Steroid-induced inflammatory neuropathy in a patient on tumor necrosis factor-α antagonist therapy

Guillain-Barré syndrome in association with antitumour necrosis factor therapy: a case of mistaken identity

Guillain-Barré syndrome (GBS) is an immune-mediated disease characterised by evolving ascending limb weakness, sensory loss and areflexia. Two-thirds of GBS cases are associated with preceding infection. However, GBS has also been described in association with antitumour necrosis factor (TNF) therapies including infliximab and adalimumab for chronic inflammatory disorders such as rheumatoid arthritis, ankylosing spondylitis and inflammatory bowel disease. We present the case of a patient who developed GBS while undergoing treatment with adalimumab in combination with azathioprine for severe fistulising Crohn's disease, and review the literature on neurological adverse events that occur in association with anti-TNF therapy. We also propose an approach to the optimal management of patients who develop debilitating neurological sequelae in the setting of anti-TNF therapy.

Non-length-dependent and length-dependent small-fiber neuropathies associated with tumor necrosis factor (TNF)-inhibitor therapy in patients with rheumatoid arthritis: expanding the spectrum of neurological disease associated with TNF-inhibitors

OBJECTIVE

Small-fiber neuropathy causes severe burning pain, requires diagnostic approaches such as skin biopsy, and encompasses two subtypes based on distribution of neuropathic pain. Such biopsy-proven subtypes of small-fiber neuropathies have not been previously described as complications of tumor necrosis factor (TNF)-inhibitor therapy.

METHODS

We therefore characterized clinical and skin biopsy findings in three rheumatoid arthritis (RA) patients who developed small-fiber neuropathies associated with TNF-inhibitors. We also conducted a systematic review of the literature to characterize subtypes of neuropathies previously reported in association with TNF-inhibitor therapy.

RESULTS

Two patients presented with a "non-length-dependent" small-fiber neuropathy, experiencing unorthodox patterns of burning pain affecting the face, torso, and proximal extremities. Abnormal skin biopsy findings were limited to the proximal thigh, which is a marker of proximal-most dorsal root ganglia degeneration. In contrast, one patient presented with a "length-dependent" small-fiber neuropathy, experiencing burning pain only in the feet. Abnormal skin biopsy findings were limited to the distal feet, which is a marker of distal-most axonal degeneration. One patient developed a small-fiber neuropathy in the context of TNF-inhibitor-induced lupus. In all patients, neuropathies occurred during TNF-inhibitor-induced remission of RA disease activity and improved on withdrawal of TNF-inhibitors.

CONCLUSIONS

We describe a spectrum of small-fiber neuropathies not previously reported in association with TNF-inhibitor therapy, with clinical and skin biopsy findings suggestive of dorsal root ganglia as well as axonal degeneration. The development of small-fiber neuropathies during inactive joint disease and improvement of neuropathic pain upon withdrawal of TNF-inhibitor suggest a causative role of TNF-inhibitors.