Dear Editor,

I have read the short communication article titled, “Achieving remission with peach sublingual immunotherapy in adults and children with lipid transfer protein syndrome without associated cofactor ” by Violán et al. with great interest.¹ This study aimed to determine the efficacy of sublingual peach immunotherapy (Pru p3 SLIT) in patients with cofactor-related and non-cofactor-related LTP syndrome through a retrospective observation of 23 patients and to evaluate changes in food tolerance before and after treatment.¹ Nevertheless, clarifying some issues that are not fully understood about the methodology and short communication will improve readers’ understanding of the article.

The conclusion of the abstract¹ states that SLIT does not resolve food tolerance issues triggered by the cofactor. The results section of the abstract¹ states that tolerance did not improve in any of the seven patients with allergic reactions to the specified foods, which were caused or exacerbated by the cofactor. Again, the abstract¹ concludes by mentioning that LTP food allergy entered clinical remission after SLIT. The use of the terms “remission,”, “resolve,” and “improve” can cause confusion about the actual outcome of this SLIT treatment protocol and the situation achieved.¹

The article¹ discusses LTP syndrome caused by both cofactor-related and non-cofactor-related food allergic reactions. Co-factors are mostly mentioned as physical exercise and the concomitant use of nonsteroidal anti-inflammatory drugs (NSAIDs). However, the article¹ does not report whether the triggering of symptoms by exercise was determined by the patient’s complaint or by oral provocation. It would also be useful to report which NSAID drug was taken.¹

Sublingual immunotherapy (SLIT-peach^®) with the Pru p3 extract has been used to develop tolerance to nonspecific lipid transfer proteins (nsLTP) in patients with allergies to multiple plant foods.² Even ultrarapid regimens lasting as little as 4 days have been developed.² Although commercial allergenic extracts of peach Pru p3 SLIT have been available in Spain since 2011, it would be beneficial to explain the protocol for the sake of researchers in countries where these preparations are not available, as an example, and to show the protocol used in the study.¹ In this study, side effects³ are briefly mentioned, and the treatment duration is unclear. In one place, it says 3.4 years, then immediately after it says 2.7 years, but Figure 1 suggests it could be between 2 and 3 years.¹ It would have been better for readers and researchers if these two points had been clarified further.

Although the study began with 80 patients, only 23 patients were included in the protocol. The results section states that 55 patients were female and provides the average age.¹ In this case, were the 25 patients included in the study male? It would have been more accurate to give the age, gender, and other clinical characteristics of the enrolled 23 patients. Again, it is stated that treatment was continued in 15 of the 49 patients analyzed, but what kind of treatment this was is not fully understood, like the other numbers given in Figure 2.¹

While 95.7% of patients tolerated the oral test with unpeeled peaches, no improvement in tolerance was observed among the seven patients with cofactor-related allergic reactions.¹ It is unclear how many participants were included in the study for these calculations. If 7 out of 23 participants were included, the result would be 30.4%, which differs from the total when added to 95.7%. There is a general confusion in the calculations and figures in the article, making it difficult to understand.

Minor point: When evaluating the success of the study, the failure to measure laboratory markers such as specific immunoglobulin E (IgE) and immunoglobulin G4 (IgG4) against peach (Pru p 3) at the start of treatment, during the first year of treatment, and at the end of therapy may be a limitation.^4,5

In conclusion, I would like to thank the authors for this excellent, high-quality short communication and its findings, which raise awareness of the diagnosis and treatment of plant-induced food hypersensitivity reactions associated with LTP syndrome and SLIT-peach^®.