T + B-Lymphocyte Differential

This test measures the ratio and absolute counts of T-lymphocytes (which fight infections and coordinate immune responses) and B-lymphocytes (which produce antibodies). It helps assess whether your immune system has a balanced population of these two critical white blood cell types.

When elevated: Elevated T or B-lymphocyte counts may indicate an active infection, immune activation, or in some cases, lymphoproliferative disorders. The specific pattern (which type is elevated) helps narrow down the underlying cause. When low: Low T or B-lymphocyte counts can suggest immunosuppression, bone marrow disorders, certain infections (like HIV), or effects of medications or treatments. A significant drop in either population warrants investigation.

T and B-lymphocyte balance is moderately relevant to athletes because intense training temporarily shifts immune cell distribution and can suppress certain populations during heavy load phases. Monitoring this differential may help identify whether your immune system is recovering adequately between training blocks, though single measurements are less predictive than trends over time.