The Role of Urinary Biomarkers as Diagnostic and Prognostic Predictors of Acute Kidney Injury Associated With Vancomycin.

Introduction: The incidence of acute kidney injury (AKI) related to vancomycin is variable, and several risk factors related to the treatment and patients may explain the nephrotoxicity. The role of urinary biomarkers in AKI related to vancomycin is unknown. Objective: The aim of this study was to evaluate the role of urinary IL-18, KIM-1, NGAL, TIMP-2, and IGFBP7 as diagnostic and prognostic predictors of AKI related to vancomycin. Methods: A prospective cohort study of patients receiving vancomycin and admitted to wards of a public university hospital from July 2019 to May 2020 was performed. We excluded patients that had AKI before starting vancomycin, hemodynamic instability, inability to collect urine, and chronic kidney disease stage 5. Results: Ninety-four patients were included, and the prevalence of AKI was 24.5%, while the general mortality was 8.7%. AKI occurred 11 ± 2 days after the first vancomycin dose. The most frequent KDIGO stage was 1 (61%). There was no difference between patients who developed and did not develop AKI due to gender, length of hospital stay, dose, and time of vancomycin use. Logistic regression identified age (OR 6.6, CI 1.16-38.22, p = 0.03), plasmatic vancomycin concentrations between 96 and 144 h (OR 1.18, CI 1.04-1.40, p = 0.04), and urinary NGAL levels between 96 and 144 h (OR 1.123, CI 1.096-1.290, p = 0.03) as predictors of AKI. The time of vancomycin use (OR 4.61, CI 1.11-22.02, p = 0.03), higher plasmatic vancomycin concentrations between 192 and 240 h (OR 1.02, CI 0.98-1.06, p = 0.26), and higher cell cycle arrest urinary biomarkers TIMP-2 multiplied by IGFBP-7 between 144 and 192 h (OR 1.33, CI 1.10-1.62, p = 0.02; OR 1.19, CI 1.09-1.39, p = 0.04, respectively) were identified as prognostic factors for non-recovery of kidney function at discharge. Conclusion: AKI related to vancomycin was frequent in patients hospitalized in wards. Age, plasmatic vancomycin concentrations, and NGAL between 96 and 144 h were identified as predictors of AKI related to vancomycin use. Plasmatic vancomycin concentrations and urinary NGAL were predictors of AKI diagnosis within the next 5 days. The urinary biomarkers of cell cycle arrest TIMP-2 and IGFBP-7 and the duration of vancomycin use were associated with non-recovery of kidney function at hospital discharge moment.

Preanalytical conditions can interfere with M. tuberculosis detection by PCR in respiratory samples.

OBJECTIVES: Tuberculosis is one of the most prevalent infections in humans. Although culture is the reference for diagnosis, its sensitivity is compromised, especially in paucibacillary samples. Because polymerase chain reaction (PCR) amplifies mycobacterial DNA, it is more sensitive than culture for the diagnosis of Mycobacterium tuberculosis (Mtb). However, its performance can be affected by intrinsic sample inhibitors and by the extraction/detection techniques used. METHODS: We evaluated the influence of preanalytical conditions on Mtb detection in samples of sputum (SPU), bronchoalveolar lavage (BAL), and pleural fluid (PF) using combinations of extraction/detection methods. Respiratory samples were prepared to contain different concentrations of red blood cells and nucleated cells to which increasing amounts of Mtb colonies were inoculated and submitted to PCR. RESULTS: Up to 102 CFU/ml of Mtb were detected in the SPU in all methods, except for the Roche extraction/detection method, regardless of the preanalytical sample condition. In BAL samples, medium and high concentrations of cells and high concentrations of red blood cells contributed to a lower Mtb detection, regardless of the extraction method used. In PF, red blood cells were the variable that most interfered with Mtb detection, with better recovery (102 CFU/ml) observed with the Qiagen/Nanogen combination. CONCLUSION: The choice of Mtb extraction and detection method is of fundamental importance for PCR analytical sensitivity, especially when paucibacillary samples and/or samples containing potential PCR inhibitors are analyzed.

Burnt sugarcane harvesting work: effects on pulmonary and systemic inflammatory markers.

Objective: To evaluate the effects of burnt sugarcane harvesting on the plasmatic and urinary concentrations of the club cell secretory protein (CC16) and inflammatory systemic biomarkers in a group of sugarcane cutters. Methods: Seventy-eight sugar cane workers were evaluated. The plasmatic and urinary concentrations of CC16, a pulmonary damage marker and inflammatory systemic biomarkers were collected at three time points: before, three months after and six months after the onset of the burnt sugarcane harvesting period. All evaluations were performed at ∼7 am, before the daily work shift. In the three-month evaluation, a post-work shift assessment (acute effect) was also performed. Results: The age of the workers was 37.9 ± 11.0 years. The PM2.5 concentrations were 27.0 (23.0-33.0) and 101.0 (31.0-139.5) µg/m3 in the pre harvest and harvest periods, respectively (p < .001). Burnt sugarcane harvesting was associated with a reduction, throughout the work during burnt sugarcane harvesting (subchronic effect), in plasmatic and urinary CC16 concentrations. Acutely, there was a decrease in plasmatic concentrations. There were acute and subchronic increases in inflammatory markers (neutrophils, monocytes) and muscle damage markers (CK and LDH) and a decrease in red blood cells. Conclusions: Harvesting of burnt sugarcane was associated with acute and subchronic reductions in the plasmatic and urinary concentrations of CC16 protein and changes in systemic inflammatory markers.

Preanalytical conditions can interfere with M. tuberculosis detection by PCR in respiratory samples

OBJECTIVES: Tuberculosis is one of the most prevalent infections in humans. Although culture is the reference for diagnosis, its sensitivity is compromised, especially in paucibacillary samples. Because polymerase chain reaction (PCR) amplifies mycobacterial DNA, it is more sensitive than culture for the diagnosis of Mycobacterium tuberculosis (Mtb). However, its performance can be affected by intrinsic sample inhibitors and by the extraction/detection techniques used. METHODS: We evaluated the influence of preanalytical conditions on Mtb detection in samples of sputum (SPU), bronchoalveolar lavage (BAL), and pleural fluid (PF) using combinations of extraction/detection methods. Respiratory samples were prepared to contain different concentrations of red blood cells and nucleated cells to which increasing amounts of Mtb colonies were inoculated and submitted to PCR. RESULTS: Up to 102 CFU/ml of Mtb were detected in the SPU in all methods, except for the Roche extraction/detection method, regardless of the preanalytical sample condition. In BAL samples, medium and high concentrations of cells and high concentrations of red blood cells contributed to a lower Mtb detection, regardless of the extraction method used. In PF, red blood cells were the variable that most interfered with Mtb detection, with better recovery (102 CFU/ml) observed with the Qiagen/Nanogen combination. CONCLUSION: The choice of Mtb extraction and detection method is of fundamental importance for PCR analytical sensitivity, especially when paucibacillary samples and/or samples containing potential PCR inhibitors are analyzed.