A diagnostic test of real-time PCR detection in the diagnosis of clinical bloodstream infection.

BACKGROUND: Blood culture remains the standard for diagnosing bloodstream infections, but it is difficult to identify bacteria directly and timeliness. The real-time polymerase chain reaction (PCR) has the potential to fill this diagnostic gap. This study intends to explore the sensitivity and specificity of PCR in detecting bloodstream infection pathogens and to compare it with routine blood culture to explore its clinical application value. METHODS: A total of 126 patients with bloodstream infections collected from various clinical departments of The First Hospital of Hebei Medical University. The patient's sample was divided into two parts. The one for multiplex PCR detection was performed using the Pathogeno Elite Multiplex PCR kit. Another blood culture was a fully automatic blood culture system from Autobio company. RESULTS: Among the 126 patients, a total of 17 pathogens were detected by PCR and blood culture both methods. PCR detected a total of 43 positive samples and 83 negative samples. Five samples were positive with blood culture, and 81 were negative. The negative predictive value of PCR was 0.98, with a sensitivity of 0.71 and a specificity of 0.68. A total of 38 specimens were positive for PCR but negative for blood culture, and 2 samples were positive for blood culture but negative for PCR. The top 5 pathogens with PCR detection were Epstein-Barr virus (27 cases), Human herpes virus 5 (9 cases), Klebsiella pneumoniae (5 cases), Staphylococcus (5 cases), and Stenotrophomonas maltophilia (4 cases). CONCLUSIONS: PCR detection can rapidly identify more pathogens and even multi-pathogen infections. Therefore, PCR testing may improve pathogen detection in patients with suspected bloodstream infections, enabling targeted treatment of patients.

Clinical Value of Cytokine Assay in Diagnosis and Severity Assessment of Lung Cancer.

Purpose: To investigate the clinical value of interleukin 2 (IL-2), interleukin 4 (IL-4), interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor α (TNF-α), and interferon-γ (IFN-γ) in diagnosis and severity assessment of lung cancer. Methods: In this observational study, 50 physical examination healthy subjects were included in the control group and 100 lung cancer patients were included in the study group. In the study group, 53 cases with pleural effusion were subgrouped to the pleural effusion group (n = 53), while 47 patients were assigned to the nonpleural effusion group (n = 47). Plasma cytokines IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ, and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores of all eligible subjects were collected and compared. Results: The study group showed significantly higher levels of plasma cytokines IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ versus healthy subjects (P < 0.05). Deterioration of lung cancer was associated with increased plasma cytokine levels and APACHE II scores. The combination assay of the above plasma cytokines showed significantly better diagnostic efficacy for lung cancer versus the single assay of the cytokines. Dead patients had higher plasma cytokine levels versus survived patients. The accuracy of plasma IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ levels in the severity assessment of lung cancer was comparable with that of the APACHE II scale. Conclusion: The plasma cytokines IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ are effective markers for the diagnosis of lung cancer. The combined assay contributes to the early diagnosis of lung cancer patients, and the persistent elevation of cytokines suggests an increased risk of death in lung cancer patients, so the detection of cytokine levels facilitates the severity assessment of lung cancer.