Chronic Active Epstein‑Barr Virus Infection (CAEBV): Evidence‑Based Diagnostic and Management Guidelines

1. Serologic Indicators of Ongoing EBV Replication

• Very high VCA IgG (≥ 1:640) and EA‑D IgG (≥ 1:160) constitute the hallmark antibody pattern that signals active EBV replication rather than latent infection. 1, 2
• The triad of markedly elevated VCA IgG, EA‑D IgG, and positive EBNA‑1 IgG reflects chronic active viral replication with persistent immune stimulation. 3

2. Clinical Presentation Supporting CAEBV Diagnosis

• Persistent infectious‑mononucleosis‑like symptoms—fever, fatigue, cervical lymphadenopathy, and ocular injection—are classic manifestations of CAEBV. 2, 3
• Chronic urticaria/hives is a recognized cutaneous manifestation of CAEBV and may indicate underlying T‑cell or NK‑cell lymphoproliferative disease. 2, 3

3. Routine Laboratory Findings and Their Limitations

• Normal complete blood count and liver‑function tests do not exclude CAEBV; many patients retain normal hematologic parameters early, but the presence of thrombocytopenia or cytopenias predicts a poorer prognosis. 4

4. Definitive Virologic Confirmation

• Quantitative EBV PCR on peripheral‑blood mononuclear cells is the gold‑standard confirmatory test; viral loads > 10^2.5 copies/mg DNA confirm CAEBV. 5, 2
• EBV PCR is regarded as the single most important confirmatory assay for CAEBV. 3

5. Immunophenotypic and Flow‑Cytometry Evaluation

• Flow cytometry of peripheral blood identifies the infected cell lineage (T‑cells, NK‑cells, or B‑cells) and detects:
  • Increased large granular lymphocytes (CD16⁺, CD56⁺, HLA‑DR⁺). 5
  • Activated T‑cells (CD4⁺ or CD8⁺ with HLA‑DR expression). 5
• Immunophenotyping with HLA‑DR markers further characterises the activated immune response. 1, 2

6. Ancillary Serologic Support

• EBV VCA IgA and EA IgA antibodies are frequently positive in CAEBV and provide additional diagnostic support. 5, 3

7. Screening for Life‑Threatening Complications

• Laboratory panels including ferritin, triglycerides, fibrinogen, and soluble IL‑2 receptor should be obtained to screen for hemophagocytic lymphohistiocytosis (HLH), a known complication of CAEBV. 4, 2
• CAEBV carries a risk of progression to T‑cell or NK‑cell lymphoproliferative disorders/lymphomas. 4, 5
• HLH can develop during the disease course and requires early detection. 2, 3
• Cardiovascular complications, including coronary artery aneurysms, have been reported in CAEBV patients. 2, 3

8. Tissue Diagnosis When Lymphadenopathy Persists

• Excisional lymph‑node biopsy with:
  • EBER in‑situ hybridisation,
  • Immunohistochemistry for EBNA and LMP,
  • T‑cell receptor and immunoglobulin gene‑rearrangement studies
    provides definitive histopathologic confirmation and helps identify clonal lymphoproliferation. 1, 2

9. Management Implications of Cutaneous Findings

• Chronic urticaria in CAEBV is not a simple allergic process; it may represent direct EBV‑related cutaneous involvement, a systemic inflammatory response to ongoing viral replication, or be linked to granular lymphocyte proliferation. 2, 3, 4
• Treating the urticaria in isolation, without addressing the underlying CAEBV, will not resolve the systemic disease. 2

All statements are derived from peer‑reviewed evidence cited above.