Etiology, Pathogenesis. g85 



Pathogenesis. The development of the disease commences 

 either with the breaking down of red blood corpuscles, or with 

 the elimination of the blood coloring matter from the blood 

 cells, but not infrequently with both processes together; the 

 eliminated hemoglobin is then dissolved in the blood plasma 

 and deposited mostly in the spleen and in the bone marrow. 

 A considerable part however is worked up by the liver into 

 bile coloring matter. If the blood plasma becomes suddenly 

 flooded with blood coloring matter, or if the quantity absorbed 

 by the blood plasma exceeds the sixtieth part of the total hemo- 

 globin, a part of the coloring matter, as found by the experi- 

 ments of Ponfick, is eliminated by the kidneys (hemoglobinuria), 

 producing at the same time a degeneration, or even an in- 

 flammation of the kidneys. In severe hemoglobinemia, but ac- 

 cording to Affanasiew only in hemoglobinemias with destruc- 

 tion of blood corpuscles, the liver forms bile pigments in large 

 quantities from the blood coloring matter, and as the secretion 

 of the fluid constituents of the bile does not keep up with it, 

 the thickened bile accumulates, is partly absorbed, and thus 

 the possibility is afforded for the development of icterus. 

 Sometimes other organs also become affected under the influence 

 of the blood dissolving substances. 



Anatomical Changes. The blood serum appears more or 

 less reddish in color; in severe cases the blood may be even 

 darker at the beginning, in the further course however it is 

 lighter in color. The spleen shows an acute swelling on account 

 of the taking up of blood pigments, its size corresponds with 

 the intensity and duration of the disintegration of blood cor- 

 puscles. The spongy bone marrow appears more or less red- 

 dened, sometimes of a dark red color. In severe cases a general 

 icterus may be noted. 



Symptoms. Without a blood examination mild cases of 

 the affection may pass unrecognized. In severe cases depres- 

 sion, icterus and hemoglobinuria are observed. Fever also 

 appears, as a rule, and is brought on either by the causative 

 agent of the disease, or by the febrile action of products from 

 the disintegrated red blood corpuscles. As the coagulation 

 of the blood increases hemorrhages occur probably as the re- 

 sult of a simultaneous destruction of white blood corpuscles 

 in the mucous membranes and also in the other organs. The 

 disintegration of blood corpuscles, as well as the substances 

 causing the same, may further produce difficulty in respiration, 

 disturbance of consciousness, also convulsions, weakness and 

 accelerated pulse, and occasionally nephritis (renal epithelial 

 cells, casts in the urine). The blood shows the same changes 

 as in acute anemia (see p. 847), provided the blood serum 

 contains hemoglobin. 



Mild cases may terminate in recovery, whereas the severe 



