OBJECTIVE To explore the expressions of calcitonin gene-related peptide (CGRP), thrombomodulin(TM), programmed cell death receptor (PD)-ligand 1 (L1) and PD-1 in the peripheral blood of the breast cancer patients with venous access port-catheter-associated bloodstream infection and analyze the significance.

METHODS Totally 101 breast cancer patients with venous access port-catheter-associated bloodstream infection who were treated in Shengjing Hospital of China Medical University from Feb. 2021 to Feb. 2023 were assigned as the infection group and were divided into the mild group with 29 cases, the moderate group with 33 cases and the severe group with 39 cases. Meanwhile, 103 breast cancer patients who did not have venous access port-catheter-associated bloodstream infection were chosen as the non-infection group. The distribution of pathogens isolated from the infection group was statistically analyzed. The levels of CGRP, TM, PD-L1 and PD-1 were compared among the groups. The values of the four indexes in diagnosis of the venous access port-catheter-associated infection and the association with the infection were observed.

RESULTS Totally 113 strains of pathogens were isolated from the 101 patients of the infection group, among which gram-negative bacteria were dominant. The levels of CGRP and PD-L1 of the infection group were lower than those of the non-infection group, while the levels of TM and PD-1 of the infection group were higher than those of the non-infection group(P < 0.05). The levels of CGRP and PD-L1 of the moderate group and the severe group were lower than those of the mild group, while the levels of TM and PD-1 of the moderate group and the severe group were higher than those of the mild group; the levels of the above indexes of the severe group were higher than those of the moderate group(P < 0.05). The CGRP and PD-L1 were negatively associated with the severity of venous access port-catheter-associated bloodstream infection(P < 0.05), while the TM and PD-1 were positively correlated with the infection(P < 0.05). The area under curve (AUC) of the joint detection of CGRP, TM, PD-L1 and PD-1 was higher than that of the single detection in diagnosis of the venous access port-catheter-associated bloodstream infection (P < 0.05).

CONCLUSIONS The gram-negative bacteria are dominant among the pathogens isolated form the breast cancer patients with venous access port-catheter-associated bloodstream infection. The abnormal expressions of CGRP, TM, PD-L1 and PD-1 are associated with the severity of infection. The joint detection of the four indexes may raise the diagnostic value.