Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

General comments

This is a review about pistachio allergy focusing on integrating molecular diagnostics and clinical phenotypes.

Tree nut allergy is a potentially life-threatening condition. In English-speaking countries, peanuts have been extensively studied; however, diagnostic tools and knowledge for other tree nuts remain limited.

This review presents a comprehensive synthesis of the existing literature.

General coments

There are too much headings that should be merged and combined. And others could be reordered. I recommend:

3. Botanical characteristics and taxonomic relationships
4. epidemiology of sensitization and allergy to pistacho. This heading could include the information of heading “nut consumption”
5. Pistacho allergens (consider interchange with 4)
6. Mechanisms of sensitization and crossreactivity
7. clinical manifestations of pistacho allergy
8. diagnosis of pistacho allergy.

8.1. clinical history

8.2. assessment of sensitization

8.3. funcional testing

8.4. Oral food challenge

9. proposed diagnostic approach for pistacho allergy. This heading would start with “Integration diagnostic data”

10 Clinical management and immunotherapy.

11 Conclusion and future perspectives

Specific coments

140. Tecnically speaking, pistachio and cashew are not allergens but a source of allergens, modify the sentence accordingly.
141. A reference is missing.

Table 1. A column including the frequencies of allergens in the population described should be of interest.

Eliminate the line of minor allergens and include Pis v 4 as it is described in the allergen.org.

If there are other allergens described in the bibliography name it in the text.

I would recommend avoiding the terminology “major allergen” and “minor allergen,” as it reflects only the frequency of sensitization and not clinical relevance or symptom severity. Moreover, for poorly characterized sources such as pistachio, this classification may be inaccurate.

Figure 1. If there is seed storage protein sensitization (Pis v1 , Ana o 3 +) and it is a high risk sensitization profile, the recommendation should be avoidance + emergency preparedness, like in the other cases or in the other line with Pis v1 , Ana o 3 – and low risk sensitization profile and positive BAT consider avoidance and no OFC. You should clarify and unify criteria.

 

Author Response

We sincerely thank you for your thorough and constructive review, which helped us to substantially improve the clarity, structure, and clinical relevance of the manuscript. We have carefully addressed all comments and revised the manuscript accordingly. Below, we provide a point-by-point response.

Comment 1: Structure of the manuscript is overly fragmented; several sections could be merged or reorganized.

Response:
We agree with this comment and have revised the structure of the manuscript to improve coherence and readability. The number of subheadings has been reduced, and related sections have been consolidated. In particular, epidemiological aspects were reorganized to avoid redundancy, and the diagnostic sections were streamlined to clearly distinguish between general diagnostic principles and the proposed phenotype-based diagnostic approach. The revised structure follows a more logical progression from epidemiology and molecular allergen characterization to clinical manifestations, diagnosis, and management.

Comment 2: Pistachio and cashew are referred to as allergens rather than sources of allergens.

Response:
We thank the Reviewer for this important clarification. Throughout the revised manuscript, terminology has been corrected to consistently refer to pistachio and cashew as sources of allergens rather than allergens per se. References to allergenic proteins and allergen components have been adjusted accordingly to ensure technical accuracy.

Comment 3: Table 1 lacks information on the frequency of sensitization to individual pistachio allergen components.

Response:
We have revised Table 1 to include qualitative information on the reported frequency of sensitization to individual pistachio allergen components, accompanied by a footnote explicitly stating that available data are heterogeneous and that robust population-level prevalence estimates are currently lacking. This approach was chosen to provide clinically useful context while avoiding overinterpretation of limited data.

Comment 4: The clinical relevance of Pis v 4 is unclear and the term “minor allergen” is potentially misleading.

Response:
We agree and have revised the description of Pis v 4. The term “minor allergen” has been removed, and Pis v 4 is now described in a neutral and critical manner, acknowledging its inclusion in the IUIS database while emphasizing the limited biochemical and clinical characterization currently available.

Comment 5: The proposed diagnostic algorithm (Figure 1) lacks clear clinical endpoints.

Response:
Figure 1 has been revised to provide clearer clinical decision pathways. High-risk sensitization profiles (defined as sensitization to seed storage proteins such as Pis v 1 and/or Ana o 3) now consistently lead to recommendations for avoidance and emergency preparedness, whereas low-risk profiles may proceed to oral food challenge or be classified as tolerant. The revised figure is fully aligned with the diagnostic approach described in the text.

Reviewer 2 Report

Comments and Suggestions for Authors

Tworowska and colleagues provide an overview on the current knowledge about pistachio allergy, the culprit allergens and how the application of molecular diagnosis can improve a patient tailored diagnosis and management of patients.

This narrative review is based on a structured literature search followed by an expert based analysis. This review provides data on nut consumption, sensitization, and allergy to pistachio. Furthermore, the authors provide an overview on the currently identified allergens and their cross reactivity to cashew allergens. Subsequently the diagnostic approach and the application of currently up to date tests is summarized as well as the clinical management and potential immunotherapy is discussed.

The authors provide also a table summarizing Pis v 1- Pis v 5 in comparison to cashew allergens. It is recommended to add also Pis v 4 (superoxide dismutase) a minor allergen. While it seems to be of lower significance for diagnosis it is already in the IUIS allergen database and a short (critical) discussion on this allergen could be added.  

Author Response

We thank you for your positive and thoughtful evaluation of our manuscript and for highlighting the clinical relevance of molecular diagnostics in pistachio allergy. We are grateful for your constructive comments and have revised the manuscript accordingly.

Regarding your suggestion to include Pis v 4 (manganese superoxide dismutase), we fully agree. In the revised manuscript, Pis v 4 has been added to Table 1 alongside Pis v 1–Pis v 5, with reference to its presence in the IUIS allergen database. We have included a short and critical discussion of this component, emphasizing that while Pis v 4 is currently considered of limited diagnostic relevance compared with seed storage proteins, its characterization as a pistachio allergen warrants acknowledgment. The text now clearly reflects the available evidence, highlighting both its documented allergen status and the current lack of robust clinical data supporting a major role in diagnosis or risk stratification.

We believe that this addition improves the completeness and scientific accuracy of the allergen overview while maintaining a clinically balanced perspective.

Thank you again for your valuable feedback, which has helped to further strengthen the manuscript.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript provides a well-structured and timely narrative review on pistachio allergy. The sections dealing with molecular allergen characterization, cross-reactivity with cashew and the advantages of component-resolved diagnostics over extract-based testing are rigorous and clinically relevant. The review successfully highlights the diagnostic challenges posed by frequent sensitization and limited true clinical allergy, and it appropriately frames pistachio allergy as part of the broader Anacardiaceae-related nut allergy spectrum. However, three aspects require refinement to strengthen the clinical relevance and align the review with current advances in food allergy management.

1. First, although the manuscript repeatedly refers to “risk stratification”, it does so exclusively in diagnostic terms and does not consider the recent therapeutic paradigm shift introduced by biologic therapies. In the last two years, anti-IgE treatment with omalizumab has emerged as a disease-modifying intervention capable of increasing reaction thresholds and reducing the risk of accidental food-induced anaphylaxis. Observational evidence  showed that omalizumab markedly increases tolerated doses, reduces anaphylactic reactions and allows safe reintroduction of previously allergenic foods in children with severe food allergy and asthma (doi: 10.1111/all.16314.). Systematic reviews and meta-analyses of randomized controlled trials further demonstrate that omalizumab significantly increases food tolerance thresholds and lowers the incidence of food-allergic reactions without relevant safety concerns (doi: 10.1016/j.waojou.2025.101069.). In parallel, the World Allergy Organization has recently issued a manifesto identifying biologic therapies as a critical tool to prevent life-threatening food-induced anaphylaxis and calling for their global implementation (doi: 10.1016/j.waojou.2025.101113.). Although these studies are not pistachio-specific, they directly concern the population of polysensitized tree-nut–allergic patients in whom pistachio allergy is most clinically relevant. Integrating this evidence into the discussion would naturally connect molecular risk profiling with emerging preventive therapeutic strategies and significantly enhance the translational impact of the review.
2. The epidemiology section correctly states that pistachio allergy is relatively uncommon, but it would benefit from a clearer distinction between prevalence of sensitization and prevalence of clinically confirmed allergy. Available data indicate that pistachio sensitization, especially in cashew-sensitized patients, is frequent, whereas OFC-proven pistachio allergy remains low in population-based cohorts. Explicitly separating these two concepts would avoid overestimation of true disease burden and improve interpretation of diagnostic test performance.
3. The current diagnostic flow-chart is scarcely legible in its present format. Redrawing the figure in a clearer format and adding a concise stepwise diagnostic pathway integrating clinical history, extract-based testing, component-resolved diagnostics, functional assays and the indication for oral food challenge would convert the conceptual framework into an actionable clinical tool. A brief indication that high-risk molecular profiles might, in the near future, guide selection of candidates for preventive biologic therapy would further strengthen the clinical message.

Author Response

We sincerely thank you for your thoughtful and detailed review and for your positive assessment of the molecular and diagnostic aspects of our manuscript. We greatly appreciate your constructive suggestions, which have helped us to further strengthen the clinical and translational relevance of the review. Our point-by-point responses are provided below.

Comment 1: The concept of risk stratification is discussed mainly in diagnostic terms and does not sufficiently incorporate recent advances in biologic therapies, particularly anti-IgE treatment with omalizumab.

Response:
We fully agree with this important observation. In the revised manuscript, we have expanded the discussion on biologic therapies, with a particular focus on anti-IgE treatment with omalizumab, framing it as part of an emerging preventive and disease-modifying paradigm in food allergy management. We now explicitly acknowledge recent observational studies, randomized controlled trials, and meta-analyses demonstrating increased reaction thresholds and reduced risk of accidental food-induced reactions with omalizumab, as well as the recent World Allergy Organization manifesto highlighting biologics as a key tool for preventing life-threatening anaphylaxis.

Although these data are not pistachio-specific, we have clarified their direct relevance to polysensitized tree nut–allergic patients, in whom pistachio allergy is most clinically relevant. Importantly, this section is explicitly framed as a translational and forward-looking perspective rather than a clinical recommendation. The revised discussion now directly links molecular risk profiling to potential future selection of candidates for preventive biologic therapy, thereby strengthening the translational impact of the review.

Comment 2: The epidemiology section would benefit from a clearer distinction between sensitization and clinically confirmed pistachio allergy.

Response:
We agree and have revised the epidemiology section to explicitly and clearly differentiate between the prevalence of pistachio sensitization and the prevalence of clinically confirmed pistachio allergy. The revised text now states that pistachio sensitization - particularly among cashew-sensitized individuals - is common, whereas oral food challenge - confirmed pistachio allergy remains relatively uncommon in population-based cohorts. This distinction is emphasized to avoid overestimation of disease burden and to improve interpretation of diagnostic test performance.

Comment 3: The diagnostic flow-chart is difficult to interpret and should be redrawn as a clearer, stepwise clinical tool integrating modern diagnostics and future therapeutic perspectives.

Response:
In response to this comment, Figure 1 has been redrawn to improve legibility and clinical usability. The revised figure now presents a concise, stepwise diagnostic pathway integrating clinical history, extract-based testing, component-resolved diagnostics, functional assays (including basophil activation testing), and the indication for oral food challenge. Clear clinical endpoints (avoidance with emergency preparedness, oral food challenge, or tolerance) are explicitly defined.

In addition, a brief forward-looking indication has been incorporated, noting that high-risk molecular sensitization profiles may, in the near future, help guide identification of candidates for preventive biologic therapy. This addition aligns the diagnostic framework with emerging therapeutic strategies while maintaining an evidence-based and cautious tone.

We are grateful for your insightful comments, which have substantially improved the clinical clarity, balance, and translational relevance of the manuscript.

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The authors addressed most of the comments