Clinical nephrology最新文献

Background: Membranous nephropathy (MN) is an immune complex-mediated disease. Massive proteinuria can lead to Fanconi syndrome, clinically manifesting as renal glycosuria. The prevalence and prognosis of M-type phospholipase A2 receptor (PLA2R)-related MN with renal glycosuria remain unknown.

Materials and methods: Patients diagnosed with PLA2R-related MN with renal glycosuria were reviewed, and the control group comprised patients with MN without renal glycosuria who were randomly selected at a ratio of 1 : 3.

Results: 50 patients diagnosed with PLA2R-related MN with renal glycosuria from January 2015 to January 2020 were included, with a prevalence of 2.3%. Compared with patients without renal glycosuria, those with renal glycosuria exhibited greater proteinuria, lower estimated glomerular filtration rate (eGFR), and higher use of diuretics, anticoagulants, antibiotics, traditional Chinese medicine, and tacrolimus within 3 months prior to renal biopsy (all p < 0.05). Histologically, patients with renal glycosuria exhibited more severe pathological stages, acute/chronic tubulointerstitial lesions, and tubulointerstitial inflammation (all p < 0.05). Of the 10 patients treated with rituximab (RTX), proteinuria remission was maintained in 6 (60%) patients, and urine glucose remission was achieved in 5 of these 6 patients (83.3%). Multivariate Cox regression analysis showed that renal glycosuria and age > 50 years were independent risk factors for end-stage renal disease (ESRD) or a 30% reduction in the eGFR in patients with PLA2R-related MN.

Conclusion: PLA2R-related MN patients with renal glycosuria presented with more severe clinicopathological manifestations and worse prognoses. Nephrotoxic drugs should be administered rationally, and RTX should be considered as a promising treatment option.

Background: If C_cr is creatinine clearance, a surrogate for glomerular filtration rate (GFR), the serum potassium concentration (K_s) is the sum of E_K/C_cr and TR_K/C_cr, which are amounts of potassium excreted and (net) reabsorbed per volume of filtrate (K_s = E_K/C_cr + TR_K/C_cr). We investigated changes in E_K/C_cr, TR_K/C_cr, and K_s through the stages of chronic kidney disease (CKD).

Materials and methods: We performed a retrospective study of 452 patients with CKD stages G1 - 5. Simultaneous measurements of serum and urine potassium and creatinine concentrations (K_s, K_u, cr_s, and cr_u) were used to calculate 1,007 individual values of E_K/C_cr and TR_K/C_cr as K_u×cr_s/cr_u and K_s - E_K/C_cr, respectively. Mean values of E_K/C_cr and TR_K/C_cr were determined in CKD stages G1 - 5. Within each stage, means of the ratios were also ascertained in subsets with hyperkalemia (K_s > 5.1 mmol/L), normokalemia (K_s 3.8 - 5.1 mmol/L), and hypokalemia (K_s < 3.8 mmol/L).

Results: In comparison to values in CKD stages G1 - 2, E_K/C_cr rose and TR_K/C_cr fell in each higher stage. Decrements in TR_K/C_cr equaled increments in E_K/C_cr in G3a and G3b, and K_s remained stable. In G4 - 5, the ascent of E_K/C_cr exceeded the decline in TR_K/C_cr, and K_s rose accordingly. Within each CKD stage, E_K/C_cr was remarkably similar in the three kalemic subsets; consequently, differences in TR_K/C_cr were the sole source of differences in K_s.

Conclusion: E_K/C_cr rises and TR_K/C_cr falls through the stages of CKD. K_s remains stable in stages G3a - 3b in association with equal and opposite changes in E_K/C_cr and TR_K/C_cr. In stages G4 - 5, K_s increases progressively because E_K/C_cr rises more than TR_K/C_cr falls. Within each CKD stage, differences in TR_K/C_cr account entirely for differences in K_s among hyper-, normo-, and hypokalemic subsets. Causes of variability of TR_K/C_cr require additional investigation.

Background: Coronary artery calcification (CAC) is a common complication in patients with end-stage renal disease (ESRD), which causes of increased cardiovascular mortality in maintenance hemodialysis patients. This study examined how sodium thiosulfate (STS) treatment affects the microRNA (miRNA) expression profiles of ESRD patients combined with CAC.

Materials and methods: A total of 18 patients with ESRD complicated with CAC were assigned to a control group that received conservative treatment or a test group that received STS treatment. The 2 groups were then sub-divided into a CGBT group (control group before treatment), TGBT group (test group before treatment), CGAT group (control group after treatment), and TGAT group (test group after treatment). Samples of peripheral venous blood were collected for analysis of biochemical indexes (hs-CRP, ALB, CHO, TG, Ca, P, BUN, Cr, bALP, iPTH, and FGF23) and used to screen for differentially expressed miRNAs that were displayed by hierarchical clustering and in a volcano plot. The functional roles of miRNA target genes were analyzed by Gene Ontology and Kyoto Encycolopedia of Genes and Genomes pathway analyses. Several miRNAs in serum samples were identified using quantitative real time PCR.

Results: STS treatment did not significantly change the biochemical indexes. A microarray analysis identified 67 miRNAs that were differentially expressed in the TGAT group vs. the TGBT group, and 28 -miRNAs that were differentially expressed in the CGAT group vs. the CGBT group. The miRNA target genes were associated with signal transduction, transcriptional regulation, cytoplasm and protein binding processes, the MAPK signaling pathway, PI3K-Akt signaling pathway, and various pathways in cancer. Validation experiments confirmed the suppressive effect of STS treatment on miR-337-5p/miR-409-5p expression and the promotive effect of STS on miR-376a-3p expression.

Conclusion: MiR-337-5p/miR-409-5p/miR-376a-3p might be key regulators involved with the therapeutic effects of STS treatment in ESRD patients associated with arterial calcification.

Background: Elevated C-reactive protein (CRP) was proposed as a biomarker instead of renal biopsy in drug-induced acute tubulointerstitial nephritis (D-ATIN) in adults. However, there is no study in which patients were followed up with serial CRP without kidney biopsy. We evaluated the significance of CRP levels in predicting the clinical course of D-ATIN in children.

Materials and methods: Children with a clinical diagnosis of D-ATIN were evaluated for sex, age, symptoms, offending drug(s), latent period after exposure, blood pressure, urine output, urinalysis, eosinophiluria, urine albumin/total protein, serum creatinine, and CRP at presentation. In addition, serial CRP and creatinine levels were recorded daily until discharge and thereafter. Correlations of CRP with creatinine and of peak CRP with creatinine normalization time were evaluated.

Results: There were 13 patients (8 female, median age 15 years). None had oliguria or hypertension. Median CRP and creatinine at presentation were 36 mg/L and 1.6 mg/dL, respectively. Median times to peak CRP and creatinine were 6 and 7 days after drug exposure, respectively. The decrease in CRP preceded the fall in creatinine. Median CRP and creatinine normalization times after their peaks were 5 and 14 days, respectively. None required renal biopsy or corticosteroid treatment. CRP was correlated with creatinine throughout the study period. However, peak CRP was not correlated with creatinine normalization time.

Conclusion: CRP was increased at presentation and decreasing CRP predicted favorable outcome. Renal biopsy and corticosteroid treatment could be postponed safely in these children.

Systemic COVID-19 disease is associated with a variety of organ involvement in infected patients. A rarely reported complication is the induction of complement-mediated thrombotic microangiopathy (TMA). TMA is an extremely rare pathological condition that results in thrombosis in capillaries and small arterioles, due to an endothelial injury. It is often combined with thrombocytopenia, Coombs-negative hemolytic anemia, and end-organ damage. This case involves a patient who was admitted to our hospital for the purpose of diagnosis and treatment of acute kidney injury (AKIN 3) with severe proteinuria after a preceding SARS-CoV-2 infection. A 77-year-old male patient had COVID-19 pneumonia in January 2021 with the need of high-flow oxygen therapy in the intensive care unit. In March 2021, he was hospitalized again due to elevated serum creatinine levels and proteinuria. The patient exhibited normal vital parameters. A renal biopsy showed severe TMA. A diagnosis of COVID-19-associated TMA was made, and treatment with high-dose glucocorticoid therapy and plasma exchange was initiated. Additionally, therapy with eculizumab was established. Unfortunately, the kidney failure was initially progressive, so that hemodialysis (HD) was temporarily necessary. In May 2021, kidney function recovered to an estimated glomerular filtration rate of ~ 30 mL/min/1.73m² corresponding to chronic kidney disease stage 3bA3 - 4A3. COVID-19-associated TMA is an extremely rare disease. TMA may be a possible long-term complication with the risk of end-stage renal disease if not properly diagnosed and treated.

Aim: BK polyomavirus infection is a challenging complication of renal transplantation. The management is not standardized and is based on reports from transplantation centers' experiences, usually with small sample sizes. Therefore, we aimed to present our countrywide experience with BK virus nephropathy (BKVN) in renal transplant recipients.

Materials and methods: Our study was carried out with the participation of 30 transplantation centers from all regions of Turkey. Only cases with allograft biopsy-proven BKVN were included in the study.

Results: 13,857 patients from 30 transplantation centers were screened, and 207 BK nephropathy cases were included. The mean age was 46.4 ±  13.1 years, and 146 (70.5%) patients were male. The mean time to diagnosis of BK nephropathy was 15.8 ± 22.2 months after transplantation. At diagnosis, the mean creatinine level was 1.8 ±  0.7 mg/dL, and the mean estimated glomerular filtration rate was 45.8 ± 19.6 mL/min/1.73m². In addition to dose reduction or discontinuation of immunosuppressive drugs, 18 patients were treated with cidofovir, 11 patients with leflunomide, 17 patients with quinolones, 15 patients with intravenous immunoglobulin (IVIG), 5 patients with cidofovir plus IVIG, and 12 patients with leflunomide plus IVIG. None of the patients receiving leflunomide or leflunomide plus IVIG had allograft loss. During follow-up, allograft loss occurred in 32 (15%) out of 207 patients with BK nephropathy.

Conclusion: BKVN is still a frequent cause of allograft loss in kidney transplantation and is not fully elucidated. The results of our study suggest that leflunomide treatment is associated with more favorable allograft outcomes.

Background: It is still uncertain whether vitamin intake is associated with better quality of life in hemodialysis patients. This study aims to assess the association between the quantity of supplemented vitamins and health-related quality of life (HRQoL) in this population.

Materials and methods: This cross-sectional study included all patients on chronic hemodialysis from three units. Vitamins and micronutrients assessed were B1, B6, B12, C, D, folic acid, menaquinone, carnitine, zinc, and coenzyme Q10. Quality of life scores included the 8 domains of SF-36 and the 11 domains of the Kidney Disease Quality of Life (KDQOL). Bivariate analysis compared two groups of patients divided based on the median of vitamin intake. Spearman Rho test assessed the correlation between number of vitamins and different dimensions of HRQoL.

Results: A total of 183 patients were included. Median number of vitamins supplemented was 2 (1,3); 112 patients had an intake of ≤ 2 vitamins, and 71 patients were taking > 2 vitamins. There was a significant association between higher vitamin intake and the burden of kidney disease that remained significant in the multivariable analysis (p = 0.03), but no correlation between the number of vitamins (0 - 13) and different HRQoL scores. Sub-analyses of each category of vitamins showed no significant difference in HRQoL scores except for Vitamin B and staff encouragement (p = 0.01) and for multivitamins and quality of social interaction (p = 0.03).

Conclusion: A higher number of vitamins in hemodialysis patients is associated with an increased perception of the burden of kidney disease. Interventional studies are needed to assess whether selective vitamin supplementation in case of deficiencies is associated with better quality of life.

Mixed cryoglobulinemia is a small vessel vasculitis associated with viral infections, mainly hepatitis C virus, however, other important causes include lymphoproliferative and autoimmune disorders. Influenza vaccine-induced cryoglobulinemia has been rarely reported. A 68-year-old male presented on three occasions following influenza vaccination with purpuric rash and lower extremities swelling. His lab work showed mixed cryoglobulins. On his most recent presentation, in addition to the purpura, he presented with thrombocytopenia and nephritic syndrome. A kidney biopsy showed endocapillary proliferative glomerulonephritis with organized deposits, consistent with mixed type cryoglobulinemic glomerulonephritis. The patient was treated with rituximab infusion with progressive improvement of the acute kidney injury (AKI) and complete recovery. It is unclear why cryoglobulins are produced as a response to a vaccination, but this association is important to be aware of for prompt monitoring and treatment.

Fibrillary glomerulonephritis (FGN) is a rare glomerular disease defined by the presence of microfibrils that deposit within the glomeruli. While initially thought to be idiopathic, FGN is now recognized to be associated with infection, malignancies, and autoimmune disorders. We describe a case of biopsy-proven FGN in a patient with seropositive rheumatoid arthritis (RA) and provide a review of the literature regarding the association of FGN with RA.