Antibodies of a blood of the person.

The doctrine about blood types and a Rhesus factor. Definition of blood types.

The blood type is genetically caused biological sign and is defined by existence or absence in plasma and cellular elements of a blood of a concrete individual of the corresponding group isoantigens and isoantibodies.

On the basis of studying of reaction of an isohemagglutination (pasting of erythrocytes of one person at their mixing with blood serum of another) K. Landsteiner in 1900-1901 for the first time allocated at the person three blood types – A, B,C.

In 1906 J. Jansky finally proved that for the person four blood types are natural, and offered classification (I, II, III, IV) which use so far around the world.

In 1928 the international classification of blood types is approved. It is accepted to distinguish four groups: O (I), A(II), B (III) and AB (IV). In Europe 44% of people have A(II) blood type; the O(I) group is the second for frequency and makes 39%, the B(III) group meets in 12%, AB(IV) group – in 4-5%.

So far in a blood of the person more than 700 various erythrocyte antigens of a blood forming 75 antigenic systems are revealed. Only 29 from them have clinical value, and 14 antigenic systems are most significant: ABO, Rh-Hr, Kell-Gellano, Duffi, Kidd, Lewis (Lewis), MNSs, Lutheran, Rp, Xq, Ji, Auberqer, Dieqo, Dombrok, Colton, Scianna and others.

Antigens of a blood of the person.

Group antigens of a blood of the person are called agglutinogens as they are usually taped by an agglutination test.

Agglutinogens possess the following properties:

1) an adjuvanticity, i.e. ability to cause formation of immune antibodies when entering the antigen in an organism which doesn't have it;

2) specificity (serologichesky activity), i.e. ability to enter with the corresponding antibody immunologic reaction, such as agglutination.

Those agglutinogens of a blood which are located on a surface of formulated elements because they are have practical value the reason of an isoimmunization (isosensibilization) and antibodies at hemotransfusions connect to these antigens, causing agglutination and a hemolysis.

Agglutinogens of systems of ABO, Rh-Hr and Kell have such locating, as was the main reason for selection of a blood for transfusion for these agglyutinogenny systems.

Antibodies of a blood of the person.

Group isoantibodies (agglutinins) of a blood represent the gamma-globulin molecules forming 5 classes. Group antibodies of classes are most significant: IgM, IgG, IgA.

One of them, agglutinins possess ability to agglutinate the antigens of a blood of the same name (property of an agglutination power) – the pasting and destruction of erythrocytes coming in a few minutes or hours. Other cytolysins (hemolysins), being fixed on erythrocytes, leucocytes or thrombocytes cause their hemolysis without preliminary pasting, but with obligatory participation of a complement. Anti-erythrocyte agglutinins have the greatest practical value.

On the mechanism of formation of an antibody are sectioned on natural, or congenital (a- and b-agglutinins which are genetically caused and existing during all life, for example) and immune, or acquired (there are at some people during any period of life as a result of immunization by blood antigens, foreign for them, for example, anti-A, anti-Rh agglutinins).

The next ways of immunization are possible:

transfusion of an other group blood – a transfusion way;

transplacental way - (mother Rh-negative, and a fetus Rh-positive).

organ transplantation and tissues without their group compatibility – a transplant way;

introduction of vaccines and Serums – an injection way;

immunization by foodstuff – an enteral way.

On a temperature optimum of activity agglutinins can be cold or thermal.

Cold antibodies (for example, α and β) are most active at a temperature of +4 ° - +6 °C (reaction is possible and at a temperature which isn't exceeding +25 ° - +30 °C) and aren't active at a temperature of +37 °C and above. That is why definition of blood types on system of ABO is carried out at the room (low) temperature. Thermal antibodies, in turn (for example, antirezusly antibodies), are more active at a temperature of +37 °C and above. In this regard definition a rhesus accessory is carried out in the conditions of a thermostat at a temperature of +46 ° - +48 °C.

Depending on medium in which agglutinins cause an agglutination test of the corresponding agglutinogens, they are sectioned into full and incomplete antibodies.

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