Background: Clozapine is a highly effective second-generation antipsychotic with few extrapyramidal reactions, making it a preferred choice among clinicians. However, instances of acute clozapine poisoning resulting from suicide attempts and misuse have been reported. Through our review of existing literature, we identified that we believe to be the highest recorded overdose of clozapine in elderly patients, resulting in a nonfatal outcome. Case presentation: The case report involves a 71-year-old female with a history of depression who ingested a dose of 10,000 mg of clozapine. Approximately 6 h after the overdose, the clozapine level was 5,200 μg/L, significantly surpassing the recommended therapeutic concentration range of 350–600 μg/L. After gastric lavage and hemoperfusion, the blood level dropped to 1847.11 μg/L. Notably, during therapeutic drugs monitoring (TDM), we found a perplexing spike in the patient’s blood level to 5554.15 μg/L after the second hemoperfusion. Conclusion: In this case we mainly focused on the abnormal fluctuations in the concentration of clozapine. We conducted a comprehensive analysis of potential factors contributing to this abnormal phenomenon in terms of the patient’s age, clinical symptoms, various laboratory test indexes, and the pharmacokinetics of clozapine. Our findings underscore the importance of timely TDM and the precision of results in managing elderly patients experiencing high-dose clozapine poisoning.

Since 2019, the coronavirus disease 2019 (COVID-19) global pandemic has caused more than 300 million cases of disease and 5 million deaths. Vaccination has been widely accepted as the most effective measure for the prevention and control of this disease. However, there is little understanding about serum anti-SARS-CoV-2 IgM/IgG levels after inactivated vaccination as well as the relationship with peripheral blood leukocytes in the non-COVID-19 infected population. A total of 16,335 male and 22,302 female participants were recruited in this study, which was conducted in the Peking University Third Hospital located in Beijing (China). The level and seroprevalence of serum anti-SARS-CoV-2 receptor-binding domain (RBD) IgM/IgG and the association with peripheral blood leukocytes classification were investigated. With an increase in the number and percentage of full immunization of COVID-19 vaccinations in Beijing, serum anti-SARS-CoV-2 IgG antibodies levels and seroprevalence were significantly elevated (p < 0.01). The serum anti-SARS-CoV-2 IgG antibodies of 60 years and older persons were significantly lower than that of individuals that are 18~60 years old (p < 0.01), and there was a positive relationship between serum anti-SARS-CoV-2 IgG antibodies levels and peripheral blood lymphocyte count. The investigation of serum anti-SARS-CoV-2 IgM/IgG antibodies and the peripheral hematological index may prompt and help understand the adaptive immune response of vaccination.

Background: To investigate the effect of hemolysis on serum procalcitonin (PCT) detected by electrochemiluminescence (ECL) and to explore the possibility of establishment of a correction equation. Methods: Fifty-one blood samples from 17 patients were collected. Hemolytic samples, of which the final concentrations of hemoglobin (Hb) were 5, 10, 15 and 20 g L⁻¹, were prepared by adding lysed homologous RBCs to serum, and then the PCT levels were detected and compared. Results: with the increasing degree of sample hemolysis, PCT bias elevated from −13.12% to −38.86% as the hemolysis degree increased from 5 g L⁻¹ to 20 g L⁻¹, respectively. There was a linear correlation of PCT levels between the original and hemolytic samples with the same hemolytic degree (r > 0.97). Using the correction equation log₁₀PCT_corr = 0.962(log₁₀PCT_hemo) +0.251(log₁₀Hb) − 0.126, the corrected PCT values from the hemolytic samples showed acceptable consistency with the original values (p > 0.05). Conclusions: Hemolysis has a negative interference on PCT values assayed by ECL. The serum PCT level is correlated negatively with the Hb level in the blood sample. The established correction equation could reduce inappropriate antibiotics application and improve the experience of patients in the emergency department.