PCT-Indicator for diagnosing and monitoring bacterial infections
PCT Components

PCT-Indicator for diagnosing and monitoring bacterial infections

PCT is a commonly used indicator for the differential diagnosis of bacterial infections[1].PCT is a very stable protein secreted by thyroid C-cells and its level is very low in healthy individuals during normal metabolism of the body. When bloodstream infection occurs, bacteria and endotoxins stimulate macrophages, neutrophils, monocytes, lymphocytes and platelets to produce colony-stimulating factor, tumor necrosis factor, interleukins, vasoactive substances and other substances, which induces an increase in the level of PCT, resulting in clinical manifestations such as fever, endotoxemia, and shock [2-3]. In recent years, PCT has received more and more attention and has become an important indicator for the diagnosis of early infection[4-5].

PCT of 0-0.5 ng/mL is normal; >0.5 ng/mL suggests that the patient is at risk of severe bacterial infection and sepsis.

PCT-Indicator for diagnosing and monitoring bacterial infections


Principles and influencing factors of PCT

PCT levels in plasma are elevated in severe bacterial, fungal, and parasitic infections, as well as in sepsis and multiple organ failure. In contrast, PCT is not elevated in autoimmune, allergic, and viral infections, limited localized bacterial infections, minor infections, and chronic inflammation.PCT reflects the degree to which the systemic inflammatory response is active. Factors affecting PCT levels include the size and type of infected organ, the type of bacteria, the degree of inflammation, and the status of the immune response.

PCT-Indicator for diagnosing and monitoring bacterial infections

Applications of PCT

PCT-Indicator for diagnosing and monitoring bacterial infections
(1) Monitoring of patients at risk of infection (e.g., post-surgical and post-transplantation immunosuppression, post-multiple injury) and patients requiring intensive care to detect the systemic effects of bacterial infection or to detect septic complications [6]. Bacterial infections are accompanied by a systemic inflammatory response, e.g.:peritonitis, soft tissue infections viral infections.
(2) PCT can be easily applied to the differential diagnosis of common diseases and syndromes in internal medicine. For example, differential diagnosis of infectious and non-infectious etiology of adult respiratory distress; Differential diagnosis of infected and aseptic necrosis in pancreatitis; Differential diagnosis of fever in infection, e.g., in oncology and hematology patients receiving chemotherapy; Differential diagnosis of acute exacerbation of chronic autoimmune diseases with rheumatic diseases with systemic bacterial infections in patients receiving immunosuppressive drugs; Differential diagnosis of bacterial meningitis versus viral meningitis; the presence of life-threatening bacterial and fungal infections in neutropenic patients undergoing chemotherapy; To identify the presence of serious bacterial and fungal infections in organ transplant patients receiving immunosuppressive therapy, and for the differential diagnosis of infection and transplant rejection.
(3) Pediatric fever is often difficult to distinguish between different sources of infection by clinical means, a problem that especially affects the accurate diagnosis of patients given immunosuppressive therapies for hematologic and neoplastic diseases. Many diseases are associated with secondary immunopathologic changes, such as rheumatic fever, making it difficult to distinguish them from primary bacterial infections. PCT has a high sensitivity and specificity for the differential diagnosis of bacterial and viral infections. Since there are essential differences in the treatment of bacterial and viral infections, PCT can provide valuable information on the treatment of patients with nonspecific symptoms of infection.

Diagreat Unique Routine Markers

Chemiluminescent Assay List

PCT-Indicator for diagnosing and monitoring bacterial infections


[1]VAN DER DOES Y,ROOD P P,RAMAKERS C,et al.Identifying patients with bacterial infections using a combination of C-reactive protein,procalcitonin ,TR AIL,and IP-10 in the emergency department:a prospective observational cohort study[J].Clin  MicrobiolInfect,2018,24(12):1297-1304.





[6]葛庆岗,阴赪宏,文艳,等.血清降钙素原与多器官功能障碍综合征严重程度相关性的临 床研究[J].中华危重病急救医学.2005,17(12):729-731

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