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Immunotherapy
Aka: Immunotherapy, Allergen Immunotherapy, Allergen Vaccine, Allergy Vaccination, Desensitization
- See Also
- Cancer Immunotherapy
- Palforzia (Peanut Allergen Powder)
- Indications
- Allergic Rhinitis
- Allergic Conjunctivitis
- Allergic Asthma
- Hymenoptera Sting systemic reaction
- Inadequate response to medical therapy of allergy
- Contraindications
- Uncontrolled Asthma
- Recent Asthma Exacerbation (last 7 days)
- Current Wheezing
- Peak Expiratory Flow below 75% of personal best
- Current Beta-Blocker or ACE Inhibitor use
- Impairs Epinephrine effect in Anaphylaxis
- Concurrent significant illness, fever or Fatigue
- Recent Insect sting or food reaction
- Mechanism
- Immunotherapy is based on active Immunity, similar to Vaccination against microbes
- Immunotherapy builds Immunity to specific Antigens and decreases symptom response on exposure
- Process
- Small subcutaneous dose given initially (see test vial technique below)
- Weekly injections are titrated with increasing dose until 6 months when maintenance dosing is performed
- Maintenance dosing (continuous dose) is administered every 2-4 weeks for 3-5 years
- Results
- Allergan specific IgG Antibody (blocking Antibody) forms and competes with allergan-specific IgE
- Mast Cells and Basophils release fewer reaction mediators
- Th2 CD4+ T Cells shift towards Th1 CD4+ T Cells
- References
- Mahmoudi (2014) Immunology Made Ridiculously Simple, MedMaster, Miami, FL
- Types: Immunotherapy Vaccines
- Factors affecting potency
- Shelf time (do not use expired Vaccines)
- Storage Temperature
- Refrigerate at 4 C or 39.2 F
- Vaccines lose potency in weeks at room Temperature
- Vaccines lose potency in days at higher Temperature
- Concentration (high concentrations are most stable)
- Vial surface area (related via volume effect)
- Increased vial surface area adheres more allergens
- Glycerol or albumin decrease volume effect
- Additives
- Preservative
- Diluent
- Mix of allergens
- Dilutes each individual allergen
- Interacts with other allergens
- Insect venom
- Fungi, Dust mites, Insect venoms, cockroaches
- Vaccine types
- Standardized Vaccines
- Potency graded by Bioequivalent Allergy Unit (BAU)
- BAUs assigned by FDA based on skin tests
- Examples of standardized Vaccines
- Cat dander
- Grass pollen
- Dust mites
- Ragweed pollen
- Unstandardized Vaccines
- Potency varies by manufacturer and lot
- Labeling reflects only content, and not potency
- Protein Nitrogen Units (PNU)
- Weight by volume (wt/V)
- Technique: Vial Test
- Technique
- Place 5 skin wheals
- High Class Antigen
- Low Class Antigen
- Saline
- Negative Control (phenylated Glycerin)
- Positive Control (histamine)
- Place 4 mm wheal (0.5cc weakest dilution) intradermal
- Read in 10 minutes
- Interpretation
- Wheal size 15 mm or less is acceptable
- Wheel size 16 mm or over requires dilution
- Dilute 0.5 cc Antigen in 2 cc of phenylated saline
- Repeat intradermal wheals as above
- Preparation
- Anaphylaxis preparation
- Albuterol MDI
- Epinephrine 0.1 to 0.3 cc 1:1000 SQ
- Oxygen Delivery
- Patient history
- Patient identifies Antigen vial
- Vial identified by patient name and date of birth
- Ask about history of delayed reactions
- Ask about present illnesses and recent exposures
- Fever or acute illness
- Asthma Exacerbation or other respiratory illness
- Current allergy exacerbation
- New medications (Beta Blockers or ACE Inhibitors)
- Vaccine Vial check
- Confirm match of patient name, birth, and MR number
- Check Immunotherapy mix components in vial
- Make certain the vial has not expired
- Check vial number
- Maintenance is number 1
- Dilutions are numbered starting from maintenance
- Check color coding (reflects concentration)
- Red: Maintenance concentration
- Yellow
- Blue
- Green
- Silver: Most dilute concentration
- Dosing
- Build-up dosing schedule (directed by allergist)
- Anticipate 6 month course to get to maintenance
- Increase from most dilute toward maintenance dose
- Serial dose increments weekly (18-27 doses)
- Maintenance dosing schedule
- Administer every 3-4 weeks for 4-5 years
- Reduce dose when starting new vial from manufacturer
- Decrease maintenance dose to 50%
- Increase dose every 7-14 days until at maintenance
- Missed Dosages
- Build-Up interrupted
- 10 days or less: Continue build up
- 11-14 days: Repeat last dose
- 15-29 days: Half last dose
- 30 days or longer: 1/5 last dose
- Maintenance doses interrupted
- Less than 7 weeks: Continue same dose
- 7 weeks: Go back 2 incremental dilutions
- 8 weeks: Go back 3 incremental dilutions
- 9 weeks: See allergist
- Technique
- See Preparation above
- Check and recheck today's dose (see above)
- Injection site: Upper arm lateral aspect
- Midpoint between Shoulder and elbow
- Inject at groove between deltoid and triceps
- Inject subcutaneously with 27 gauge needle
- Aspirate first (do not inject if blood aspirated)
- Slowly inject (do not raise wheal or cause pain)
- Hold pressure at injection site for one minute after
- Do not rub injection site due to increased absorption
- Observe for at least 20 minutes after injection
- Adverse Effects: Systemic Reaction Symptoms (onset often within minutes)
- Itchy palms or hands
- Rapid nasal congestion
- Sneezing or coughing
- Urticaria (Hives) or Angioedema
- Vomiting or Diarrhea
- Headache or Nausea
- Shortness of Breath
- Management: Allergy Vaccine reaction
- Local reaction (wheal/flare with Pruritus at <30 min)
- Local Cold Therapy
- Oral Antihistamine (e.g. Diphenhydramine)
- Topical Corticosteroid
- Consider allergy premedication (e.g. Diphenhydramine)
- Large local induration (Arthus with pain and swelling)
- Oral Corticosteroids
- NSAIDS
- Oral Antihistamine (e.g. Diphenhydramine)
- Systemic reaction (see symptoms above)
- Tourniquet above injection site
- See Anaphylaxis for specific management
- Delayed reaction
- Oral Antihistamine (e.g. Diphenhydramine)
- Oral Prednisone 5 to 20 mg PO q12 hours for 1 day
- Efficacy: Grass Pollen Immunotherapy
- Sustained response 3 years after injections stopped
- Effects long-term clinical course
- Decreased immediate sensitivity
- Eliminated late phase response
- Decreased immune markers
- Decreased CD3+ T-Cells
- Decreased cells containing Interleukin-4 RNA
- References
- Durham (1999) N Engl J Med 341:468-75 [PubMed]
- References
- Huggins (2004) Am Fam Physician 70:689-704 [PubMed]
- (2003) Ann Allergy Asthma Immunol 90:1-40 [PubMed]