Serum cytokines, a diagnostic tool for herniated lumbar disc type

Abstract

Inflammatory mediators such as cytokines have been suggested to be important in the pathophysiology of disc herniation. However, few studies have been ever conducted for evaluating the serum levels of these cytokines. This study aimed at assessing the agreement of serum and operation-field cytokines in diagnosis of herniated lumbar disc type. In this study, 43 patients with lumbar disc herniation were recruited in Tabriz Imam Reza Hospital during a 12-month period. According to the type of herniation, the patients were categorized in two groups: with excursion or sequestration (group A) and with bulging (group B) of disc, with 22 and 21 cases, respectively. The level of interleukin (IL)-1α, IL-6 and tumor necrosis factor (TNF)-α was determined in nucleus pulposus (NP) and serum of the patients by employing enzyme-linked immunosorbent assay (ELISA) method. Agreement rate between the two readings was determined. There was full agreement between the serum and NP readings for all the studied parameters. The optimal cut-off points for serum IL-1α, IL-6 and TNFα were ≤0.25, ≤0.05 and ≤0.7 pg/ml, respectively, for discrimination between the extrusion and bulging discs. Serum levels of IL-1α, IL-6 and TNFα may be applicable for preoperative diagnosis of the type of the herniated lumbar disc, especially TNFα, and IL-6 parameters which have a high sensitivity and specificity for differentiation between bulging and extrusion or sequestration discus.

Key words: Intervertebral disk displacement, IL-1α, IL-6, TNFα, serum.