The EBV EliSpot (latent) measures how many of your T-cells release interferon-gamma when exposed to latent-phase Epstein–Barr virus (EBV) antigens—the proteins the virus expresses while lying dormant in cells. Results are given as a Stimulation Index (SI) that compares your immune response to a negative control. Reference ranges: 0–1 SI = negative, 2–3 SI = weak positive, >3 SI = positive. Because this assay reflects cellular immunity, it complements (but doesn’t replace) standard EBV antibody tests (VCA-IgM/IgG, EBNA-1 IgG, EA-IgG) and EBV DNA PCR (viral load). A positive latent EliSpot (>3 SI) indicates a clear T-cell response to latent EBV antigens. On its own, this shows that your immune system recognizes latent EBV strongly; in context—especially with symptoms such as prolonged fatigue, lymph node swelling, or post-infectious malaise—it may support the possibility of recent or ongoing immune engagement with EBV latency, but it does not prove active replication or disease by itself. Next steps typically include correlating with symptoms and exam, reviewing serology to help stage infection/reactivation, and ordering PCR if there’s concern for active replication or if results would change management. For monitoring, trends are more informative than a single value—many clinicians repeat testing in 4–6 weeks alongside symptom tracking. Factors that can influence EliSpot results include immunosuppressive medications, acute intercurrent illness, and sample handling. Always interpret using the performing lab’s reference ranges and your clinical context.
EBV EliSpot (latent)
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