[Study on the pathogenetic role of alginate produced by mucoid Pseudomonas aerugiosa in diffuse panbronchiolitis]

It has scarcely been known that the pathogenetic role of mucoid Pseudomonas aeruginosa being colonised on the airway surface in diffuse panbronchiolotis DPB. The role of alginate, a main component of mucoid substance of Pseudomonas aeruginosa was demonstrated in reference to DPB. 1. Clinical Observation Serum titer of anti-alginate antibody IgG in the group of Pseudomonas-positive DPB was higher than that of the groups of Pseudomonas-negative DPB (p < 0.01) and healthy volunteers (p < 0.01). The concentration of immune complex in Pseudomonas-positive DPB group at serum level was also higher than that of the above two groups (p < 0.01), and it was well correlated between activity in the patient's symptom and the patient's prognosis. 2. Experimental Observation In the immunised mice made by free alginate injections, a lymphocyte infiltration around small vessels and small airways in lung was characteristically found at the early stage after the inhalation with mucoid Pseudomonas aeruginosa PT1252. It disappeared 14-15 days after the inhalation. By repeating the inhalation for 6 days, such a lymphocyte infiltration had been persisted and lymphocyte granulomatous change was formed around small airways. The transformation and narrowing of the small airway occurred by lymphocyte granulomatous change. At the same time, some degree of neutrophil infiltration into the airway was also observed. These findings were closely similar to that of human diffuse panbronchiolitis. 3. Conclusive Words From the above, the pathogenetic role of alginate in mucoid Psuedomonas aerginosa colonised on airway surface in DPB patient will be explained as follows. Local immunoreaction of antigen and antibody through alginate evolved lymphocyte infiltration around small airway area. A persistent localization of antigen (alginate) makes such an immunoreaction repeat. Consequently, lymphocyte-granulomatous change is formed around the small airway. On the other hand, a state of excess antigen introduced by long term colonization of mucoid Pseudomonas aeruginosa forms an immune complex in the host side. Neutrophil combined with the immune complex deposited on the airway surface may act in a destructive manner for the lung tissue of DPB patient.