7. Does Cutibacterium acnes (C. acnes, formerly Propionibacterium acnes) play a role in degenerative disc disease?

BACKGROUND CONTEXT

Degenerative disc disease (DDD) is a major burden to society, leading to disability and loss in productivity. In 2005, an estimated $86 billion was spent in the United States for management of neck and back problems. Recent evidence suggests that Cutibacterium acnes (C. acnes), an anaerobic bacterium, may latently reside in intervertebral discs (IVDs) and contribute to DDD.

PURPOSE

To determine the presence of C. acnes in IVD specimens and to correlate this with Pfirrmann grading on MRI.

STUDY DESIGN/SETTING

The intervertebral discs of 63 DDD patients and 5 control patients were collected prospectively.

PATIENT SAMPLE

Sixty-eight patients presenting to a single academic center for spine surgery were enrolled.

OUTCOME MEASURES

Pfirrmann grading, presence of C. acnes based on taxonomic identification.

METHODS

We collected human IVD specimens from surgical patients undergoing discectomy and interbody fusion from a single institution from 8/2019 to 9/2020. Disc degeneration was graded according to the 5-level Pfirrmann grading system on MRI imaging taken prior to surgery. IVD specimens from trauma patients (Pfirrmann grades I-II) were included in the control group, and IVD specimens were included in the degenerative group with Pfirrmann grades III-V. IVD specimens were processed for DNA extraction, and 16S rRNA libraries were constructed and analyzed for taxonomic data.

RESULTS

There were 63 patients included within the DDD group and 5 patients within the control group. Within the degenerative group, IVD specimens were taken from patients who had undergone spine surgery within the lumbar spine (n = 42; 66.7%), cervical spine (n = 19; 30.2%), and thoracic spine (n = 2; 3.2%). The average age of the DDD group was 54.3 ±13.9 years old, 57.1% (36/63) were male, and 85.7% (54/63) were Caucasian. A total of 31.7% (20/63) of DDD specimens were identified with the presence of C. acnes. There were 28.6% (12/42) of lumbar spine IVD specimens, 42.1% (8/19) of cervical spine IVD specimens, 0% (0/2) of thoracic spine IVD specimens that were identified with C. acnes. There was no difference in the presence of C. acnes when comparing the cervical, thoracic, and lumbar spine specimens (p = 0.36). When stratifying the DDD specimens by MRI Pfirmann grading, there were 31.3% (5/16) of specimens with a Pfirmann grade of 3, 31.3% (10/32) of specimens with a Pfirrmann grade of 4, and 33.3% (5/15) of specimens with a Pfirrmann grade of 5 that were identified with C. acnes. There was no difference in the presence of C. acnes when comparing the DDD specimens based on Pfirrmann grading (p = 0.99). There were 5 IVD specimens included within the control group with an average age of 39.8 ±20.5 years old, and 80% (4/5) were Caucasian males. The control group included IVD specimens taken from two lumbar and three cervical spine surgerie. Four of five (80%) of the specimens had a Pfirrmann grade of 2 on MRI, and 1/5 (20%) had a Pfirrmann grade of 1. No control specimens were identified with the presence of C. acnes.

CONCLUSIONS

Of the DDD specimines, 31.7% (20/63) were identified with the presence of C. acnes, while none of the specimens of the control group were identified with this bacterium. These results suggest that indolent C. acnes infection may be one of the factors contributing to degenerative disc disease.

FDA DEVICE/DRUG STATUS

This abstract does not discuss or include any applicable devices or drugs.