Prevalence of Pol d 1 Sensitization in Polistes dominula Allergy and Its Diagnostic Role in Vespid Double-Positivity.

BACKGROUND: Stings by Polistes species frequently cause allergic reactions. However, standard allergy diagnostics are often unable to differentiate between primary sensitization and cross-reactivity in case of Vespula/Polistes double-sensitization because antigen 5 is the only Polistes venom molecule currently available in diagnostics (Pol d 5). OBJECTIVE: To evaluate the frequency of phospholipase A1 in Polistes venom allergy (Pol d 1) and its diagnostic role in vespid allergy. METHODS: We performed component-resolved diagnostics in patients with vespid allergic reactions who were positive to Polistes venom. A prevalence analysis was performed and the diagnostic accuracy of Pol d 1 was evaluated to detect primary Polistes sensitization in double-sensitized patients. RESULTS: Blood samples were collected from 132 patients. Pol d 1 was present in 97% to 100% of 128 Polistes-positive patients. It was frequently involved in case of positivity to a single Polistes molecule (48% in double- and 80% in mono-sensitized patients). Furthermore, Pol d 1 was positive in 95% of Pol d 5-negative subjects. The diagnostic accuracy of Pol d 1 was good (folded type: area under the curve = 87%; 82% sensitivity and 77% specificity at the best cutoff of 5.773), and even better when used combined with the whole extract ratio (area under the curve = 99%; 91% sensitivity and 100% specificity). CONCLUSIONS: The study shows that Pol d 1 is the most frequent Polistes allergen in Italian patients. It can distinguish Polistes primary sensitizations with good diagnostic accuracy, which supports its use in clinical practice.

Immune Response to Rotavirus and Gluten Sensitivity.

Rotavirus is a double-stranded RNA virus belonging to the family of Reoviridae. The virus is transmitted by the faecal-oral route and infects intestinal cells causing gastroenteritis. Rotaviruses are the main cause of severe acute diarrhoea in children less than 5 years of age worldwide. In our previous work we have shown a link between rotavirus infection and celiac disease. Nonceliac gluten sensitivity (NCGS) is emerging as new clinical entity lacking specific diagnostic biomarkers which has been reported to occur in 6-10% of the population. Clinical manifestations include gastrointestinal and/or extraintestinal symptoms which recede with gluten withdrawal. The pathogenesis of the disease is still unknown. Aim of this work is to clarify some aspects of its pathogenesis using a gene array approach. Our results suggest that NCGS may have an autoimmune origin. This is based both on gene expression data (i.e., TH17-interferon signatures) and on the presence of TH17 cells and of serological markers of autoimmunity in NCGS. Our results also indicate a possible involvement of rotavirus infection in the pathogenesis of nonceliac gluten sensitivity similarly to what we have previously shown in celiac disease.

Normal or defective immune response to Hepatitis B vaccine in patients with diabetes and celiac disease.

A defective production of protective levels of antibodies to Hepatitis B (HB) vaccine is reported to occur in 4-10% of healthy subjects and a correlation with the presence of specific human leukocyte antigen (HLA) molecules, including DQ2, which also confers genetic predisposition to celiac disease (CD) and type I diabetes mellitus (T1DM), has been suggested.   The aim of this study was to analyze the serological response to HB vaccine and measles-containing vaccines in 69 diabetic patients (T1DM), 42 patients with celiac disease (CD) and 79 healthy control subjects (CT). The median interval between the third dose of HB vaccine and serum collection was 6.8, 3.5, and 4.7 years for T1DM, CD and CT groups, respectively. 50/69 (72%) T1DM patients, 32/42 (76%) CD patients and 61/79 (77%) CT subjects showed protective anti-HBs antibodies after vaccination, with no statistically significant difference. On the contrary, a lower statistically significant difference was found in the mean HBsAb level of T1DM subjects when compared with the other two groups. No correlation between HLA DQ2 expression in T1DM and vaccine response was detected. The comparison of serological response to measles after vaccination also showed no statistically significant differences in the three groups. Contrasting results between these data and those reported in the literature might be due to differences in the time intervals between vaccination and testing. Prospective studies in pathological and healthy groups with the same age at HBV vaccination and with the same time interval for blood sample collection to determine antibody titers are necessary in order to provide more conclusive data.