OBJECTIVE To explore the Toll-like receptor 9 (TLR9) gene polymorphisms and changes of NSE and HBP in the craniocerebral trauma children with postoperative intracranial infection.

METHODS A total of 86 craniocerebral trauma children with postoperative intracranial infection who were treated in Ningbo Women′s and Children′s Hospital from Sep. 2020 to Sep. 2023 were assigned as the study group and were divided into the bacterial infection group with 32 cases and the viral infection group with 54 cases. Totally 101 craniocerebral trauma children who did not have postoperative infection were chosen as the control group. The TLR9 gene polymorphisms were compared between the study group and the control group. The levels of serum C-reactive protein (CRP), cerebrospinal fluid lactic acid (LA), lactic dehydrogenase (LDH), neuron specific enolase (NSE) and heparin binding protein (HBP) were observed and compared between the study group and the control group as well as between the bacterial infection group and the viral infection group. The diagnostic values of the five indexes were analyzed.

RESULTS The frequencies of TLR9 genotype GG and allele G of the study group were lower than those of the control group (P < 0.05); the frequencies of genotype AA and allele A of the study group were higher than those of the control group(P < 0.05). The levels of serum CRP, cerebrospinal fluid LA, LDH, NSE and HBP of the study group were higher than those of the control group(P < 0.05), the levels of serum CRP, cerebrospinal fluid LA, LDH and HBP of the bacterial infection group were higher than those of the viral infection group (P < 0.05), and the NSE level of the bacterial infection group was lower than those of the viral infection group(P < 0.05). The area under the curve (AUC) of the joint detection of the five indexes was higher than that of the single detection in diagnosis of postoperative intracranial infection in the craniocerebral trauma children (P < 0.05).

CONCLUSIONS The incidence of postoperative intracranial infection in the craniocerebral trauma children is associated with the TLR9 gene polymorphisms. The craniocerebral trauma children with postoperative intracranial bacterial infection show the high expressions of CRP, LA, LDH, NSE and HBP but the low expression of NSE. The joint detection of the five indexes has high value in diagnosis of the postoperative intracranial infection in the craniocerebral trauma patients.