Pattern of sensitization to Juniperus oxycedrus 4EF-hand polcalcin, Jun o 4, compared with the 2EF-hand grass homolog Phl p 7 in a general Italian population of subjects suffering from pollinosis

Cupressaceae pollen causes allergic reactions worldwide with long-lasting symptomatic periods. Currently, no cypress polcalcin is available for diagnostic purposes. With the aim to investigate the pattern of sensitization to a cypress polcalcin, a synthetic gene of Jun o 4, the Juniperus oxycedrus 4EF-hand polcalcin, was cloned and expressed in Escherichia coli. Its features were investigated in comparison with the grass 2EF-hand Phl p 7. Rhinitis was the symptom most frequently reported in a cohort of Italian patients sensitized to rJun o 4 and/or rPhl p 7. The detection of many pollen allergic patients sensitized to the cypress polcalcin, but negative to Phl p 7, indicates that Phl p 7 cannot be further considered a marker of sensitization towards all the polcalcins. A 4EF-hand cypress polcalcin claims the inclusion in allergy diagnostic tests. In addition, the sensitivity of polcalcins to gastrointestinal digestion is reported and discussed for the first time. [Display omitted] •Often the sensitization to Jun o 4 is not associated with that to Phl p 7.•Based on the patterns of sensitization to Jun o 4, a cohort of allergic patients could be divided in four groups.•Phl p 7 cannot be considered a marker of sensitization towards all the polcalcins.•Both Jun o 4 and Phl p 7 proved to be sensitive to gastric and intestinal digestion.•It can be hypothesized that ingested polcalcins could contribuite to cause mild symptoms localyzed in the mouth.