Table 2

Comparison of results after subgrouping horses due to clinical and light microscopic findings


n
Histological score: median (span)
IHC (MP): median (span)
IHC (PII): median (span)
IHC (BE): median (span)
IHC (percentage): median (span)
PCR: positive cases (percentage)

Subgroup I
15
0 (0–2)
0 (0–1)
0 (–-4)
6 (–-63)
0.359 (0–4,79)
5 (33.3)
Subgroup II
5
5 (4–6)
0 (0–1)
0 (0–2)
76 (11–119)
4.853 (0.88–8.92)
4 (80)
Subgroup III
16
1 (0–5)
0 (0–1)
0 (0–2)
81.5 (4–474)
6.065 (0.20–25.4)
13 (81.2)
Subgroup IV
9
22 (12–29)
1 (0–4)
22 (0–63)
246 (20–535)
21.024 (1.37–37.1)
2 (22.2)
Mann-Whitney-U *exact Fisher test

I vs. II: p < 0.001
I vs. III: p = 0.033
I vs. IV: p < 0.001
II vs. III: p = 0.003
II vs. IV: p = 0.001
III vs. IV: p < 0.001
I vs. II: p = n. s.
I vs. III: p = n. s.
I vs. IV: p = 0.041
II vs. III: p = n. s.
II vs. IV: p = n. s.
III vs. IV: p = 0.037
I vs. II: p = n. s.
I vs. III: p = n. s.
I vs. IV: p < 0.001
II vs. III: p = n. s.
II vs. IV: p = 0.007
III vs. IV: p < 0.001
I vs. II: p = 0.033
I vs. III: p < 0.001
I vs. IV: p < 0.001
II vs. III: p = n. s.
II vs. IV: p = 0.042
III vs. IV: p = 0.023
I vs. II: p = 0.015
I vs. III: p < 0.001
I vs. IV: p < 0.001
II vs. III: p = n. s.
II vs. IV: p = 0.042
III vs. IV: p = 0.020
I vs. II: p = n. s.*
I vs. III: p = 0.019*
I vs. IV: p = n. s.*
II vs. III: p = n. s.*
II vs. IV: p = n. s.*
III vs. IV: p = 0.009*

Subgroup I: Clinically healthy horses without histological changes of RAO

Subgroup II: Clinically healthy horses with a low inflammation score of 4–6

Subgroup III: Horses with clinical signs of RAO, but without or only slight histological changes and a score of 0–5

Subgroup IV: Horses with symptoms and histological changes of RAO with a score > 10

IHC: Number of CP antigen-positive cells in 3 high power fields

MP: macrophages, PII: type II pneumocytes, BE: bronchiolar epithelial cells

IHC (percentage): number of all CP antigen-positive cells in 3 high power fields in relation to all cells

Theegarten et al. Respiratory Research 2008 9:14   doi:10.1186/1465-9921-9-14