Component resolved diagnosis in real life: the risk assessment of food allergy using microarray-based immunoassay

BACKGROUND

The development of component-resolved diagnostics constitutes a potential breakthrough in food allergy testing, as detection of specific IgE (sIgE) to individual allergens may make it possible to establish the risk of a mild versus severe reaction.

OBJECTIVE

To compare allergists' risk assessment based on the current decision making process with that of virtual allergen-oriented risk assessment through microarray-based immunoassay.

METHODS

An observational, real-life study was performed on 86 adults with food allergy. The prescription of epinephrine was the surrogate marker of a severe reaction. In the same patients, the prescription of epinephrine based on the current decision making of the allergist and the independently established allergen-oriented risk assessment determined by microarray-based immunoassay were compared.

RESULTS

Fair degree of agreement between the specialists' risk assessment and that of the microarray-based immunoassay (k index 0.372 (95% CI: 0.185- 0.559) p < 0.001) was documented. Three causes of discrepancy emerged: the poor sensitivity of the allergen microarray-immunoassay (51.9%), the differences in risk assessment established by the specialist and the microarray-immunoassay (33.3%), the non-inclusion of the causative allergen in the microarray-immunoassay platform (14.8%).

CONCLUSION

Improvement of the diagnostic accuracy of microarray-immunoassay, combined with marrying its results to clinical information, could one day soon lead to changes in clinical practice in food allergy.

Hen egg hair mask-induced food allergy: a case report

We report the case of a 46-year-old woman who treated her hair with a homemade egg-white based mask. After one year of weekly applications, the ingestion of egg triggered rhinitis, choking and systemic urticaria. Though the breakdown of oral tolerance to egg has been reported elsewhere in the literature, to the best of our knowledge, this is the first case of hair mask-induced allergy.

Congruence between international guidelines and mite specific immunotherapy prescribing practices

Both rhinitis (ARIA) and asthma (GINA) guidelines recommend allergen-specific immunotherapy (SIT) tailored to the specific levels of severity of each disease. Real world studies evaluating congruence between these recommendations and prescribing practice in the single patient with comorbidity are lacking. An observational polycentric study was carried out in 518 patients recruited from 34 allergy centers throughout Italy. A questionnaire was administered to each consecutive patient over a span of four months. Taking into account guideline recommendations for both diseases, concomitant in the same patient, three subsets resulted: patients not eligible for SIT (11%); patients eligible for SIT for one disease only (60%); patients eligible for SIT for both diseases (29%). SIT was prescribed in 257 (49.6%) subjects. The level of SIT prescription was about 50% in all three groups. Consistent with the ARIA guidelines, a correlation between the prescription of SIT and the severity of rhinitis was documented (r=0.87; p=0.001). An association with asthma severity was found (p=0.02), but the trend was inconsistent with the GINA recommendations. Young age was the most important factor for SIT prescription both in the eligible for one disease and in the eligible for both diseases subset. The tendency towards worsening of symptoms was a factor for SIT in the eligible for one disease subset. In mite allergic patients with rhinitis and asthma comorbidity, the severity of rhinitis and the young age are the most important factors driving the SIT prescription. The congruence of SIT prescription was better for the ARIA than GINA guidelines.

Characterization and comparison of commercially available mite extracts for in vivo diagnosis

BACKGROUND

Assessment of sensitization by allergen-specific IgE testing and skin prick testing (SPT) are primary tools in routine clinical diagnosis of allergies. To perform a correct diagnosis, it is critical that the allergen reagent used contains an adequate amount of all relevant components. This study aimed at evaluating commercially available mite extracts for in vivo diagnosis from eight manufacturers.

METHODS

Eight extracts from Dermatophagoides pteronyssinus and eight from Dermatophagoides farinae were analysed for total protein content by Bradford and for major allergen content by ELISA. SDS-PAGE, immunoblotting and SPT were also carried out.

RESULTS

The protein amount ranged from 27.7 microg/ml extract to 361.1 microg/ml (D. pteronyssinus) and from 20.3 to 353.0 microg/ml (D. farinae). In regards major allergen concentration, Der p 1 ranged from 9.6 to 36.2 microg/ml, Der f 1 26.5-196.1 microg/ml, mite group 2 0.7-31.7 microg/ml in D. pteronyssinus and 1.3-10.4 microg/ml in D. farinae. SDS-PAGE experiments showed that some components are poorly represented or absent in extracts from most manufacturers. Similar results were obtained by IgE-immunoblotting and SPT with 10 mite allergic patients confirmed a broad spectrum of reactivity of the extracts in the same subject.

CONCLUSIONS

Immunochemical analysis showed a heterogeneous amount of component/s among mite extracts from different manufacturers. These data were confirmed by in vivo testing, suggesting that, for some of the patient tested, the absence of relevant allergens could strongly affect the diagnosis.

Allergic rhinitis and associated pathologies: the rationale for steroid options

The aim of this review article is to provide greater insight into the relationship between allergic rhinitis and the three most frequently diagnosed conditions of exacerbating viral infections, chronic rhinosinusitis with polyps and obstructive sleep apnoea syndrome. The alleged physiopathological effects of steroids are also investigated within the scope of this paper. Regarding the exacerbating viral infections, seems to establish a dynamic and counter relationship between the load and nature of the viral infection on one hand and widespread and pre-existing allergic inflammation on the other. If chronic rhinosinusitis with polyps and allergic rhinitis present overlapping picture of inflammatory cell and cytokine, the etyiological relationship between the two conditions appears to be influenced by the type of antigenic stimulus. Allergic rhinitis can influence the presence of OSAS through both obstructive and inflammatory mechanical factors. Topical corticosteroid therapy is a promising candidate as a new therapeutic tool able to improve symptoms and quality of life in patient with chronic rhinosinusitis with polyps and obstructive sleep apnoea syndrome. Other study are necessary to elucidate relationship between corticosteroids therapy and hypothetical benefit effect on viral infection when concomitant atopy inpatient.

Evolution of HVR-1 Quasispecies after 1-Year Treatment in HIV/HCV-Coinfected Patients According to the Pattern of Response to Highly Active Antiretroviral Therapy

Hepatitis C virus (HCV) variability is mainly attributed to the ability of the virus to respond to host immune pressure, acting as a driving force for the evolution of quasispecies. This study was aimed at studying the changes in HVR-1 heterogeneity and the evolution of HCV quasispecies in HIV/HCV-coinfected patients according to the pattern of response to highly active antiretroviral therapy (HAART).

Sixteen HIV/HCV-coinfected patients harbouring HCV genotype 1 and who had been on HAART for at least 1 year, 8 showing increasing CD4+T-cell counts (immunological responders) and 8 showing a stable or decreasing CD4+ T-cell counts (immunological non-responders), were selected from a prospective cohort study.

After 1 year of HAART, 11 patients showed HIV viral load <2.6 log10 cp/ml (virological responders), and 5 showed HIV viral load above this value (virological non-responders). Plasma samples, collected before starting therapy and after 1 year of HAART, underwent clonal sequence analysis for HVR-1 region of HCV. Non-synonymous/synonymous substitutions ratio (Ka/Ks), aminoacidic complexity (normalized Shannon entropy) and diversity (p-distance), were considered as parameters of quasispecies heterogeneity. After 1 year of HAART, heterogeneity of HVR-1 quasispecies significantly decreased in virological non-responders, whereas the heterogeneity tended to increase in virological responders. The differences in the evolution were less stringent, when considering immunological response. On the other hand, profound qualitative modifications of HVR-1 quasispecies were observed only in patients with both immunological and virological HAART response.

On the whole, these findings suggest that, in patients undergoing HAART, the extent of HCV variability and the evolution of HVR-1 quasispecies is influenced by the pattern of response to antiretroviral therapy.

Response to Haart and Gb Virus Type C Coinfection in a Cohort of Antiretroviral-Naive HIV-Infected Individuals

The prognostic role of GB virus type C (GBV-C) viraemia in HIV-infected subjects treated with highly active antiretroviral therapy (HAART) is still undefined, The aim of this analysis is to assess the relationship between GBV-C infection and response to antiretroviral therapy among HIV-infected subjects initiating HAART when antiretroviral-naive.

A prospective, observational study of 400 HIV-infected patients with measurements of GBV-C RNA, hepatitis C virus (HCV) antibodies and HCV RNA determined from plasma stored prior to HAART initiation, Time to virological (achieving HIV RNA ≤500 copies/ml) and immunological success (a CD4+ count increase of ≥200cells/μl), and the time to virological relapse (confirmed HIV RNA >500 copies/ml) were assessed by Kaplan-Meier methods and Cox proportional hazard regression model.

Of the subjects, 117 (29.3%) were GBV-C positive and, overall, 351 (87.8%) patients achieved virological success, After controlling for a number of confounders including HCV RNA, GBV-C viraemic patients experienced a significantly lower risk of HIV rebound than those who were GBV-C negative [relative hazard (RH)=0.56, 95% CI: 0.34–0.93, P=0.03], Conversely, the probability of achieving initial virological success or CD4+ count response after HAART did not differ between GBV-C-negative and -positive subjects, These results suggest that GBV-C coinfection may play a role in determining the rate of HIV rebound possibly by competing with HIV replication after HIV load has been successfully suppressed by HAART.