[The relationship of immunological reactivity to blood groups]

The relationship of blood groups and level of immunological reactivity was studied in 500 patients with different diseases and 246 healthy subjects. Distribution of genetic markers of blood groups in the healthy and patients showed certain characteristic features. It was found that the A (11) blood group in the healthy may be considered a marker of high levels of immunological reactivity resulting in a milder course of diseases in persons of this blood group. It was shown that different pathological states are characterized by variations of immunological reactivity depending on the blood group--on the content of populations and subpopulations of lymphocytes, immunoglobulin of different classes, normal antibodies, grade of immunodeficiency.