About Lymphocytes
Lymphocytes are the immune cells responsible for adaptive immunity — including B cells (which produce antibodies) and T cells (which directly kill infected or cancerous cells). Elevated lymphocytes can signal a viral infection, certain leukaemias, or autoimmune conditions; low lymphocytes are associated with HIV, high-dose steroids, autoimmune disease, or severe nutritional deficiency. Tracking the lymphocyte-to-monocyte ratio provides additional insight into immune activation and systemic inflammation.