Predictive values of interleukin-2 and soluble interleukin 2 receptor in serum and cerebrospinal fluid for intracranial infection after craniotomy

Objective To evaluate the predictive values of interleukin (IL)-2 and soluble interleukin 2 receptor (sIL-2R) in the serum and cerebrospinal fluid in early intracranial infection, and provide the reference for choosing diagnostic markers of early intracranial infection after craniotomy. Methods From January 2014 to January 2016, 36 patients with intracranial infection after craniotomy in our hospital were chosen as infection group, and 45 patients without intracranial infection were as non-infection group. The body temperature and levels of cerebrospinal fluid glucose, blood white blood cell (WBC), cerebrospinal fluid WBC, serum IL-2, cerebrospinal fluid IL-2, serum sIL-2R and cerebrospinal fluid sIL-2R were compared between the two groups. The diagnosis values of IL-2 and sIL-2R in serum and cerebrospinal fluid in intracranial infection were analyzed by receiver operating characteristic curve (ROC) curve. The sensitivity and specificity of IL-2 and sIL-2R in the serum and cerebrospinal fluid in intracranial infection were compared between the two groups. Results The body temperature of the two groups showed no statistical difference (P>0.05). As compared with those in the non-infection group, the glucose of cerebrospinal fluid in the infection group significantly decreased (P<0.05), the blood WBC, cerebrospinal fluid WBC, serum IL-2, cerebrospinal fluid IL-2, serum sIL-2R and cerebrospinal fluid sIL-2R in the infection group significantly increased (P<0.05). The areas under of curve for body temperature, glucose of cerebrospinal fluid, blood WBC, cerebrospinal fluid WBC, serum IL-2, cerebrospinal fluid IL-2, serum sIL-2R and cerebrospinal fluid sIL-2R, respectively, were 0.671, 0.718, 0.698, 0.741, 0.714, 0.927, 0.722 and 0.968; the sensitivity of those indexes, respectively, was 61.1%, 63.9%, 69.4%, 91.7%, 88.9%, 91.7%, 86.1% and 94.4%; the specificity of those indexes, respectively, was 48.9%, 82.2%, 60.0%, 55.6%, 62.2%, 88.9%, 66.7% and 91.1%. Conclusion The IL-2 and sIL-2R levels in serum and cerebrospinal fluid have decided values in diagnosis of intracranial infection after craniotomy, but the sensitivity and specificity of IL-2 and sIL-2R in cerebrospinal fluid are higher than others. Key words: Interleukin-2; Solubility interleukin-2 receptor; Intracranial infection; Cerebrospinal fluid