Figure 1.

Flow cytometric T cell analyses in cryopreserved equine bronchoalveolar lavage cells. Horses were characterised as HE (n=9) or having MEA (n=3) or SEA (n=8). (A) The horses’ age, body condition score (BCS, range 1–9), history (HOARSI, range 1–4), clinical score (sum, range 0–21), and endoscopic mucus score (range 0–5) were assessed and are plotted. The bars represent group medians. Statistical comparisons using Mann–Whitney tests are indicated by lines with p-values if p<0.1. (B) BALC were microscopically differentiated on cytospins, and the percentages of the neutrophils, eosinophils, and mast cells of all leukocytes are plotted. Most asthmatic horses (MEA and SEA) had neutrophilic BAL cytology. (C) BALC and PBMC of the horses were cryopreserved, thawed, and analysed by flow cytometry. Singlets (conservative), live cells, and lymphocytes were gated in a hierarchical manner, as illustrated in a representative example BALC (HE, freeze-thaw). All further analyses were performed on lymphocytes. (D) CD4 and CD8 positive T cell proportions were determined by spider gates, as illustrated in representative examples of lymphocytes in BALC from HE and SEA. (E) The CD4:CD8 ratio was calculated for each sample (after thawing), except those from two horses (one HE and one SEA), the cells of which did not stain for CD8. SEA BALC had a lower CD4:CD8 ratio than HE BALC.