1910. ] Red Blood Cells in Trypanosomiasis. 257 
found in the blood. I have had under observation a goat, infected with 
T. gambiense, in which trypanosomes have never been seen in the blood, but 
in which a well marked auto-agglutination had developed. The blood was 
shown to be infective by injection into rats. 
The last point to be decided in considering the value of the phenomenon 
as a diagnostic sign is whether it occurs in other diseases besides trypano- 
somiasis. In addition to the three cases mentioned by Todd, auto-agglutina- 
tion has occasionally been noted in persons suffering from other diseases than 
Sleeping Sickness. : 
Klein,* in 1890, found auto-agelutination of the red blood cells in a case of 
hepatic cirrhosis (Hanot), Dudgeont mentions the case of a West Indian 
negro which was considered to be one of tertiary hepatic syphilis, where the 
blood exhibited spontaneous clumping. He also found auto-agglutinin in 
the blood of a case of long standing epilepsy. Martin and Darré{ assert 
that the phenomenon is to be met with in certain forms of icterus due to 
hemolysis. 
Quite recently Nattan-Larrier§ described the existence of auto-agelutination 
in rats infected with the Sprrilla obermieret. It is interesting to note in this 
connection that of Todd’s three cases which exhibited well marked auto- 
agelutination, but were not infected with trypanosomes, one was a case of 
relapsing fever and another a case of syphilis, as was also the only definite 
instance of the phenomenon seen by Dudgeon. It is of importance to know 
whether auto-agglutination is often present in spirochaetal infections. 
In conclusion it may be stated that in the light of the information 
obtainable a well-marked degree of auto-agglutination of the red blood 
cells is an extremely rare occurrence, apart from infection with try- 
panosomes. 
Summary. 
' Autc- and iso-agelutinin are present in the blood of cases of Sleeping 
Sickness and of animals infected with trypanosomiasis. 
Reaction between auto-agglutinin and red blood cells takes place only 
at low temperatures. 
Auto-agglutinin can be removed from plasma by absorption with the 
erythrocytes of the same animal at 0° C. 
The reaction between auto-agglutinin and red blood cells is reversible. 
* “Ueber die Untersuchung der Formelemente des Blutes und ihre Bedeutung fiir die 
praktische Medicin,” ‘Wien. Klin. Woch.,’ 1890, Nos. 36—40. 
¥ Loc. cit. 
t ‘Bull. et Mémoires Soc. Méd. des Hépitaux de Paris,’ 1909, p. 599. 
§ “L’Autoagglutination des Hématies dans la Spirillose Expérimentale,” ‘Bull. Soc. 
Path. Exot.,’ 1910, p. 425. 
