Is the pathophysiology and treatment of Chronic Inflammatory Demyelinating Polyneuropathy (CIPD) characterized by immune-mediated demyelination, remyelination by Schwann cells, and autoantibodies against components of the nodes of Ranvier, with treatment options including corticosteroids, Intravenous Immunoglobulin (IVIG), and immunosuppressive drugs?

Pathophysiology of Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

Yes, your description of CIDP pathophysiology is correct. CIDP involves macrophage-mediated myelin destruction, Schwann cell remyelination leading to onion bulb formation, and autoantibody-mediated disruption of nodal/paranodal proteins causing abnormal nerve conduction.

Pathophysiological Mechanisms

• CIDP is an immune-mediated peripheral neuropathy characterized by inflammatory demyelination that manifests as slowed conduction velocities, temporal dispersion, and conduction block on nerve conduction studies 1

• The primary pathological process involves macrophages phagocytosing myelin sheaths, leading to demyelination of peripheral nerves 1

• Following demyelination, Schwann cells attempt remyelination, which over time leads to characteristic onion bulb formation visible on nerve biopsies 1

• Autoantibodies target nodal and paranodal proteins, causing detachment of myelin sheaths around the nodes of Ranvier, resulting in abnormal nerve conduction 2, 1

Clinical Presentation

• CIDP typically presents as a symmetrical, motor-predominant peripheral neuropathy with both distal and proximal weakness 1

• Large-fiber abnormalities (weakness and ataxia) predominate, while small-fiber abnormalities (autonomic dysfunction and pain) are less common 1

• The disease can present in various subtypes, with classical symmetrical polyradiculoneuropathy being most common, followed by localized asymmetrical forms (multifocal CIDP) 1

Diagnostic Features

• Nerve conduction studies show demyelinating features including slowed conduction velocities, prolonged distal latencies, conduction block, and temporal dispersion 1

• Cerebrospinal fluid typically shows elevated protein levels, though this finding is not specific to CIDP 1

• Nerve biopsies may reveal segmental demyelination, onion-bulb formations, and endoneurial inflammatory infiltrates 1

Treatment Options

• Three well-established first-line treatments for CIDP are available:

  1. Intravenous immunoglobulin (IVIG) - most commonly used as first-line therapy 1, 3
  2. Corticosteroids - effective for both induction and maintenance therapy 1, 4
  3. Plasma exchange (plasmapheresis) - effective particularly as induction treatment 1, 4

• Treatment response rates with conventional first-line immunotherapies are approximately 77%, with comparable efficacy between IVIG and corticosteroids 5

• For maintenance therapy, both intravenous and subcutaneous immunoglobulin infusions have been introduced 3, 4

• Immunosuppressants such as azathioprine, mycophenolate mofetil, and methotrexate are commonly used as steroid-sparing agents or for additional immunosuppression in refractory cases 5

• Treatment response should be judged by objective measures, including improvement in neurological examination or electrophysiological parameters 1

Treatment Challenges and Considerations

• Non-responders to first-line therapy are often patients with progressive forms of typical CIDP or those with distal acquired demyelinating symmetric neuropathy (DADS) 5

• Approximately 81% of patients with persistent neurological deficits require maintenance therapy 5

• Some patients (approximately 14%) may eventually achieve cure or clinical remission without ongoing treatment 5

• Treatment needs to be individualized based on disease subtype, progression pattern, and response to initial therapy 1