Phospholipase A2 in Herniated Lumbar Discs: Its Relevance to Pain / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: A prospective study. OBJECTIVE: To determine whether phospholipase A2(PLA2) activity in herniated lumbar disc is correlated with clinical, radiographic and anatomic signs of the patients with herniated nucleus pulposus. SUMMARY OF LITERATURE REVIEW Several studies have suggested inflammation around nerve root as a mechanism of sciatica and PLA2 emerges as a key enzyme of the inflammation. However, consensus about association between PLA2 and sciatica has been lacking. In addition, there has been no report that investigated the relationship between cytosolic and membrane PLA2 in herniated disc and patient's symptoms. MATERIALS AND METHODS: Human intervertebral disc materials were obtained from 33 patients who underwent discectomy for HNP. The information was noted about smoking history, medication of NSAID, symptom duration, pain score on a visual analog scale(VAS), positive angle of straight leg raising test (SLR), neurologic deficits, Thompson grade of herniated disc, volume of herniation shown by the MRI and type of herniation based on the operative record. These data were matched to the PLA2 a ctivity in herniated disc measured using Western blotting analysis. PLA2 activity was expressed as the relative percentage compared to that of a 33-year-old female disc obtained during an operation for spinal fracture. The analysis was carried out using Mann-Whitney test, Pearson correlation analysis, simple linear regression analysis. A value of p<0.05 was considered significant. RESULTS: Cytosolic and membrane PLA2 activity showed no statistical relationship to clinical, radiographic and anatomic characteristics of herniated disc. However, membrane PLA2(active form) activity was correlated with the pain score on VAS(p=0.013, r=0.481), while cytosolic PLA2(latent form) showed no statistically significant correlation with the pain score. CONCLUSION: This study demonstrates that membrane PLA2 activity is correlated with the pain score. It also suggests that selective PLA2 inhibitors could be used for the alternative treatment modality of HNP.