Immune system is involved in pathological processes. The involvements are classified into 5 types.
I. Immune system is essentially healthy (adequate).
II. Primary immune deficiencies are the genetic defects of immune system cells such as: ❖ Syndromes with AB deficiency; ❖ Syndromes with T-lymphocyte deficiency; ❖ Combined T- and B-deficiencies; ❖ Syndromes with deficient complement components; ❖ Syndromes with defective NK; ❖ Syndromes with defective phagocytes; ❖ Syndromes with defective adhesion molecules.
III. Secondary immune deficiencies are the dysfunctions of immune system caused by severe systemic pathogenic effects on the organism, namely:
1. Factors causing reversible dysfunctions (immune deficiency) of immune system (in this case reversibility is relative and depends on magnitude and duration of pathogen-mediated effect): ❖ extreme starvation and deficiency of vitally important components in the diet; ❖ curable metabolic diseases (diabetes mellitus, Icenko-Cushing syndrome; ❖ dysfunction of parathyroid glands, etc.); ❖ mental depression; ❖ curable burn disease; ❖ temporary stress of any nature.
2. Factors to provoke physical "amputation" (to some extent) of lymphoid tissue (consequent irreversible immune deficiency): ❖ HIV-infection;
❖ injury of immune system by other infections (hyperstimulation of immune system by superantigens in viral, fungal, bacterial infections, and by other mechanisms) namely: measles, hepatitis, cytomegalovi-rus infections, rubella, Epstein-Barr virus infection, staphylococcal infections, tuberculosis, leprosy, coccidiomycosis, aspergillosis, etc.;
❖ ionizing radiation; ❖ lymphotoxic chemical substances; ❖ lympho-proliferative diseases; ❖ probably some other malignancies.
IV. Autoimmune diseases: ❖ true autoimmune diseases; ❖ diseases with defects in immune response suppression.