Association Between Peach and Olive Pollen Non-Specific Lipid Transfer Protein Allergy and HLA Class II Phenotype.

Concomitant sensitisation to non-specific lipid transfer proteins (nsLTPs) from olive pollen (Ole e 7) and peach (Pru p 3) has been observed in the south of Spain. In the search for reasons to explain this observation, we studied a potential causal relationship between Human Leukocyte Antigen (HLA) molecules and nsLTP sensitisation. For this purpose, eighteen Ole e 7-monosensitised (MONOLE) patients, 22 Pru p 3-monosensitised (MONPRU) patients, and 22 bisensitised (BI) patients were genotyped for HLA class II alleles. Complementarily, T-cell epitopes were predicted with the Immune Epitope Database analysis tool to test HLA epitope presentation. Our results showed a significant increase in DRB111 and DQB103 frequencies in MONPRU patients and DRB104 frequency in MONOLE patients. Additionally, T-cell epitope analysis revealed high binding affinity between the predicted Pru p 3 epitopes and DRB111 and between the predicted Ole e 7 epitopes and DRB104, suggesting that presentation of these epitopes may be favoured and predisposing individuals to sensitisation. Conversely, low DQB105 frequency and poor binding ability of predicted epitopes from both nsLTPs postulated this allele as a possible protective factor to sensitisation. Variations in the binding affinity between nsLTP epitopes and HLA molecules may underlie individual susceptibility to nsLTP allergy.