[Experimental studies on the reaction of the immunological system during chronic otitis media and about the course of this disease (author's transl)].

During chronic otitis media intact immunoglobulins are split due to the proteolytic activity of extracellular bacterial proteinases into fragments of different molecular weight. The most malignant bacterial proteinases are the proteinases of pseudomonas aeruginosa (pyrocyanea). These proteinases can only be inhibited by alpha-2-macroblobulin of human blood serum. Because of its high molecular weight we find this inhibitor only in a very low concentration in the middle ear secretion. The destruction of the immunoglobulins is certainly one of the factors of weakening the immunological system in the middle ear. The inhibitory system with alpha-1-antitrypsin, inter-alpha-trypsin inhibitor and alpha-1-antichymotrypsin is unable to inhibit these bacterial proteinases of pseudomonas aeruginosa. The only possibility to get a high concentration of alpha-2-macroglobulin in the middle ear secretion is the liberation of this inhibitory by injuring blood vessels during a tympanoplasty. By this procedure the proteinases of pseudomonas aeruginosa with maximum activity at pH 7.8 and with a high proteolytic activity are almost completely inhibited. By blocking these proteinases combined with an appropriate antibiotic therapy and with the reconstruction of the destroyed parts of the middle ear by a tympanoplasty we can produce a preponderance of the immunological system as compared with the proteolytic activity of the proteinases. This high proteolytic activity can be a cause of the destruction of the small processes of the ossicular bones, especially of the lenticular process of incus. In order to demonstrate that there are proteolytic splitting processes of intact immunoglobulins, a quantitative analysis of the immunoglbulins IgG, IgA and IgM was done pre- and postoperatively. By these studies we found postoperatively a much higher level of intact immunoglobulins, particulary in cases of chronic otitis media associated with cholesteatoma. The blocking of the proteinases and the increase of the level of intact immunoglobulins combined with the reconstruction of physiological conditions in the chronically inflamed middle ear by a tympanoplasty lead to a stabilsation of the immunological and inhibitory system and create the prerequisites for a healing process in chronic otitis media. It is the purpose of further studies to learn about the capability of the split-products of the immunoglobulines to attach and to absorb antigens and toxins during a chronic inflammation in the middle ear.