House dust mite allergy and shrimp allergy: a complex interaction

Summary

Background and Objective. Sensitization and allergy to shrimp among Italian house dust mite allergic patients are not well defined and were investigated in a large multicenter study. Methods. Shrimp sensitization and allergy were assessed in 526 house dust mite (HDM)-allergic patients submitted to the detection of IgE to Der p 10 and 100 atopic control not sensitized to HDM. Results. Shrimp allergy occurred in 9% of patients (vs 0% of 100 atopic controls not sensitized to HDM; p minor 0.001). Shrimp-allergic patients were less frequently hypersensitive to airborne allergens other than HDM than crustacean-tolerant subjects (35% vs 58.8%; p minor 0.005). Only 51% of tropomyosin-sensitized patients had shrimp allergy, and these showed significantly higher Der p 10 IgE levels than shrimp-tolerant ones (mean 22.2 KU/l vs 6.2 KU/l; p minor 0.05). Altogether 53% of shrimp-allergic patients did not react against tropomyosin. Conclusions. Shrimp allergy seems to occur uniquely in association with hypersensitivity to HDM allergens and tropomyosin is the main shrimp allergen but not a major one, at least in Italy. Along with tropomyosin-specific IgE levels, monosensitization to HDM seems to represent a risk factor for the development of shrimp allergy among HDM allergic patients.

Diagnostic relevance of IgE sensitization profiles to eight recombinant Phleum pratense molecules

BACKGROUND

Grass pollen-related seasonal allergic rhinoconjunctivitis (SARg) is clinically heterogeneous in severity, comorbidities, and response to treatment. The component-resolved diagnostics disclosed also a high heterogeneity at molecular level. Our study aimed at analyzing the characteristics of the IgE sensitization to Phleum pratense molecules and investigating the diagnostic relevance of such molecules in childhood.

METHODS

We examined 1120 children (age 4-18 years) with SARg. Standardized questionnaires on atopy were acquired through informatics platform (AllergyCARD™). Skin prick tests were performed with pollen extracts. Serum IgE to airborne allergens and eight P. pratense molecules (rPhl p 1, rPhl p 2, rPhl p 4, rPhl p 5b, rPhl p 6, rPhl p 7, rPhl p 11, rPhl p 12) were tested by ImmunoCAP FEIA.

RESULTS

The analysis of IgE responses against eight P. pratense molecules showed 87 profiles. According to the number of molecules recognized by IgE, the more complex profiles were characterized by higher serum total IgE, higher grass-specific serum IgE, and higher number and degree of sensitization to pollens. The most frequent IgE sensitization profile was the monomolecular Phl p 1. Sensitization to Phl p 7 was a reliable biomarker of asthma, whereas Phl p 12 of oral allergy syndrome. Sensitization to Phl p 7 was associated with a higher severity of SARg, and complex profiles were associated with longer disease duration.

CONCLUSIONS

In a large pediatric population, the complexity of IgE sensitization profiles against P. pratense molecules is related to high atopic features although useless for predicting the clinical severity. The detection of serum IgE to Phl p 1, Phl p 7, and Phl p 12 can be used as clinical biomarkers of SARg and comorbidities. Further studies in different areas are required to test the impact of different IgE molecular profiles on AIT response.

Endotypes of pollen-food syndrome in children with seasonal allergic rhinoconjunctivitis: a molecular classification

BACKGROUND

Pollen-food syndrome (PFS) is heterogeneous with regard to triggers, severity, natural history, comorbidities, and response to treatment. Our study aimed to classify different endotypes of PFS based on IgE sensitization to panallergens.

METHODS

We examined 1271 Italian children (age 4-18 years) with seasonal allergic rhinoconjunctivitis (SAR). Foods triggering PFS were acquired by questionnaire. Skin prick tests were performed with commercial pollen extracts. IgE to panallergens Phl p 12 (profilin), Bet v 1 (PR-10), and Pru p 3 (nsLTP) were tested by ImmunoCAP FEIA. An unsupervised hierarchical agglomerative clustering method was applied within PFS population.

RESULTS

PFS was observed in 300/1271 children (24%). Cluster analysis identified five PFS endotypes linked to panallergen IgE sensitization: (i) cosensitization to ≥2 panallergens ('multi-panallergen PFS'); (ii-iv) sensitization to either profilin, or nsLTP, or PR-10 ('mono-panallergen PFS'); (v) no sensitization to panallergens ('no-panallergen PFS'). These endotypes showed peculiar characteristics: (i) 'multi-panallergen PFS': severe disease with frequent allergic comorbidities and multiple offending foods; (ii) 'profilin PFS': oral allergy syndrome (OAS) triggered by Cucurbitaceae; (iii) 'LTP PFS': living in Southern Italy, OAS triggered by hazelnut and peanut; (iv) 'PR-10 PFS': OAS triggered by Rosaceae; and (v) 'no-panallergen PFS': mild disease and OAS triggered by kiwifruit.

CONCLUSIONS

In a Mediterranean country characterized by multiple pollen exposures, PFS is a complex and frequent complication of childhood SAR, with five distinct endotypes marked by peculiar profiles of IgE sensitization to panallergens. Prospective studies in cohorts of patients with PFS are now required to test whether this novel classification may be useful for diagnostic and therapeutic purposes in the clinical practice.

Characteristics of patients with allergic polysensitization: the POLISMAIL study

BACKGROUND

The natural history of respiratory allergy is commonly characterized by a worsening of symptom severity, frequent comorbidity of rhinitis and asthma, and polysensitization to aeroallergens. The polysensitization phenomenon starts since childhood and is rare to find monosensitized adult patients. However, there are few studies investigating the characteristics of polysensitized patients.

METHODS

This study was performed on a large cohort of patients with allergic rhinitis (assessed by ARIA criteria) and/or mild to moderate asthma (assessed by GINA). The kind and the number of sensitizations, their patterns, and the relation with quality of life (QoL) measured by the Juniper's RQLQ guestionnaire, were evaluated.

RESULTS

Globally 418 patients (50.2% males, 49.8% females, mean age 26.4 years, range 3.5-65 years, 64 smokers, 371 non-smokers) were enrolled: 220 had allergic rhinitis alone, and 198 allergic rhinitis and asthma. The mean number ofsensitizations was 2.6. Three hundred-five patients (73%) had persistent rhinitis (PER), 220 of them with moderate-severe form. There was no significant derence in rate of rhinitis and asthma in monosensitized or polysensitized patients. Most patients were sensitized to pollens, whereas only 24.2% of them were sensitized to perennial allergens. Polysensitization was significantly associated with some issues of QoL, confirming previous findings, but not with number ofsensitizations.

CONCLUSIONS

This study provides data confirming for poly-sensitized patients the relevance of ARIA classification of AR. PER is the most common form of AR in this cohort, symptoms are frequently moderate-severe, and asthma is present in about the half of patients with AR.

Intermittent and Persistent Allergic Rhinitis and Association with Asthma in Children

The natural history of allergic rhinitis (AR) is commonly characterized by worsening of symptom severity, frequent comorbidity with asthma, and polysensitization to aeroallergens. The polysensitization phenomenon starts in early childhood. AR classification has been recently revised, and some studies investigated the new types: intermittent (IAR) and persistent (PER) AR. However, no study has been carried out on children regarding this issue. This preliminary study was performed on a large cohort of children with allergic rhinitis to evaluate the type and severity of rhinitis and its possible association with asthma, including severity grade. One hundred and thirty-nine children (86 males, 53 females, mean age 11.8 years, range 3.5–17.7 years) with allergic rhinitis were prospectively and consecutively evaluated. Seventy-one children had rhinitis alone and 68 had rhinitis associated with asthma. Forty children had IAR, 30 of whom with moderate-severe grade. Ninety-nine children had PER, 65 of whom had moderate-severe grade. The severity of AR was not associated with asthma presence (Fisher χ2 = 0.5765; Prob.=0.9018). Regarding asthma severity, 30 children had the intermittent form, whereas 38 had the persistent form: 15 mild, 22 moderate, and 1 severe. This study provides the first evidence concerning the ARIA classification in children, partially confirming findings obtained in adulthood.

Comparison of ammoniated and nonammoniated extracts in children with latex allergy

BACKGROUND

The use of ammoniated or nonammoniated latex extracts for the diagnosis of latex allergy is still a matter of debate. The aim of our study was to compare the characteristics of the two types of extracts by immunoblotting and RAST techniques in children with ascertained latex allergy.

METHODS

Ammoniated (AL) and nonammoniated latex (NAL) extracts were prepared and blotted on SDS-PAGE to resolve their components. Also a solid phase for RAST assays was prepared with the two extracts. The sera from 18 children (mean age 11.4 years, range 6-15 years), with ascertained latex allergy (clinical history, skin test, CAP-RAST and provocation) were used for the experiments.

RESULTS

The NAL extract is resolved in many bands (5-100 kDa), whereas AL showed only few components, likely Hev b 4, 6 and 7. IgE reactivity against AL was observed only in 5/18 patients, whereas 12/18 were positive with NAL. The blotting profile against NAL was complex and the IgE recognition pattern involved different bands.

CONCLUSION

The extract obtained from NAL is able to detect specific IgE against a greater number of allergenic determinants, and therefore a greater diagnostic accuracy can be expected.

The major allergen of sesame seeds (Sesamum indicum) is a 2S albumin

BACKGROUND

Allergic reactions induced by ingestion of foods containing sesame seeds are a well recognized cause of severe food-induced anaphylaxis.

OBJECTIVE

This study aimed to identify and characterize the clinically most important major allergen of sesame seeds.

METHODS

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and IgE immunoblotting were performed on sera of 10 patients selected for severe and documented allergic reaction after eating food containing sesame. The major allergen was purified by gel filtration and characterized by isoelectric point (pI), glycosylation and amino acid sequencing.

RESULTS

All the patients had positive IgE antibodies and skin prick tests (SPTs) to sesame. The major, clinically most important allergen was a protein with molecular mass of about 9000. It was not glycosylated, the amino acid sequence showed it was a 2S albumin with a pI of 7.3; the small and the large subunits, forming the whole protein, showed pI values of 6.5 and 6.0.

[Chronic mononucleosis: a case of difficult diagnosis]

Here is referred the case history of a boy - age 6 yrs - who was hospitalised for a persistent high temperature with generalised limphonodes hypertrophy. The limphonode biopsy together with decreased NK activity and increased antiEAD and antiVCA antibodies allowed the diagnosis of chronic mononucleosis.

Immune status in children with acute lymphocytic leukemia. Observations in 67 cases

67 children affected with acute lympocytic leukemia were immunologically evaluated for lymphocytic markers, serum immunoglobulins and delayed hypersensitivity skin tests at the onset, in remission and after cessation of therapy. E, EA rosettes and surface Ig assayed significantly lower in leukemic children than in matched controls, except for three cases of T-cell leukemia in which E rosettes were very high. After cessation of therapy almost normal results were obtained. As for serum Ig, the only abnormal finding was that of low IgM during therapy. The skin tests with Varidase, Candidine, Mumps antigen and DNCB were not significantly different at onset and in remission. As for DNCB test, the negative responses at onset often became positive in remission, but only when the test was performed before any treatment (anamnestic-like response?). One of the three patients with T-cell leukemia relapsed after 8 months: strangely enough, no surface marker could be detected on that occasion. We could not find any relationship between various immunological tests, or between these tests and prognosis; chemotherapy proved active in suppressing cellular immunity, especially the primary cellular response.