Interleukin-6 and ACE in the long-term cytokine response: possible causes of neuropathic pain, high blood pressure and tachycardia

Many people with acute sarcoidosis experience chest or joint pain, raised blood pressure or a change in heart rhythm. This article discusses two factors that may be associated with these symptoms: interleukin-6 (IL-6) and angiotensin-converting enzyme (ACE).

1. Interleukin-6 (IL-6)
IL-6 is a cytokine that can act both as a pro-inflammatory cytokine and as an anti-inflammatory myokine. When pathogens enter the body, macrophages release IL-6, which supports the production of neutrophils and the growth of lymphocytes involved in the immune response. IL-6 can also influence the hypothalamus and raise body temperature.

IL-6 participates in inflammatory and autoimmune processes, including sarcoidosis. An incorrectly presented antigen may lead to excessive IL-6 production and contribute to the acute phase of the disease. Stress, disrupted sleep and hormonal changes may also influence this pathway. C-reactive protein (CRP), a standard clinical marker of inflammation, can be produced in response to IL-6.

Persistently high IL-6 levels may affect the nervous system. Neuroinflammation is considered an important mechanism in pathological pain, and studies have found increased IL-6 and IL-6-receptor expression in the spinal cord and dorsal-root ganglia. Research suggests that IL-6 inhibitors may reduce some forms of pathological pain, but treatment decisions belong to a specialist.

2. Angiotensin-converting enzyme (ACE)
ACE is part of the renin–angiotensin system, which helps regulate blood pressure and body-fluid volume. It converts angiotensin I into the active vasoconstrictor angiotensin II. ACE is produced in several tissues and may also be produced by epithelioid cells derived from activated macrophages in sarcoid granulomas.

Serum ACE can correlate with granuloma burden in some people with sarcoidosis, but ACE is not diagnostic on its own. A raised result must be interpreted with symptoms, imaging and other tests; a normal result does not exclude sarcoidosis. Long-term multi-organ inflammation can contribute to arthritis, neuropathy or cardiac problems, so timely medical assessment and follow-up are important.

This information is educational and does not replace a medical examination or medical advice.

Dino-Josip Ključarić