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.

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.

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.

Objective:To analyze the clinical and pathological characteristics, treatment and prognosis of renal changes in patients with Kimura disease and improve the clinicians′ understanding on renal manifestations of Kimura disease.Methods:The clinical data of Kimura disease patients with definite diagnosis and detailed data in Peking Union Medical College Hospital from January 1980 to August 2020 were retrospectively analyzed. The patients were divided into renal impairment group and non-renal impairment group according to whether the kidney was involved or not and the related clinical data between the two groups were compared. The patients presenting with nephrotic syndrome were followed up.Results:There were 60 patients with Kimura disease confirmed by pathological diagnosis with 48 males. The median age was 33(3, 62) years old, and the median duration was 36(12, 111) months. There were 18 cases complicated with renal injury in 49 patients with complete routine urine and renal function examination and the main manifestations of renal injury were proteinuria and/or microscopic hematuria. There was no significant difference at age, sex and absolute value of eosinophils between the two groups (all P>0.05). Compared with the renal inpairment group, patients in non-renal inpairment group had longer course of disease, higher levels of hypersensitive C-reactive protein and erythrocyte sedimentation rate, and lower median values of total eosinophils and total IgE, but there was no statistically significant difference (all P>0.05). Among the patients with renal involvement, 6 patients met the diagnostic criteria for nephrotic syndrome, and 5 of them completed renal biopsies. The renal pathological diagnosis was membranous nephropathy in 2 cases and minimal change disease in 3 cases, and no interstitial eosinophil infiltration was found in renal biopsy tissues. These patients had a good response to glucocorticoids and/or immunosuppressive therapy, and achieved complete remission of nephrotic syndrome; at the same time, lymphadenopathy caused by Kimura disease could be well controlled. Conclusions:Kimura disease can combine with various renal lesions, and the pathology of nephrotic syndrome can be membranous nephropathy or minimal change nephropathy. After energetic treatment of glucocorticoids and/or immunosuppressive therapy, nephrotic syndrome can be completely relieved, and lymphadenopathy can be well controlled. The relationship between Kimura disease and renal disease needs further study.

A 65-year-old woman presented with intermittent right hand numbness and elevated serum creatinine for more than 2 months. The histological examination of kidney biopsy showed renal arterioles occlusion and interstitial fibrosis. Pathological abnormality was originally considered as a part of systemic atherosclerosis. Thus, rosuvastatin 20 mg/d, fosinopril 10 mg/d, metoprolol 47.5 mg/d and aspirin 0.1g/d were administrated. No improvement of renal function was seen. Further Congo red staining was applied. Diffuse amorphous eosinophilic substance was deposited in interlobular artery and small arteriolar artery. Combined with the abnormal free light chain (FLC) level and ratio (serum κ 340 mg/L, κ/λ 10.932), the diagnosis of systematic light-chain amyloidosis was confirmed. The patient received 3 courses of chemotherapy regimen as BCD (bortezomib 2 mg d1, 8, 15, 22, cyclophosphamide 0.3 g d1, 8, 15, 22 and dexamethasone 40 mg d1, 8, 15, 22). A hematologic partial response was achieved and serum creatinine decreased to 180 μmol/L.

Objective To investigate the clinical and pathological features of patients with a combination of Sjogren's syndrome (SS) and antineutrophil cytoplasmic antibody (ANCA) associated vasculitis with renal involvement.Methods By searching the Peking Union Medical College Hospital medical database and literature between January 1990 and June 2017,patients had a combination of SS and ANCA associated vasculitis with renal involvement were included.Data of clinical information,autoimmune antibodies,renal manifestations and renal pathology were retrieved and analyzed.Results Eighteen patients were enrolled:4 from our hospital and 14 from literature.SS was diagnosed no later than ANCA associated vasculitis in all the patients,among which 83.3％(15/18) of patients had extra-glandular and extra-renal organs involved.All the patients were tested positive for myeloperoxidase (MPO)-ANCA,and only two were protein 3 (PR3)-ANCA positive concurrently.The positivity rates of antinuclear antibody (ANA),rheumatoid factor (RF),anti-SSA antibody,and anti-SSB antibody were 83.3％(15/18),55.6％(10/18),77.8％(14/18),and 38.9％(7/18),respectively.The renal manifestations were characterized by renal insufficiency with a median serum creatinine of 174 μmol/L,hematuria,moderate proteinuria with a median 24 hour urine protein of 1.70 g,and necrotizing vasculitis with oligo-immune complex and varying degrees of interstitial damage in pathology.Conclusions A combination of Sjogren's syndrome and ANCA associated vasculitis with renal involvement is rare in clinical setting,and almost all of the patients are MPO-ANCA positive,with high probability of ANA positivity and extra-glandular involvement.Physicians should beware of ANCA associated glomerulonephritis in SS patients with inexplicable renal dysfunction and renal biopsy should be carried out in time.

Objective To analyze serum amyloid protein A (SAA) subtype and amino acid mutation sequence of the renal biopsy specimens from patients with renal amyloidosis secondary to ankylosing spondylitis (AS) by laser microdissection combined with mass spectometry.Methods Kidney biopsy formalin-preserved paraffin-embedded (FFPE) specimen slices were stained by Congo red,the positive areas of Congo red staining were selected by microdissection,after trypsin hydrolysis and filtration,peptide samples were subjected to liquid chromatography tandem mass spectrometry.Analysis softwares were used to evaluate the results,and the patient's amino acid sequence of SAA protein was compared to mutant amino acid sequence reported by literature or deduced from mutant SAA gene to determine whether there was a variation.Results SAA1 and SAA2 proteins with high abundance were identified by mass spectrometry,serum amyloid P and apolipoprotein E were also detected.No variation of SAA1 and SAA2 protein was detected.Conclusions The SAA1 and SAA2 proteins in AA amyloidosis secondary to ASwere identified for the first time,which enriched the pathogenesis of amyloidosis secondary to AS and provided a new method for the accurate classification of AA amyloidosis.

Objective To analyze the clinical features and prognosis of patients with infective endocarditis(IE) and acute kidney injury(AKI),and to evaluate the effect of timely operation on prognosis of renal function.MethodsClinical data of 45 IE and AKI cases in Peking Union Medical College Hospital from January 2010 to May 2016 were retrospectively reviewed;among them 8 cases underwent renal biopsy and the pathologies were analyzed.Patients were divided into Operation group(22 cases) and Non-operation group(23 cases),the clinical data and prognosis were compared.Results The ratio of male to female was 2.46:1 and the average age was 48.3±16.6.35.6% of cases were found with basic valve diseases,the congenital valve diseases were the most common type.The most frequently infected valves were mitral valve(46.7%),aortic valve(28.9%) and prosthetic valve(8.9%) ordinally.The most common pathogenic bacteria were streptococcus(46.7%) and staphylococcus(35.6%).Some rare and special pathogen could also be found in these cases.In 8 cases underwent renal biopsy,3 cases were diagnosed as crescentic nephritis,2 cases were diagnosed as focal proliferative glomerulone-phritis and mesangial prolif-erative glomerulonephritis respectively,1 case was diagnosed as acute interstitial nephritis.C3 sedimentation was the most common phenomenon found in immunofluorescence.There was no significant difference between the baseline data of Operation and Non-operation groups,and neither was the survival rate.However,renal function recovered better in Operation group(P<0.05): the serum creatinine declined remarkably in 7 days(P<0.05) and 30 days(P<0.01)post operation,compared with the peak valve before operation.Conclusions The underline valve diseases and pathogen have been changed in IE as compared with traditional description.Crescentic nephritis is common in renal pathologic manifestation when parenchymal lesion is developed after the onset of IE.Timely operation can improve the renal prognosis in patients with IE and AKI.