Minor pollinosis fromCryptomeria japonica in Varese,northern Italy. Aerobiological monitoring and main clinical features

In the last 2 years, we have conducted an aerobiological monitoring program ofCryptomeria japonica, a plant belonging to the family of Taxodiaceae that sometimes causes pollinosis in the period from February to April. Throughout 1994, we checked the incidence of its sensitization and the clinical effects in 85 subjects with correlated seasonal symptoms, who gave a positive skin prick test (SPT) for Betulaceae and/or Corylaceae. Twenty-five patients (29.4%; 19 M; 6 F; mean age, 38.8 years) all with oculorhinitis, were SPT positive to an allergenic extract ofCryptomeria. RAST confirmed this positivity in 44% of the cases. No patients showed monosensitization forCryptomeria to either SPT or RAST. Two subjects gave a positive result on specific nasal provocation. RAST inhibition showed no cross-reaction betweenCryptomeria and birch pollen. During the pollen season each patient made a list, scoring symptoms and specifying any drugs used, so we could correlate these elements with aerobiological observations. The pollen concentration probably exceeded the allergizing threshold forCryptomeria on 8 days during 3 months of recording. The intensity and duration of symptoms seemed to be mainly influenced by sensitization to Betulaceae and Corylaceae. It is thus possible that a combination of ‘minor’ pollinosis may produce seasonal symptoms in allergic patients.     

Oleaceae in Trieste (NE Italy): aerobiological and clinical data

Oleaceae pollen concentrations in the Trieste area are low (<10%) compared to the total number of airborne pollen grains, with only one pollination peak at the beginning of June when the Oleaceae concentration reached 62% of the total pollen count in 1992. This peak was due to an exceptionally high pollination of olive trees in 1992, when airborne pollen concentration rose to 1357 pollen grains/m³ on June 3. Sensitization toOlea increased from 1989 to 1993, when it was present in 23.4% of symptomatic patients, but the role ofOlea in inducing allergic respiratory symptoms is difficult to evaluate because almost all patients were sensitized to other pollens, and in particular to Gramineae: only four subjects were sensitized toOlea alone (1.4%). Despite the low Oleaceae pollen counts, this pollinosis is increasing, probably because of increased cultivation ofOlea in recent years. However, although skin prick test positivity is common in polysensitized patients, its role in inducing sensitization and symptoms is presently less important than that of other pollens.     

Minor pollinosis fromCryptomeria japonica in Varese,northern Italy. Aerobiological monitoring and main clinical features

In the last 2 years we have conducted an aerobiological monitoring program ofCryptomeria japonica, a plant belonging to the family of Taxodiaceae that sometimes causes pollinosis in the period from February to April. Throughout 1994, we checked the incidence of its sensitization and the clinical effects in 85 subjects with correlated seasonal symptoms, who gave a positive skin prick test (SPT) for Betulaceae and/or Corylaceae. Twenty-five patients (29.4%; 19 M; 6 F; mean age, 38.8 years) all with oculorhinitis, were SPT positive to an allergenic extract ofCryptomeria. RAST confirmed this positivity in 44% of the cases. No patients showed monosensitization forCryptomeria to either SPT or RAST. Two subjects gave a positive result on specific nasal provocation. RAST inhibition showed no cross-reaction betweenCryptomeria and birch pollen. During the pollen season each patient made a list, scoring symptoms and specifying any drugs used, so we could correlate these elements with aerobiological observations. The pollen concentration probably exceeded the allergizing threshold forCryptomeria on 8 days during 3 months of recording. The intensity and duration of symptoms seemed to be mainly influenced by sensitization to Betulaceae and Corylaceae. It is thus possible that a combination of minor pollinosis may produce seasonal symptoms in allergic patients.     

The relationships between the concentrations of airborne pollen and allergic symptoms in Trieste (Northern Italy) in 1989

Summary Concentrations of airborne pollens recorded in Trieste in 1989 are evaluated in relation to allergic complaints in 113 patients with skin prick tests positive to one pollen species. Analysis of the result enable the two most important allergens to be confirmed as: Poaceae in 70.7% of patients and Parietaria in 18.6%. Few people had monosensitation to Compositae (Artemisia), Corylaceae and Fagaceae.Sympotoms are related to the flowering period when pollen levels climbed to daily averages of 15–20 grains/m³ but they started later than airborne peak concentrations and finished later than pollen decline. Pollen concentration recording can be a useful way to predict the clinical manifestation in sensitive patients but other factors are involved in determining symptoms like subjective mucosal reactions, polysensitization, patients living and working environment.     

Phenological and aerobiological monitoring of allergenic flora in padua (Italy). Preliminary data

A phenological study on allergenic plants was carried out in Padua during 1995 in order to identify spontaneous and cultivated allergenic species in an urban area and their distribution, and to evaluate the relationship between anthesis length and airborne pollen concentrations. In some cases, there was no temporal overlap between phenological and aerobiological data, in particular forCorylaceae, Betulaceae, Chenopodiaceae, Amaranthaceae, Polygonaceae and Fagaceae.     

Ragweed pollen: The aeroallergen is spreading in Italy

Presently in Europe, ragweed pollen as an aeroallergen is not as important as Poaceae,Parietaria or Betulaceae, even if in some countries the plant is beginning to influence the local composition of the airborne pollen spectra. In northern Italy, the presence of ragweed airborne pollen has only been reported since the beginning of the 1980’s and it is increasingly spreading from year to year. Given this situation, the allergologists have begun to regard the potential risk of sensitisation to ragweed pollen with much attention. Up to now, such pollen has not been included in the routine allergological tests. In 1995 in some sites of northern Italy (Turin, Milan, Trieste), the concentration values of ragweed pollen were remarkable (∼ 20–30 p/m³) and on the increase with respect to the previous years. This investigation aims at focusing the atmospheric concentration trend on this new aeroallergen (Ambrosia sp.) in Italy from 1991 throughout 1995.     

The first approach towards recognising allergy-provoking flora in Belluno and its relationship with allergic phenomena

Summary The town of Belluno has a high number of wild and cultivated plants whose pollen has various degrees of importance from an allergological point of view.In this preliminary study we have taken into consideration the distribution and the flowering period of these species, correlating them with the data on the quantity and type of pollen collected by a sampler placed on the roof of the City Hospital, and also with the results of the allergometric tests (Prick Tests) carried out in the Broncho-Pneumological Department during the first 9 months of 1990.The wild specis of spring-flowering trees which can be found in the woods surrounding the city (Fagaceae, Betulaceae, Corylaceae) and along the gravel banks of the Piave river (Salicaceae) as well as the Graminaceae which are widespread both in the urban area and in the fields outside the city and some cultivated species (Robinia, Tilia, Acer) which flower a little later, are the species which produce most pollen and which are held responsible for allergies. However, only the pollen of the Graminaceae gave rise to cases of mono-sensitivity (16%) (apart from one case of Betulaceae and Corylaceae and one case ofArtemisia as well asDermatophagoides) (9.7%). For the other species, the positive reactions were associated with the positive reactions to the pollen of other species belonging to different families and/or to other factors.     

Pollinosis in trentino (Northern Italy). Aerobiological and clinical research

Summary A study to evaluate and define the atmospheric pollen concentration in Trentino was carried out through the aerobiologic sampling in three localities chosen according to their different climatic conditions.1375 patients with pollinosis living in Trentino were studied retrospectively over the period ranging from 1986 to 1988 and selected according to the area they came from.Results have proved that the most allergenic pollen types are the following: Poaceae, Urticaceae (Parietaria), Compositae (Artemisia) and the tree pollen of Betulaceae and Corylaceae (Alnus, Betula, Corylus), and that pollinosis caused by such pollen, types has different features and frequencies according to the different localities.As far as symptoms are concerned, our data shows that rhinoconjuntivitis is more frequent in those patients who are allergic toParietaria while asthma results being more frequent in patients who are allergic to tree pollen.     

Airborne pollen in Genoa (NW-Italy): a comparison between two pollen-sampling stations

A comparison between two pollen-sampling stationsin the city area of Genoa is presented. The samplingsites are placed 3 km apart, respectively in theeastern urban area (St. Martino Hospital – S.M.) andin the historical centre (Botanical Garden – B.G.).Pollen sampling was carried out during the years1995–1997 at the two different sites by volumetricHirst-type sampler and then compared. The dailyairborne pollen concentration of Urticaceae, Poaceae,Cupressaceae/Taxaceae, Corylaceae/Betulaceae andOleaceae resulted prevailingly higher at S.M., while a good correspondence was observed from a phenologicpoint of view. Asteraceae have shown the bestqualitative-quantitative consistency. In springtime adifference was recorded for Urticales, maybe due tolocal occurence (B.G.) of Broussonetia papyrifera(Moraceae). On the whole, the correspondence betweenthe two different sampling stations proved to besatisfactory.     

Comparison between Urticaceae (Parietaria) pollen count and hay fever symptoms: assessment of a «threshold-value»

Summary A comparison betweenParietaria pollen count and allergic symptoms of rhino-conjunctivitis in the early season was used in utilized to determine a «threshold-value» for this pollen. Clinical data were obtained from diary-cards of 34 allergic patients and pollen data from a volumetric sampling, carried out by means of a Hirst-Burkard pollen-trap. A significant correlation (r=0.98) was found between pollen count and symptom scores. Mild symptoms were registered with concentrations above 10–15 pollens/m³. Severe symptoms occurred when pollen count exceeded 80/m³/24 h., and over 90% of patients recorded symptoms. The importance of the late reactions and of the total allergenic airborne content are emphasized.     

Trend of herbaceous pollen diffusion and allergic sensitisation in Genoa, Italy

In order to investigate the relationship betweenallergenic load and allergic sensitisation prevalenceon a long period, we analysed the annual data ofherbaceous pollen airborne diffusion in Genoa(NW-Italy) for 17 years (1981–1997), with particularregard to the most important allergenic species:Poaceae, Parietaria, Artemisia, Ambrosia. Weevaluated the relative trend and compared it with theprevalence data of patients sensitisation to thesepollens in the same period.The analysis of annual pollen amount revealed asignificant rising trend (r = 0.73, p < 0.05) of Parietaria pollen (average 14.324 grains/m³/year),whereas Poaceae (2048/year) and Artemisia(170/year) pollen count did not show any significantchange. Ambrosia (average 70/year) has been rising since 1989 (r = 0.87, p < 0.05) and reached themaximum pollen count in the last three years.The prevalence of pollen sensitisation resulted to bevery high (about 75%) in our atopic patients withrespiratory symptoms and did not change significantlyin the years: Parietaria pollen allergy waspresent in about 70% of patients with at least oneSPT positive to pollens (and 55% of atopicsubjects), and this frequency, much higher than theone found in North Italy, showed low year-to-year variability.Among pollinotics patients, Poaceae cutaneoussensitisation was found at a quite stable rate in theabove mentioned period (about 51%), as well as thatto Artemisia pollen (8%). Ambrosia skinprick test positivity is very rare (about 0.5%),without any evident increase.The present study shows that, for some of theherbaceous species, we cannot demonstrate astraightforward relationship between the trend ofairborne pollen and the frequency of sensitisation inexposed people. However, in the case of Parietaria, the high level of pollen amount in theair is clearly related with the high rate of cutaneous positivity in patients, but it seems tosuggest a ``plateau' that is not modified by anyfurther increase in airborne pollen (perhaps forgenetic limiting factors). On the other hand, Ambrosia pollen count, even if increasing in Genoa'satmosphere, could still be too low, and it would takesome more time to cause allergic sensitisation in exposed people.This kind of study, pointing out the influence ofairborne allergen exposure on hypersensitivitymechanisms, should be extended in time and world-wideto obtain general conclusions.     

Airborne allergenic pollens in Padua: 1991–1996

Graminaceae, Urticaceae, Compositae, Betulaceae, Corylaceae and Oleaceae are the most representative allergenic taxa in Italy. In this paper the airborne pollen counts of the main allergenic families collected for a six-year period (1991–1996) in Padua's area were analysed. We observed a significant variability for all allergenic pollen types considered. This revised version was published online in June 2006 with corrections to the Cover Date.     

Allergy to ragweed: clinical relevance in Turin

This study evaluates the contribution of ragweed tothe development of allergic manifestations in a groupof outpatients and the atmospheric pollenconcentration trend in the city of Turin (Italy) fromJanuary 1996 to December 1997.We examined 5680 subjects affected byrhinoconjunctivitis and/or bronchial asthma duringspring and summer or by perennial respiratory symptomswith seasonal increase. All subjects were submittedto: (a) a clinical questionnaire; (b) skin prick testswith standard inhalant allergens battery includingpollens of Gramineae, Compositae (Artemisia andAmbrosia), Parietaria, Plantago,Olea, Betula, house dust mite, cat and dogdanders, mould spore (Alternaria and Cladosporium); (c) measurement of specific IgEantibodies in serum (RAST). A weekly programmed Hirstspore-trap was used to sample airborne pollengrains. Pollen was identified and quantified at thePlant Biology Institute of Turin University.The highest concentration of ragweed pollen was 28.6 P/m³ in 1996 and 9.66 P/m³ in 1997.The number of subjects allergic to Ambrosiapollen alone was 8 (0.14% of the total), while thenumber of those allergic to Artemisia absinthiumwas 22 (0.38% of the total). The subjects allergicto both pollens of the Compositae family was 57(1%).Our results show a low prevalence of sensitization toragweed pollen, which is contrary to what we see inother Italian regions like Lombardy and Veneto. Onecause of low sensitization may be the low percentageof Ambrosia pollen in the atmosphere.     

Biochemical and immunochemical characterization of hop-hornbeam (Ostrya Carpinifolia Scop.) pollen

In the last few years Ostrya carpinifolia pollen is consideredas an important cause of respiratoryallergy in Mediterranean areas. The concentration ofthe pollen was measured over a period of fifteen yearsfrom 1981 to 1996 in an area around Genoa; the resultsof this study have clearly indicated an increasingtrend that correlate with persons sensitization.In this study we sought to define the immunochemical andbiochemical properties of hop-hornbean pollen. Soluble proteins extracted from Ostryacarpinifolia pollen and from the taxonomicallyrelated species Corylus Avellana, were analyzedby polyacrylamide gel electrophoresis (SDS-PAGE), byhorizontal isoelectrofocusing (IEF) and by twodimensions electrophoresis (2D-PAGE). Allergenicproteins were identified with sera of sensibilizedpatients and cross-reactivity was evaluated byimmunoblotting techniques. The electrophoreticanalysis showed a partial identity between theproteins from Ostrya and Corylus extracts. The immunoblotting assay, developed withhuman IgE from subjects allergic to hop-hornbeampollen, displayed the major IgE reactivity for acomponent with a molecular weight of 17 kDa expressedin both Ostrya and Corylus extracts. This reactivity is consistent with the presence ofBet v 1 that is described as the major pollen allergenin the Betulaceae and Corylaceae families. Sera fromsubjects allergic to Ostrya were then preadsorbed with recombinant Bet v 1 immobilized in the Pharmacia CAP System; a significant reduction ofthe IgE binding activity was observed after thetreatment. We therefore suggest that Bet v 1 couldbe one of the allergenic proteins present in theOstrya pollen possibly being responsible forcross-reactivity with other members of taxonomicallyrelated families.     

Ragweed in the Czech Republic

During the last years, a well documented expansion ofragweed (Ambrosia artemisiifolia L., Ambrosia trifida L.) over the Mediterranean andtemperate Europe has been in progress. The currentdistribution of ragweed plants in the Czech Republicis summarized and the ragweed pollen concentration asmonitored by 12 pollen stations in the country isdiscussed. The present situation in the ragweed pollensensitization among children and adults with pollenallergy in Brno is described. So far no dangerousexpansion of ragweed plants in our country has beenobserved. Ragweed pollen concentration is occasionallysignificant in the Brno station only, other pollenstations are reporting insignificant amounts ofragweed pollen during August-September periods,although there has been a steady increase in ragweedpollen concentration in the Prague area over the lastfive years. Skin prick tests and/or specific IgEmeasurements with ragweed allergen were performed on94 children with pollen allergy in the Brno region in1995 and on 206, 210 and 229 adult allergic patientsin 1995, 1996 and 1997, respectively. Positive skinreaction or positive specific IgE to ragweed was foundin 22% children and in 25% (1995), 19% (1996) and 25% (1997) adults with pollen allergy. It isconcluded that ragweed does not seem to represent anyimminent major threat to the allergic population inthe Czech Republic until now, however, it remains apotentially very dangerous allergen.     

Pollinosis related to Zygophyllum fabago in a Mediterranean area

Zygophyllum fabago is a herbaceous plant withairborne pollen found widely in the MurciaRegion, in the Southeast of Spain. Although itsallergenicity has been recently reported,little is known of its involvement inpollinosis. Aerobiological study andsensitization in pollinotics weremeasured using a Hirst volumetric trap. Wehave measured the atmospheric concentrationsof this pollen and other allergenicpollen types in our region, between March 1993 andMarch 1997. Z. fabago pollen wascollected for a morphometric study of thepollen grain, and a lyophilized extract wasprepared for skin prick tests. We haveconducted skin tests with different pollen typesfrom our region and with Z. fabago in1736 patients with symptomssuggesting pollinosis. The size of the pollengrain averages 15.17 × 17.35 µm. Thepollination period extends from May to August,with a mean accumulated concentration of 448grains/m³. Out of 1736 pollinotics,263 (15.15%) showed a positive skin test forZ. fabago, 6 were monosensitized and 257were sensitized to other common pollen types fromour Region. Specific IgE to Z. fabago wasequal or higher than 0.35 ku/l in 86.56% ofsensitized patients. Chenopodiaceae pollinateduring spring and autumn and sensitize a largernumber of patients; Urticaceae reach thehighest pollen concentrations for a longerperiod but are not the primary cause ofpollinosis. This study shows that Z. fabagopollen becomes airborne, elicits an IgEresponse and, like other pollens, contributestowards triggering allergic symptoms.It should therefore be considered arelevant allergen and accordingly beincluded in skin test procedures.     

The importance of hornbeam (Carpinus sp.) pollen hypersensitivity in spring allergies

Hornbeam (Carpinus sp.) flowering occurs generallysimultaneously with birch anthesis. While birch pollenis known as the major tree-allergen in central andnorthern Europe, the quantitative and qualitative roleof hornbeam pollen in allergy has not been evaluated.In some regions of Switzerland, the annual ratiohornbeam SPI / birch SPI reaches 20–30% on average,and 50–180% some years. The relative importance ofhornbeam pollen hypersensitivity has been evaluated inmore than 200 patients suffering from spring allergiesto pollen during the last five years (1993–1997) inthe region of Geneva. Among symptomatic patientsduring the March-April period, 73.5% werehypersensitive to Betulaceae pollen. Overall, 71.7%of the patients allergic to Betulaceae pollen werefound to be sensitive to hornbeam, and 12.5% of thesame group of patients were sensitive to hornbeampollen only. Among this last group, half of thepatients, besides allergic rhino-conjunctivitis, werealso suffering from asthma. Hornbeam pollen isabundant and appears to have a significativeimportance in spring allergies. In some cases,specific immunotherapy to hornbeam pollen shouldperhaps be considered.     

Predicting the grass pollen count from meteorological data with regard to estimating the severity of hayfever symptoms in Melbourne (Australia)

In Melbourne, Australia, grass pollen is the predominant cause of hayfever in late spring and summer. The grass pollen season has been monitored in Melbourne, using a Burkard spore trap, for 13 years (1975–1981, 1985 and 1991–1997). Total counts for grass pollen were highly variable from one season to the next (approximately 1000 to >8000 grains/m³). The daily grass pollen counts also showed a high variability (0 to approximately 400 grains/m³). In this study, the grass pollen counts of the 13 years (12 grass pollen seasons, extending from October to January) have been compared with meteorological data in order to identify the conditions that can determine the daily amounts of grass pollen in the air. It was found that the seasonal total of grass pollen was directly correlated with the rainfall sum of the preceding 12 months (1 September–31 August): seasonal total of grass pollen (counts/m³)=18.161 × rainfall sum of the preceding 12 months (mm) −8541.5 (r _s=0.74,P<0.005,n=12). The daily amounts of grass pollen in the air were positively correlated with the corresponding daily average ambient temperatures (P<0.001). The daily amount of grass pollen which was to be expected with a certain daily average temperature was linked to the seasonal total of grass pollen: in years with high total grass pollen counts, a lower daily average temperature was required for a high daily pollen count than in years with low total grass pollen counts. As the concentration of airborne grass pollen determines the severity of hayfever in sensitive patients, an estimation of daily grass pollen counts can provide an indication of potential pollinosis symptoms. We compared daily grass pollen counts with the reported symptomatic responses of hayfever sufferers in November 1985 and found that hayfever symptoms were significantly correlated to the grass pollen counts (P<0.001 for nasal,P<0.005 for eye symptoms). Thus, a combination of meteorological information (i.e. rainfall and temperature) allows for an estimation of the potential daily pollinosis symptoms during the grass pollen season. Here we propose a symptom estimation chart, allowing a quick prediction of eye and nasal symptoms that are likely to occur as a result of variations in meteorological conditions, thus enabling both physicians and patients to take appropriate avoidance measures or therapy.     

Ragweed (Ambrosia) pollen presence in Livorno,Central Italy: Aerobiological and sensitization data

We have studied Ragweed pollen concentration in the atmosphere of Leghorn (Livorno). where Ragweed is not widespread. Our data, from 1991 to 1995, confirm the presence of Ragweed pollen in the atmosphere of Leghorn in low concentrations (highest value of 11 pollen grains/m³) from August to the end of September. Even if the sensitization level in our area is 6.76%, the clinical significance of Ragweed pollinosis is still very low.     

Ragweed (Ambrosia) pollen presence in Livorno,Central Italy: Aerobiological and sensitization data

We have studied Ragweed pollen concentration in the atmosphere of Leghorn (Livorno), where Ragweed is not widespread. Our data, from 1991 to 1995, confirm the presence of Ragweed pollen in the atmosphere of Leghorn in low concentrations (highest value of 11 pollen grains/m³) from August to the end of September. Even if the sensitization level in our area is 6.76%, the clinical significance of Ragweed pollinosis is still very low.