Predicting pulmonary embolism in patients infected with COVID-19 based on D-dimer levels and days between diagnosis of the infection and D-dimer determination.

Ruling out pulmonary embolism (PE) can be challenging in a situation of elevated D-dimer values such as in a case of COVID-19 infection. Our objective was to evaluate the difference in D-dimer values of subjects infected with COVID-19 in those with PE and those without and to analyze the predictive value of D-dimer for PE in these subjects based on the day of D-dimer determination. This was an observational, retrospective study, conducted at a tertiary hospital. All subjects with PCR-confirmed COVID-19 infection requiring hospital admission at our institution between the months of March and April 2020 were included in the study. We compared D-dimer levels in subjects who went on to develop a PE and those who did not. We then created a model to predict the subsequent development of a PE with the current D-dimer levels of the subject. D-dimer levels changed over time from COVID-19 diagnosis, but were always higher in subjects who went on to develop a PE. Regarding the predictive model created, the area under the curve of the ROC analyses of the cross-validation predictions was 0.72. The risk of pulmonary embolism for the same D-dimer levels varied depending on the number of days elapsed since COVID-19 diagnosis and D-dimer determination. To conclude, D-dimer levels were elevated in subjects with a COVID-19 infection, especially in those with PE. D-dimer levels increased during the first 10 days after the diagnosis of the infection and can be used to predict the risk of PE in COVID-19 subjects.

Prophylaxis with enoxaparin for prevention of venous thromboembolism after lung transplantation: a retrospective study.

Venous thromboembolism (VTE) is a frequent complication after solid organ transplantation (SOT) and, specifically, after lung transplantation (LT). The objectives of this study were to evaluate prophylaxis with enoxaparin and to describe risk factors for VTE after LT. We retrospectively reviewed the clinical records of 333 patients who underwent LT in our institution between 2009 and 2014. We compared two consecutive cohorts: one that received enoxaparin only during post-transplant hospital admissions and a second cohort that received 90-day extended prophylaxis with enoxaparin. Cumulative incidence function for competing risk analysis was used to determine incidence of VTE during the first year after transplantation. Risk factors were analyzed using a Cox proportional hazards regression model. The cumulative incidence of VTE was 15.3% (95% CI: 11.6-19.4). Median time from transplant to the event was 40 (p25-p75, 14-112) days. Ninety-day extended prophylaxis did not reduce the incidence of VTE. In this study, the risk factors associated with VTE were male gender and interstitial lung disease. VTE is a major complication after LT, and 90-day extended prophylaxis was not able to prevent it. Large, multicenter, randomized clinical trials should be performed to define the best strategy for preventing VTE.

Risk factors, survival, and impact of prophylaxis length in cytomegalovirus-seropositive lung transplant recipients: A prospective, observational, multicenter study.

BACKGROUND: The optimal length of cytomegalovirus (CMV) prophylaxis in lung transplantation according to CMV serostatus is not well established. METHODS: We have performed a prospective, observational, multicenter study to determine the incidence of CMV infection and disease in 92 CMV-seropositive lung transplant recipients (LTR), their related outcomes and risk factors, and the impact of prophylaxis length. RESULTS: At 18 months post transplantation, 37 patients (40%) developed CMV infection (23 [25%]) or disease (14 [15.2%]). Overall mortality was higher in patients with CMV disease (64.3% vs 10.2%; P<.001), but only one patient died from CMV disease. In the multivariate analysis, CMV disease was an independent death risk factor (odds ratio [OR] 18.214, 95% confidence interval [CI] 4.120-80.527; P<.001). CMV disease incidence was higher in patients with 90-day prophylaxis than in those with 180-day prophylaxis (31.3% vs 11.8%; P=.049). Prophylaxis length was an independent risk factor for CMV disease (OR 4.974, 95% CI 1.231-20.094; P=.024). Sixteen patients withdrew from prophylaxis because of adverse events. CONCLUSION: CMV infection and disease in CMV-seropositive LTR remain frequent despite current prophylaxis. CMV disease increases mortality, whereas 180-day prophylaxis reduces the incidence of CMV disease.

Predictive Value of Immune Cell Functional Assay for Non-Cytomegalovirus Infection in Lung Transplant Recipients: A Multicenter Prospective Observational Study.

INTRODUCTION: Immune cell functional assay (ImmuKnow®) is a non-invasive method that measures the state of cellular immunity in immunosuppressed patients. We studied the prognostic value of the assay for predicting non-cytomegalovirus (CMV) infections in lung transplant recipients. METHODS: A multicenter prospective observational study of 92 patients followed up from 6 to 12 months after transplantation was performed. Immune cell functional assay was carried out at 6, 8, 10, and 12 months. RESULTS: Twenty-three patients (25%) developed 29 non-CMV infections between 6 and 12 months post-transplant. At 6 months, the immune response was moderate (ATP 225-525ng/mL) in 14 (15.2%) patients and low (ATP<225ng/mL) in 78 (84.8%); no patients had a strong response (ATP≥525ng/mL). Only 1 of 14 (7.1%) patients with a moderate response developed non-CMV infection in the following 6 months compared with 22 of 78 (28.2%) patients with low response, indicating sensitivity of 95.7%, specificity of 18.8%, positive predictive value (PPV) of 28.2%, and negative predictive value (NPV) of 92.9% (AUC 0.64; p=0.043). Similar acute rejection rates were recorded in patients with mean ATP≥225 vs. <225ng/mL during the study period (7.1% vs. 9.1%, p=0.81). CONCLUSION: Although ImmuKnow® does not seem useful to predict non-CMV infection, it could identify patients with a very low risk and help us define a target for an optimal immunosuppression.

Predictive Value of Immune Cell Functional Assay for Non-Cytomegalovirus Infection in Lung Transplant Recipients: A Multicenter Prospective Observational Study.

INTRODUCTION: Immune cell functional assay (ImmuKnow®) is a non-invasive method that measures the state of cellular immunity in immunosuppressed patients. We studied the prognostic value of the assay for predicting non-cytomegalovirus (CMV) infections in lung transplant recipients. METHODS: A multicenter prospective observational study of 92 patients followed up from 6 to 12 months after transplantation was performed. Immune cell functional assay was carried out at 6, 8, 10, and 12 months. RESULTS: Twenty-three patients (25%) developed 29 non-CMV infections between 6 and 12 months post-transplant. At 6 months, the immune response was moderate (ATP 225-525ng/mL) in 14 (15.2%) patients and low (ATP<225ng/mL) in 78 (84.8%); no patients had a strong response (ATP≥525ng/mL). Only 1 of 14 (7.1%) patients with a moderate response developed non-CMV infection in the following 6 months compared with 22 of 78 (28.2%) patients with low response, indicating sensitivity of 95.7%, specificity of 18.8%, positive predictive value (PPV) of 28.2%, and negative predictive value (NPV) of 92.9% (AUC 0.64; p=0.043). Similar acute rejection rates were recorded in patients with mean ATP≥225 vs. <225ng/mL during the study period (7.1% vs. 9.1%, p=0.81). CONCLUSION: Although ImmuKnow® does not seem useful to predict non-CMV infection, it could identify patients with a very low risk and help us define a target for an optimal immunosuppression.

D-dimer in patients infected with COVID-19 and suspected pulmonary embolism.

OBJECTIVE: To analyze the risk factors for pulmonary embolism (PE) in patients infected with COVID-19. METHODS: We conducted an observational, retrospective study. Patients with severe infection with COVID-19 and suspected PE were included. RESULTS: Patients with higher levels of D-dimer and those requiring intubation were at a higher risk of developing PE. Higher D-dimer levels were associated with a greater probability of PE 3, 6, 9 and 12 days after determining D-dimer levels with an OR of 1.7, 2.0, 2.4 and 2.4, respectively. CONCLUSION: In conclusion, patients infected with COVID-19 requiring OTI with higher levels of D-dimer have an increased risk of developing PE.

Pharmacokinetic Study of Conversion Between 2 Formulations of Once-daily Extended-release Tacrolimus in Stable Lung Transplant Patients.

BACKGROUND: The aim of this study was to compare the pharmacokinetic profile, tolerability, and safety of a novel once-daily extended-release formulation of tacrolimus (LCPT) with that of once-daily prolonged-release tacrolimus (ODT) in stable adult lung transplant (LT) recipients. METHODS: Phase II, open-label, single-arm, single-center, prospective pilot pharmacokinetic study. Study population comprised 20 stable LT recipients receiving ODT, mean age 55.9 years (range, 38-67 years), 13 (65%) men. Patients were switched to LCPT in a 1:0.7 (mg/mg) conversion dose. Follow-up was 6 months, and cystic fibrosis patients were excluded. Two 24-hour pharmacokinetic profiles were obtained for each patient, the first on day -14 and the second on day +14 after switching to LCPT. Pharmacokinetic parameters and safety were compared. RESULTS: Mean (SD) area under the concentration-time curve from 0 to 24 hours was 253.97 (61.90) ng/mL per hour for ODT and 282.44 (68.2) ng/mL per hour for LCPT. Systemic exposure was similar in both (Schuirmann two 1-sided test). Mean (SD) dose was 5.05 (1.67) mg in ODT and 3.36 (1.03) mg in LCPT (P = 0.0002). Time to maximum concentration was 125 minutes for ODT and 325 minutes for LCPT (P < 0.001). Correlation between area under the concentration-time curve from 0 to 24 hours and C24 was 0.896 (r) for ODT and 0.893 (r) for LCPT. There were no differences in adverse effects. At 6 months, conversion dose was 1:0.59 (mg/mg) in patients with unchanged minimum plasma concentration target levels. CONCLUSIONS: Switching from ODT to LCPT was safe and well tolerated in stable LT recipients without cystic fibrosis. A significantly lower dose of LCPT allows similar bioavailability. A conversion ratio 1:0.6 could be enough to maintain similar target levels.