was followed by gross hematuria and proteinuria. Laboratory studies revealed significantly elevated inflammatory markers. Endoscopic examinations showed multiple jejunal and ileal ulcers. Renal biopsy suggested mesangial proliferative glomerulonephritis with crescent formation, necrosis of capillary loops, and mesangial IgA deposits. IgA vasculitis without purpura was considered as a possible diagnosis, and the treatment with prednisone led to remission of both gastrointestinal and renal diseases.

Since the discovery of anti-phospholipase A2 receptor antibodies, the diagnosis of primary membranous nephropathy has evolved from reliance on renal tissue biopsy to the use of serum assays in certain patients, owing to continuously developing and improving methodologies. The advancement of detection methods and the discovery of new antigens are driving primary membranous nephropathy to personalized diagnosis and treatment. This article summarizes the evolution of antigens and antibodies detection techniques related to primary membranous nephropathy, aiming to explore the advantages, disadvantages, and possible future directions of methodology.

A 31-year-old man sought medical evaluation for a 2-year history of edema and proteinuria, with prior pathology suggesting atypical membranous nephropathy (MN). Despite treatment with a combination of steroids, calcineurin inhibitors, and four courses of rituximab (1 g, intravenous injection), the patient′s nephrotic syndrome showed no relief (24 h urine protein peaked at 31.18 g/d), indicating refractory nephrotic syndrome. Later in the disease course, a sudden surge of creatinine level (322.5 μmol/L) prompted a renal biopsy, which revealed concurrent acute interstitial nephritis. Further treatment involving steroids, cyclophosphamide, and a fifth rituximab infusion (1 g, intravenous injection) resulted in improvement in renal function (serum creatinine: 322.5?147 μmol/L), but the MN failed to achieve partial relief. Subsequent treatment with the novel humanized CD20 monoclonal antibody obinutuzumab (1 g, intravenous injection) was initiated. In the latest follow-up, anti-phospholipase-A2-receptor antibody (PLA2R) antibody were negative, B cells were eliminated, serum albumin was 36 g/L, urine protein-to-creatinine ratio was 4 810 mg/g, and serum creatinine was 162 μmol/L. This case underscores the potential efficacy of obinutuzumab in refractory MN. For advanced MN cases, prompt identification of the cause of acute kidney injury is crucial, emphasizing the need for targeted interventions to potentially stall renal function decline.

A 65-year-old male patient was admitted for recurrent lymph node enlargement for 5 years and elevated creatinine for 6 months. This patient was diagnosed with angioimmunoblastic T-cell lymphoma 5 years ago and underwent multiple lines of anti-tumor therapy, including cytotoxic chemotherapy; epigenetic modifying drugs such as chidamide and azacitidine; the immunomodulator lenalidomide; and targeted therapy such as rituximab, a CD20-targeting antibody, and brentuximab vedotin, which targets CD30. Although the tumor was considered stable, multiple virus activation (including BK virus, JC virus, and cytomegalovirus) accompanied by the corresponding organ damage (polyomavirus nephropathy, cytomegalovirus retinitis, and progressive multifocal leukoencephalopathy) occurred during anti-tumor treatment. Anti-tumor therapy was suspended and ganciclovir was used. The serum viral load decreased and organ functions were stabilized. The purpose of this report was to raise clinicians′ awareness of opportunistic virus reactivation during anti-tumor treatment.

Objective:To investigate the clinicopathological features and the prognosis of IgA nephropathy (IgAN) in children with massive proteinuria.Methods:It was a retrospective cohort study. Clinical data of IgAN children with massive proteinuria admitted to the Department of Nephrology, Children's Hospital Affiliated to Capital Institute of Pediatrics from January 2008 to December 2021 were retrospectively analyzed. Patients were divided into effective group and ineffective group according to whether urine protein turned negative after 6 months of initial treatment. The follow-up endpoint event was defined as a reduction in proteinuria of less than 50% or end-stage renal disease (ESRD) achievement. MedCalc software was used to perform Kaplan-Meier survival analysis, and Log-rank test was used to compare the difference of renal survival between the two groups.Results:A total of 127 patients were diagnosed as primary IgAN by renal biopsy, of whom 57 patients with IgAN showed massive proteinuria. These 57 IgAN patients with macroproteinuria accounted for 44.9% of the total IgAN patients and were enrolled in the study. Among the 57 cases, 33 cases (57.9%) were Lee's grade Ⅲ, 11 cases (19.3%) were below Lee's grade Ⅲ, and 13 cases (22.8%) were above Lee's grade Ⅲ. The follow-up time was 4.0 (3.0,5.8) years. In the initial treatment, among 57 patients, 46 (80.7%) were effective (effective group) and 11 (19.3%) were ineffective (ineffective group). Compared with the effective group, the ineffective group had a higher proportion of concurrent AKI at the onset of disease and longer recovery time of renal function, with significant difference (7/11 vs. 13/46, χ2=4.878, P=0.027). Compared with the effective group, the proportion of Lee grade Ⅲ or above was higher in the ineffective group, and the difference was statistically significant (5/11 vs. 8/46, χ2=3.971, P=0.046). There were significant differences in endocapillary hypercellularity (E1), segmental glomerulosclerosis or adhesion (S1) and cellular/fibrocellular crescents (C2) of Oxford classification between IgAN children with Lee grade Ⅲ or below and those over Lee grade Ⅲ (11/13 vs. 20/44, χ2=6.204, P=0.013; 12/13 vs. 17/44, χ2=11.566, P=0.001; 9/13 vs. 7/44, χ2=14.131, P=0.001). Among 57 patients, endpoint events occurred in 2 patients who both were urinary protein unmitigated, and none of the children progressed to ESRD. There was no significant difference in cumulative renal survival between the two groups by Kaplan-Meier survival analysis and Log-rank test ( χ2=0.537, P=0.460) after addition of calcineurin inhibitors (CNIs) to the initial treatment ineffective group. Conclusions:Macroproteinuria is the prominent manifestation of IgAN in children. The pathological type is mainly Lee grade Ⅲ. Children with macroproteinuria have a good prognosis in the short and medium term after active treatment. For IgAN with macroproteinuria that does not respond well to initial treatment, AKI is more common at onset, and renal function recovery time is longer. The application of CNIs may have a certain effect on improving the renal outcome of IgAN with massive proteinuria.

Primary biliary cirrhosis/cholangitis is an autoimmune disease. Renal tubular acidosis is a common form in PBC cases, but Fanconi syndrome is rarely reported. The paper reported a 66-year-old female patient with fatigue, renal insufficiency and elevated bile duct enzymes. The patient presented with type 2 proximal renal tubular acidosis and complete Fanconi syndrome. Laboratory examinations showed high-titer-positive anti-mitochondrial antibodies, elevated serum IgM, and type 3 cryoglobulinemia. Renal biopsy revealed interstitial nephritis, and electron micrographs showed abnormal mitochondria in proximal tubular epithelial cells. The patient's renal function ameliorated, and acid-base imbalance and electrolyte disturbances were corrected after high-dose glucocorticoid treatment.

The article reported one case of renal damage caused by lenvatinib in the treatment of advanced primary liver cancer. The patient was a 63-year-old male who was admitted to the hospital due to "liver cancer for 4 years, blood pressure elevation for nearly 2 years, and edema for 7 months". During the treatment of liver tumors with atezolizumab combined with lenvatinib, blood pressure increased and renal insufficiency aggravated progressively. Pathological light microscopy of renal biopsy showed endothelial cell lesion and tubulointerstitial damage, and electron microscopy showed moderate proliferation of mesangial cells and deposition of mesangial matrix. There were many agglomerated low-electron density deposits in the mesangial area, and a small amount of electron dense deposits in the subendothelium. The pathological diagnosis was endothelial cell disease (thrombotic microangiopathy) and secondary focal segmental glomerulosclerosis. Renal injury was considered as secondary to lenvatinib. After discontinuing lenvatinib and giving angiotensin receptor antagonist treatment, blood pressure was normal, urine protein turned negative, and renal function improved significantly after 8 months of outpatient follow-up.