Bronchoalveolar eosinophilia in random-source versus purpose-bred dogs

Eosinophils (EOS) have been implicated in changes in airway and vascular reactivity in a variety of disease states. Analysis of cells in bronchoalveolar lavage samples from chronic, heartworm-free random-source (RS) dogs indicated higher leukocyte counts with markedly higher percent and total numbers of EOS than were present in purpose-bred (PB) animals. Bronchoalveolar lavage fluid (BALF) obtained from RS dogs had a significantly elevated total nucleated cell count: 0.8 x 10(6) vs 0.4 x 10(6) for the PB dogs. RS dogs had 24% +/- 5% and PB dogs had 3% +/- 0.7% EOS. The RS animals with elevated EOS had similar percentages of neutrophils: 4% +/- 0.6% as the PB animals. Despite aggressive anthelminthic treatment, the abnormal BALF cellular profile of the RS animals persisted even though circulating levels of EOS in this group decreased. Analysis of BALF for thromboxane B2 (TxB2) and 6-keto-prostaglandin F1(1a) (6-keto-PGF1a) indicated that only the TxB2 levels were significantly different between groups. The RS BALF TxB2 levels were 73 +/- 14 pg/ml vs 23 +/- 3 pg/ml for the PB group (P < 0.05). Regression analysis of the relationship between increasing TxB2 levels and the absolute number of EOS per milliliter of BALF obtained from the RS dogs indicated a significant correlation (r = 0.83, P < 0.0001). No difference in plasma levels of these mediators was observed. Other physiologic parameters also differed between the two groups: the RS group had significantly increased heart rates and cardiac output under baseline conditions.(ABSTRACT TRUNCATED AT 250 WORDS)