Degenerative Disc Disease Risk and Management in Mixed Connective Tissue Disease

Pathophysiology of MCTD

Mixed connective tissue disease is an autoimmune disorder that primarily targets pulmonary parenchyma, with interstitial lung disease occurring in 40‑80 % of patients【@1】.
The disease does not involve intervertebral discs; disc degeneration proceeds via mechanical wear, aging, and metabolic factors that are unrelated to autoimmune inflammation【@1】.

Obesity increases mechanical load on lumbar discs, accelerating degenerative changes【@4】.
Smoking compromises microvascular supply to discs, impairing nutrition and promoting degeneration【@4】.
Sedentary lifestyle leads to weakened paraspinal musculature and reduced disc hydration, both of which predispose to disc degeneration【@5】.
Age‑related disc dehydration and loss of proteoglycans are universal aging processes that contribute to disc degeneration【@4】.

Mechanical low‑back pain from degenerative disc disease worsens with activity, improves with rest, and is not accompanied by systemic inflammatory signs【@2】.

Baseline high‑resolution chest CT (HRCT) and pulmonary function tests should be performed at MCTD diagnosis because interstitial lung disease is present in 40‑80 % of cases and often asymptomatic【@1】.
Mortality is 20.8 % in patients with severe pulmonary fibrosis versus 3.3 % in those with a normal HRCT, underscoring the importance of early pulmonary screening【@2】.
For patients with a systemic‑sclerosis phenotype, pulmonary function tests are recommended every 6 months and an annual HRCT for the first 3‑4 years【@2】.

Assessment of esophageal dysmotility is critical, as it predicts the risk of interstitial lung disease and aspiration pneumonitis【@2】.
Mycophenolate should be used as first‑line immunosuppressive therapy to prevent irreversible pulmonary fibrosis, rather than to treat degenerative spine disease【@2】.