Estimated glomerular filtration rate in clinical practice: Consensus positioning of the Brazilian Society of Nephrology (SBN) and Brazilian Society of Clinical Pathology and Laboratory Medicine (SBPC/ML).

Chronic kidney disease (CKD) represents one of today's main public health problems. Serum creatinine measurement and estimation of the glomerular filtration rate (GFR) are the main tools for evaluating renal function. There are several equations to estimate GFR, and CKD-EPI equation (Chronic Kidney Disease - Epidemiology) is the most recommended one. There are still some controversies regarding serum creatinine measurement and GFR estimation, since several factors can interfere in this process. An important recent change was the removal of the correction for race from the equations for estimating GFR, which overestimated kidney function, and consequently delayed the implementation of treatments such as dialysis and kidney transplantation. In this consensus document from the Brazilian Societies of Nephrology and Clinical Pathology and Laboratory Medicine, the main concepts related to the assessment of renal function are reviewed, as well as possible existing controversies and recommendations for estimating GFR in clinical practice.

Diagnostic and prognostic utility of WBC counts and cell population data in patients with COVID-19.

INTRODUCTION: Early diagnosis and identification of potential critical cases for timely treatment are crucial for COVID-19 patients. The aim of this study was to analyze the diagnostic and prognostic implications of WBC and cell population data (CPD) abnormalities related to COVID-19 at disease onset. METHODS: Baseline WBC counts and CPD data were analyzed in one hundred COVID-19 patients presenting to emergency department and subsequently discharged (n=49), admitted (n=51) or deceased (n=22), and in 47 healthy subjects. RESULTS: Lymphopenia and eosinopenia were observed in all COVID-19 patients, with more intensity in the admitted and deceased groups, that also presented increased WBC and neutrophil counts. On CPD analysis, COVID-19 was associated with increased volume of neutrophils, lymphocytes, and monocytes, whereas conductivity was decreased for neutrophils and increased for lymphocytes. The ROC curve analysis showed good performance for lymphocyte counts in predicting COVID-19 diagnosis (AUC=0.858), for neutrophil counts in predicting admission for COVID-19 (AUC=0.744) and for monocytes volume in predicting COVID-19 diagnosis (AUC=0.837). CONCLUSION: WBC counts and CPD parameters at disease onset in COVID-19 patients can improve diagnostic characterization and aid in the discrimination between severe and nonsevere presentations.