Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is an autoimmune disorder that causes progressive weakness and sensory loss in the arms and legs. It is the chronic counterpart of Guillain-Barré syndrome and is characterized by immune-mediated demyelination of peripheral nerves. CIDP represents the most common chronic autoimmune neuropathy worldwide.
- Prevalence: 1-2 per 100,000 population
- Age of onset: Can occur at any age, most commonly in adults aged 40-60
- Gender distribution: Slight male predominance (M:F = 1.5:1)
- Course: Variable—some patients have monophasic illness, others have relapsing-remitting or progressive pattern
CIDP is characterized by immune-mediated damage to the myelin sheath of peripheral nerves. The exact trigger is unknown, but the disease involves both cellular and humoral immune responses:
- T-cell mediated damage: Autoreactive T-cells target myelin proteins
- Macrophage-mediated demyelination: Activated macrophages attack myelin
- Antibody-mediated injury: Autoantibodies target myelin proteins and lipids
In some cases, CIDP may be associated with other conditions:
- Diabetes mellitus
- HIV infection
- Monoclonal gammopathy (MGUS)
- Lymphoma
- Systemic lupus erythematosus
- Progressive weakness: Arms and legs, typically symmetric
- Sensory loss: Numbness, particularly in hands and feet
- Loss of deep tendon reflexes: Diminished or absent
- Difficulty walking: Gait disturbance
- Fatigue: Generalized fatigue
- Pain: Particularly in back and legs
- Balance problems: Due to sensory and motor impairment
- Typical CIDP: Classic presentation with symmetric proximal and distal weakness
- Atypical CIDP: Includes pure sensory, pure motor, or focal variants
- MADSAM: Multifocal acquired demyelinating sensory and motor neuropathy (Lewis-Sumner syndrome)
Diagnosis is based on a combination of:
- Clinical presentation: Progressive,relatively symmetric motor and sensory neuropathy
- Nerve conduction studies: Showing demyelination (temporal dispersion, conduction block, slowed velocities)
- Cerebrospinal fluid analysis: Elevated protein with normal cell count (albuminocytologic dissociation)
- Nerve biopsy: May be performed in atypical cases
- Neurological examination: Assess strength, sensation, reflexes
- Nerve conduction studies/EMG: Confirm demyelination
- Lumbar puncture: CSF protein elevation
- Blood tests: Rule out associated conditions
- Nerve biopsy: In selected cases
CIDP must be distinguished from:
- Guillain-Barré syndrome (acute inflammatory demyelinating polyradiculoneuropathy)
- Multifocal motor neuropathy
- Charcot-Marie-Tooth Disease (hereditary)
- Diabetic neuropathy
- Vasculitic neuropathy
- Corticosteroids (prednisone): Effective but significant long-term side effects
- Intravenous immunoglobulin (IVIG): Often preferred due to rapid onset and favorable side effect profile
- Plasma exchange (plasmapheresis): Used in severe or refractory cases
¶ Second-Line and Adjunctive Therapies
- Immunosuppressive agents: Azathioprine, mycophenolate, cyclophosphamide, rituximab
- Subcutaneous immunoglobulin: Alternative for maintenance therapy
- IVIG: Response in 50-70% of patients; effects typically last weeks to months
- Corticosteroids: Effective in many patients; require maintenance therapy
- Plasma exchange: Particularly useful for acute exacerbations
The prognosis for CIDP varies significantly among patients:
- Monophasic course: Some individuals experience complete recovery
- Relapsing-remitting pattern: Periodic treatments needed
- Progressive course: Gradual worsening despite treatment
Factors associated with better outcomes:
- Early diagnosis and treatment
- Fewer relapses
- Younger age at onset
- Absence of underlying disease
Current research focuses on:
- Biomarkers for treatment response: Identifying predictors of therapeutic benefit
- Underlying autoimmune mechanisms: Understanding the exact pathophysiology
- Novel therapies: Investigating targeted immunosuppressive agents
- Stem cell therapy: Exploring regenerative approaches
- Gene therapy: Potential future treatments