Characterisation of systemic reactions to subcutaneous immunotherapy with airborne allergens and classification according to WAO 2010.

BACKGROUND: Systemic reactions (SR) to subcutaneous immunotherapy (SCIT) are rare but potentially severe. The use of different definitions and classifications hampered comparability between studies. AIMS: To determine the frequency of SR to SCIT with airborne allergens, and to characterise and classify them according to the WAO 2010 recommendations. METHODS: Cross-sectional, retrospective study. Data on patients, immunotherapy and SR to SCIT were collected from the SCIT record forms. During the study period, 22,332 SCIT injections were administered (3732 patients). RESULTS: A total of 26 SR (0.1% of administrations) were recorded in 16 (0.6%) patients (median age 22 years, nine males, all with rhinitis and nine with asthma). Twenty-one (81%) SR occurred during the induction phase; eight (31%) in the first hour after administration. According to the WAO 2010 classification, 12 (46%) were grade 1 and 14 (54%) were grade 2. Most grade 2 reactions occurred in asthmatics, presented as mild asthma symptoms and resolved without need for medical observation. Only two individuals without asthma presented grade 2 reactions, both with concurrent cutaneous and low respiratory symptoms; both required medical observation and treatment despite late onset; 82% (n=12) of grade 2 reactions were late. No grade 3-5 reactions were registered and only one patient needed adrenaline treatment. No risk factors for SR to SCIT were identified in this study. CONCLUSIONS: SCIT is a safe treatment when administered by trained staff. The WAO 2010 classification might be useful for retrospectively classifying the severity of reactions, although its usefulness in treatment decision needs further research.

Tetranychus urticae allergy in a population without occupational exposure.

BACKGROUND: Tetranychus urticae is a phytophagus mite found in the leaves of numerous plants. High sensitization rates have been demonstrated, however, provocation tests have only been performed in an occupational setting. OBJECTIVE: To assess accuracy of skin prick tests and clinical relevance of T. urticae sensitization by means of conjunctival provocation tests (CPT) in a population without occupational exposure and to evaluate possible environmental risk factors for T. urticae allergy. METHODS: Patients ≥ 18 years old sensitized to T. urticae (n = 12) and a non-sensitized control group (n = 12) were invited to perform CPT with T. urticae and fulfill a questionnaire including demographic data, questions on environmental exposure to T. urticae and allergy symptoms/diagnosis. A single-blinded placebo-controlled CPT with T. urticae (Leti®) was performed with increasing concentrations (0.002, 0.02, 0.2 and 2 mg/mL) and considered positive if conjunctival hyperemia, palpebral edema or lacrimation were observed in the tested eye. RESULTS: Of T. urticae sensitized patients (mean wheal 4.4 ± 1.5 mm), 9 had a positive CPT, including 3 monosensitized. A good diagnostic accuracy was found for skin prick tests: AUC = 0.952, sensitivity = 100%, specificity = 80%, positive likelihood ratio = 5 and negative likelihood ratio = 0 for a 3 mm wheal. No differences were found between allergic and non-allergic subjects regarding atopy, allergic disease or farming activities. CONCLUSIONS: A high prevalence of allergy to Tetranychus urticae was found in the north of Portugal. Future studies with a larger number of patients are needed to evaluate its relation to clinical symptoms and the impact of environmental factors.

Costs of treatment affect compliance to specific subcutaneous immunotherapy.

BACKGROUND: Specific subcutaneous immunotherapy (SCIT) is cost-effective; however its economical burden can lead to non-adherence. We aimed to identify the reported reasons, patient's personal or socio-demographic characteristics and SCIT-related factors associated with non-adherence to SCIT. METHODS: This is a cross-sectional, observational study held in a Portuguese University Hospital. All records from patients starting SCIT in the last 4 years were reviewed in July 2011. Those without registry of SCIT administration in the previous 3 months were included (n = 181). A telephonic survey was performed and 56 were confirmed as non-adherent; reasons for discontinuation were assessed. Univariate and multiple logistic regression models were developed using characteristics previously described as being associated with non-adhesion. RESULTS: Economical burden of SCIT was the most important factor leading to treatment discontinuation (40%). In the univariate analysis, presence of family history of allergic disease treated with immunotherapy was associated with decreased OR of non-adherence to SCIT (OR [95%CI] = 0.31 [0.11- 0.88]). In the multiple logistic regression model, none of the factors was significantly associated with non-adherence. CONCLUSION: Adherence is influenced by economic factors. More attention should be given to the impact of economic changes in allergic patient's treatment.

Tuberculosis screening in Portuguese healthcare workers using the tuberculin skin test and the interferon-gamma release assay.

The prevalence of latent tuberculosis (TB) infection (LTBI) and the incidence of active tuberculosis in healthcare workers (HCWs) in a Portuguese hospital were examined. This cross-sectional study comprises 4,735 hospital workers screened between May 2005 and September 2008. Tuberculin skin test (TST) and interferon-gamma release assay (IGRA) were used simultaneously in 1,219 HCWs (25.7%). Radiographs were taken in symptomatic HCWs or in test-positive HCWs. The tests were repeated annually or bi-annually depending on risk assessment. IGRA was positive in 32.6% and TST in 74.2% of the HCWs. Years spent in healthcare were a risk factor for a positive IGRA, but not for a positive TST. Repeated bacillus Calmette-Guérin vaccination increased the probability of TST+/IGRA- discordance (35.4% versus 54.4%, respectively). In those tested three times with TST during the study period (n = 59), the mean diameter of TST increased from 5 to 7 to 10 mm. Within 3 yrs, 31 HCWs were diagnosed with active TB (annual incidence rate 191 out of 100,000 people). In eight HCWs with active TB, TST and IGRA were performed at the time of diagnosis and each test was positive. TB burden in HCWs in Portugal is high. With IGRA, the number of radiographs needed to exclude active TB could have been reduced by about half without missing a case of active TB. Therefore IGRA should be introduced into TB screening programmes.

Indoor mite allergens in patients with respiratory allergy living in Porto, Portugal.

We investigated the levels of mite allergens (Der p 1, Der f 1, Der 2, and Lep d 1) in dust samples from the homes of 59 patients with asthma, 36 sensitized to house-dust mites (HDM) and 23 to grass pollen (controls), living in Porto, northern Portugal. The relationship between exposure and sensitization to HDM and the influence of housing conditions on mite-allergen levels were also evaluated. Der p 1 (median 9.2 micrograms/g) and Der 2 (4.6 micrograms/g) were the main allergens, while Der f 1 and Lep d 1 levels were always < 1 microgram/g dust and undetectable in 11% and 47% of samples, respectively. All HDM-sensitized asthmatics were exposed to Der p 1 levels > 2 micrograms/g and their homes contained significantly higher levels of Der p 1 (median 12.5 vs 6.4 micrograms/g; P = 0.008) and Der 2 (6.2 vs 3.0 micrograms/g; P = 0.004) when compared to the control group. A significant correlation was observed between the exposure to Der p 1 and the wheal area at skin testing with the Dermatophagoides pteronyssinus (Dp) extract (P = 0.01) as well as with serum specific IgE levels to Dp (P = 0.03). Patients with higher levels of serum specific IgE (> or = 17.5 HRU/ml) were also more frequently exposed to Der p 1 levels > or = 10 micrograms/g (P = 0.002). Old homes, presence of carpets, and signs of dampness were conditions associated with significantly higher levels of mite allergens. In conclusion, we found high levels of Der p 1 and Der 2 particularly in the homes of HDM-sensitized patients and we confirm the relationship between exposure and sensitization to HDM, assessed by both in vivo and in vitro methods. In additional to a favorable outdoor climate, we found in our region housing conditions propitious to mite growth, suggesting that specific geographic characteristics must also be taken into account for the correct planning of mite-avoidance measures.

Effects of immunotherapy on symptoms, PEFR, spirometry, and airway responsiveness in patients with allergic asthma to house-dust mites (D. pteronyssinus) on inhaled steroid therapy.

The present study was designed to investigate the effects of immunotherapy (IT) with an extract of Dermatophagoides pteronyssinus (Alergo-Merck Depot) during a 27-month period in patients with allergic asthma to house-dust mites. We included 11 patients (mean age 18 years) treated with a combination of IT and inhaled beclomethasone dipropionate (BDP) in comparison to another 11 (mean age 22 years) treated with BDP alone. We evaluated symptom scores, salbutamol use, peak expiratory flow rates (PEFR), spirometry, and bronchial hyperresponsiveness (BHR) during 18 months of therapy with BDP and in the 9 months after BDP interruption. The two kinds of treatment were efficient and comparable in relation to symptom score, salbutamol use, morning PEFR, FVC, and FEV1, but patients treated with IT and BDP had a faster improvement of BHR and PEFR variability. The interruption of BDP after 18 months of therapy was linked to an impairment of all end points, which were more pronounced in patients previously treated only with BDP. These findings suggest that in selected asthmatic patients allergic to house-dust mites, the association of IT and BDP is more effective than therapy with this inhaled steroid alone due to a faster and more striking improvement during the first months of treatment and to a lower rate of relapse after the interruption of therapy with BDP.

[Cockroach allergy: a study of its prevalence using skin tests with commercial extracts]. / Alergia a la cucaracha: estudio de su prevalencia mediante pruebas cutáneas con extractos comerciales.

Cockroaches have been increasingly recognized as an important source of indoor allergens. In this study we assessed the prevalence of cockroach sensitization among an outpatient population observed at our Department (155 patients with a mean age of 29 +/- 12 years), based on skin "prick" tests with four commercial cockroach extracts along with a common battery of standardized inhalant allergens. We found a positive wheal to at least one of these four extracts in 27 patients: 26 (96.2%) to Blatta orientalis, 10 (37%) both to Blatella germanica and 1 (3.7%) exclusively to Blatella germanica, with no significant concordance between them. We also observed in patients with cockroach positive skin "prick" test an association with atopy (p < 0.001) and with cutaneous reactivity to other indoor allergens, namely house dust mites (p = 0.02), danders (p = 0.01) and fungi (p = 0.01). These data confirm the higher risk of cockroach sensitization among the atopic population sensitized to indoor allergens. However, the heterogeneity of the positive cutaneous responses obtained in this study, possibly reflecting the incomplete standardization of cockroach extracts, questions the real prevalence and clinical significance of this particular sensitization.