Simultaneous determination of nirmatrelvir and ritonavir in human plasma using LC-MS/MS and its pharmacokinetic application in healthy Chinese volunteers.

Paxlovid, a copackaged medication of nirmatrelvir tablets (150 mg) and ritonavir tablets (100 mg) developed by Pfizer, is one of the first orally accessible COVID-19 antiviral medicines to be approved for emergency usage. In this research, an efficient LC-MS/MS method for simultaneous determination of nirmatrelvir and ritonavir in human plasma was established and validated with remdesivir as an internal standard. Chromatographic separations were carried out on a Thermo BDS Hypersil C18 column (4.6 × 100 mm, 2.4 µm) using deionized water and methanol as mobile phase, both added with 0.1% (v/v) formic acid. Based on the positive electrospray ionization mode, nirmatrelvir and ritonavir were analyzed by selective reaction monitoring. Excellent precision, accuracy, recovery, and linearity were demonstrated, covering the range of 50-5000 ng/mL for nirmatrelvir and 10-1000 ng/mL for ritonavir. Then, the established method was used for determining the pharmacokinetic profile of Paxlovid in healthy Chinese volunteers. The pharmacokinetic parameters, including Cmax , Tmax , t1/2 , and AUC0 - ∞ of Western volunteers, correspond well with the results of this pharmacokinetic investigation.

Acute Respiratory Distress Syndrome in a Patient With Acute Promyelocytic Leukemia: Overlapping Between Differentiation Syndrome and COVID-19.

Differentiation syndrome (DS) is a relatively common and severe complication in acute promyelocytic leukemia (APL) patients undergoing induction therapy with all-trans retinoic acid (ATRA) and/or arsenic trioxide (ATO). DS is a multisystem disorder with pulmonary involvement. The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is also a systemic disorder with similar pulmonary and other clinical manifestations as DS. Here, we report an APL case with overlapping between DS and COVID-19. After admission to the hospital, the patient was diagnosed with APL and underwent differentiation therapy with ATRA/ATO. In the meantime, COVID-19 was diagnosed with a positive polymerase chain reaction test of SARS-CoV-2 from an oropharyngeal swab. The patient developed acute respiratory distress syndrome, coagulopathy, and acute kidney injury, which fit the clinical pictures of both DS and COVID-19. The patient died at last and this complicate case imposed big challenges for clinicians due to the laboratory and imaging findings of DS disguised in the context of COVID-19. Therefore, comprehensive treatment strategy should be considered to balance the risk and benefit of differentiation therapy in the context of COVID-19.

Elevated Plasma Fibrinogen Is Associated With Excessive Inflammation and Disease Severity in COVID-19 Patients.

Background: The coronavirus disease-19 (COVID-19) is characterized with intense inflammatory response, cardiac involvement, and coagulopathy. Fibrinogen, as a biomarker for inflammation, cardiovascular disease, and coagulation, has not been fully investigated yet. The aim of this study was to assess the clinical application of fibrinogen in COVID-19 patients. Methods: We retrospectively analyzed the demographic and laboratory characteristics of 119 COVID-19 patients in the University of Alabama of Birmingham Medical Center. Correlations of fibrinogen on admission with intensive care unit (ICU) admission, disease severity, and laboratory parameters were analyzed. Results: Among the 119 COVID-19 patients, 77.3% (92/119) had severe disease, and 59.5% (71/119) patients were admitted to the ICU. Elevated fibrinogen was detected in 67.2% (80/119) of the patients. Fibrinogen levels were significantly associated with inflammatory markers and disease severity, but not with cardiac injury biomarker high sensitivity troponin I. Patients with severe disease had increased fibrinogen levels upon admission compared to patients with non-severe disease (P = 0.001). Fibrinogen level at 528.0 mg/dl was the optimal cutoff to predict disease severity, with a sensitivity and specificity of 66.7% and 70.3% (area undty -60er the curve [AUC] 0.72, P = 0.0006). Conclusions: Fibrinogen is commonly elevated in COVID-19 patients, especially in those with severe disease. Elevated fibrinogen correlates with excessive inflammation, disease severity, and ICU admission in COVID-19 patients.

Clinical laboratory characteristics in patients with suspected COVID-19: One single-institution experience.

OBJECTIVES: Since December 2019, the outbreak of coronavirus disease 2019 (COVID-19) has become a worldwide pandemic. The aim of the study is to investigate the demographic, clinical, and laboratory characteristics in suspected COVID-19 patients in our institution. METHODS: In this retrospective study, we investigated suspected COVID-19 patients admitted to the University of Alabama at Birmingham with a request for an interleukin-6 send-out test, from March 28 to June 27, 2020. Patients' demographic, clinical, and laboratory characteristics were collected by chart review. RESULTS: Fifty patients suspected with COVID-19 were included in our study, of whom 24 patients were positive with severe acute respiratory syndrome coronavirus-2 infection and 26 were negative. During the observation period, 30 patients were discharged, 17 died during hospitalization, and three remained in hospital. Compared to non-COVID-19 patients, COVID-19 patients had older age, more comorbidities, and elevated levels of inflammation markers such as erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), serum ferritin, and lactate dehydrogenase (LDH). However, there was no significant difference in laboratory data between survivors and nonsurvivors in COVID-19 patients in our study. CONCLUSION: This study indicated that potential risk factors of older age, multiple comorbidities, and high levels of ESR, CRP, serum ferritin, and LDH could help the clinician to identify potential COVID-19 patients. However, this data needs to be further validated in a larger population.