Isolated Bronchi of Patients with COPD Show Decreased Histamine Responsiveness Compared to Smokers with Normal Lung Function

Figures & data

Table 1 Patients' characteristics and results of in vitro measurements

	Control	COPD
Sex (f/m)	1/7	0/9
Age (y)	62 ± 4 (53–71)	64 ± 2 (61–68)
Height (cm)	176 ± 3 (169–184)	176 ± 2 (173–180)
BMI (kg/m^2)	26.2 ± 1.3 (23.1–29.3)	25.2 ± 1.0 (22.9–27.4)
Packyears of smoking	47 ± 6 (32–62)	54 ± 6 (40–68)
Total serum IgE (U/mL)§	83.3 ÷ 1.5 (32–217)	57.2 ÷ 1.9 (13–261)
FEV1 (L)	3.27 ± 0.25 (2.67–3.87)	1.73 ± 0.14 (1.41–2.05)**
FEV1 (%predicted)	101 ± 4 (92–109)	53 ± 5 (41–65)**
FEV1/FVC (%)	73 ± 1 (70–76)	52 ± 4 (42–62)**
Δ FEV1 Salbutamol (%)	1.3 ± 0.4 (0.4–2.2)	15.4 ± 2.8 (8.9–22.0)**
Δ FEV1 Salbutamol (mL)	43 ± 11 (16–69)	228 ± 40 (133–322)**
DLCO (%predicted)	84 ± 4 (75–93)	63 ± 5 (52–74)**
PC20FEV1 Histamine§ (mg/mL)	> 8	0.59 ÷ 1.50 (0.23–1.51)**
pED50 (-log10 M)	5.29 ± 0.15 (4.94–5.64)	4.67 ± 0.08 (4.50–4.85)**
Emax (mg)	772 ± 120 (489–1056)	672 ± 86 (473–870)
Emax per mass (mg/mg)	18.9 ± 5.2 (6.2–31.7)	22.3 ± 5.2 (10.4–34.2)

For abbreviations see text. Mean values ± SEM are given. Numbers in parentheses are 95%-confidence intervals. §Owing to data distribution geometric mean and SEM (expressed as factor to be multiplied with the mean and indicated by ÷) are given. ** p < 0.005 regarding the comparison between groups.

Figure 1 Mean (±SEM) concentration-response curves (mg tension vs molar concentration of histamine) obtained in control smokers (open circles) and patients with COPD (closed circles).

Figure 2 Relationship between histamine responsiveness of isolated bronchi in vitro in terms of the potency pED₅₀ (x-axis) and responsiveness to histamine in vivo in terms of the provocative concentration PC₂₀FEV₁ (panel A, log scale), % change of FEV₁ after inhalation of salbutamol (panel B), baseline FEV₁ %predicted (panel C), and the mass of bronchial specimens (panel D). Control patients are represented by open circles, patients with COPD by closed circles.