Bronchially instilled IgY‐antibodies did not decrease pulmonaryp. aeruginosaconcentration in experimental porcine pneumonia

Abstract

Pseudomonas aeruginosa is a pathogen in humans known to host several antibiotic resistance mechanisms. 1,2 Ventilator-associated pneumonia (VAP) caused by P. aeruginosa is a common intensive care unit (ICU) problem with a mortality of approximately 30%-40%. [3][4][5] Nonconventional anti-microbial therapies are thus of interest against P. aeruginosa infections.IgY-antibodies are produced in hens and resemble mammalian IgG. The IgY antibodies, due to eggs being part of the human diet, pose little risk of adverse immune reactions. 6 The production of IgY is inexpensive. After inoculation with P. aeruginosa hens produce eggs containing specific polyclonal anti-P. aeruginosa antibodies (Pa-IgY). 7These antibodies bind primarily to the flagella of P. aeruginosa augmenting the phagocytic activity of polymorphonuclear neutrophils. 8 Previous studies have shown increased time to airway colonization

Intravenous anti-P. aeruginosa IgY-antibodies do not decrease pulmonary bacterial concentrations in a porcine model of ventilator-associated pneumonia

“…These results are in line with previous work in our lab where a bronchial injection of Pa- IgY did not reduce pulmonary concentrations of Pa- IgY. 21 However, they contradict our first study where a nebulization of Pa- IgY decreased the concentration of P. aeruginosa in the large airways. 4 Our results contradict the results from trials on patients with cystic fibrosis, mice with pneumonia and in vitro experiments.…”

“…In our previous study with intrabronchial injection of Pa- IgY we detected anti- P.aeruginosa activity in plasma which was a magnitude lower than in this study. 21 This might imply that only a small fraction of Pa- IgY crosses the capillary-alveolar membrane. Immunoglobulin G has similar characteristics in that alveolar levels are generally 1000 times lower than in the circulation.…”

“…Interestingly, these circulatory changes are the opposite compared to when Pa- IgY is delivered intra-bronchially. 21 Since increased HR can lead to both increased CI and increased DO 2 , it is likely that the difference in HR is causing the differences observed in CI and DO 2 . We also observed higher ΔpCO 2 /ΔcO 2 in the intervention group, this might be explained by inadequacy of microcirculatory function.…”

IgYs: on her majesty’s secret service

“…did not register any significant reduction in the bronchoalveolar lavage concentration of P. aeruginosa . In these trials, antibodies were administered intravenously (100 mg per animal) ( 57 ) or injected bronchially (100 mg per animal) ( 56 ). The results contradicted those obtained in in vitro assays, in the pneumonia mice model, and in patients with CF; however, it is difficult to compare because different administration routes were applied ( 50 , 112 ).…”