Differential Diagnosis
- Single most likely diagnosis
- Viral infection (e.g., EBV, CMV): The elevated absolute CD3+ and CD8+ counts, along with high immunoglobulin G levels, are consistent with a viral infection triggering an immune response. CD8+ cells are often elevated in response to viral infections.
- Other Likely diagnoses
- Chronic lymphocytic leukemia (CLL): Although CLL typically presents with an increase in CD19+ and CD5+ B cells, some cases can have elevated CD8+ counts. However, the immunoglobulin G level would need to be interpreted in the context of other clinical findings.
- Autoimmune disorders: Certain autoimmune diseases can lead to elevated immunoglobulin levels and alterations in T cell subsets, including CD3+ and CD8+ cells.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Lymphoma: Both Hodgkin and non-Hodgkin lymphoma can present with abnormal lymphocyte counts and immunoglobulin levels. Missing a diagnosis of lymphoma could have severe consequences.
- HIV infection: HIV can cause significant alterations in immune cell subsets, including CD3+, CD4+, and CD8+ T cells. Elevated immunoglobulin levels can also occur in the context of HIV infection.
- Rare diagnoses
- Immunodeficiency disorders: Certain immunodeficiency disorders, such as Wiskott-Aldrich syndrome or DiGeorge syndrome, can present with abnormal T cell subsets and immunoglobulin levels, although these conditions are rare.
- Castleman disease: This rare disorder can cause an increase in immunoglobulin levels and alterations in lymphocyte subsets, including CD3+ and CD8+ cells.