Self-perpetuating arthritis was induced in knee joints of rabbits by intraarticular injections of large amounts of cell free extract derived from group A streptococci disintegrated mechanically. The pathological alterations were characterized by synovial lining cell proliferation, polymorphonuclear and mononuclear cell infiltration with the appearance of pseudo-follicles and pannus formation. Electron microscopical proliferation of B cells was predominant. An active inflammatory exudate and numerous new capillaries were also seen. The induced arthritis was self-perpetuating and appears to resemble human rheumatoid arthritis.

In previous reports (1, 2) it has been shown that lysosomal enzymes derived from various populations of mammalian leukocytes failed to degrade 14C-Iabeled group A streptococci in vitro, On the other hand, Staphylococcus albus, Micrococcus Iysodeikticus and Escherichia coli were degraded to a large extent by leukocyte lysosomal enzymes. It was thus of interest to study the degradation of a variety of labeled microorganisms in vivo in inflammatory lesions in the thigh muscle of the mouse induced by the injection of heat-killed microorganisms. The results indicate that there may be a correlation between the degree of degradation of microorganisms by leukocyte lysates in vitro (1, 2) and the length of their persistence in lesion sites in vivo.

In previous reports (1-3), it has been shown that lysosomal enzymes derived from a variety of mammalian leukocyte populations degrade 14C-Iabeled Micrococcus lysodeikticus and Staphylococcus albus extensively. On the other hand, group A streptococci are very resistant to lysis by leukocyte lysates. It has also been shown that, unlike S. albus and M. lysodeikticus, streptococci which are resistant to lysis in vitro persist for long periods in granulomatous lesions in mouse and rabbit tissues (1, 2). Other reports (4, 5) have shown that bacteria coated with specific antibodies are degraded at a slower rate following phagocytosis, as compared with untreated bacteria. Cationic polyelectrolytes, such as polylysine and polyarginine, agglutinate a variety of bacteria (6), and cationic proteins derived from leukocytes as well as from calf thymus histone are bactericidal for a variety of microorganisms (7). The possibility was therefore investigated that, by analogy to antibodies, cationic proteins may coat bacterial cells and thus interfere with their degradation by leukocyte lysosomal enzymes.

The evaluation of the streptozyme test in sera from 34 patients with streptococcal pyodermal nephritis was studied. Ninety-seven percent of the patients developed high titers of antistreptozyme antibodies on the first bleeding after hospitalization, in contrast to only 40% of patients who developed elevated antistreptolysin O titers. The high antistreptozyme titers declined during convalescence and reached normal levels in the sixth month after onset of the disease. The most significant fall in titers occurred between 1 and 2 months from the onset of disease. The streptozyme test may be particularly helpful as a rapid screening test for antibodies in streptococcal pyodermal nephritis.