[Reprinted from The Medical News, April 6, 1895.] 
THE SPLEEN AS A BACTERICIDE. 
By HENRY S. UPSON, M.D , 
PROFESSOR OF NEUROLOGY IN THE MEDICAL SCHOOL, 
CLEVELAND, OHIO. 
Recent progress in therapeutics has been marked 
in two directions, one in serum-therapy, the other, 
by means of what are known as the organic extracts. 
Of the latter it is necessary sharply to distinguish 
two classes. The first, including cerebrin, medullin, 
cardein, and the like, have a value at least doubtful; 
the second includes the administration of the 
thyroid gland for myxedema, and bone-marrow for 
pernicious anemia. The success of both of these 
forms of treatment is assured, and they rank among 
the most brilliant of recent achievements in medi- 
cine. In the case of both of the last-named 
methods, organs are used that without doubt act by 
supplying important constituents of the blood ; in 
the case of marrow formative elements of the red 
blood-cells, in case of the thyroid some substance 
unknown, possibly a ferment, which, in a way also 
unknown, controls nutrition-processes. 
The organs that have to do in especial with the 
blood are the thyroid, bone-marrow, and the spleen. 
Of the functions of the spleen little more is definitely 
known than was known a short time ago of the 
thyroid gland. It has been thought, however, to 2 
be the birthplace of the white blood-cells. There 
are facts that point strongly to it as a possible agent 
in conferring immunity from certain diseases. Some 
authorities have held that the white blood-cells are 
the active agents in destroying bacteria that gain 
lodgment in the body. Whether this is true or not, it 
is certain that some persons live for years in very 
malarial regions without contracting the disease; 
that some people resist typhoid better than others, 
and that most men are exposed to tuberculous infec- 
tion, and that when the disease is contracted, while 
some succumb, many do not. In all of these dis- 
eases—malaria, typhoid fever, acute tuberculosis, as 
well as pneumonia and some other germ-diseases— 
the spleen is markedly enlarged, as if from over- 
stimulation in an effort to throw off the disease. 
It is at least conceivable that the bacteria-killing 
substances, which undoubtedly exist in those diseases 
that admit of spontaneous cure, are elaborated in 
the spleen. The opinion that pulmonary tuberculosis 
and malaria are to a degree incompatible tends to 
confirm this view. Without discussing this question 
at length it is enough to say that Davidson (Geo- 
graphical Pathology, vol. ii, p. 858), after giving 
many instances in support of the theory, summarizes 
as follows : 
The facts, therefore, seem to establish two of the 
conclusions arrived at by Lombard, first, that con- 
sumptives are less numerous in those districts where 
malaria is dominant than in those where it is less 
prevalent; second, that this inverse relation is not 
entirely explained by differences in climate. 
The foregoing lends some color to the supposition 3 
that the malaria-soaked inhabitants of swampy re- 
gions possess an immunity from pulmonary tuber- 
culosis. It suggests the thought that the spleen, 
enlarged and abnormally active from its long battle 
with malaria, more easily overcomes the inroads of 
the tubercle-bacillus. If a main function of the 
spleen is to furnish to the blood bactericides, the 
reason of our present ignorance of its function is 
apparent. Removal of the spleen is a rare opera- 
tion, and statistics of the power of resistance to 
germ-diseases of persons so operated on are not 
procurable. That the spleen does contain sub- 
stances that kill germs is beyond question. This 
fact is pointed out by Vaughan (The Medical 
News, December 23, 1893), who says, “it is certain 
that the spleen contains a germicidal substance, but 
whether we can extract it by the method of Hankin 
we do not know.” The question of extraction may 
be interesting chemically; clinically it might be as 
well to administer spleen by the mouth, or in the 
form of extract hypodermically. The former method 
is surprisingly successful in the case of thyroid and 
bone-marrow. 
To sum up : In acute infectious diseases the spleen 
is enlarged, as if in an effort to combat the effect of 
the poison. Some men and certain entire species 
of animals possess immunity, and recovery takes 
place from these diseases by germicides produced in 
some part of the body ; the spleen does without 
doubt contain germicides, and probably, therefore, 
elaborates them. 
It is hoped that experiments with the administra- 
tion of spleen in this class of diseases, particularly 4 
in tuberculosis, malaria, and typhoid fever, may 
yield not only favorable results, but may throw ad- 
ditional light on the functions of the spleen analo- 
gous to that which has been thrown on those of the 
thyroid gland. Such experiments should be made 
as far as possible with the spleens of animals immune 
from the diseases experimented on. 
While the foregoing considerations are purely 
theoretic, they are given in advance of actual ex- 
periment, with a view to induce others also to 
investigate the subject. 
341 Prospect Street.