Sepsis-induced organ failure is characterized by a massive inflammatory response and oxidative stress. Acute kidney injury (AKI) occurs in approximately half of patients in septic shock, and the mortality associated with sepsis-induced AKI is unacceptably high. Klotho is a protein expressed by renal cells and has anti-senescence properties. Klotho has also been shown to protect the kidneys in ischemia-reperfusion injury and to have antioxidant properties. To analyze the role of Klotho in sepsis-related organ dysfunction and AKI, we used a cecal ligation and puncture (CLP) model of sepsis in heterozygous Klotho-haploinsufficient mice and their wild-type littermates (CLP- Kl/+ and CLP-WT mice, respectively). In comparison with the CLP-WT mice, CLP- Kl/+ mice showed lower survival, impaired renal function, impaired hepatic function, greater oxidative stress, upregulation of inflammatory pathways (at the systemic and kidney tissue levels), and increased NF-κB activation. It is noteworthy that CLP- Kl/+ mice also showed lower heart-rate variability, less sympathetic activity, impaired baroreflex sensitivity to sodium nitroprusside, and a blunted blood pressure response to phenylephrine. We also demonstrated that sepsis creates a state of acute Klotho deficiency. Given that low Klotho expression exacerbates sepsis and multiple organ dysfunction, Klotho might play a protective role in sepsis, especially in elderly individuals in whom Klotho expression is naturally reduced.

Introduction: Urinary CD80 has been shown to have good specificity for minimal change disease (MCD) in children. However, the investigation of circulating factors such as soluble urokinase plasminogen activator receptor (suPAR) as biomarkers of focal segmental glomerulosclerosis (FSGS) is quite controversial. The objective of this study was to determine whether urinary CD80 and serum suPAR can be used for the diagnosis of MCD and FSGS, respectively, in the adult population of Brazil. We also attempted to determine whether those biomarkers assess the response to immunosuppressive treatment. Methods: This was a prospective study in which urine and blood samples were collected for analysis of CD80 and suPAR, respectively, only in the moment of renal biopsy, from patients undergoing to diagnostic renal biopsy. At and six months after biopsy, we analyzed serum creatinine, serum albumin, and proteinuria in order to evaluate the use of the CD80 and suPAR collected in diagnosis as markers of response to immunosuppressive treatment. In healthy controls were collected urinary CD80 and proteinuria, serum suPAR, and creatinine. Results: The results of 70 renal biopsies were grouped, by diagnosis, as follows: FSGS (n = 18); membranous nephropathy (n = 14); MCD (n = 5); and other glomerulopathies (n = 33). There was no significant difference among the groups in terms of the urinary CD80 levels, and serum suPAR was not significantly higher in the FSGS group, as would have been expected. Urinary CD80 correlated positively with nephrotic syndrome, regardless of the type of glomerular disease. Neither biomarker correlated with proteinuria at six months after biopsy. Conclusion: In adults, urinary CD80 can serve as a marker of nephrotic syndrome but is not specific for MCD, whereas serum suPAR does not appear to be useful as a diagnostic or treatment response marker.

Rapidly progressive glomerulonephritis (RPGN) is a syndrome which presents rapid loss of renal function. Vasculitis represents one of the major causes, often related to anti-neutrophil cytoplasmic antibodies (ANCA). Herein, we report a case of methimazole-induced ANCA-associated vasculitis. A 35-year-old woman complained of weight loss and fatigue for 2 weeks and attended the emergency room with alveolar hemorrhage. She had been diagnosed with Graves’ disease and had been taking methimazole in the past 6 months. Her physical examination showed pulmonary wheezing, hypertension and signs of respiratory failure. Laboratory tests revealed urea 72 mg/dL, creatinine 2.65 mg/dL (eGFR CKD-EPI: 20 mL/min/1.73 m²), urine analysis with >100 red blood cells per high-power field, 24 h-proteinuria: 1.3 g, hemoglobin 6.6 g/dL, white-cell count 7700/mm³, platelets 238,000/mm³, complement within the normal range, negative viral serological tests and ANCA positive 1:80 myeloperoxidase pattern. Chest tomography showed bilateral and diffuse ground-glass opacities, and bronchial washing confirming alveolar hemorrhage. A renal biopsy using light microscopy identified 27 glomeruli (11 with cellular crescentic lesions), focal disruption in glomerular basement membrane and fibrinoid necrosis areas, tubulitis and mild interstitial fibrosis. Immunofluorescence microscopy showed IgG +2/+3, C3 +3/+3 and Fibrinogen +3/+3 in fibrinoid necrosis sites. She was subsequently diagnosed with crescentic pauci-immune glomerulonephritis, mixed class, in the setting of a methimazole-induced ANCA vasculitis. The patient was treated with methimazole withdrawal and immunosuppressed with steroids and cyclophosphamide. Four years after the initial diagnosis, she is currently being treated with azathioprine, and her exams show creatinine 1.30 mg/dL (eGFR CKD-EPI: 52 mL/min/1.73 m²) and negative p-ANCA.

Introduction: Focal segmental glomerulosclerosis (FSGS) is a pattern of kidney injury with diverse causes and pathogeneses, resulting in podocyte injury and depletion. It can be classified as primary, genetic, or secondary. Because FSGS classically has a worse prognosis in patients with nephrotic syndrome, most studies have focused on the treatment and evolution of these patients, resulting in a lack of data related to patients without nephrotic syndrome. The objective of this study was to establish the main etiologies, characteristics, and evolution of renal disease in FSGS patients with nephrotic and non-nephrotic proteinuria. Methods: This was a retrospective, single-center study that included 140 patients with a biopsy-confirmed diagnosis of FSGS in the 2009–2017 period. Patients were separated into those with and those without nephrotic syndrome at diagnosis, and these two groups were compared in terms of the clinical characteristics, histological profile, and outcome. Non-nephrotic patients with unfavorable progression were selected for ultrastructural analysis with electron microscopy. Results: During the study period, 32.9% of the patients with FSGS had non-nephrotic proteinuria at diagnosis. This group had a larger proportion of patients with hypertension and a not otherwise specified FSGS variant on histology. The proportion of patients with secondary forms of FSGS was comparable between the two groups, with HIV infection and systemic lupus erythematosus being predominant. Progression to renal replacement therapy occurred in 31.3% of the patients in the nephrotic group and in 26.8% of those in the non-nephrotic group, with no statistical difference between them. All of the non-nephrotic group patients who progressed to renal replacement therapy were analyzed by electron microscopy, the diagnosis of FSGS was confirmed, and there was the finding of high chronicity in these patients. Conclusions: Among patients with FSGS, those without nephrotic syndrome had a poor renal outcome at a frequency similar to that of those with nephrotic syndrome. Factors related to better renal survival were having had a complete response to treatment in the case of those with nephrotic syndrome and having achieved proteinuria values of less than 1.5 g/day in the case of those without nephrotic syndrome.

Introduction: IgA nephropathy (IgAN) is the most common primary glomerulopathy worldwide. According to the Oxford Classification, changes in the kidney vascular compartment are not related with worse outcomes. This paper aims to assess the impact of thrombotic microangiopathy (TMA) in the outcomes of Brazilian patients with IgAN. Materials and Methods: Analysis of clinical data and kidney biopsy findings from patients with IgAN to assess the impact of TMA on renal outcomes. Results: The majority of the 118 patients included were females (54.3%); mean age of 33 years (25;43); hypertension and hematuria were observed in 67.8% and 89.8%, respectively. Median creatinine: 1.45mg/dL; eGFR: 48.8ml/min/1.73m ² ; 24-hour proteinuria: 2.01g; low serum C3: 12.5%. Regarding to Oxford Classification: M1: 76.3%; E1: 35.6%; S1: 70.3%; T1/T2: 38.3%; C1/C2: 28.8%. Average follow-up: 65 months. Histologic evidence of TMA were detected in 21 (17.8%) patients and those ones presented more frequently hypertension (100% vs. 61%, p <0.0001), hematuria (100% vs 87.6%, p =0.0001), worse creatinine levels (3.8 vs . 1.38 mg/dL, p =0.0001), eGFR (18 vs. 60 ml/min/1.73m ² ), p =0.0001), low serum C3 (28.5% vs . 10.4%, p =0.003), lower hemoglobin levels (10.6 vs. 12.7g/dL, p< 0.001) and platelet counts (207,000 vs . 267,000, p=0.001). Biopsy findings of individuals with TMA revealed only greater proportions of E1 (68% vs. 32%, p = 0.002). Individuals with TMA were followed for less time (7 vs . 65 months, p<0.0001) since they progressed more frequently to chronic kidney disease (CKD) requiring renal replacement therapy (RRT) (71.4% vs . 21,6%, p<0.0001). Male sex, T1/T2, and TMA were independently associated with progression to CKD-RRT. Conclusions: In this study patients with TMA had worse clinical manifestations and outcomes. In terms of histologic evidence, E1 distinguished patients with TMA from other patients. These findings indicate that vascular compartment may also be a prognostic marker in IgAN patients.

Background/Objectives: IgA nephropathy (IgAN) is the most common primary glomerulopathy worldwide; it is characterized by a complex pathophysiology involving several inflammatory pathways. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway may be critical in this process. This study aimed to investigate the role of this pathway in IgAN and examine related tissue inflammatory markers. Methods: We analyzed 63 biopsy-confirmed patients with IgAN and performed immunohistochemical analysis on renal samples. A panel of antibodies targeting the JAK/STAT pathway, including JAK2, JAK3, p-STAT, STAT3, and MAPK/ERK, was used for this analysis. Six kidney tumor border samples were used as controls. Additionally, CD68 staining was used to evaluate tissue inflammation in the kidney biopsies. Results: Patients with IgAN showed a significantly higher cellular density of JAK3 staining at the glomerular level compared to controls, indicating JAK3 activation (p < 0.0002). Nevertheless, the correlation between JAK3 positivity in glomeruli and clinical parameters such as the initial and final estimated glomerular filtration rate (eGFR) and proteinuria was not statistically significant. Identical results were obtained with CD68+ macrophage counts in the glomerular compartment, which did not show any correlation with clinical parameters, while CD68+ tubulointerstitial staining demonstrated a significant correlation with both initial (p = 0.002) and final eGFRs (p = 0.0014), proteinuria (p = 0.010), and interstitial fibrosis (p < 0.001), as well as with renal disease progression (p = 0.005). Conclusions: Patients with IgAN exhibited activation of the JAK/STAT pathway, in contrast to controls. Macrophage CD68 staining in the tubulointerstitial area increased and was associated with clinical and laboratory parameters such as eGFR and proteinuria. Additionally, MEST-C histological parameters, such as segmental glomerulosclerosis (S0/S1), tubular atrophy/interstitial fibrosis (T0/T1/T2), and crescents (C0/C1/C2), were associated with a higher number of CD68+ cells.