Atopy in omani patients with asthma

الملخص EN

Objectives : to determine the range of serum IgE in healthy subjects and in asthmatic patients in Oman and to assess the degree of atopy in the asthmatic patients.

Method : serum IgE and in vivo (the skin prick test) and in vitro (the Immuno CAP test) allergen- specific IgE levels were measured in 44 patients with asthma.

Control groups were 19 healthy subjects and 27 asymptomatic allergic subjects.

Results : the normal range for serum IgE in the Omani population was established at ≥ 101 IU / ml.

The geometric mean (and 95% confidence interval) for asthmatic patients was 468 IU / ml (323–676).

Positive results for allergen-specific IgE, defined as responses to ≥ 1 allergen mix in the Immuno CAP and to ≥ 3 allergens in the skin prick test, occurred in 26 / 35 (74%) and in 34 / 44(77%) asthmatic patients respectively.

Six out of 38 patients with serum IgE ≥ 101 IU / ml and 2 / 6 with levels <101 IU / ml gave negative and positive results respectively in the skin prick test.

Overall, the degree of reactivity in the skin prick test correlated with the level of total serum IgE (r = 0.54, p<0.001).

A similar correlation could not be established with ImmunoCAP reactivity, but sIgE levels ≥ 101 IU / ml were supported by a high frequency of positive ImmunoCAP responses for the majority of allergen mixes. Conclusions : total serum IgE levels should be routinely monitored in asthmatic subjects as this may give an indication of atopy where skin prick testing is not indicated.

Since in a minority of patients serum IgE levels and skin prick results do not predict in the same direction, all laboratory data should be interpreted in context of clinical history.