What is lymphocytic vasculitis?

Lymphocytic Vasculitis

Lymphocytic vasculitis is a form of vascular inflammation characterized by lymphocytic infiltration of blood vessel walls with evidence of vessel wall damage, which can lead to structural and functional impairment of affected vessels.

Definition and Pathology

Lymphocytic vasculitis is defined by:

• Predominant lymphocytic infiltrate involving and surrounding blood vessel walls 1
• Evidence of vessel wall damage, which may include:
  • Fibrin deposition within vessel walls
  • Endothelial cell hyperplasia
  • Lamination by pericytes 2

Unlike leukocytoclastic vasculitis (which is neutrophil-mediated), lymphocytic vasculitis involves T-cell mediated inflammation of blood vessels. The infiltrating lymphocytes are predominantly T cells, with CD4+ cells being dominant 3.

Classification

Lymphocytic vasculitis can be categorized based on:

1. Vessel size affected:

   • Small vessel lymphocytic vasculitis (most common)
   • Medium vessel lymphocytic vasculitis
   • Large vessel lymphocytic vasculitis (rare)

2. Morphological patterns:

   • Lymphocytic endovasculitis
   • Lymphocytic lichenoid vasculitis
   • Granulomatous vasculitis 1

3. Etiology:

   • Primary (idiopathic)
   • Secondary to underlying conditions

Clinical Presentations

Lymphocytic vasculitis can manifest as:

• Cutaneous manifestations:

  • Hemorrhagic acral livedo
  • Purpura
  • Skin ulcerations
  • Chronic urticaria 4, 5

• Systemic manifestations (when part of systemic vasculitis):

  • Neurological involvement (peripheral neuropathy, CNS vasculitis)
  • Renal involvement
  • Pulmonary involvement 6

Associated Conditions

Lymphocytic vasculitis can be associated with:

• Autoimmune diseases (early undifferentiated connective tissue disease, systemic lupus erythematosus) 4
• Drug reactions (most common identifiable cause) 5
• Livedoid vasculopathy (found in 38.3% of cases) 3
• Chronic urticaria 5
• Infections
• Malignancies

Diagnostic Approach

1. Histopathology (gold standard):

   • Skin or affected tissue biopsy showing:
     • Lymphocytic infiltration of vessel walls
     • Evidence of vessel wall damage
     • Endothelial cell hyperplasia
     • Fibrin deposition 2, 5

2. Laboratory studies:

   • Complete blood count
   • Erythrocyte sedimentation rate (ESR)
   • Autoantibody screening (ANA, ANCA, anti-RNP)
   • Complement levels (often normal) 5
   • Cryoglobulins (if cryoglobulinemic vasculitis suspected) 7

3. Imaging studies (for systemic involvement):

   • MRI (for CNS involvement)
   • Angiography (for larger vessel involvement) 6

Treatment

Treatment depends on the underlying cause and severity:

1. For primary lymphocytic vasculitis:

   • Mild cases: Topical or low-dose systemic corticosteroids
   • Moderate-severe cases: Higher-dose systemic corticosteroids plus immunosuppressants

2. For secondary lymphocytic vasculitis:

   • Treatment of underlying cause (e.g., discontinuation of offending drug)
   • For autoimmune-associated: Immunosuppressive therapy based on the specific condition
   • For HCV-associated cryoglobulinemic vasculitis: Antiviral therapy plus immunosuppression if severe 7

3. For severe or refractory cases:

   • Combination immunosuppressive therapy
   • Biological agents (e.g., rituximab for cryoglobulinemic vasculitis) 7, 6

Prognosis

The prognosis varies depending on:

• Underlying cause
• Extent of organ involvement
• Prompt diagnosis and treatment
• Response to therapy

Early diagnosis and appropriate treatment are essential to prevent irreversible organ damage and improve outcomes.

Key Distinctions

It's important to distinguish lymphocytic vasculitis from:

• Perivascular dermatitis (lacks vessel wall damage)
• Leukocytoclastic vasculitis (neutrophil-predominant)
• Non-vasculitic lymphocytic infiltrates

Some experts debate whether lymphocytic vasculitis represents a specific clinicopathologic entity or a reactive process secondary to severe lymphocytic inflammation 5. However, the presence of vessel wall damage with lymphocytic infiltration remains the key diagnostic feature.