Table 1: Classification of immune reactions causing disease [11].

Type I. A llergy and Anaphylaxis. Parasite-defence mechanism reacting to non-parasite antigens [52, 53]. Fault: a B lymphocyte IgE clone with specificity for a non-parasite foreign antigen. For example, hay fever, anaphylaxis, gut allergy, skin allergy, contact dermatitis.

Type II. Serum Sickness and Immune Complex Disease. Fault: excessive quantity of antigen. This swamps complement-neutralising mechanisms, leading to complement-mediated damage. Anti-microbial immune defence is designed to cope with picogram quantities of antigen, not milligrams of horse serum protein nor micrograms of released intra-cellular protein, such as nuclei [36, 54]. For example, serum sickness following passive immunisation against diphtheria toxin with horse serum, systemic lupus, erythaematosus, lupus nephriti.

Type III. Autoimmunity. Fault: forbidden clones, which are anti-microbial lymphocyte clones with accidental host antigen-specificity arising from unlucky somatic mutations in their V genes [19, 36].

Type III B. Diseases caused by B lymphocyte forbidden clones: for example, Graves’ disease [9], myasthenia gravis [55], rheumatoid arthritis [56].

Type III T. Diseases caused by T lymphocyte forbidden clones: for example, Diabetes Type 1 [57, 58], experimental autoimmune encephalomyelitis [59], diabetic retinopathy [27], and presumptively Addison’s disease, hypoparathyroidism, multiple sclerosis, and other autoimmune diseases with specific parenchymal cell destruction [11].