What is the correlation between Tuberculosis (TB) and backache?

From the Guidelines

Tuberculosis (TB) can cause back pain when it affects the spine, a condition known as spinal TB or Pott's disease, and early diagnosis through imaging and tissue sampling is crucial for effective treatment and prevention of long-term spinal complications. The connection between TB and back pain exists because Mycobacterium tuberculosis can travel through the bloodstream from the lungs to the spine, particularly affecting the thoracic and lumbar regions, as noted in the 2015 IDSA clinical practice guidelines for the diagnosis and treatment of native vertebral osteomyelitis in adults 1.

Key Points to Consider

• The bacteria cause an inflammatory response that leads to bone destruction and potential vertebral collapse, resulting in pain and possible spinal deformity.
• Symptoms typically include persistent back pain, stiffness, and in severe cases, neurological complications like weakness or paralysis.
• Treatment requires a multi-drug regimen including isoniazid, rifampin, ethambutol, and pyrazinamide for at least 6-9 months, sometimes extending to 12 months for spinal TB, as per standard treatment protocols.
• Surgery may be necessary if there is significant bone destruction, spinal instability, or neurological compromise.
• MRI of the spine has a sensitivity of 97%, specificity of 93%, and an accuracy of 94% in diagnosing NVO, making it a crucial diagnostic tool 1.
• The 2021 ACR Appropriateness Criteria for suspected spine infection also emphasize the importance of imaging and clinical suspicion in diagnosing spine infections, including those caused by TB 1.

Diagnostic Approach

• Imaging studies, particularly MRI, are essential for diagnosing spinal TB and assessing the extent of infection.
• Laboratory parameters such as serum erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and white blood cell (WBC) count with differential can support the diagnosis.
• Spine biopsy with microbiologic and histopathologic analysis of the infected tissue may be required for diagnostic confirmation, especially when the imaging appearance overlaps with other noninfectious pathologic entities.

From the Research

Correlation between TB and Backache

• The correlation between TB and backache is primarily associated with tuberculous spondylitis (TS), a form of TB that affects the spine 2.
• TS is considered the most common and most dangerous form of TB infection, and delay in diagnosis and management can lead to spinal cord compression and spinal deformity 2.
• The most common clinical findings in TS patients include backache (98.5%), fever, spinal tenderness, paraparesis, and kyphosis 2.
• Laboratory results for TS patients often show elevated sedimentation rate (ESR) and positive CRP 2.
• Risk factors for TS include older age, male gender, chronic peritoneal dialysis, imprisonment, and previous TB infection 2.

Diagnosis and Treatment of TB

• The diagnosis of TB involves testing individuals at increased risk of latent TB infection (LTBI) with an interferon-gamma release assay or tuberculin skin testing 3.
• The treatment of drug-susceptible TB disease typically includes an eight-week intensive phase with four drugs (isoniazid, rifampin, pyrazinamide, and ethambutol), followed by a continuation phase lasting 18 weeks or more 3, 4.
• For patients with isoniazid-resistant tuberculosis, a regimen of isoniazid, rifampin, pyrazinamide, and ethambutol given daily for 6 months has been shown to produce successful outcomes 5.

Pharmacokinetics of TB Drugs

• The pharmacokinetics of rifampin, isoniazid, pyrazinamide, and ethambutol can vary significantly among patients, and several factors have been identified as determinants of this variation, including HIV infection, formulation factors, gender, age, and dose per kilogram of body weight 6.