The history of the blood irradiation therapy has been
traced to the beginning of the XX century. There was an idea of applying
in medicine the known bactericidal properties of UV rays by irradiating
the blood of patients to destroy infectious organisms in the blood.
American researchers E. Knott and V. Hancock, using E. Knott's device for
extracorporeal UV blood irradiation (UBI), conducted the first successful
treatment of septic infection in 1928. Later the positive influence of UBI
on blood-supply, immune, respiratory, hormonal and other systems was
shown, as well as improvement of microcirculation and rheological
properties of the blood was demonstrated.
The equipment for extracorporeal UBI has two basic
elements: a source of UV light and an irradiation chamber for irradiation
of blood. The irradiation chamber is made from quartz glass, permeable for
UV radiation. The treatment is carried out with different frequency - from
daily up to weekly base, on a course from 3 up to 8 sessions, with
irradiation of 100-250 ml of the blood during each session of UBI.
Extracorporeal UV blood irradiation launches the cascade
of photochemical processes in the blood. These photochemical processes are
conjugated with changes of proteins and lipids of plasma, blood cells,
antioxidant and other ferment systems.
At the same time the
leading role has membrane modification activity of UV radiation on
erythrocytes, leukocytes and thrombocytes, which determines, on the one
hand, changes in functional state and properties of these cells, and on
the other - elimination from and entering in the blood circulatory channel
different biologically active substances and components of the cell
surface. It was determine, that UV radiation invokes photolysis of
proteins - disintegration of composite albumin molecules with formation of
products both with smaller, and with greater, than initial, molecular
weight. These substances play a role of antigens, launching the
appropriate immune reactions in the organism of the patient. Some studies
suggested that UV radiation with wavelength of 254 nm induces structural
and conformational changes of thermolabile proteins of plasma, hemoglobin,
ceruloplasmin, albumin, globulin etc., which cause considerable changes of
functional activity of blood proteins. As a result UV radiation induced
synthesis of biologically active substances - prostaglandins, hormones and
so on, appearing in the blood.
One of the mechanisms of medical
activity of extracorporeal UBI is the stimulation of processes of
hemopoesis. UV irradiation has positive influence on morpho-functional
properties of erythrocytes. As a result of irradiation the quantity of
misshapen red cells is decreasing, together with increasing their
steadiness towards chemical influences. The release into the peripheral
blood circulation of young cells with high metabolic and receptor activity
is also recorded. The transfusion of UV irradiated blood results changing
in quantitative and functional state of leukocytes. Simultaneously the
changes in population of leukocytes take place - the number of immature
cells is diminishes and the amount of lymphocytes, monocytes and
eosinophils is enlarged. The amount of lymphocytes is enlarged in higher
degree, than other leukocytes.
Extracorporeal UBI has normalizing
influence on the function of hemostasis system: development of
hypocoagulating effect at high hemostatic level and normalization of
function of the system of hemostasis at predilection to hypocoagulation of
a blood. Extracorporeal UBI affects both parts of the hemostasis system:
factors of coagulation, and factors of inhibition of coagulation of a
blood, but the activation of fibrinolysis, as a rule, is more expressed.
Extracorporeal UBI also reduces viscosity of the blood and improves the
deformability of erythrocyte membranes, i.e. influences on hemorheology
system.
It is marked that after extracorporeal UBI the oxygen
transport function of blood is rising, as well as increasing artero-venous
difference between oxygen and carbon dioxide level, which reflects
enriching utilization of oxygen by tissues and activating the oxidize -
reduction processes in them.
The bactericidal activity of
extracorporeal UBI is implemented by double ways - not only and not so
much due to the direct bactericidal effect of UV ray, as due to activity
of the immune answer of the organism. Extracorporeal UBI results in
changes of functional trends of all parts of immunodefence. UV irradiation
of blood by small doses in vitro is accompanied by augmentation of
phagocytic function of granulocytes, rising of an expression of receptors
of lymphocytes, increasing of activity of immunoglobulins. The transfusion
of UV irradiated blood in the organism causes rearrangement of the immune
status, the trends and depth of which depends of its initial condition. In
case of normal functioning of immune system the influence of
extracorporeal UBI is not detected, in case of hyperfunction of certain
elements - suppressive effect and finally normalization of the immune
response of the organism is recorded. For patients with initial
immunodeficiency extracorporeal UBI invokes growth of levels of Ò- and B-
cells with simultaneous rising of function activities of these cells,
increase of concentration of immunoglobulins A, M, G with parallel
accumulation of antimicrobial antibodies, augmentation of phagocytic
activity of granulocytes and humoral nonspecific factors.