A Patho-physiological Study on Rheumatic Fever

Abstract

It is known that there is a close connection between rheumatic fever and streptococcal infection, but the etiology is not yet clearly understood. In dealing with the subject of rheumatic fever we should first consider the pathological changes caused by streptococcal infection in the body. In order to study these changes, especially the changes in the heart we used macaca cynomolga monkeys to carry out a basic experiment, the results of which we wish to disclose.
The monkeys used in this experiment ranged from 2.0 kg to 3.0 kg in weight. Streptococcus hemolyticus (A Group, type 12) was injected interravenously into these monkeys.
To induce hypersensitivity in the monkeys, we injected 0.5 ml of cow blood serum every other day until four injections had been given to monkeys in Group A and Group B. Monkeys in Group C and Group D were not injected with cow blood serum.
Monkeys in Group A and Group C were inoculated with streptococcal bacilli at a dosage of 0.005 mg per kg. Those in Group B and Group D were given a dosage of 0.2 mg per kg. After one month they were inoculated again with these same dosages.
1. From the day after innoculation for a period of two or three days all groups showed a fever of 38-39cC. Group B and D showed only a slightly higher temperature than Groups A and C.
2. Joint symptoms were the most pronounced in Group D and were increasingly less severe in the other groups in the following order: Group B, Group C, Group A. Three out of the four monkeys in Group D showed symptoms such as knee joint swelling, limp swelling of the eyelids, etc.
3. Cardiac symptoms were particularly observable in the B Group. In this group the electrocardiogram showed a change in the QRS axis, a prolongation of the PQ interval, V- T wave lowering, abnormality in the P wave, a change in the ST segment and also arrhythmia. It is hard to say conclusively that the abnormalities observed through comparing pre-innoculation and post innoculation electrocardiograms definately indicated carditis but these findings suggested the existence of pathological changes in the heart. It seems logical to infer that these changes were induced by streptococcal infection.
4. Sludge test results: In the B Group sluge test results were significantly positive, with the sludge phenomenon also being observable in the eye ground following innoculation.
5. Antistreptolysin 0 test results: There was a significant rise in ASL-0 units in groups B and D.
6. There was an increase in r-gl in all groups.
7. In the post mortem examination no maked changes attributable to rheumatic fever were recognized.