The effect of respiratory immunization on cell-mediated immune effector cells of the lung

In order to understand the mechanisms of cellular immune injury in hypersensitivity pneumonitis, the effect of type of antigen on cell-mediated immunity in guinea-pigs receiving respiratory immunization was studied. Lymphocytes obtained by pulmonary lavage were compared with those from peritoneal exudate following immunization with either a soluble protein, human serum albumin, or a particulate suspension of Thermoactinomyces vulgaris. Assays were obtained without mixing cells from these two sources. Statistically significant increases (13-22%) in the number of alveolar rosette-forming cells (RFC) were found in the animals immunized with either antigen, but only the particulate T. vulgaris was also capable of inducing a systemic increase of such cells. That this increase in RFC could be due to specifically reactive lymphocytes was demonstrated by the production of antigen-stimulated macrophage migration inhibition. Some evidence was obtained that indicated that T. vulgaris could act both as a non-specific B-cell stimulant and a specific T-cell activator. The concept of a hypothetical pulmonary 'barrier' is discussed which must be overcome to induce systemic immune responses following respiratory immunization. T. vulgaris must be added to the list of known agents or means for overcoming this 'barrier'.     

Outcome of unsuspected pneumococcemia in children not initially admitted to the hospital

The records were reviewed of 97 episodes of unsuspected pneumococcemia in children not initially admitted to the hospital. Antimicrobial agents were prescribed at the first visit for 46 children; at the second visit 37 of them were improved and nine were not. No antimicrobial agents were prescribed at the first visit for 51; at the second visit 16 of these patients were improved and 35 were not. Pneumococcemia persisted in two treated children and in 13 untreated children. Meningitis was identified later in four children (two treated and two untreated). Although pneumococcemia in children may be a transient event, it may also persist or result in meningitis or other localized infections.