Table 2.

The association ofGSTP1 genotype with atopic status and degree of airway reactivity/obstruction

	Total	Skin test	Skin test	IgE ≤	IgE >
Genotype	group	negative	positive	100 IU/ml	100 IU/ml	Group 1	Group 2	Group 3	Group 4
AA	79 (42.4)	29 (40.9)	50 (41.7)	42 (43.3)	27 (38.6)	17 (29.3)	4 (26.7)	21 (41.2)	23 (48.9)
AB	66 (34.6)	21 (29.6)	45 (37.5)	30 (30.9)	30 (42.9)	24 (41.4)	6 (40.0)	21 (41.2)	14 (29.8)
AC	26 (13.6)	10 (14.1)	16 (13.3)	11 (11.3)	11 (15.7)	7 (12.1)	3 (20.0)	6 (11.8)	7 (14.9)
AD	2 (1.1)	0 (0)	2 (1.7)	1 (1.0)	1 (1.4)	1 (1.7)	0 (0)	0 (0)	1 (2.1)
BB	7 (3.7)	4 (5.6)	3 (2.5)	5 (5.2)	0 (0)	3 (5.2)	1 (6.7)	1 (2.0)	1 (2.1)
BC	9 (4.7)	7 (9.9)	2 (1.7)*	7 (7.2)	0 (0)	5 (8.6)	1 (6.7)	1 (2.0)	1 (2.1)
BD	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
CC	2 (1.1)	0 (0)	2 (1.7)	1 (1.0)	1 (1.4)	1 (1.7)	0 (0)	1 (2.0)	0 (0)
CD	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
DD	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
Alleles
GSTP1*A	0.660	0.627	0.679	0.649	0.686	0.569	0.567	0.676	0.731
GSTP1*B	0.233	0.254	0.221	0.242	0.214	0.302	0.300	0.235	0.172
GSTP1*C	0.102	0.120	0.092	0.103	0.093	0.121	0.133	0.088	0.086
GSTP1*D	0.005	0	0.008	0.005	0.007	0.009	0	0	0.011

Atopic status was defined as positive skin test and IgE 100 IU/ml or less. Groups were defined as follows: group 1, percentage predicted >80%/PC₂₀ >16 mg/ml; group 2, percentage predicted >80%/PC₂₀ 8-16 mg/ml; group 3, percentage predicted >80%/PC₂₀ 0-8 mg/ml; and group 4, percentage predicted ≤ 80%. Values are expressed as number (%) for the genotype frequencies, or as proportions for the allele frequencies.^*Logistic regression analysis for skin test: uncorrected GSTP1 BC versus GSTP1 AA, OR 0.17, 95% CI 0.03-0.85 (P = 0.031); and corrected for age and sex, OR 0.18, 95% CI 0.04-0.96 (P = 0.045). Trend test analysis across groups 1-4: uncorrected GSTP1 BC versus GSTP1AA, P = 0.031; and corrected for age and sex, P = 0.02.