***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: A double-blind , placebo-controlled trial of immunotherapy was conducted in patients with Dermatophagoides pteronyssinus rhinitis . Thirty patients received an extract with a high content of Der p I ( Pharmalgen ) , 20 received a conventional mite extract ( Allpyral )  , and 30 patients received histamine chloride ( placebo ) . Specific IgG and subclasses were measured before and after 3 and 12 months of treatment by RIA and /or ELISA , and specific IgE by RAST . Clinical outcome was assessed by skin prick tests , nasal challenge , visual analogue , and diary-card symptom and drug scores ; from these findings , a clinical index was derived . An IgG response occurred only in the Pharmalgen-treated group : D. pter IgG and IgG1 increased by 3 months ( p less than 0.05 ) and then plateaued to 12 months ( p less than 0.05 ) . IgG4 levels increased throughout treatment ( p less than 0.05 and p less than 0.01 ) , as did the IgG/IgE ratio . A subclass switch from IgG1 to IgG4 occurred . D. pter IgE rose at 3 months ( p less than 0.05 ) . Clinical improvement occurred at 3 and 12 months in the Pharmalgen-treated group only . Pretreatment levels of IgE , IgG1 , or IgG4 did not predict clinical outcome . Our findings are compatible with the hypothesis that IgG subclasses may modulate antigen-IgE interactions , although the antibody response to this potent extract need not be causally related to improvement The present work reports the results of a double‐blind clinical trial , comparing the effects of hyposensitization treatment versus placebo in 33 patients with allergic rhinitis , sensitive to a crude extract of the pollen of four different grasses ( Dactylis glamerata , Lolium perenne , Secale cereale , and Phlewn pratense ) . The distribution of these patients in the two groups was done r and omly and gave two comparable groups , as far as clinical and biological features are concerned . The treatment course included five low doses of the aqueous extract followed by 12 injections of Al(OH)3‐adsorbed aliquots of the same extract . Evaluation of the clinical scores was based on diary cards on which symptoms and medications were recorded . A reevaluation of the significance of the symptom and medication scores is presented and the link between both scores is studied . Particular attention is given to the method ological and statistical problems raised during this study . The non‐parametric tests reveal a significant difference ( P < 0.03 ) in the total clinical score between the treated and the placebo groups for the second half of the observation period , when the pathology was most intense Background Little information is available on the effect of allergen-specific immunotherapy on airway responsiveness and markers in exhaled air . The aims of this study were to assess the safety of immunotherapy with purified natural Alt a1 and its effect on airway responsiveness to direct and indirect bronchoconstrictor agents and markers in exhaled air . Methods This was a r and omized double-blind trial . Subjects with allergic rhinitis with or without mild/moderate asthma sensitized to A alternata and who also had a positive skin prick test to Alt a1 were r and omized to treatment with placebo ( n = 18 ) or purified natural Alt a1  ( n = 22 ) subcutaneously for 12 months . Bronchial responsiveness to adenosine 5'-monophosphate ( AMP ) and methacholine , exhaled nitric oxide ( ENO ) , exhaled breath condensate ( EBC ) pH , and serum Alt a1-specific IgG4 antibodies were measured at baseline and after 6 and 12 months of treatment . Local and systemic adverse events were also registered . Results The mean ( 95 % CI ) allergen-specific IgG4 value for the active treatment group increased from 0.07 μg/mL ( 0.03 - 0.11 ) at baseline to 1.21 μg/mL ( 0.69 - 1.73 , P < 0.001 ) at 6 months and to 1.62 μg/mL ( 1.02 - 2.22 , P < 0.001 ) at 12 months of treatment . In the placebo group , IgG4 value increased nonsignificantly from 0.09 μg/mL ( 0.06 - 0.12 ) at baseline to 0.13 μg/mL ( 0.07 - 0.18 ) at 6 months and to 0.11 μg/mL ( 0.07 - 0.15 ) at 12 months of treatment . Changes in the active treatment group were significantly higher than in the placebo group both at 6 months ( P < 0.001 ) and at 12 months of treatment ( P < 0.0001 ) . However , changes in AMP and methacholine responsiveness , ENO and EBC pH levels were not significantly different between treatment groups . The overall incidence of adverse events was comparable between the treatment groups . Conclusion Although allergen-specific immunotherapy with purified natural Alt a1 is well tolerated and induces an allergen-specific IgG4 response , treatment is not associated with changes in AMP or methacholine responsiveness or with significant improvements in markers of inflammation in exhaled air . These findings suggest dissociation between the immunotherapy-induced increase in IgG4 levels and its effect on airway responsiveness and inflammation Background Calcium phosphate‐adsorbed allergen extracts are used for subcutaneous immunotherapy to avoid the use of aluminium adjuvants Inl and areas of northern California have an intense grass pollination in the spring of each year . This is accompanied by a stirking rise in the incidence of asthma . We documented this relationship and design ed a trial to test the efficacy of immunotherapy for grass-pollen asthma . Aeroallergen counts were performed on the roof of the allergy clinic of David Grant Medical Center from January 1981 to December 1984 by a gravity collector . These counts were compared to counts done on a Rotorod at a nearby hospital from July 1982 to September 1984 . Climatologic factors were also tabulated . Visits for asthma and rhinitis to our emergency room and asthma admissions to our hospital were counted for the 4-year period . A r and omized , double-blinded , placebo-controlled trial of immunotherapy with grass-pollen extract was performed from November 1984 to June 1985 . Two groups of clinical ly and immunologically well-matched subjects were started on an accelerated preseasonal trial of immunotherapy . One group received a st and ardized grass extract , and the other group did not . Both groups received other extracts of aeroallergens to which they were skin test positive that occur locally in the spring and summer . This was done because of our dissatisfaction with a histamine placebo used in a previous pilot study . Symptom medication scores ( SMS ) and immunologic parameters were followed . For the 4-year period , grass-pollen count ( GPC ) correlated strongly with asthma emergency room visits ( r = 0.90 ; p less than 0.001 ) and for rhinitis ( r = 0.92 ; p less than 0.001 ) . Asthma admissions also correlated strongly with GPC ( r = 0.72 ; p less than 0.001 ) . Other aeroallergens either did not correlate significantly or occurred in such small numbers that they could not be seriously considered . Rotorod counts supported these conclusions with the exceptions of some Basidiomycetes . Climatologic factors demonstrated no relationship to the incidence of asthma . Asthma SMS were lower in the grass-treated group , p less than 0.05 . Rhinitis SMS were also lower but did not reach significance , p = 0.11 . RGGI sIgE did not rise significantly in the grass-treated group but did in the placebo-treated group . RGGI sIgE rose in both groups , although to significantly higher levels in the grass-treated group , p less than 0.001 . The asthma SMS were inversely related to increasing RGGI cumulative dose , p less than 0.10 . Linear regression analysis of the dose-response scattergram suggests that a cumulative dose of approximately 90 micrograms of RGGI may be desirable . ( ABSTRACT TRUNCATED AT 400 WORDS We have performed a comparative study to evaluate seasonal and perennial schedules after 3 years of immunotherapy . Sixty patients suffering from rhinitis and /or asthma due to grass pollen sensitization were r and omly allocated to receive a semi-depot extract of Phleum pratense according to a perennial or seasonal schedule . The last year of the study , 14 patients were recruited as a control group without immunotherapy .  The cumulative dose was 602 BU in the perennial group and 372 BU in the seasonal group . The frequency and severity of side-effects were similar and very low in both treated groups . The IgE level was significantly lower after perennial immunotherapy at the end of the first 2 years . A seasonal decrease in specific IgG levels was observed in patients who interrupted immunotherapy , while this was not observed in patients under the perennial schedule . Symptoms and medication scores did not show differences between groups . Nevertheless , we found a significant difference between treated patients and the control group OBJECTIVE --To evaluate the efficacy and safety of immunotherapy ( hyposensitisation ) in patients with severe summer hay fever . DESIGN --A r and omised , double blind , placebo controlled study of a biologically st and ardised depot grass pollen extract . SETTING --Allergy clinic , Royal Brompton and National Heart Hospital , London . PATIENTS --40 adults ( mean age 35 years ) with a history of severe grass pollen allergy uncontrolled by st and ard antiallergic drugs . Patients with perennial asthma were specifically excluded . INTERVENTION-- Patients were r and omised to receive either an active preparation ( Alutard SQ , a grass pollen ( Phleum pratense ) extract ) or placebo at a rate of two subcutaneous injections a week in increasing doses until a maintenance dose was reached . This maintenance dose was given once a month . MAIN OUTCOME MEASURES -- Clinical efficacy was evaluated by symptom and drug diary cards , visual analogue scores during the grass pollen season , and a postseasonal assessment by the patients and a doctor . Conjunctival and skin sensitivity to local allergen provocation was measured before and after eight months of treatment . RESULTS --There was a highly significant decrease ( median Alutard SQ v median placebo ( 95 % confidence interval for difference between medians ] in total symptom scores ( p=0.001 ) in the Alutard SQ treated group ( 360 v 928 ( 238 to 825 ] . Significant differences were also found in total drug use ( p=0.002 , 129 v 627 ( 178 to 574 ] . Visual analogue symptom scores were also reduced in the active group ( p=0.02 , 2.2 v 5.5 ( -4.8 to -0.5 ] . The postseasonal assessment , by either the doctor or the patients , showed a large improvement ( p less than 0.001 ) in favour of Alutard SQ . Provocation tests showed a greater than 10-fold reduction for the active group in immediate conjunctival allergen sensitivity ( p=0.001 ) , a 40 % decrease in early phase response ( p=0.02 ) , and a 57 % decrease in the late phase ( p=0.001 ) cutaneous response after intradermal allergen . A total of 523 active injections were given . There was one systemic reaction at 10 minutes after injection , which was rapidly reversed with intramuscular adrenaline . There was one mild delayed urticarial reaction at 2 1/2 hours . CONCLUSION --Immunotherapy is effective in patients with severe summer hay fever , but immediate anaphylactic reactions limit its use to specialised centres . Patient selection is extremely important , and chronic perennial asthma should be specifically excluded . As serious reactions occur within minutes a two hour wait for all patients after each injection seems unnecessary BACKGROUND Grass pollen immunotherapy for allergic rhinitis is a disease-modifying treatment that results in long-term clinical tolerance lasting years after treatment discontinuation . Active treatment is associated with generation of inhibitory grass pollen-specific IgG antibodies capable of blocking allergen-IgE interactions . OBJECTIVES We sought to investigate the involvement of IgG-associated inhibitory antibodies with long-term clinical tolerance after discontinuation of grass pollen immunotherapy . METHODS We conducted a 4-year study in which patients who had moderate-to-severe allergic rhinitis underwent a r and omized , double-blind ,  placebo-controlled discontinuation of subcutaneous grass pollen immunotherapy .  All subjects received grass pollen immunotherapy injections for 2 years ( n = 13 ) , followed by a further 2 years of either active ( n = 7 ) or placebo ( n = 6 ) injections . Clinical outcomes included seasonal symptoms and use of rescue medication . Serum specimens were collected at baseline and after 2 and 4 years for quantification of allergen-specific IgG antibodies . Sera were also tested for IgG-dependent inhibitory bioactivity against IgE-allergen binding in cellular assays by using flow cytometry and confocal microscopy to detect binding of IgE-grass pollen allergen complexes to B cells . RESULTS Clinical improvement was maintained after 2 years of discontinuation . Although immunotherapy-induced grass pollen-specific IgG1 and IgG4 levels decre 
    Output:
    
The literature provides high- grade evidence that SCIT reduces asthma symptoms , asthma medication usage , rhinitis/rhinoconjunctivitis symptoms , conjunctivitis symptoms , and rhinitis/rhinoconjunctivitis disease-specific quality of life in comparison to placebo or usual care .
There is moderate evidence that SCIT decreases rhinitis/rhinoconjunctivitis medication usage .
Respiratory reactions were the most common systemic reaction .
Generally moderate to strong evidence supports the effectiveness of SCIT for treatment of allergic rhinitis and asthma , particularly with single-allergen immunotherapy regimens .
Adverse reactions to SCIT are common , but no deaths were reported in the included studies