Serum Procalcitonin and sCD14-ST useful diagnostic markers for postoperative spinal infection

Identifying biomarkers for early diagnosis of postoperative spinal infection is essential to avoid complications after spine surgery. The study by Zhu et al evaluated serum levels of procalcitonin (PCT), C-reactive protein (CRP), and soluble CD14 subtype (sCD14-ST) in patients who underwent spinal surgery to assess the diagnostic values of PCT and sCD14-ST.

PCT is the peptide precursor of calcitonin, a hormone that is synthesized by the parafollicular C cells of the thyroid and is involved in calcium homeostasis. PCT has higher specificity than conventional markers of inflammation for indicating postoperative infection.

Soluble CD14 subtype (sCD14-ST) is the soluble form of a glycoprotein expressed on the surface membranes of monocytes and macrophages. sCD14-ST is released into the circulation through proteolytic cleavage on stimulated monocytes upon a pro-inflammatory signal against infectious agents. It increases in response to a variety of microbial infections and inflammation. Moreover, serum levels of sCD14-ST are highly correlated to a variety of bacterial infections, including infections after trauma and invasive surgical procedures.

Serum levels of PCT, CRP, and sCD14-ST were measured in 490 (289 male/201 female) patients who underwent spinal surgery (SS) before and 1 day after surgery. PCT and sCD14-ST levels of patients diagnosed with postoperative infection (PI) and patients diagnosed with postoperative non-infection (PN) were compared.

The observations of the study were:

• Serum levels of PCT, CRP, and sCD14-ST were significantly increased after surgery (F=58.393, P=0.000).

• In patients diagnosed as having a PI, serum levels of PCT and sCD14-ST were positively correlated with each other (r=0.90, P< 0.01) and with operation duration (r=0.92, 0.88, P< 0.01).• Receiver operating characteristic (ROC) models showed that both PCT (AUC=0.817, optimal cutoff: 0.69 ng/ml, P=0.000) and sCD14-ST (AUC=0.824, optimal cutoff: 258.27 pg/ml, P=0.000) can distinguish PI versus PN patients well.

The authors concluded that - "the serum levels of PCT and sCD14-ST could be used as sensitive and specific diagnostic biomarkers for postoperative infection after spine surgery, providing new ideas for diagnosing infection at an early stage."

Further reading:

Usage of procalcitonin and sCD14-ST as diagnostic markers for postoperative spinal infection

Xi Zhu, Kaige Li et al

Journal of Orthopaedics and Traumatology (2022) 23:25

https://doi.org/10.1186/s10195-022-00644-9