Immunestatus

Immunestatus refers to the state of an individual's immune system at a given time, reflecting its capacity to respond to pathogens, clear infections, and maintain tolerance to self. It encompasses both innate and adaptive immunity and includes cellular components (neutrophils, monocytes, natural killer cells, T and B lymphocytes) and humoral factors (immunoglobulins, complement, cytokines).

Immune status is influenced by genetics, age, nutrition, medications, infections, vaccination history, chronic disease, stress, and the microbiome. It can be affected by acute illness, recent vaccination, or immunosuppressive therapies, and may thus fluctuate over time.

Assessment of immunestatus involves clinical evaluation and laboratory testing. Common measures include complete blood count with differential, quantitative immunoglobulins (IgG, IgA, IgM), lymphocyte subsets by flow cytometry (CD4+ and CD8+ T cells, B cells, NK cells), and functional assays such as mitogen-induced lymphocyte proliferation. Specific antibody responses to vaccines and past infections (serology) help gauge humoral immunity, while complement levels (C3, C4) can reflect innate pathway activity. In certain contexts, more specialized tests or dynamic challenge tests may be employed. Importantly, immunestatus is not a fixed attribute; it can change with infections, treatments (chemotherapy, steroids, biologics), vaccination, or remission of diseases.

Classification typically includes immunocompetent versus immunodeficient states, with distinctions between primary (congenital) and secondary (acquired) immunodeficiencies. Age-related changes, such as immunosenescence, also shape immune status. Clinically, understanding immunestatus aids in assessing infection risk, vaccine responses, and suitability for transplantation or immunotherapy, while acknowledging that no single test fully captures immune function.