Department of Neurosurgery, North Estonian Medical Centre, J. Sütiste tee 19, Tallinn, 13419, Estonia.
Department of Anatomy, Institute of Biomedicine and Translational Medicine, University of Tartu, Ravila 19, Tartu, 50411, Estonia.
BMC Musculoskelet Disord. 2024 Nov 6;25(1):882. doi: 10.1186/s12891-024-07996-9.
Intervertebral disc (IVD) degeneration (IVDD) is one of the main causes of low back pain. One of the most important features of IVDD is the loss of extracellular matrix (ECM) with its structural components. Cartilage intermediate layer proteins (CILPs), minor glycoproteins residing in ECM, have been found to be increased in IVD as degeneration and aging progresses. The aim of the present study was to evaluate the expression of CILP-2 in the IVD of patients with lumbar radiculopathy.
The IVD samples were collected from 25 patients during spinal surgery (interlaminectomy, herniated disc removal). The control IVD samples were obtained from nine patients who underwent lateral corpectomies in the thoracic region. CILP-2 expression was detected by immunohistochemistry. The patients were divided into two groups - aged under or over 50 years. A standardized clinical examination with assessment of radicular signs and deficits was performed. Subjective disability and pain were assessed using the visual analogue scale and Oswestry Disability Index (ODI). The pre-operative MRI was graded for the degree of IVD degeneration by Pfirrmann grading system. IVD samples obtained during operations were subjected to the standardized histopathological analysis applying modified Boos classification. The data were analysed by t-test, Mann-Whitney U-test, and Spearman correlation test.
Both histopathology scores and Pfirrmann grades did not differ between patients' groups. Also, no correlations were found between histopathology and Pfirrmann grades, neither were any differences seen when correlating both grades to ODI, back pain or leg pain scores. CILP-2 staining was noted in all studied samples, notably strong staining was seen around large cell clusters. However, no differences in CILP-2 staining were seen between the age groups of patients. No correlations were found between CILP-2 staining and Pfirrmann grades. Grading of CILP-2 immunostaining in nine control patient samples resulted in significantly lower values. The difference is statistically significant (P = 0.002) compared to CILP-2 staining scores of all 25 patients' samples.
In this study, we detected increased CILP-2 expression in the human IVD as compared to the control group patients. CILP-2 can be a possible IVDD marker; however, as knowledge about the role of CILP-2 is limited, further studies are required.
椎间盘（IVD）退变（IVDD）是腰痛的主要原因之一。IVDD 的一个最重要特征是细胞外基质（ECM）及其结构成分的丢失。软骨中层蛋白（CILP）是 ECM 中存在的一种次要糖蛋白，随着退变和老化的进展，发现其在 IVD 中增加。本研究的目的是评估软骨中层蛋白 2（CILP-2）在腰椎神经根病患者的 IVD 中的表达。
在脊柱手术（椎板切除术、椎间盘切除术）期间从 25 名患者中收集 IVD 样本。对照组 IVD 样本取自 9 名在胸区行侧方椎体切除术的患者。通过免疫组织化学检测 CILP-2 表达。将患者分为年龄小于或大于 50 岁的两组。对有神经根体征和缺损的患者进行标准化的临床检查。使用视觉模拟量表和 Oswestry 残疾指数（ODI）评估主观残疾和疼痛。术前 MRI 采用 Pfirrmann 分级系统对 IVD 退变程度进行分级。手术中获得的 IVD 样本进行标准化的组织病理学分析，采用改良 Boos 分类法。采用 t 检验、Mann-Whitney U 检验和 Spearman 相关检验对数据进行分析。
两组患者的组织病理学评分和 Pfirrmann 分级均无差异。此外，组织病理学和 Pfirrmann 分级之间没有相关性，也没有观察到这两种分级与 ODI、腰痛或腿痛评分之间的差异。在所有研究样本中均观察到 CILP-2 染色，特别是在大细胞簇周围观察到强烈染色。然而，在患者年龄组之间，CILP-2 染色没有差异。CILP-2 染色与 Pfirrmann 分级之间也没有相关性。对 9 名对照组患者样本的 CILP-2 免疫染色分级结果表明，评分明显较低。与所有 25 名患者样本的 CILP-2 染色评分相比，差异具有统计学意义（P=0.002）。
在这项研究中，与对照组患者相比，我们在人 IVD 中检测到 CILP-2 表达增加。CILP-2 可能是 IVDD 的一个标志物；然而，由于对 CILP-2 作用的了解有限，还需要进一步的研究。
