Tomato nsLTP as an "In Vivo" Diagnostic Tool: Sensitization in a Mediterranean Population

BACKGROUND

Tomato allergies have been extensively studied but component-resolved in vivo diagnosis with purified allergens has yet to be performed.

OBJECTIVES

To evaluate the prevalence of sensitization to Sola l 3 in a Mediterranean population, and to compare the resulting sensitization profile with that of individuals sensitized to tomato, peach, and/or purified lipid transfer protein (LTP).

METHODS

Sola l 3 was purified, characterized, and used to prepare skin prick tests (SPTs). Two groups of patients were selected. Group 1 consisted of patients with at least 1 positive SPT to tomato, peach, or LTP mixture (marker extracts) who were subsequently tested with Sola l 3 (n = 280). Group 2 (prevalence study) consisted of patients who underwent simultaneous SPT with the 3 marker extracts and Sola l 3 (n = 658). Patients from either group who were positive to any of the 4 extracts were studied in detail (study group, n = 1 23). ELISA and immunoblot assays were performed in individuals with a positive SPT to Sola l 3 to detect the presence of specific IgE antibodies to this allergen.

RESULTS

Prevalence of sensitization to Sola l 3 was 3.2% overall and 54.7% in tomato-positive patients. Most tomato-sensitized patients were asymptomatic. Symptoms were more common in Sola l 3-positive individuals. Sensitization to peach and the LTP mixture did not discriminate between Sola l 3-positive and Sola l 3-negative patients.

CONCLUSIONS

This study confirms that LTP, not only from peach but also from other fruit and vegetables, including tomato, is an important allergen in the Mediterranean area. Sensitization to Sola l 3 is associated with more symptoms in tomato-sensitized patients.

Goji berries (Lycium barbarum): risk of allergic reactions in individuals with food allergy

BACKGROUND

New foods are frequently introduced in Western diets for their healthy properties; however, they may produce adverse effects.

OBJECTIVE

After attending a patient who experienced an allergic reaction to Goji berries, we evaluated the allergenic potential of this food in plant food-allergic individuals, a group that is considered to be at high risk of experiencing a reaction.

METHODS

We recruited 30 additional plant food-allergic individuals in Spain during 3 months in 2010. Four patients reported symptoms on intake, 6 tolerated the berries, and 20 had never tried Goji berries. Patients underwent skin prick tests with Goji berries, as well as with peach peel and plant food panallergens as markers of cross-reactivity between unrelated foods. We carried out in vitro tests in symptomatic patients.

RESULTS

Skin tests to Goji berries were positive in 24 patients (77%): 5 symptomatic patients and 19 asymptomatic patients. Positivity to Goji berries was associated with positivity to peach peel and to the panallergen nonspecific lipid transfer protein (LTP). Nearly half of the patients reported symptoms (45%), but 89% of the skin test-positive patients had never eaten Goji berries. We detected specific immunoglobulin E to Goji berries in all cases, and several individuals recognized 2 protein bands in the immunoblot. Addition of LTP to sera mostly inhibited immunoglobulin E binding to an LTP-like band, suggesting a role for this panallergen in sensitization to Goji berries.

CONCLUSIONS

Our results demonstrate the allergenic potential of Goji berries in high-risk individuals, which is probably due to cross-reactivity with LTP from other foods. The risks of Goji berries should be taken into consideration in individuals with food allergy, especially those who are allergic to LTP.

Sensitization to tomato peel and pulp extracts in the Mediterranean Coast of Spain: prevalence and co-sensitization with aeroallergens

BACKGROUND

Tomatoes (Lycopersicon esculentum) are consumed world-wide. The prevalence of sensitization to tomatoes remains unknown.

OBJECTIVE

To determine the prevalence of skin test reactivity to tomato and to describe the characteristics of tomato-sensitized subjects.

METHODS

Individuals attending for the first time during the period of the study to six Allergy centres, located along the Mediterranean coast of Spain, reporting respiratory and/or cutaneous symptoms, were included. All patients were skin prick tested with a battery of inhalant allergens and with peel and pulp of Canary tomato extracts.

RESULTS

The study included 1734 individuals (757 males, 977 females; 31.9+/-17.8 years old). The prevalence of sensitization to tomato was 6.52% (113 patients; 65 males, 48 females; 29.5+/-13 years old). The peel extract was positive in 110 patients and the pulp extract in 47 patients; three patients were positive exclusively to pulp. Only 1.8% of individuals reported symptoms with tomato; 44% of them had skin test negative to both extracts. Among tomato-sensitized subjects, 16% reported symptoms with tomato, 97% were sensitized to inhalant aeroallergens, including 84% to pollens (mainly Artemisia vulgaris and Platanus hybrida), with differences between Northern and Southern centres.

CONCLUSIONS

The prevalence found of skin test sensitivity to tomato is high. Peel extracts detected most of the sensitized subjects. Most of the sensitized subjects were asymptomatic and some patients reported symptoms without skin test sensitivity. Positive subjects were very frequently sensitized to pollens, suggesting allergen cross-reactivity. Regional differences may exist, possibly related to the pattern of sensitization to cross-reacting pollens.

Myocardial ischemia due to severe amoxicillin allergy

A patient suffered a myocardial injury as a manifestation of anaphylactic reaction to amoxicillin-clavulanic acid administration. A cardiologic study (ergometry and catheterization) showed no obstructive coronary disease and prick test to amoxicillin was positive. Anaphylaxis may cause myocardial injury and the mechanism is likely to be vasospasm induced by mast cells and basophil mediators.

Impaired type-1 activity and increased NK cells in Gleich's syndrome

BACKGROUND

An altered production of cytokines has been described in Gleich's syndrome. Our aim was to study the cytokine production at the single-cell level in a patient with Gleich's syndrome and to determine whether it changed during a flare episode.

METHODS

Blood samples were obtained from a 30-year-old woman diagnosed with Gleich's syndrome before and during the subsequent flare of edema of trunk and arms and weight gain. The major lymphoid subsets (CD4+, CD8+, and CD19+) and natural killer (NK) cells were measured by flow cytometry. Cytokine-producing T cells (IL-2, IFN-gamma, and IL-4) were quantified in whole blood by intracellular staining with specific monoclonal antibodies and flow cytometry analysis after polyclonal stimulation with phorbol 12-myristate 13-acetate and ionomycin.

RESULTS

Increased numbers of immature CD4+CD8+ T cells and NK cells were observed in peripheral blood during the asymptomatic period. The latter population significantly decreased during the flare. Type-1 cells were decreased in both asymptomatic and, more markedly, during the attack with respect to healthy subjects.

CONCLUSIONS

The decreased type-1 response demonstrated in this patient might be the basis of the hypereosinophilia of Gleich's syndrome. Besides, the NK cells might play a role in the pathogenesis of these inflammatory episodes.

Stevens-Johnson syndrome from tetrazepam

We present a case of a patient showing a cutaneous and systemic affectation compatible with the Stevens-Johnson syndrome due to the intake of tetrazepam as a muscular relaxant. The symptoms remitted after the suspension of the involved medicines and after treatment with systemic corticoids. Months later, a study with patch tests, with the standard battery and the medicines that she took (indapamide, tetrazepam, acetyl salicylic acid, botriozolam and levomepromazine) was carried out. She presented positivity to tetrazepam at 48 and 96 hours. The oral provocations with the other medicines, which she consumed, were negative. The study of cross reactivity with other benzodiazepines was negative. In the medical literature, different cutaneous affectations regarding benzodiazepine use (generalised drug eruptions, contact dermatitis, erythema multiforme, ...) have been described byt non Stevens-Johnson syndrome. The patch tests are useful in the diagnosis of this type of cutaneous reactions, avoiding in this way the achievement of oral provocations, with the potential risk for the patient that they imply. The absence of cross-reactions with other substances of the same group has to be pointed out, even with those with which keeps great structural similarity as the diazepam. In spite of the absence of cross reactions with the rest of benzodiazepines, faced with the seriousness of the case presented, it is advised to the patient to avoid this type of medicines.