Proliferating cell nuclear antigen in hypertrophied spinal ligaments. Immunohistochemical localization of proliferating cell nuclear antigen in hypertrophied posterior longitudinal ligament of the cervical spine.
METHODS
An experimental immunohistochemical investigation using an antibody for proliferating cell nuclear antigen. Surgically-extirpated specimens of posterior longitudinal ligament tissues from patients with hypertrophy of the posterior longitudinal ligament and other disorders of the cervical spine were analyzed.


OBJECTIVE
To analyze the developmental mechanism of hypertrophy of the posterior longitudinal ligament, the authors evaluated the growth activity of cells in the posterior longitudinal ligament tissues by examining the immunolocalization of the proliferating cell nuclear antigen.


BACKGROUND
Although a number of cases of hypertrophy of the posterior longitudinal ligament have been reported, the pathophysiology of ligament hypertrophy is still unclear. It is well established that the proliferating cell nuclear antigen is a cell proliferation marker, and immunohistochemical analysis using an anti-proliferating cell nuclear antigen antibody is of value in assessing the cell growth activity of several tissues.


METHODS
During anterior decompression surgery in the cervical spine, the authors extirpated posterior longitudinal ligament tissues in one piece from patients with hypertrophy of the posterior longitudinal ligament, ossification of the posterior longitudinal ligament, cervical disc herniation, and cervical spondylotic myelopathy. Midsagittal sections of the specimens were stained with an antibody against the proliferating cell nuclear antigen.


RESULTS
In cases of hypertrophy of the posterior longitudinal ligament, immunostaining with the proliferating cell nuclear antigen was detected in cells in the posterior longitudinal ligament, not only at the vertebral endplate level, but also at the midvertebral level. A similar distribution of proliferating cell nuclear antigen-positive cells was observed in cases of ossification of the posterior longitudinal ligament. In cases of cervical disc herniation, however, proliferating cell nuclear antigen-positive cells in posterior longitudinal ligament tissues were restricted to the vertebral endplate level. No immunostaining with the proliferating cell nuclear antigen was seen in posterior longitudinal ligament tissues in cases of cervical spondylotic myelopathy.


CONCLUSIONS
Cell growth activity was accelerated in posterior longitudinal ligament tissues in cases of hypertrophy of the posterior longitudinal ligament; such an unusual phenotype of posterior longitudinal ligament cells was also expressed in cases of ossification of cervical disc herniation and cervical spondylotic myelopathy. Therefore, up-regulation of the growth of posterior longitudinal ligament cells may contribute to the development of hypertrophy of the posterior longitudinal ligament, and some common regulatory mechanism(s) on the proliferation of posterior longitudinal ligament cells seem to underlie the development of hypertrophy of the posterior longitudinal ligament and ossification of the posterior longitudinal ligament.
Motegi
H
H
Department of Orthopaedic Surgery, School of Medicine, Chiba University, Japan.
Yamazaki
M
M
Goto
S
S
Mikata
A
A
Moriya
H
H
D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D006984:Hypertrophy / Q000473:pathology; D007150:Immunohistochemistry; D007405:Intervertebral Disc Displacement / Q000473:pathology; D017846:Longitudinal Ligaments / Q000378:metabolism* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009192:Myelography; D017887:Ossification of Posterior Longitudinal Ligament / Q000473:pathology; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism*; D013117:Spinal Cord Compression / Q000473:pathology; D013128:Spinal Osteophytosis / Q000473:pathology; D014057:Tomography, X-Ray Computed
D018809:Proliferating Cell Nuclear Antigen