The safety of multi-dose vials in allergy immunotherapy

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.

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.