Biomedical subjects

Miguel Casanovas

Publications and source records attributed to Miguel Casanovas.

3 recordsLinked to original sources

PubMed2006

Successful management of mite-allergic asthma with modified extracts of Dermatophagoides pteronyssinus and Dermatophagoides farinae in a double-blind, placebo-controlled study.

BACKGROUND: Mite sensitivity is highly prevalent in tropical and subtropical regions, such as the Canary Islands. OBJECTIVES: To evaluate the clinical efficacy and safety of a depigmented polymerized allergen vaccine containing a 50% mixture of Dermatophagoides pteronyssinus and Dermatophagoides farinae. METHODS: Sixty-four patients participated in the study. It was prospective, double-blind, and placebo-controlled, with random allocation of patients to receive active treatment or placebo. The active group received a mixture of modified allergen extracts containing 50% D pteronyssinus and 50% D farinae; the control group received placebo. All individuals were diagnosed with mild/moderate asthma and rhinoconjunctivitis caused by sensitization to D pteronyssinus and D farinae. Bronchial provocation test (BPT) was considered the main outcome to document clinical efficacy. RESULTS: Fifty-four patients completed the study. The active group experienced a significant improvement in BPT (P < .001), whereas the placebo group did not (P = .648). At the end of the study, 20 patients in the active versus 9 in the placebo group (P = .013; odds ratio, 5.71 [1.76, 18.51]) needed more than twice the amount of allergen to obtain a positive BPT. The median improvement in the active group over placebo was 53.76% in total symptom and 58.09% in medication scores. CONCLUSION: Immunotherapy with a mixture of modified allergen extracts of D pteronyssinus and D farinae is safe and efficacious to treat mite-allergic asthma. CLINICAL IMPLICATIONS: This immunotherapy modifies the natural course of the illness because it improves all clinical outcomes measured and prevents the worsening of specific bronchial hyperreactivity.

Adult↗

PubMed2006

Mite immunotherapy.

Dermatophagoides pteronyssinus and D. farinae are the most common house dust mites and are among the most common sources of indoor allergens worldwide. These species are very common in humid regions, where most allergic individuals are sensitized to house dust mites. Specific immunotherapy with mite extracts has demonstrated clinical benefits in several double-blind, placebo-controlled trials that are included in recent reviews of subcutaneous immunotherapy, including pediatric and adult patients with rhinoconjunctivitis and or asthma. Most successful studies of mite immunotherapy have used native allergen extracts adsorbed onto aluminum hydroxide, or chemically modified mite-allergen extracts. Several studies have also shown efficacy using sublingual immunotherapy in pediatric and adult patients with asthma and/or rhinitis. Additionally, the efficacy of subcutaneous immunotherapy has been demonstrated in patients with atopic dermatitis, although more double-blind, placebo-controlled studies are needed. Based on several studies, it cannot be concluded that mite immunotherapy is more dangerous or safer than immunotherapy with grasses, epithelia, or animal epithelia. Because the delivery of high doses of allergen carries with it the risk for immunoglobulin E (IgE)-mediated events, several methods have been developed to reduce specific IgE binding to mite-allergen extracts. An important challenge for future mite immunotherapy modalities is the delivery of relatively high doses without a significant risk for severe reactions.

Allergens↗

PubMed2005

Comparative study of tolerance between unmodified and high doses of chemically modified allergen vaccines of Dermatophagoides pteronyssinus.

BACKGROUND: The physiochemical modification of allergens to reduce allergenicity, while retaining immunogenicity, provides a chance for the administration of higher doses of immunotherapy, with a decreased risk of systemic reactions. OBJECTIVE: To evaluate the safety of doses of depigmented glutaraldehyde-polymerized vaccine of Dermatophagoides pteronyssinus increasing those used in normal clinical conditions in comparison with regular doses of a non-modified vaccine. MATERIALS AND METHODS: The study was double-blind, parallel and included two patient groups. Twenty-three patients were treated weekly during 9 visits for the build-up phase, followed by 2-weekly maintenance doses (a total of 11 injections per patient). Eleven patients (mean age 22 years) received immunotherapy with the standardized modified vaccine. The maximum dose used was the result of depigmenting and polymerizing 100 times the maximum dose used with the native extract. The maximum concentration used was 990 mug/ml of freeze-dried material. Twelve patients (mean age 24 years) received a standardized, unmodified allergenic extract. The maximum concentration used was 70 mug of freeze-dried material/ml, with a potency of 10 HEP(L)/ml. The tolerance was evaluated recording all the side reactions related to immunotherapy and graded following the recommendations of the European Academy of Allergology and Clinical Immunology. RESULTS: In both groups, all immediate local reactions were clinically not relevant. Patients treated with the native extract experienced 42 local immediate and 24 delayed reactions (1 of them had a diameter >10 cm), whereas patients treated with the modified extract experienced 30 local immediate and 21 delayed reactions (2 of them had a diameter >10 cm). Four systemic reactions in 2 patients, 1 immediate of grade 1 and 3 delayed of grade 2 were reported in the group treated with native extract and 1 delayed of grade 2 in the group treated with the modified preparation. CONCLUSIONS: The modified extract of D. pteronyssinus, used at concentrations which are 10 times higher than those regularly administered in clinical practice, demonstrated to be safe to treat D. pteronyssinus-sensitive patients. The majority of the local reactions (immediate and delayed) were clinically not relevant (diameter <5 cm). No systemic reactions of grade 3 or 4 were noted.

Adolescent↗