Home > DARE Reviews > Analyse der Effektivitat der subkutanen...

PubMed Health. A service of the National Library of Medicine, National Institutes of Health.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet]. York (UK): Centre for Reviews and Dissemination (UK); 1995-.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet].

Analyse der Effektivitat der subkutanen Immuntherapie mit Hausstaubmilbenextrakten bei Erwachsenen mit allergischer Rhinitis und/oder Asthma bronchiale [Analysis of the efficacy of specific immunotherapy with house-dust mite extracts in adults with allergic rhinitis and/or asthma]

D Polzehl, T Keck, and H Riechelmann.

Review published: 2003.

CRD summary

This review assessed the efficacy of subcutaneous specific immunotherapy with house-dust mite extracts in adults with rhinitis and/or asthma. The review concluded that the therapy is effective and safe in adults when administered under optimal conditions. The conclusion has to be regarded with caution given the limitations in its methodology.

Authors' objectives

To assess the efficacy of subcutaneous specific immunotherapy with Dermatophagides pteronyssinus (Der p) or farinae (Der f) in adults with rhinitis and/or asthma.

Searching

The reviewers searched MEDLINE and EMBASE from 1970 to 2001 and the Cochrane Controlled Trials Register. Bibliographies of reviews were checked and drug companies were contacted. Only English and German language articles were eligible for inclusion in the review.

Study selection

Study designs of evaluations included in the review

Double-blind placebo-controlled trials were eligible for inclusion in the review.

Specific interventions included in the review

Trials investigating subcutaneous specific immunotherapy with house-dust mite extracts (Der p or Der f) were eligible for inclusion. Studies on sublingual, oral, intranasal and inhalation immunotherapy were excluded, as were those on therapies with antigen-antibody-complex or house-dust extracts. The patients had to have undergone a skin prick test regarding Der p or Der f. Studies were restricted to mono-sensitisation against Der p and/or Der f; those of sensitisation on several perennial allergens were excluded. In the included studies therapy lasted between 7 weeks and 2 years. Patients in some of the included studies also received a systemic steroid.

Participants included in the review

Adult patients with persistent perennial rhinitis or asthma bronchial and clinical symptoms, a positive skin prick test for Der p and/or Der f, and evidence for specific immunoglobulin E against Der p or Der f, were eligible for inclusion. Symptoms severity varied greatly in the included studies. The age of the participants varied between 5 to 50 and 13 to 68 years.

Outcomes assessed in the review

The studies had to report on subjective symptoms (using a visual analogue scale or a diary method), use of medication, lung function, or bronchial, nasal or conjunctival provocative test. Most of the included studies reported on bronchial provocative test reactions.

How were decisions on the relevance of primary studies made?

The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.

Assessment of study quality

The authors did not state that they assessed validity, but the inclusion criteria specified that trials needed to be double-blind.

Data extraction

The authors did not state how many reviewers performed the data extraction. The numbers of patients with a positive effect or no effect of subcutaneous specific immunotherapy were extracted. The authors stated that 2x2 tables for a chi-squared analysis of odds ratios (ORs) and 95% confidence intervals (CIs) were computed for each study. For continuous outcomes, the effect size was computed by calculating the difference in the scores between the active therapy and placebo groups.

Methods of synthesis

How were the studies combined?

The studies were compared in a narrative review that looked at symptom scores, medication scores, lung function, organ provocation and side-effects separately. A vote count (improvement or not) was tabulated for the symptom scores and medication scores. The percentage of visual analogue scale values for the two arms of the studies before and after treatment were displayed graphically for each study reporting them. For organ provocation results, the ORs and 95% CIs were displayed graphically for each study that provided enough data.

How were differences between studies investigated?

Differences between the study designs and results were discussed in the text. Several potential explanations for different results were followed up, for example the quality of the used extracts before 1980.

Results of the review

Thirteen randomised controlled trials (n=442) were included in the review.

Symptom score.

Seven studies showed a significant improvement of symptoms after therapy; in 5 studies no change was noted. Six of 8 studies published after 1980 showed an improvement after therapy.

Medication score.

Five studies showed a significant decrease in medication requirements after therapy; 5 studies showed no significant effect. Studies of patients with medium or severe asthma showed no improvement (4 studies), while most studies with patients with persistent allergic rhinitis and mild bronchial asthma showed improvement after therapy (4 studies).

Lung function.

None of the 8 studies that appeared to have assessed lung function through peak flow or spirometry showed a significant change.

Organ provocation.

Three studies showed a significant nasal desensitisation of Der p, one study showed no difference, and one study showed a reduction in conjunctival hyper-reactivity.

Side-effects.

Seven of the 13 studies showed no major adverse events. Four studies reported systemic adverse effects. In one study 7 patients had to terminate therapy on account of side-effects.

Authors' conclusions

Specific immunotherapy using a standardised house-dust mite extract is effective and safe in adults when administered under optimal conditions.

CRD commentary

The review had a clear question and clear inclusion criteria. The search was relatively wide but a language restriction was applied, thus potentially relevant studies published in languages other than English and German might have been missed. No measures appear to have been taken to reduce bias and errors in the study selection or data extraction processes. The included studies were heterogeneous, e.g. some studies included patients with severe asthma treated additionally with cortisone. All of the included studies employed a powerful study design (double-blind randomised controlled trial), but the samples were small. The validity of the included studies was not assessed.

Diverse outcomes were reviewed. The presentation of the individual study results varied and, overall, was rather limited: e.g. for most outcomes no numbers were reported, so the size of the effects was unclear. Despite the review being aimed at adults, 8 of the 13 studies involved participants younger than 18 years. It was not always clear how many studies had initially assessed the discussed feature, e.g. where only the number of not effective studies was given. It was not explicitly stated whether the review did not find any worsening of symptoms after therapy or whether the data extraction did not cover this event. The results of the included studies varied and several potentially relevant differences between study results were followed up. Although trends were identified, the source of heterogeneity did not appear to have been as clearly identified as the conclusions suggest: e.g. the majority of studies published after 1980 showed more positive results, but not all.

It is difficult to evaluate the conclusion of the review given the limitations in the review methodology and reporting. Overall, the conclusion should be interpreted with caution.

Implications of the review for practice and research

Practice: The authors stated that the allergen provocation test can be recommended as a useful and sensitive parameter during specific immunotherapy.

Research: The authors did not state any implications for further research.

Bibliographic details

Polzehl D, Keck T, Riechelmann H. Analyse der Effektivitat der subkutanen Immuntherapie mit Hausstaubmilbenextrakten bei Erwachsenen mit allergischer Rhinitis und/oder Asthma bronchiale [Analysis of the efficacy of specific immunotherapy with house-dust mite extracts in adults with allergic rhinitis and/or asthma] Laryngo-Rhino-Otologie 2003; 82(4): 272-280. [PubMed: 12717603]

PubMedID

12717603

Indexing Status

Subject indexing assigned by NLM

MeSH

Adult; Antigens, Dermatophagoides /administration & dosage /adverse effects /immunology; Asthma /drug therapy /immunology; Desensitization, Immunologic /adverse effects /methods; Double-Blind Method; Humans; Injections, Subcutaneous; Pyroglyphidae /immunology; Randomized Controlled Trials as Topic; Rhinitis, Allergic, Perennial /drug therapy /immunology; Treatment Outcome

AccessionNumber

12003001024

Date bibliographic record published

31/07/2006

Date abstract record published

31/07/2006

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.

CRD has determined that this article meets the DARE scientific quality criteria for a systematic review.

Copyright © 2014 University of York.

PMID: 12717603

PubMed Health Blog...

read all...

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...