Cannabis: An Emerging Occupational Allergen?

Bioaerosol Exposures and Respiratory Diseases in Cannabis Workers

PURPOSE OF REVIEW

This review investigates occupational inhalation hazards associated with biologically derived airborne particles (bioaerosols) generated in indoor cannabis cultivation and manufacturing facilities.

RECENT FINDINGS

Indoor cannabis production is growing across the US as are recent reports of respiratory diseases among cannabis workers, including occupational asthma morbidity and mortality. More information is needed to understand how bioaerosol exposure in cannabis facilities impacts worker health and occupational disease risk. Preliminary studies demonstrate a significant fraction of airborne particles in cannabis facilities are comprised of fungal spores, bacteria, and plant material, which may also contain hazardous microbial metabolites and allergens. These bioaerosols may pose pathogenic, allergenic, toxigenic, and pro-inflammatory risks to workers. The absence of multi-level, holistic bioaerosol research in cannabis work environments necessitates further characterization of the potential respiratory hazards and effective risk prevention methods to safeguard occupational health as the cannabis industry continues to expand across the US and beyond.

[Climate change and type I allergies at the workplace]

The consequences of climate change, the increasing frequency, duration and intensity of extreme events such as excessive drought, heat waves, large-scale forest fires, heavy rainfall and associated flooding also affect workers' conditions in the workplace in many ways. Allergic diseases of the respiratory tract and skin due to workplace exposure can also arise or be influenced by direct and indirect consequences of climate change. This affects outdoor workers not only through increased exposure to pollen allergens, but also through climate-related increases in typical workplace allergens. As an indirect effect of climate change, manufacturing processes and exposure at workplaces are changing, which can also cause new sensitization and allergies. Lifestyle changes, which are primarily intended to contribute to climate protection and sustainability, can also lead to new or changed products and thus to changed manufacturing processes and exposures in the workplace, so this should also be considered an indirect effect of climate change on the health of workers. The emergence of new occupational sources of sensitization due to new or changed allergen exposures must be considered in the context of occupational health and safety and requires proactive measures to protect workers.

Cannabis use and the prevalence of current asthma among adolescents and adults in the United States

OBJECTIVES

Cannabis use has increased among adolescents and adults in the United States (US) in recent years. Few data are available on the prevalence of asthma by frequency of cannabis use. This study aimed to estimate the prevalence of asthma by frequency of past 30-day cannabis use among US individuals.

METHODS

Data were drawn from the 2020 National Survey on Drug Use and Health (NSDUH), a nationally representative, annual cross-sectional survey of US individuals aged 12 and older in the United States (N = 32,893). Logistic regression models were used to examine the relationship between frequency of any cannabis and/or blunt (i.e., cannabis smoked in a hollowed-out cigar) use in the past 30 days and current asthma, adjusting for demographics and current cigarette smoking.

RESULTS

Current asthma was more common among US individuals who reported cannabis use in the past 30-days, relative to those who did not (9.8% vs. 7.4%, p < 0.0001). The odds of asthma was significantly greater among individuals reporting cannabis use 20-30 days/month (Adjusted Odds Ratio [AOR] = 1.67, 95% CI:1.21, 2.31), blunt use 6-15 and 20-30 days/month (AOR = 1.9, 95% CI:1.1, 3.2; AOR = 2.2, 95% CI:1.4, 3.6), respectively, than among those without. A positive linear relationship was observed between frequency of a) cannabis use (p < 0.0001) and b) blunt use (p < 0.0001) and current asthma prevalence.

CONCLUSIONS

Findings suggest a dose-response relationship between frequency of current cannabis use and the prevalence of current asthma in the US individuals.

Proteomics-Based Approach for Detailing the Allergenic Profile of Cannabis Chemotypes

Allergic sensitization to cannabis is an emerging public health concern and is difficult to clinically establish owing to lack of standardized diagnostic approaches. Attempts to develop diagnostic tools were largely hampered by the Schedule I restrictions on cannabis, which limited accessibility for research. Recently, however, hemp was removed from the classified list, and increased accessibility to hemp allows for the evaluation of its practical clinical value for allergy diagnosis. We hypothesized that the proteomic profile is preserved across different cannabis chemotypes and that hemp would be an ideal source of plant material for clinical testing. Using a proteomics-based approach, we examined whether distinct varieties of cannabis plant contain relevant allergens of cannabis. Cannabis extracts were generated from high tetrahydrocannabinol variety (Mx), high cannabidiol variety (V1-19) and mixed profile variety (B5) using a Plant Total Protein Extraction Kit. Hemp extracts were generated using other standardized methods. Protein samples were subjected to nanoscale tandem mass spectrometry. Acquired peptides sequences were examined against the Cannabis sativa database to establish protein identity. Non-specific lipid transfer protein (Can s 3) level was measured using a recently developed ELISA 2.0 assay. Proteomic analysis identified 49 distinct potential allergens in protein extracts from all chemotypes. Most importantly, clinically relevant and validated allergens, such as profilin (Can s 2), Can s 3 and Bet v 1-domain-containing protein 10 (Can s 5), were identified in all chemotypes at label-free quantification (LFP) intensities > 106. However, the oxygen evolving enhancer protein 2 (Can s 4) was not detected in any of the protein samples. Similarly, Can s 2, Can s 3 and Can s 5 peptides were also detected in hemp protein extracts. The validation of these findings using the ELISA 2.0 assay indicated that hemp extract contains 30-37 ng of Can s 3 allergen per µg of total protein. Our proteomic studies indicate that relevant cannabis allergens are consistently expressed across distinct cannabis chemotypes. Further, hemp may serve as an ideal practical substitute for clinical testing, since it expresses most allergens relevant to cannabis sensitization, including the validated major allergen Can s 3.

Impact of climate change on allergic diseases in Germany

Background

Allergic diseases, especially inhalation allergies, have reached epidemic levels and environmental factors play an important role in their development. Climate change influences the occurrence, frequency, and severity of allergic diseases.

Methods

The contents of this article were selected by the authors and developed section by section according to their expertise and the current state of knowledge. The sections were then discussed and agreed upon amongst all authors.

Results

The article highlights direct and indirect effects of climate change on allergies. It goes into detail about the connections between climate change and (new) pollen allergens as well as (new) occupational inhalation allergens, explains the effects of climate change on the clinical picture of atopic dermatitis, discusses the connections between air pollutants and allergies, and provides information about the phenomenon of thunderstorm asthma.

Conclusions

There is a need for action in the field of pollen and fungal spore monitoring, allergy and sensitisation monitoring, urban planning from an allergological perspective, and changes in the working environment, among others.

A review of cannabis allergy in the early days of legalization

Cannabis allergy is a burgeoning field; consequently, research is still in its infancy and allergists' knowledge surrounding this topic is limited. As cannabis legalization expands across the world, it is anticipated that there will be an increase in cannabis use. Thus, we hypothesize that a concomitant rise in the incidence of allergy to this plant can be expected. Initiatives aimed at properly educating health care professionals are therefore necessary. This review presents the most up-to-date information on a broad range of topics related to cannabis allergy. Although the clinical features of cannabis allergy are becoming more well described and recognized, the tools available to make a correct diagnosis are meager and often poorly accessible. In addition, research on cannabis allergy is still taking its first steps, and new and potentially groundbreaking findings in this field are expected to occur in the next few years. Finally, although therapeutic approaches are being developed, patient and physician education regarding cannabis allergy is certainly needed.

EAACI Molecular Allergology User's Guide 2.0

Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the "EAACI Molecular Allergology User's Guide" (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.

Impact of cannabis knowledge and attitudes on real-world practice

BACKGROUND

Increased cannabis consumption worldwide challenges allergists because of an upsurge in cannabis allergy and need to discuss cannabis with patients.

OBJECTIVE

To determine the knowledge, attitudes, and practices regarding cannabis among allergists and their approach to recognizing and diagnosing suspected cannabis allergy.

METHODS

The International Allergist Canna Knowledge, Attitudes, and Practices Survey was completed by members from 3 International Allergy Societies. Survey questions included the following: 13 on cannabis attitudes, 7 on cannabis knowledge, and 4 on real-world allergy practices. Knowledge level was dichotomized and Statistical Package for the Social Sciences TwoStep Cluster Analysis grouped participants by attitudes. Multivariate analysis determined the relationship of knowledge and attitude to practice delivery.

RESULTS

Of 570 eligible surveys started, 445 (78.1%) were completed. Participants were 49.7% of female sex, 65.9% aged 24 to 56 years, approximately 70% in practice for more than or equal to 10 years, and 29.2% practicing in an area where cannabis use is illegal. Of the respondents, 43.1% reported consulting on patients with suspected cannabis allergy and 54.7% had undertaken skin prick testing, in vitro cannabis testing, or both. Statistically significant differences were found between the 3 societies for most variables analyzed. Analysis of attitudes revealed 3 clusters named Traditional, Progressive, and Unsure. Those with more progressive attitudes toward cannabis and who had more knowledge were more comfortable speaking to patients about cannabis and more often asked patients on how often and how they used cannabis (all P < .001).

CONCLUSION

Varying knowledge and attitudes toward cannabis affecting comfort communicating with patients about cannabis were found in members of 3 allergy societies supporting the need for more cannabis research and education.

[Inhaled marijuana and the lung, a toxic cocktail?]

Unlike the well-documented effects of tobacco smoke on the lung, the effects of cannabis smoke remain controversial, the main bias consisting in co-consumption of tobacco. That said, the composition of joint smoke is close to that of cigarettes, containing many compounds that are carcinogenic and/or alter the respiratory epithelium. Confirmed respiratory effects in chronic cannabis smokers include aggravated chronic bronchitis symptoms, a cumulative effect with tobacco on COPD and emphysema occurrence, an increased risk of bullous emphysema, and pneumothorax with heightened risk of recurrence after pleural symphysis. Recent prospective studies have shown a negative impact on lung function, with not only damage to the airways, but also DLCO alteration and an accelerated drop in FEV1. Finally, cannabis smoking is very common among young patients with lung cancer. Its consumption could lead to a different lung cancer profile, potentially more undifferentiated and less accessible to targeted therapy. Questioning about cannabis consumption must be systematic and targeted medical care should be offered.

Cannabis-related allergies: An international overview and consensus recommendations

Cannabis is the most widely used recreational drug in the world. Cannabis sativa and Cannabis indica have been selectively bred to develop their psychoactive properties. The increasing use in many countries has been accelerated by the COVID-19 pandemic. Cannabis can provoke both type 1 and type 4 allergic reactions. Officially recognized allergens include a pathogenesis-related class 10 allergen, profilin, and a nonspecific lipid transfer protein. Other allergens may also be relevant, and recognition of allergens may vary between countries and continents. Cannabis also has the potential to provoke allergic cross-reactions to plant foods. Since cannabis is an illegal substance in many countries, research has been hampered, leading to challenges in diagnosis since no commercial extracts are available for testing. Even in countries such as Canada, where cannabis is legalized, diagnosis may rely solely on the purchase of cannabis for prick-to-prick skin tests. Management consists of avoidance, with legal issues hindering the development of other treatments such as immunotherapy. Education of healthcare professionals is similarly lacking. This review aimed to summarize the current status of cannabis allergy and proposes recommendations for the future management of this global issue.

Surveillance of work-related asthma including the emergence of a cannabis-associated case series in Washington State

OBJECTIVE

We conducted surveillance for work-related asthma (WRA) in Washington State to identify the industry sectors and asthma exposures most commonly affecting injured workers and in need of prevention activities.

METHODS

Using workers' compensation data as the primary data source, valid cases were classified as work-aggravated asthma (WAA) or new onset asthma that includes occupational asthma (OA) and reactive airways dysfunction syndrome (RADS). The source of exposure that caused the worker's asthma, their industry and occupation were determined.

RESULTS

There were 784 valid work-related asthma cases identified for the period 2009-2016, WAA (n = 529) was most common followed by occupational asthma (n = 127) and RADS (n = 12). The Health Care and Social Assistance industry had the highest number of cases (n = 170) with 82% classified as WAA. The highest overall proportions of new onset asthma are occurring in Agriculture, Forestry, Fishing and Hunting (33% of work related asthma cases), Manufacturing (31%) and Construction (30%). The leading substances associated with new onset asthma across all industries include hop plant dust, wood and cedar dust, mineral and inorganic dust, mold, and cleaning materials. We describe ten cases of cannabis-associated asthma including seven from workers in the legalized cannabis industry, four of whom had OA.

CONCLUSION

State-based work-related asthma surveillance is critical in identifying the workers and exposures associated with this occupational disease, including the detection of a case-series in the cannabis industry.

Occupational Allergies to Cannabis

Within the last decade there has been a significant expansion in access to cannabis for medicinal and adult nonmedical use in the United States and abroad. This has resulted in a rapidly growing and diverse workforce that is involved with the growth, cultivation, handling, and dispensing of the cannabis plant and its products. The objective of this review was to educate physicians on the complexities associated with the health effects of cannabis exposure, the nature of these exposures, and the future practical challenges of managing these in the context of allergic disease. We will detail the biological hazards related to typical modern cannabis industry operations that may potentially drive allergic sensitization in workers. We will highlight the limitations that have hindered the development of objective diagnostic measures that are essential in separating "true" cannabis allergies from nonspecific reactions/irritations that "mimic" allergy-like symptoms. Finally, we will discuss recent advances in the basic and translational scientific research that will aid the development of diagnostic tools and therapeutic standards to serve optimal management of cannabis allergies across the occupational spectrum.

Cannabis attitudes and patterns of use among followers of the Allergy & Asthma Network

BACKGROUND

Cannabis use in patients with allergy/asthma, a high-risk group for adverse effects to cannabis, is unknown.

OBJECTIVE

To determine the patterns of use and attitudes toward cannabis in patients with allergy/asthma.

METHODS

An anonymous online survey on cannabis attitudes and use was conducted through the Adult Allergy & Asthma Network. The Asthma Control Test assessed asthma burden. Cluster analyses determined group phenotypes and factor analyses condensed cannabis subjective effects into similar response patterns.

RESULTS

A total of 88 of 489 respondents (18.0%) currently use cannabis with most at the age of less than 50 years old, of female sex, and of White race. Of the noncannabis users (N = 401), 2.5% reported cannabis allergy. Cluster analysis revealed that a liberal attitude toward cannabis was associated with current cannabis use (P < .001). Among current cannabis users, 40.9% of their physicians inquired on cannabis use; only 37.5% of users wanted to discuss cannabis. In addition, 65.9% used cannabis for medical or medical/recreational purposes. Cannabinoids used were tetrahydrocannabinol (33.0%), cannabidiol (19.3%), or both (47.7%). Smoked and vaped cannabis were reported by 53.4% and 35.2%, respectively. Furthermore, 51 cannabis users (58.0%) reported current asthma with 39.2% uncontrolled; of these, 50% smoked cannabis. Compared with current participants with asthma not using cannabis, those currently using cannabis experienced similar levels of asthma control, quality of life, and frequency of asthma exacerbations. Positive effects were endorsed more than negative effects to cannabis (P < .001). Moreover, 19.3% of cannabis users reported coughing that was associated with smoking cannabis (P < .001).

CONCLUSION

Cannabis was used by less than 20% of the respondents with positive effects more frequent than negative effects. Half of cannabis users with uncontrolled asthma smoke cannabis, but only a minority of the physicians inquire about its use.