Therapeutic drug monitoring of linezolid and exploring optimal regimens and a toxicity-related nomogram in elderly patients: a multicentre, prospective, non-interventional study.

BACKGROUND: The concentrations of linezolid, its optimal regimen and the associated side effects in elderly patients remain unclear. METHODS: In this multicentre, prospective study, elderly patients receiving linezolid at four tertiary hospitals in Beijing between May 2021 and December 2022 were included. Linezolid concentrations and haematological toxicity were monitored dynamically. Risk factors for linezolid overexposure and moderate-to-severe linezolid-induced thrombocytopenia (M/S LIT) were analysed, and a predictive model of M/S LIT was developed. RESULTS: A total of 860 linezolid concentrations were measured in 313 patients. The median trough concentrations of linezolid were 24.4 (15.3, 35.8) mg/L at 36-72 h and 26.1 (17.0, 38.1) mg/L at 5-10 days (P = 0.132). Severe linezolid exposure was independently associated with age, estimated glomerular filtration rate (eGFR) and the worst SOFA score (SOFA1), and we further recommended dose regimens for elderly patients based on these findings. The incidences of linezolid-induced thrombocytopenia(LIT) and M/S LIT were 73.5% and 47.6%, respectively. M/S LIT was independently correlated with treatment duration, average trough concentration (TDMa), baseline platelet count, eGFR and baseline SOFA score (SOFA0). The developed nomogram predicted M/S LIT with an area under the curve of 0.767 (95% CI 0.715-0.820), a sensitivity of 71.1% and a specificity of 73.2%. CONCLUSIONS: Linezolid trough concentrations increased dramatically in the elderly, by about 10 mg/L in patients aged 65-80 years, followed by a further increase of 10 mg/L for every 10 years of age. Therapeutic drug monitoring is recommended in elderly patients receiving linezolid. The developed nomogram may predict M/S LIT and guide dosage adjustments of linezolid. Clinical trial registration number: ChiCTR2100045707.

Necessity for higher teicoplanin doses in older adults: a multicenter prospective observational study in China.

BACKGROUND: Many older adult patients receive low-dose teicoplanin with varied regimens, leading to a lack of clarity on its optimal regimens and toxicity profiles in China. This study aimed to clarify these aspects by analyzing teicoplanin treatment concentrations and toxicities. METHODS: We included older adult patients administered teicoplanin at four tertiary hospitals in Beijing from June 2021 to July 2023, targeting a trough concentration (Cmin) ≥ 10 mg/L. Teicoplanin concentrations and toxicities were monitored dynamically. RESULTS: From 204 patients, we obtained 632 teicoplanin concentrations. Most patients (83.3%) received low-dose regimens. Suboptimal concentrations were found in 66.4% of patients within 7 days of treatment and 17.0% after 15 days. Cmin gradually increased with treatment duration and was influenced initially by creatinine and by both body weight and creatinine from days 8 to 14. The target concentration was achieved in 53.1%, 33.9%, 15.6%, and 5.5% of patients at 3, ≤ 7, 8-14, and ≥ 15 days after withdrawal, respectively. Slow elimination was associated with average Cmin and eGFR. Nephrotoxicity, hepatotoxicity, and thrombocytopenia occurred in 12.5%, 4.1%, and 31.5% of patients, respectively, without significant differences between concentrations. CONCLUSIONS: Most older adult patients were underdosed, indicating a need for dose adjustment. Given the varied risk factors for suboptimal concentrations in different treatment stages, a one-size-fits-all regimen was ineffective. We recommend an initial dose of 400 mg at 12-h intervals for the first three days, with subsequent doses from days 4 to 14 adjusted based on creatinine and body weight; after day 14, a maintenance dose of 200 mg daily is advised. TRIAL REGISTRATION: ChiCTR2100046811; 28/05/2021.

Simvastatin attenuates acute lung injury by activation of A2B adenosine receptor.

To explore the protective mechanism of simvastatin in acute lung injury (ALI), the lipopolysaccharide (LPS) induced (5 mg/kg) ALI rat model was used to examine the effects of simvastatin. Following simvastatin treatment, the histopathological evaluation of lung tissues was made using hematoxylin and eosin (H&E) staining. Also, myeloperoxidase (MPO) activity and the levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), and IL-10 were determined by ELISA. Blood gas analyses of arterial blood samples were performed to assess the pulmonary gas exchange. Moreover, the neutrophil count and total protein content were determined in the bronchoalveolar lavage (BAL) fluid. The ratio of wet lung to dry lung (W/D) and the alveolar fluid clearance (AFC) were calculated to estimate the severity of edema. Lastly, the levels of A2BAR, CFTR, claudin4, and claudin18 were also measured by qRT-PCR and Western blotting. Simvastatin treatment, in a dose-related manner, markedly improved the lung histological injury and decreased the levels of TNF-α, IL-1ß, and increased IL-10 in LPS induced ALI. Also, pulmonary neutrophil count was alleviated. Besides, a decreased ratio of W/D lung also confirmed the simvastatin intervention. Notably, simvastatin reduced the levels of A2BAR, CFTR, and claudin18 but upregulated claudin4 in lung tissues. Additionally, treatment with PSB1115, an antagonist of A2BAR, countered the protective effect of simvastatin in ALI. Our study demonstrates that simvastatin has a protective effect against LPS-induced ALI by activating A2BAR and should be exploited as a novel therapeutic target for the treatment of ALI.

Dual targeting of MEK and PI3K effectively controls the proliferation of human EGFR-TKI resistant non-small cell lung carcinoma cell lines with different genetic backgrounds.

BACKGROUND: Molecular targeted therapy for non-small cell lung carcinoma (NSCLC) is restricted due to resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). This study evaluated the effects of dual targeting of MEK and PI3K in human EGFR-TKI resistant NSCLC cell lines. METHODS: EGFR-TKI resistant NSCLC cell lines H1975, H460, and A549, with different mutation and amplification status in EGFR, K-RAS, PIK3CA, and MET genes, were treated with a MEK162 (MEK inhibitor) and BKM120 (PI3K inhibitor) combination or a BIBW2992 (EGFR inhibitor) and ARQ197 (MET inhibitor) combination and assayed for cell proliferation, apoptosis, and cell cycle distribution. RESULTS: Dual targeting of MEK and PI3K efficiently inhibited the cell proliferation, induced apoptosis and the G0/G1 cell cycle, and decreased the phosphorylation of ERK1/2, AKT, S6, and 4E-BP1. H460 cells with K-RAS and PIK3CA mutation were most sensitive to MEK162 and BKM120 combinations. H1975 cells with EGFR and PIK3CA mutation and MET amplification were sensitive to BIBW2992 and ARQ197 combinations. CONCLUSION: Dual targeting regulated the proliferation of EGFR-TKI-resistant NSCLC cells, especially mutants in K-RAS and PIK3CA that are promising for EGFR-TKI-resistant NSCLC therapeutics.

Early warning of bloodstream infection in elderly patients with circulating microparticles.

BACKGROUND: The difficulty of early diagnosis of bloodstream infection in the elderly patients leads to high mortality. Therefore, it is essential to determine some new methods of early warning of bloodstream infection in the elderly patients for timely adjustment of treatment and improvement of prognosis. METHODS: Patients aged over 65 years with suspected bloodstream infections were included and divided into bloodstream infection (BSI) and non-bloodstream infection (non-BSI) groups based on blood culture results. The morphology of microparticles (MPs) was observed by using transmission electron microscopy, and the number of MPs was dynamically monitored by flow cytometry. RESULTS: A total of 140 patients were included in the study: 54 in the BSI group and 86 in the non-BSI group. Total MPs (T-MPs) ≥ 6000 events/µL (OR, 7.693; 95% CI 2.944-20.103, P < 0.0001), neutrophil-derived MPs (NMPs) ≥ 500 events/µL (OR, 12.049; 95% CI 3.574-40.623, P < 0.0001), and monocyte counts ≤ 0.4 × 109/L (OR, 3.637; 95% CI 1.415-9.348, P = 0.007) within 6 h of fever were independently associated with bloodstream infection in the elderly patients. We also developed an early warning model for bloodstream infection in the elderly patients with an area under the curve of 0.884 (95% CI 0.826-0.942, P < 0.0001), sensitivity of 86.8%, specificity of 76.5%, positive predictive value of 70.8%, and negative predictive value of 89.8%. CONCLUSION: The early warning model of bloodstream infection based on circulating T-MPs, NMPs, and monocyte counts within 6 h of fever in the elderly patients was helpful in early detection of bloodstream infection and therefore promptly adjustment of treatment plan.

Prediction of the Therapeutic Effects of Pembrolizumab and Nivolumab in Advanced Non-Small Cell Lung Cancer by Platelet-Derived Microparticles in Circulating Blood.

BACKGROUND: There are limited methods to predict the therapeutic effect of immune checkpoint inhibitors (ICIs). The purpose of this study was to explore the value of circulating microparticles (MPs) in predicting thetherapeutic effects of immunotherapy. METHODS: A prospective study was conducted at the cancer center of PLA general hospital, including all patients with advanced non-small cell lung cancer (NSCLC) who were treated with pembrolizumab or nivolumab from December 2018 to December 2019. The patients were divided into an immune-related objective response (iOR) group and an immune-related disease progression (iPD) group.The numbers of total MPs, platelet-derived microparticles (PMPs) and T-lymphocyte-derived microparticles (T-LyMPs) at baseline and after immunotherapy were detected using a flow cytometer. Univariate analysis and multivariate logistic regression analysis were used to determine the independent influencing factors. RESULTS: We identified 32 patients in the iOR group and 18 patients in the iPD group. No significant difference were found intotal MPs, PMPs and T-LyMPs at the baseline between the 2 groups. While total MPs, PMPs and T-LyMPs in the iPD group were significantly higher than those in the iOR group after immunotherapy(P < 0.05). In the multivariate logistic regression analysis, PMPs ≥80 events/µL after immunotherapy(OR, 7.270; 95% CI, 1.092-48.404, P = 0.04) were associated with disease progression in advanced NSCLC and could independently predict the therapeutic effect of immunotherapy. CONCLUSIONS: PMPs after immunotherapy independently predicted the therapeutic effects of ICIs, making it possible to monitor the therapeutic effect in real time and rapidly adjust treatment regimens. In addition, this study found for the first time that elevated circulating T-LyMPs were associated with disease progression in advanced NSCLC.

Incidence and Associated Risk Factors for Lactic Acidosis Induced by Linezolid Therapy in a Case-Control Study in Patients Older Than 85 Years.

Background: Serum lactic acid is considered a prognostic indicator in critically ill patients. However, studies on linezolid-induced lactic acidosis (LILA) are still limited. Individuals older than 85 years old (very elderly) have limited capacity for organ compensation, and LILA data from these patients are lacking. In this study, we evaluated the risk factors for LILA in patients older than 85 years and established a risk prediction model for geriatric practice. Methods: In this retrospective cohort study, blood gas analysis data and arterial lactate levels were monitored in patients older than 85 years during the use of teicoplanin or linezolid. After propensity score matching analyses, we compared the incidence of lactic acidosis between the teicoplanin and linezolid therapy groups and identified the risk factors of LILA. Results: The incidence of lactic acidosis was found to be much lower in the group receiving teicoplanin than those receiving linezolid therapy (0 vs. 35.7%; p < 0.0001). A duration of linezolid therapy ≥ 9 days [odds ratio (OR), 3.541; 95% confidence interval (CI), 1.161-10.793; p = 0.026], an arterial blood glucose level ≥ 8 mmol/L (OR, 4.548; 95% CI, 1.507-13.725; p = 0.007), and a high sequential organ failure assessment score (OR, 1.429; 95% CI, 1.213-1.685; p < 0.0001) were risk factors for LILA. The constructed risk model could be used to predict LILA (area under the curve, 0.849; specificity, 65.1%; sensitivity, 91.4%, with a negative predictive value of 93.2% and a positive predictive value of 59.3%). Conclusions: LILA can occur in patients older than 85 years after a relatively shorter duration of linezolid therapy. Therefore, close monitoring of blood gas and arterial lactate levels during linezolid therapy in the very elderly population is necessary.

[Early diagnostic value of circulating microparticles in super-elderly patients with infection].

OBJECTIVE: To investigate the level and changing trend of microparticles (MPs) in super-elderly infected patients, and explore its early warning effect on infection. METHODS: The infected patients ≥ 85 years old admitted to the Second Medical Center of Chinese PLA General Hospital from December 2018 to March 2019 were selected as the observation group, and the healthy volunteers ≥ 85 years old in the same period were selected as the control group. Venous blood samples were collected at the 2nd hour, the 2nd day and the 7th day after fever, and the inflammatory markers such as white blood cell count (WBC), neutrophil percentage (NEUT), C-reactive protein (CRP) and procalcitonin (PCT) were measured. The levels of MPs were determined by flow cytometry. Annexin V labeled CD11b positive MPs (Annexin V+/CD11b+ MPs) represented leukocyte microparticles (LMPs), and Annexin V labeled CD66b positive MPs (Annexin V+/CD66b+ MPs) represented neutrophil microparticle (NMPs). The differences of each index at different time points between the two groups were compared, and the predictive value of each index to the infection of elderly patients was analyzed by receiver operating characteristic (ROC) curve. RESULTS: A total of 38 subjects were enrolled, including 28 cases in the observation group and 10 cases in the control group. The levels of LMPs and NMPs in the observation group increased to the peak at the 2nd hour after fever, and were significantly higher than those in the control group [LMPs (cells/µL): 55.0 (28.8, 197.2) vs. 19.0 (13.5, 28.3), NMPs (cells/µL): 226.5 (123.3, 516.5) vs. 26.5 (22.0, 48.8), both P < 0.01]. With the control of the disease, LMPs and NMPs decreased gradually. The NMPs on the 2nd day was significantly lower than that at the 2nd hour of fever [cells/µL: 106.0 (40.0, 309.0) vs. 226.5 (123.3, 516.5), P < 0.05], and the LMPs and NMPs on the 7th day were significantly lower than those on the 2nd day [LMPs (cells/µL): 17.0 (12.5, 43.8) vs. 42.0 (13.0, 117.0), NMPs (cells/µL): 30.0 (15.8, 62.0) vs. 106.0 (40.0, 309.0), both P < 0.05]. There was no significant difference in the levels of LMPs and NMPs between the two groups on the 7th day. Among the inflammatory markers, the NEUT in the observation group was significantly higher than that in the control group at the 2nd hour of fever (0.70±0.09 vs. 0.59±0.04, P < 0.01), but there was no significant difference in WBC, CRP and PCT between the two groups. On the 2nd day, the inflammatory markers in the observation group reached the peak and were significantly higher than those in the control group [WBC (×109/L): 9.33±2.44 vs. 6.37±1.28, NEUT: 0.78±0.08 vs. 0.57±0.04, CRP (mg/L): 5.67±2.99 vs. 0.33±0.18, PCT (µg/L): 0.80±0.67 vs. 0.07±0.03, all P < 0.01]. On the 7th day, the inflammatory markers in the observation group decreased significantly, and there was no significant difference between the observation group and the control group. ROC curve analysis showed that the area under ROC curve (AUC) and 95% confidence interval (95%CI) of LMPs and NMPs on the day of fever were higher than those of WBC, NEUT, CRP and PCT [0.888 (0.763-1.000), 0.973 (0.931-1.000) vs. 0.679 (0.346-0.811), 0.829 (0.700-0.958), 0.607 (0.404-0.811), 0.554 (0.358-0.749)]. CONCLUSIONS: LMPs and NMPs are significantly increased in the early stage of fever, which can predict the incidence of infection in the super-elderly patients.