Background and objectives: For addressing the influence of muscle mass on serum and urinary creatinine and serum cystatin C, body composition was assessed by skinfold thickness measurement and bioelectrical impedance analyses. Design, setting, participants, & measurements: A total of 170 healthy individuals (92 women, 78 men) were classified as sedentary or with mild or moderate/intense physical activity. Blood, 24-h urine samples, and 24-h food recall were obtained from all individuals. Results: Serum and urinary creatinine correlated significantly with body weight, but the level of correlation with lean mass was even greater. There was no significant correlation between body weight and lean mass with cystatin C. Individuals with moderate/intense physical activity presented significantly lower mean body mass index (23.1 ± 2.5 versus 25.7 ± 3.9 kg/m²) and higher lean mass (55.3 ± 10.0 versus 48.5 ± 10.4%), serum creatinine (1.04 ± 0.12 versus 0.95 ± 0.17 mg/dl), urinary creatinine (1437 ± 471 versus 1231 ± 430 mg/24 h), protein intake (1.4 ± 0.6 versus 1.1 ± 0.6 g/kg per d), and meat intake (0.7 ± 0.3 versus 0.5 ± 0.4 g/kg per d) than the sedentary individuals. Conversely, mean serum cystatin did not differ between these two groups. A multivariate analysis of covariance showed that lean mass was significantly related to serum and urinary creatinine but not with cystatin, even after adjustment for protein/meat intake and physical activity. Conclusions: Cystatin C may represent a more adequate alternative to assess renal function in individuals with higher muscle mass when mild kidney impairment is suspected.

Background and objectives: FSGS recurrence after kidney transplantation is a major risk factor for graft loss. However, the natural history, clinical predictors, and response to treatment remain unclear because of small sample sizes and poor generalizability of single-center studies, and disease misclassification in registry-based studies. We therefore aimed to determine the incidence, predictors, and treatment response of recurrent FSGS in a large cohort of kidney transplant recipients. Design, setting, participants, & measurements: The Post-Transplant Glomerular Disease (TANGO) project is an observational, multicenter, international cohort study that aims to investigate glomerular disease recurrence post-transplantation. Transplant recipients were screened for the diagnosis of idiopathic FSGS between 2005 and 2015 and details were recorded about the transplant, clinical outcomes, treatments, and other risk factors. Results: Among 11,742 kidney transplant recipients screened for FSGS, 176 had a diagnosis of idiopathic FSGS and were included. FSGS recurred in 57 patients (32%; 95% confidence interval [95% CI], 25% to 39%) and 39% of them lost their graft over a median of 5 (interquartile range, 3.0–8.1) years. Multivariable Cox regression revealed a higher risk for recurrence with older age at native kidney disease onset (hazard ratio [HR], 1.37 per decade; 95% CI, 1.09 to 1.56). Other predictors were white race (HR, 2.14; 95% CI, 1.08 to 4.22), body mass index at transplant (HR, 0.89 per kg/m²; 95% CI, 0.83 to 0.95), and native kidney nephrectomies (HR, 2.76; 95% CI, 1.16 to 6.57). Plasmapheresis and rituximab were the most frequent treatments (81%). Partial or complete remission occurred in 57% of patients and was associated with better graft survival. Conclusions: Idiopathic FSGS recurs post-transplant in one third of cases and is associated with a five-fold higher risk of graft loss. Response to treatment is associated with significantly better outcomes but is achieved in only half of the cases.

Background. Studies about the prevalence of renal and particularly glomerular diseases in Brazil are still scarce. Methods. We evaluated retrospectively the reports of 9,617 renal biopsies, analyzed by the same pathologist, from January 1993 to December 2007. Results. The 9,617 renal biopsies performed in subjects of all ages in native kidneys. 4,619 were primary glomerulopathies (GN), the most frequent was focal segmental glomerulosclerosis (FSGS, 24.6%), followed by membranous nephropathy (MN, 20.7%), IgA nephropathy (IgAN, 20.1%), minimal change disease (MCD, 15.5%), mesangioproliferative non IgAN (nonIgAN, 5.2%), diffuse proliferative GN (DPGN, 4.7%) and membranoproliferative GN (MPGN, 4.2%). Lupus nephritis was responsible for most cases which etiology was determined, i.e., 950 out of 2,046 cases (45.5%), followed by post infectious GN (18.9%), diabetic nephropathy (8.5%), benign and malignant nephroangiosclerosis (7.3%), haemolytic–uraemic syndrome and thrombotic thrombocytopenic purpura (HUS/TTP), amyloidosis (4.8%) and vasculitis (4.7%). There was a predominance of secondary GN in the North, mostly due to lupus nephritis (LN); FSGS was very common in Northeast (27.7%), Central (26.9%) and Southeast regions (24.1%); IgAN was most frequent in South (22.8%) and MN in North (29.6%); the total prevalence of MPGN was low, and its regional distribution has not changed along the years. Conclusion. FSGS was the most frequent primary glomerular disease, followed closely by MN and IgAN. The predominance of FSGS is in accordance with recent studies all over the world that revealed its frequency is increasing. Lupus nephritis predominated among secondary GN in most regions, a finding observed in other studies.

The coronavirus disease 2019 (COVID-19) pandemics is a challenge without precedent for the modern science. Acute Respiratory Discomfort Syndrome (ARDS) is the most common immunopathological event in SARS-CoV-2, SARS-CoV, and MERS-CoV infections. Fast lung deterioration results of cytokine storm determined by a robust immunological response leading to ARDS and multiple organ failure. Here, we show cysteine protease Cathepsin L (CatL) involvement with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and COVID-19 from different points of view. CatL is a lysosomal enzyme that participates in numerous physiological processes, including apoptosis, antigen processing, and extracellular matrix remodeling. CatL is implicated in pathological conditions like invasion and metastasis of tumors, inflammatory status, atherosclerosis, renal disease, diabetes, bone diseases, viral infection, and other diseases. CatL expression is up-regulated during chronic inflammation and is involved in degrading extracellular matrix, an important process for SARS-CoV-2 to enter host cells. In addition, CatL is probably involved in processing SARS-CoV-2 spike protein. As its inhibition is detrimental to SARS-CoV-2 infection and possibly exit from cells during late stages of infection, CatL could have been considered a valuable therapeutic target. Therefore, we describe here some drugs already in the market with potential CatL inhibiting capacity that could be used to treat COVID-19 patients. In addition, we discuss the possible role of host genetics in the etiology and spreading of the disease.

Atualmente, é amplamente aceita a definição da doença renal crônica (DRC) que se baseia em alterações na taxa de filtração glomerular e/ou presença de lesão parenquimatosa mantidas por pelo menos três meses. Embora os critérios para diagnóstico de DRC estejam agora bem mais claros, a proporção de pacientes com DRC em estágio avançado vista pela primeira vez por nefrologista imediatamente antes do início de tratamento dialítico ainda é inaceitável. O diagnóstico precoce e o encaminhamento imediato para o nefrologista são etapas essenciais no manuseio desses pacientes, pois possibilitam a educação pré-diálise e a implementação de medidas preventivas que retardam ou mesmo interrompem a progressão para os estágios mais avançados da DRC, assim como diminuem morbidade e mortalidade iniciais. Nesta revisão, discutimos a complexidade da DRC, a multiplicidade de intervenções atualmente recomendadas na sua prevenção secundária e diferentes modelos de prestação de cuidados à saúde, além de examinarmos o racional do atendimento interdisciplinar e a evolução dos pacientes seguidos em clínicas que já adotaram esse modelo. At present, chronic kidney disease (CKD) is broadly defined on the basis of changes in the glomerular filtration rate and/or the presence of parenchymal damage present for at least 3 months. Although the diagnosis of CKD is now quite straightforward, the proportion of patients with end-stage renal disease seen by a nephrologist for the first time immediately before the initiation of dialysis is still unacceptable. Early diagnosis and immediate nephrology referral are key steps in management because enable predialysis education, allow implementation of preventive measures that delay or even halt progression of CKD to end stage renal disease, as well as decrease initial morbidity and mortality. In this review, we discuss the complexity of CKD and the multiplicity of interventions currently recommended in its secondary prevention, different models of healthcare delivery, and examine the rational and outcomes of patients followed in interdisciplinary care clinics

Background. The Paulista Registry of Glomerulopathies was created in May 1999 and comprises several centres of São Paulo, the most populous Brazilian State, that concentrates people from all regions of the country who look for health care. Methods. This report includes data from 2086 patients from Brazil submitted to renal biopsy due to the presumed diagnosis of glomerular diseases, registered prospectively since May 1999 until January 2005. Data were collected by the integrants of the 11 centres involved, utilizing a standardized questionnaire. Results. The mean age of the patients was 34.5 ± 14.6 years. Primary glomerular diseases were more frequent in males (55.1%) than in females; on the other hand, secondary glomerular diseases were more frequent in females (71.8%). The most common clinical presentation was nephrotic syndrome and the frequency of hypertension, at this time, was 55.5%. There was a predominance of indication of biopsies in the third, fourth and fifth decades of life. The most common primary glomerular diseases were focal and segmental glomerulosclerosis (29.7%), followed by membranous nephropathy (20.7%), IgA nephropathy (17.8%), minimal change disease (9.1%), membranoproliferative glomerulonephritis (7%), crescentic glomerulonephritis (4.1%), advanced chronic glomerulopathy (4%), non-IgA mesangial glomerulonephritis (3.8%), diffuse proliferative glomerulonephritis (2.5%), focal segmental proliferative glomerulonephritis (1%) and others (0.3%). The most frequent secondary glomerular disease was lupus nephritis, corresponding to 66.2% of the cases, followed by post-infectious glomerulonephritis (12.5%), diabetic nephropathy (6.2%), diseases associated to paraproteinaemia (4.9%), hereditary diseases (4.6%), vasculitis (3.2%), malignancies (0.9.%), secondary focal segmental glomerulosclerosis (0.6%) and others (0.9%). Conclusion. Focal segmental glomerulosclerosis was the most frequent primary glomerular disease, followed by membranous nephropathy and IgA nephropathy. Lupus nephritis predominated over all the other secondary glomerular diseases.