Detection of Mycobacterium tuberculosis DNA in the sclerotic spinal wall.

Recent studies have shown that the major spinal lesion in spinal tuberculosis is predominantly sclerotic and accounts for >70% of the lesion. In this type of sclerosis, apart from spinal reactive hyperplasia and increased bone density, the most severe lesion is the formation of a hard outer osteoid shell (the sclerotic wall) around the cheese-like substances and granulated tissues. In the current study, polymerase chain reaction detection of Mycobacterium tuberculosis in the sclerotic wall was performed. Surgical specimens were obtained from 18 patients with spinal tuberculosis with peripheral sclerotic wall (as shown by computed tomography) and included the sclerotic wall, subnormal bone tissue outside the sclerotic wall, and iliac bone tissue (control). The IS986 gene in the samples was amplified by polymerase chain reaction followed by DNA sequencing. The obtained sequences were then compared with the published sequences in GenBank using DNATools version 5.1 software (International Centre for Genetic Engineering and Biotechnology, Trieste, Italy). The polymerase chain reaction results showed that 16 specimens from the sclerotic spinal wall, 3 from the subnormal bone, and 0 from the controls were positive for M tuberculosis, indicating a statistically significant difference (P<.05). These results indicated that M tuberculosis was present in the spinal sclerotic wall. Combined with our previous studies, we conclude that the sclerotic wall should be considered a lesion in patients with spinal tuberculosis.