Proliferation assays were used to determine peripheral blood T cell responses to affinity-purified
Der p I,
Der p II, and
Der f II allergens. Patients studied were sensitive to the house dust mite (HDM) either alone or in combination with other
allergens. Control subjects were both nonatopic and atopic non-HDM sensitive. In general, only HDM-sensitive patients responded to the mite
allergens. Mean stimulation indices (SI) were 10.2 +/- 2.8 (SEM) for
Der p I and 10.0 +/- 2.2 for
Der p II in HDM-sensitive individuals, and 2.0 +/- 0.2 and 2.8 +/- 0.6 for non-HDM sensitive control subjects (p less than 0.001). Patients sensitive to HDM and other
allergens had higher responses than subjects sensitive to HDM alone, and the degree of proliferation to
Der p I and
Der p II was well correlated in individual patients (r = 0.71; p less than 0.001). Total
IgE levels were elevated in the allergic patients, and values were highly correlated with the SI for both
Der p I and
Der p II (p less than 0.001). Responses to
Der p II and
Der f II were equivalent in 82% of individuals; however, in 18%, there was a marked discordance with strong responses to
Der p II only. SIs were compared between different clinical groups of patients, and patients with
asthma had significantly higher values to both
Der p I and
Der p II than patients with
rhinitis alone (17.0 +/- 5.4 versus 5.7 +/- 1.0 for
Der p I, p less than 0.05; 14.3 +/- 6.8 versus 5.0 +/- 1.0 for
Der p II, p less than 0.05).