In vitro stability of B-type natriuretic peptide (BNP) in plasma stored under different conditions when measured with the Lumipulse® assay.

Natriuretic peptides are a laboratory tool with significant implications for the diagnosis and prognosis of heart failure (HF). The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) recommended that assays must be examined for sample stability because there appears to be assay dependent. We aimed to evaluate the in vitro stability of B-type natriuretic peptide (BNP) under different handling conditions and using a BNP assay from Fujirebio Diagnostics (Tokyo, Japan). BNP concentrations were measured in plasma EDTA samples from 11 subjects to evaluate the in vitro stability at room temperature and at 4 °C and in 10 subjects to check the in vitro stability of samples stored at -20 °C during 1 and 3 months. Stability limit was defined according to Spanish Society of Laboratory Medicine (SEQC-ML) recommendations. At room temperature and 4 °C, BNP concentrations decreased progressively in samples collected in both groups, remaining stable within four hours from collection. BNP concentrations also were stable within four hours from collection in whole blood at room temperature. Finally, at -20 °C, BNP concentrations remained stable in both groups at 1 and 3 months, respectively. According to our results, BNP, stored at room temperature or at 4 °C, should be assayed in the first four hours after collection. Besides, BNP was shown to be stable in whole blood for at least four hours at room temperature. If the testing cannot be performed within the first four hours, the plasma should be frozen and kept at -20 °C for up to 3 months.

Increased concentrations of procalcitonin in patients with paracetamol intoxication.

Objectives: Paracetamol intoxication is one of the causes of elevated procalcitonin concentrations unrelated to infection. We report a case series of two patients intoxicated with paracetamol whose laboratory data revealed a significant elevation of serum procalcitonin concentrations without clinical, radiological and/or biological evidence of infection. The underlying mechanism by which paracetamol triggers an increase in procalcitonin concentrations is still unclear. Case presentation: We report two cases of paracetamol intoxication. Both patients were admitted to the Emergency Department (ED) and subsequently transferred to the Intensive Care Unit (ICU). The patients exhibited elevated procalcitonin levels during the first hours of admission without clinical and/or microbiological evidence of infection that could explain such increase. Notably, only Case 1 developed liver injury, with alterations in alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin and esterified bilirubin concentrations, which were not observed in Case 2. Conclusions: The two patients showed elevated procalcitonin concentrations resulting from paracetamol intoxication, although only a patient exhibited signs of liver injury. These findings suggest that increased procalcitonin levels induced by a paracetamol overdose cannot be fully explained by hepatocyte injury alone, but other mechanisms involving other organs and tissues may also be associated. In any case, although this mechanism is not well understood, it is important to be aware of this limitation when using procalcitonin as a biomarker of infection in patients intoxicated with paracetamol.

Circulating MR-proADM levels, as an indicator of endothelial dysfunction, for early risk stratification of mid-term mortality in COVID-19 patients.

OBJECTIVES: Thromboinflammation, resulting from a complex interaction between thrombocytopathy, coagulopathy, and endotheliopathy, contributes to increased mortality in COVID-19 patients. MR-proADM, as a surrogate of adrenomedullin system disruption, leading to endothelial damage, has been reported as a promising biomarker for short-term prognosis. We evaluated the role of MR-proADM in the mid-term mortality in COVID-19 patients. METHODS: A prospective, observational study enrolling COVID-19 patients from August to October 2020. A blood sample for laboratory test analysis was drawn on arrival in the emergency department. The primary endpoint was 90-day mortality. The area under the curve (AUC) and Cox regression analyses were used to assess discriminatory ability and association with the endpoint. RESULTS: A total of 359 patients were enrolled, and the 90-day mortality rate was 8.9%. ROC AUC for MR-proADM predicting 90-day mortality was 0.832. An optimal cutoff of 0.80 nmol/L showed a sensitivity of 96.9% and a specificity of 58.4%, with a negative predictive value of 99.5%. Circulating MR-proADM levels (inverse transformed), after adjusting by a propensity score including eleven potential confounders, were an independent predictor of 90-day mortality (HR: 0.162 [95% CI: 0.043-0.480]) CONCLUSIONS: Our data confirm that MR-proADM has a role in the mid-term prognosis of COVID-19 patients and might assist physicians with risk stratification.

Predictive values of colon microbiota in the treatment response to colorectal cancer.

The crosstalk between the colon mucosa and the microbiota represents a complex and delicate equilibrium. Gastrointestinal diseases such as inflammatory bowel disease and colorectal cancer (CRC) are associated with a state of altered microbiota composition known as dysbiosis, which seems to play a causative role in some of these illnesses. Recent reports have shown that the colorectal microbiome is responsible for the response and safety to treatments against CRC, especially immunotherapy, hence opening the possibility to use bacteria as a predictive marker and also as a therapeutic agent. The review objective is to summarize updated reports about the the implication of the colorectal microbiome in the development of CRC, in treatment response and its potential as a therapeutic approach.