CHANGES IN SERUM SAA, STROM-1, VCAM-1 AND D-DIMER LEVELS IN PATIENTS WITH SEVERE PNEUMONIA AND THEIR CORRELATIONS WITH THE SEVERITY OF THE DISEASE

Objective: To analyse the changes of serum amyloid A (SAA), soluble intercellular adhesion molecule-1 (strom-1), vascular cell-adhesion molecule-1 (VCAM-1) and D-dimer levels in patients with severe pneumonia and their correlations with the severity of the disease. Methods: A total of 126 patients with pneumonia admitted to our hospital from April 2018 to January 2020 were selected as the research objects. According to the severity of the patients' conditions, they were divided into the severe group (55 cases) or the mild -to-moderate group (71 cases). According to the Apache II score, they were divided into the low-risk group (36 cases), medium-risk group (53 cases) or high-risk group (37 cases). Serum SAA, strom-1 and VCAM-1 water were detected by ELISA. The level of D-dimer in patients was measured by automatic coagulator, and the ROC curve was used to analyse the clinical value of each index in the diagnosis of severe pneumonia. Results: The serum levels of SAA, strom-1, VCAM-1 and D-dimer were significantly higher in the severe group and the mild-to -moderate group than in the control group (P<0.05). The serum levels of SAA, strom-1, VCAM-1 and D-dimer were significantly higher in the severe group than in the mild-to-moderate group (P<0.05). The serum levels of SAA, strom-1, VCAM-1 and D-dimer in the high -risk and middle-risk groups were significantly higher than those in the low-risk group (P<0.05), and the serum levels of SAA, strom-1, VCAM-1 and D-dimer in the high-risk group were significantly higher than those in the middle-risk group (P<0.05). The levels of SAA, strom-1, VCAM-1 and D-dimer in patients with bacterial and mycoplasma pneumonia were significantly higher than those in the group with viral pneumonia (P<0.05). The levels of SAA, strom-1, VCAM-1 and D-dimer in patients with bacterial pneumonia were significantly higher than those in the group with mycoplasma pneumonia (P<0.05). The results of the ROC-curve analysis showed that the areas under the curve (AUC) of SAA, strom-1, VCAM-1 and D-dimer were 0.808, 0.871, 0.842 and 0.891, respectively, which could be used as biomarkers for the diagnosis of severe pneumonia. Conclusion: SAA, strom-1, VCAM-1 and D-dimer are highly expressed in the sera of patients with severe pneumonia, and they are of great significance to distinguish patients with pneumonia of different severity and bacterial infection, which is helpful for the clinical diagnosis of severe pneumonia and can be used as an important clinical-observation index.