The diagnosis and treatment of infectious diseases is of great importance in clinical practice. To better identify, assess and treat infections, doctors usually rely on a range of biomarkers, i.e., infection indicators. These indicators not only help doctors to determine if infection exists, but also provide important information on the type of infection, its severity and the effectiveness of treatment. Several common infection indicators will be described in detail in this paper, including external hemoglobin cells, erythrocyte deposition (ESR), C Reaction Protein (CRP), serum starch samples Protein A (SAA), calcium reduction (PCT), albino-6 (IL-6) and hepatin combined protein (HBP) and their clinical significance.
I. HOLY BLOOD CLASS
Peripheral leukaemia from bone marrow is the most basic and commonly used indicator for the clinical initial identification of infection. Changes in white cell counts and their classification (neutral particle cells, lymphocytes, acidist particle cells, etc.) can in part reflect the type and severity of the infection. For example, the increase in composite meso-particle cell increases in white cells usually point to acute bacterial infections, especially in the Geran positive pyrocyte; the increase in combined lymphocytes in white cells tends to occur in acute viral infections; and the reduction of white cells may be caused by infections in viruses, atypical pathogens (e.g., husks, chlamydia, etc.). It should be noted, however, that changes in white cell count and classification may also be influenced by non-infective diseases such as tumours, vascular disease and physiological factors (e.g. newborns, pregnancy, menstruation, etc.) and therefore require a combination of other indicators and clinical performance.
II. Red cell deposition rate (ESR)
The erythrocyte deposition rate (ESR) is a non-specific indicator of inflammation response and its rise suggests inflammation processes in the body. In cases of acute bacterial inflammation, the ESR usually accelerates within two to three days. However, the ESR is less specific and vulnerable to a variety of factors, such as anaemia, pregnancy, tumours, etc., and therefore has limited clinical significance for the identification of the infection, the evaluation of the severity of the infection and its prognosis. Nevertheless, ESR has some reference value in the diagnosis of secondary infections of nodules or implants. In addition, the ESR has been found to have a much higher value for rheumatological diseases than for infectious diseases and to be used to observe their activity.
III. C RESPONSE POTENTIALS (CRP)
C Reacting Protein (CRP) is an acute, reverse protein synthesized from hepatocellular cells and is one of the most widely applied indicators of inflammation in clinical terms. Normally, the value of healthy human CRP is low, with 90 per cent of normal human CRP <1.0 mg/L. When inflammated by inflammation, such as microbial intrusion or tissue damage, CRP began to rise within 6-8 hours of the onset of the disease, peaking at 24-48 hours, with a positive correlation to the severity of the infection or inflammation. The rise of CRP and the level of bacterial infection are positively related and are therefore often used as identifying diagnostic indicators for bacterial and viral infections. When CRP level 50 mg/L, multi-introduce bacterial infections; when 10-99 mg/L, multi-introduce cooking or shallow infections; and when CRP level 100 mg/L, multi-introduce sepsis or invasive infections. In addition, CRP can be used for self-immunological disease identification and pre-post evaluation of malignant tumours.
IV. Serosol starry protein A (SAA)
The serum starch protein A (SAA) is another type of acute, reverse protein synthesized from liver cells, normally containing very low levels in healthy human serum (1-5 mg/L). SAA begins to rise within 3-6 hours of infection, which can be 10 to 1,000 times higher, and can be rapidly reduced to normal levels once pathogens are removed. SAA is more sensitive than CRP, especially in the early years of the virus, when it rises more frequently. Thus, joint SAA and CRP tests allow early identification of bacterial and viral infections. When SAA rises at the same time as CRP, it suggests the possibility of bacterial infection; if SAA rises and CRP does not, it suggests the possibility of viral infection.
v. Calcium reduction (PCT)
Calcium-reducing (PCT) is a non-hormonally active glucose protein, which increases in plasma during severe bacterial, fungi, parasitic infections and sepsis and multi-organ functional failure. The increase in the PCT is directly related to the severity of bacterial infections, which usually begin to increase after 2-3 hours of infection, with a rapid increase in concentrations of 6-8 hours, peaking at 12-48 hours and returning to normal after 2-3 days. PCTs do not increase or increase slightly in cases of viral diseases and can therefore serve as identifying diagnostic indicators for bacterial and viral infections. At PCT ≥ 0.25 μg/L, there is a high risk of bacterial infection in persons suspected to be infected with the lower respiratory tract; at ≥0.50 μg/L, it contributes to the diagnosis of sepsis; and at ≥10 μg/L, there is a high risk of infection of the gland vaginal bacteria.
White medium-6 (IL-6)
The white medium-6 (IL-6) is a multi-purpose glucose protein that is involved in the incidence and development of many diseases, including inflammation, viral infections, self-immunisation diseases, etc. In the case of inflammation, IL-6 rises earlier than CRP and PCT and begins to rise one hour after the infection reaches its peak in two hours, a common indicator of infection assessment and detection. The IL-6 rise is consistent with the severity of the inflammation, which is important for determining the severity of the sepsis. When IL-6 > 7 pg/mL, hints of possible inflammation or other infection; when 7-150 pg/mL, hints of mild inflammation or infection; and when 150-250 pg/mL, indications of a general bacterial infection or a general inflammation response.
Hepatin combined protein (HBP)
Hepatin combined protein (HBP) is an acute, reverse protein when the body activates the release of a neutral particle-occult acidic particles, which can increase significantly in inflammatory response between 1-2 hours and peaks in sepsis in 10 hours. HBP has a rapid diagnostic value at an early stage of acute bacterial infection, which is particularly important for assessing the severity of disease in sepsis patients and for early diagnosis and efficacy testing of sepsis patients. HBP 120 ng/mL suggests acute inflammation response, circulatory disorder or high probability of developing into anaesthesia, organ dysfunction, low blood pressure, shock within 72 hours.
In summary, the various infection indicators vary in their sensitivity and specificity in clinical practice and in their respective clinical significance. However, no single biomarker is absolutely sensitive and unique, and a disease cannot be diagnosed solely by a change in a biomarker. The correct diagnosis requires a combination of clinical performance, medical history and other laboratory findings. Through the rational use of these infection indicators, doctors can improve the diagnosis and treatment of infectious diseases by identifying the type of infection more accurately, assessing the severity of the infection, guiding treatment decisions and monitoring its effectiveness.
White cell anomaly.
