Allergen vial mixing and immunotherapy: Risks of infections and vial contamination

United States Pharmacopeia guidance for compounding of allergenic extracts for allergen immunotherapy

Patient-specific allergen-specific subcutaneous immunotherapy (SCIT) has been used as a disease modifying treatment for type 1 IgE mediated allergy to inhalants for > 100 years. Traditionally, the extracts used for a treatment set have been “mixed” under the supervision of allergists in their clinics. Until 2008, there were no specific requirements for mixing procedures. Allergenic extracts are classified as biologics by the U.S. Food and Drug Administration (FDA) and are subject to the biologics license application requirements. One of the conditions is that it must be prepared in accordance with U.S. Pharmacopeia (USP) Chapter 797, which was first published in 2008. What allergists have always considered “mixing” of allergen extracts is considered “compounding” by the FDA and other state and federal regulatory agencies. A revision of USP Chapter 797 was proposed after a series of “never events,” including deaths, from compounded products. No reports of infections from SCIT have ever been reported. “Allergy” (ACAAI, AAAAI, AAOA, and other stakeholders) worked cooperatively with the USP Compounding Expert Committee to develop Section 21. “Compounding Allergenic Extracts” of what is expected to be accepted as the next version of USP Chapter 797 in mid 2022.

The infection rate of intralesional triamcinolone and the safety of compounding in dermatology for intradermal and subcutaneous injection: A retrospective medical record review

BACKGROUND

Intralesional injection of sterile medications remains a mainstay in dermatology, enabling a tailored, low-cost, in-office therapy. After the 2012 United States outbreak of fungal meningitis from contaminated intrathecally administered corticosteroids, there has been increased regulation of in-office compounding, regardless of the administration route. Studies demonstrating the safety data of in-office corticosteroid compounding for intradermal or subcutaneous use are lacking.

OBJECTIVE

To assess the incidence of infection caused by compounded in-office intralesional triamcinolone.

METHODS

A retrospective medical record review identified patients who received in-office intralesional corticosteroid injections in 2016. Medical documentation within 30 days of injection was reviewed for suspected infection.

RESULTS

The records of 4370 intralesional triamcinolone injections were assessed, of which 2780 (64%) were compounded triamcinolone with bacteriostatic saline. We identified 11 (0.25%) suspected localized infections, with 4 of the 11 in the compounding cohort. Of these, 7 of 11 occurred after injection of an "inflamed cyst." No hospitalizations or deaths occurred. No temporal or locational relationships were identified.

LIMITATIONS

This study was limited to 2 academic institutions. A 30-day postinjection time frame was used.

CONCLUSION

In-office compounding for intralesional dermal and subcutaneous administration is safe when sterile products are used by medical practitioners. There is no increased risk of compounded triamcinolone relative to noncompounded triamcinolone.

Mining social media data to assess the risk of skin and soft tissue infections from allergen immunotherapy

BACKGROUND

Allergen immunotherapy (AIT) treatment for allergic rhinitis and asthma is used by 2.6 million Americans annually. Clinical and sterility testing studies identify no risk of contamination or infection from extracts prepared using recommended aseptic techniques, but regulatory concerns persist. Social media can be used to investigate rare adverse effects not captured by traditional studies.

OBJECTIVE

We sought to investigate large social media databases for suggestion of AIT skin and soft tissue infection (SSTI) risk and compare this risk to a comparator procedure with a sterile pharmaceutical.

METHODS

We analyzed US-restricted data from more than 10 common text-based social media platforms including Facebook, Twitter, and Reddit between 2012 and 2016. We used natural language processing (NLP) to identify posts related to AIT and, separately, influenza vaccination (comparator procedure). NLP was followed by manual review to identify posts suggesting a possible SSTI associated with either AIT or influenza vaccination. SSTI frequencies with 95% CIs were compared.

RESULTS

We identified 25,126 AIT posts, which were matched by social media platform to 25,126 influenza vaccination-related posts. NLP identified 4088 (16.3%) AIT posts that required manual review, with 6 posts (0.02%; 95% CI, 0.005%-0.043%) indicative of possible AIT-related SSTI. NLP identified 2689 (10.7%) influenza posts that required manual review, with 7 posts (0.03%; 95% CI, 0.007%-0.048%) indicative of possible influenza vaccination-related SSTI.

CONCLUSIONS

Social media data suggest that SSTI from AIT and influenza vaccination are equally rare events. Given that AIT's SSTI risk appears comparable to the risk using a sterile pharmaceutical based on social media data, current aseptic technique procedures seem safe.

Safety considerations in providing allergen immunotherapy in the office

PURPOSE OF REVIEW

This review highlights the risks of allergy immunotherapy, methods to improve the quality and safety of allergy treatment, the current status of allergy quality metrics, and the future of quality measurement. In the current healthcare environment, the emphasis on outcomes measurement is increasing, and providers must be better equipped in the development, measurement, and reporting of safety and quality measures.

RECENT FINDINGS

Immunotherapy offers the only potential cure for allergic disease and asthma. Although well tolerated and effective, immunotherapy can be associated with serious consequence, including anaphylaxis and death. Many predisposing factors and errors that lead to serious systemic reactions are preventable, and the evaluation and implementation of quality measures are crucial to developing a safe immunotherapy practice. Although quality metrics for immunotherapy are in their infancy, they will become increasingly sophisticated, and providers will face increased pressure to deliver safe, high-quality, patient-centered, evidence-based, and efficient allergy care.

SUMMARY

The establishment of safety in the allergy office involves recognition of potential risk factors for anaphylaxis, the development and measurement of quality metrics, and changing systems-wide practices if needed. Quality improvement is a continuous process, and although national allergy-specific quality metrics do not yet exist, they are in development.

Safety of immunotherapy with glutaraldehyde modified allergen extracts in children and adults

BACKGROUND

Glutaraldehyde-modified natural allergen extracts show significant reduction in the IgE-binding capacity and proteolytic activity. This allows the administration of higher doses in a shorter period of time, and to mix different allergen extracts.

OBJECTIVE

Evaluate the safety of different concentrations and mixtures of glutaraldehyde-modified allergen extracts in a large group of paediatric and adult patients undergoing specific immunotherapy treatment.

MATERIALS AND METHODS

1855 patients (1156 adults and 699 children), suffering from rhinoconjunctivitis and/or asthma, participated in an observational multicentre cohort study, to evaluate the safety of immunotherapy using vaccines containing modified allergen extracts. Patients were monosensitised, or polysensitised, and received a therapeutic vaccine containing polymerised allergen extracts adsorbed onto aluminium hydroxide. Safety was assessed by recording all side reactions related to immunotherapy.

RESULTS

The clinically relevant local reactions totalled 120, (90 immediate and 30 delayed) (1.02% of injections). Of them, 31 (0.26% of injections) occurred in children (26 immediate and 5 delayed) and 89 (0.76% of injections) in adults (64 immediate and 25 delayed). There were 38 systemic reactions. Eleven reactions were immediate (9 of grade 1 and 2 of grade 2) and 27 delayed (22 of grade 1 and 5 of grade 2). There were seven grade 2 systemic reactions (0.06% of the injections). No differences (P>0.05) in the number of reactions were observed between adults and children and between treatments were found in systemic reactions. All systemic reactions were mild and resolved spontaneously without the need of medication.

CONCLUSION

Specific immunotherapy using natural modified allergen vaccines is safe to treat allergic patients, even at higher doses and in mixtures of unrelated allergen extracts. The percentage of adverse reactions detected is lower than those reported in the literature with native unmodified allergen extracts.

Defining quality metrics and improving safety and outcome in allergy care

BACKGROUND

The delivery of allergy immunotherapy in the otolaryngology office is variable and lacks standardization. Quality metrics encompasses the measurement of factors associated with good patient-centered care. These factors have yet to be defined in the delivery of allergy immunotherapy. We developed and applied quality metrics to 6 allergy practices affiliated with an academic otolaryngic allergy center.

METHODS

This work was conducted at a tertiary academic center providing care to over 1500 patients. We evaluated methods and variability between 6 sites. Tracking of errors and anaphylaxis was initiated across all sites. A nationwide survey of academic and private allergists was used to collect data on current practice and use of quality metrics.

RESULTS

The most common types of errors recorded were patient identification errors (n = 4), followed by vial mixing errors (n = 3), and dosing errors (n = 2). There were 7 episodes of anaphylaxis of which 2 were secondary to dosing errors for a rate of 0.01% or 1 in every 10,000 injection visits/year. Site visits showed that 86% of key safety measures were followed. Analysis of nationwide survey responses revealed that quality metrics are still not well defined by either medical or otolaryngic allergy practices. Academic practices were statistically more likely to use quality metrics (p = 0.021) and perform systems reviews and audits in comparison to private practices (p = 0.005).

CONCLUSION

Quality metrics in allergy delivery can help improve safety and quality care. These metrics need to be further defined by otolaryngic allergists in the changing health care environment.

Allergen immunotherapy extract treatment set preparation: making a safer and higher quality product for patients

The best possible allergen immunotherapy clinical outcomes require the provision of high quality and safe allergen immunotherapy extract preparations. Evolving national guidelines and regulatory bodies have devoted special attention to the safe compounding of sterile products, including allergen extracts. It is incumbent upon allergists preparing extract treatment sets for patients to be familiar with and adopt training, procedures and safety measures that lead to standardized high quality products. Preparers and supervisors must maintain ongoing competency in aseptic technique and prescribing principles, such as probable effective dose ranges, allergen cross-reactivity, and separation of high protease-containing extracts from susceptible extracts. Accordingly, knowledge and application of vial labeling, diluent selection, standard operating procedures, mixing log documentation, and mixing condition principles are a necessity. Although there have been no instances of infectious complications from allergen immunotherapy in a century of clinical practice, continued vigilance in the use of measures that ensure extract sterility is paramount. A review of allergen immunotherapy preparation recommendations and best practices based on published national guidelines is presented. Further study of preparation measures and prescribing principles will continue to advance the practice of allergen immunotherapy and offer opportunities for refinement of current recommendations.

Antibacterial properties of additives used in injection immunotherapy

BACKGROUND

Previous studies have reviewed the safety of preparing and administering allergy injection immunotherapy in a physician's office, and showed no evidence of infectious complications. The current study examines the antimicrobial properties of the common additives used in preparation of multidose immunotherapy vials.

METHODS

Vials were prepared with varying concentrations of glycerin (0-25%), phenol (0-0.4%) and combinations of glycerin with phenol. A standard inoculum of Staphylococcus aureus was introduced in each vial and incubated. Optical densities were measured and colony counts were performed at 24 and 48 hours. Follow-up broth microdilution assays were performed using varying inocula of bacteria and the highest concentrations of additives to determine the number of bacteria for which these solutions were bacteriostatic and/or bactericidal. Optical densities were measured and colony counts were performed as in the vial assays.

RESULTS

All vials with varying dilutions of glycerin, phenol, and their combination showed bacterial growth with the standard inoculum of Staphylococcus aureus. Visible turbidity and optical density were inversely related to additive concentration. Follow-up microdilution assays with differing concentrations of bacteria demonstrated bactericidal activity with inocula of 1 × 10(3) colony forming units (CFU) of Staphylococcus aureus at clinically used concentrations of glycerin and phenol.

CONCLUSION

Higher concentrations of additives show better inhibition of bacterial growth. Solutions containing glycerin showed superior bactericidal activity than those containing only phenol. At concentrations of additives used in preparing allergy immunotherapy vials, antibacterial effects were observed with inoculation of 1 × 10(3) CFU or less of Staphylococcus aureus.

Allergen immunotherapy practice in the United States: guidelines, measures, and outcomes

To discuss recent issues pertinent to allergen immunotherapy practice in the United States. Allergen extract preparation guidelines, updated allergen immunotherapy practice parameter (AIPP) guidelines, and evolving trends in how immunotherapy outcomes will be measured and assessed. Allergen extract preparation guidelines have been established by 2 entities: the US Pharmacopeia and an American Academy of Allergy, Asthma, and Immunology/American College of Allergy, Asthma, and Immunology/Joint Council of Allergy, Asthma, and Immunology Joint Task Force. Minor differences exist between these guidelines, but both focus on aseptic techniques and require that compounding personnel pass a written examination and annual media fill test. The AIPP third update provides new dosing recommendations for Bermuda grass, imported fire ant, and nonstandardized extracts distinguishing between pollen (0.5 mL of a 1:100 or 1:200 vol/vol) and mold/fungi or cockroach (highest tolerated dose) extracts. Because of limited and sometimes conflicting data on high and low proteolytic-containing extract compatibility, the AIPP continues to recommend against mixing these together. Although the AIPP does not specifically recommend a specific diluent, recent evidence suggests normal saline may not be as effective a stabilizer for extract dilutions as glycerin or human serum albumin. Currently, immunotherapy efficacy is determined with subjective assessments that rely on patient reporting, but this may change as health care reform evolves. It will likely become more important for US allergy/immunology practices to demonstrate immunotherapy comparative-effectiveness and report quality measures. Recent comparative-effectiveness studies have demonstrated the cost-effectiveness of immunotherapy compared with symptomatic drug treatment.

Injectable immunotherapy: recommendations for safe allergen vial preparation in the office setting

PURPOSE OF REVIEW

To review the proper technique for preparing allergen vials to be used in subcutaneous immunotherapy in the office setting, examine the potential for bacterial contamination during mixing and handling and associated risk factors and review the data relevant to contamination during vial mixing.

RECENT FINDINGS

Existing literature on the subject of safe vial preparation suggests that the incidence of bacterial contamination of allergen vials is very low. Historically, there is no report of bacterial infection for subcutaneous immunotherapy using vials prepared in the office setting or otherwise when using the proper sterile technique.

SUMMARY

In-office compounding of vials is a safe practice with literature to support continuing this practice of preparation.

Risks of allergy vial contamination: comparison of mixing in-office versus under ventilation hood

OBJECTIVE

Compare the risk of bacterial contamination of allergy immunotherapy vials prepared in-office versus those mixed under a ventilation hood.

STUDY DESIGN

Prospective single-blinded study.

SETTING

Tertiary otolaryngology outpatient clinic.

RESULTS

Five hundred thirty-seven vials were prepared and cultured for aerobes and anaerobes over an 11-month period. Three hundred twenty vials were arbitrarily assigned to in-office preparation and 217 to under-hood preparation. A total of two positive cultures occurred in vials prepared in-office and one from under-hood preparation. Follow-up cultures of these three vials were all negative. No patients receiving injections had signs or symptoms of skin or systemic infections from the injections.

CONCLUSION

Our results suggest that the risk of bacterial contamination in immunotherapy vials in both groups is rare.

The safety of multi-dose vials in allergy immunotherapy

OBJECTIVE

To prospectively evaluate the risks of vial contamination after routine clinical use of multiple-dose vials for immunotherapy.

STUDY DESIGN

Prospective observational study of immunotherapy vial cultures from June 2007 to January 2008.

SETTING

Tertiary care outpatient otolaryngology clinic.

RESULTS

Over an 8-month period, 136 consecutive vials were cultured for aerobic and anaerobic bacteria at the 3-month expiration date after regular use in an outpatient allergy clinic and dispensation of multiple doses of injection immunotherapy from each vial. All vials had negative cultures.

CONCLUSION

Immunotherapy vials are at low risk to undergo contamination in routine use. Important factors include aseptic technique, bacteriostatic agents, and expiration dating.

Impact of newly revised sterile medication compounding guidelines USP (797) on allergy vial preparation

Objectives

To highlight newly revised guidelines on sterile medication compounding released by the United States Pharmacopeia (USP (797)) in December 2007, and the implications on immunotherapy vial preparation.

Study Design and Methods

A policy review.

Results

The newly revised USP chapter on sterile medication guidelines was released December 2007 and becomes effective June 2008. The revised USP (797) now has specific guidelines addressing immunotherapy vial preparation that are a significant change from the previous version. The revised guidelines should be a useful tool for clinicians who are developing and setting office mixing standards.

Conclusions/Significance

Offices preparing immunotherapy vials should consider formalizing and implementing vial preparation guidelines. These guidelines should be based on expert opinion, experience, and scientific literature.