As a result of any inflammatory process, there is a physiological
reaction or stimulus leading to an increase in the number of
neutrophilic leucocytes found in the peripheral circulation. As long
as this increase does not crowd out other cells, red and white,
sufficiently to interfere with their ability to function there is
nothing but gain to the body of the character of more efficient
bacterial destruction. After the need for these cells has passed,
their number is decreased by destruction and the lessening of their
production, until an equilibrium is reached which will be maintained.
This same process of making and destroying is constantly going on
for all of the different classes of cells found in the blood stream.
Over-production of any type will lead to actual increase of that sort
of cell in circulation, and, if unaccompanied by over-production of
other types, will lead to a relative decrease of the other elements.
It is very difficult for the body to furnish normal cells very much in
excess, relatively, of the normal number, so that when the stimulus
leading to immense over-production is at work immature cells in great
numbers are apt to be thrown into the blood stream. As an example, the
case of leucocytosis which has a white count of 60,000 is extreme and
the patient nearing death, yet it may not show many, if any, abnormal
types of cells. A case of myelogenous leucemia with a white count of
60,000 would not be proportionately sick, and would be a mild case—yet
the greater part of his white blood content would be made up of cells
not found in normal blood. The leucocytosis patient is suffering more
from the =cause= of his increase in number of cells, while usually the
leucemia patient suffers because =of= the increase of cells. In one,
the cause is usually extrinsic, and, in the other, it is intrinsic as
far as the blood is concerned.
In general, then, the symptoms of a leucemia parallel in intensity the
increase in cells. It takes energy to make these cells—other tissues
are made to suffer from lack of this energy. Erythrocytes and white
cells cannot occupy the same space at the same time. The increase
in white therefore crowds the red cells out of function. Disease in
relative and absolute content of erythrocytes decreases the oxygen
carrying capacity of the blood stream. Hence, metabolism of the whole
body suffers. Often, then, the whole apparent symptomatology of a
severe leucemia is that of a secondary anemia.
The primary pathology is of hyperplasia of the particular genetic
tissue of the type of cells which are in excess, and is proportionate
in amount to the excess developed.