Gennaro D'Amato

Environmental risk factors and allergic bronchial asthma.

The prevalence of allergic respiratory diseases such as bronchial asthma has increased in recent years, especially in industrialized countries. A change in the genetic predisposition is an unlikely cause of the increase in allergic diseases because genetic changes in a population require several generations. Consequently, this increase may be explained by changes in environmental factors, including indoor and outdoor air pollution. Over the past two decades, there has been increasing interest in studies of air pollution and its effects on human health. Although the role played by outdoor pollutants in allergic sensitization of the airways has yet to be clarified, a body of evidence suggests that urbanization, with its high levels of vehicle emissions, and a westernized lifestyle are linked to the rising frequency of respiratory allergic diseases observed in most industrialized countries, and there is considerable evidence that asthmatic persons are at increased risk of developing asthma exacerbations with exposure to ozone, nitrogen dioxide, sulphur dioxide and inhalable particulate matter. However, it is not easy to evaluate the impact of air pollution on the timing of asthma exacerbations and on the prevalence of asthma in general. As concentrations of airborne allergens and air pollutants are frequently increased contemporaneously, an enhanced IgE‐mediated response to aeroallergens and enhanced airway inflammation could account for the increasing frequency of allergic respiratory allergy and bronchial asthma. Pollinosis is frequently used to study the interrelationship between air pollution and respiratory allergy. Climatic factors (temperature, wind speed, humidity, thunderstorms, etc) can affect both components (biological and chemical) of this interaction. By attaching to the surface of pollen grains and of plant‐derived particles of paucimicronic size, pollutants could modify not only the morphology of these antigen‐carrying agents but also their allergenic potential. In addition, by inducing airway inflammation, which increases airway permeability, pollutants overcome the mucosal barrier and could be able to ‘prime’ allergen‐induced responses. There are also observations that a thunderstorm occurring during pollen season can induce severe asthma attacks in pollinosis patients. After rupture by thunderstorm, pollen grains may release part of their cytoplasmic content, including inhalable, allergen‐carrying paucimicronic particles.

Salmeterol and formoterol in partially reversible severe chronic obstructive pulmonary disease: a dose-response study

When testing the response to beta 2-agonist drugs in severe chronic obstructive pulmonary disease (COPD), a dose-response assessment should be undertaken. This study compares the time course of inhaled salmeterol (25, 50 and 75 micrograms) and formoterol (12, 24 and 36 micrograms) at different doses in a group of 12 patients with partially reversible, but severe COPD (FEV1 of 12-32% of predicted values after beta 2-agonist drugs had been withheld for 24 h). All doses of salmeterol and formoterol induced a significant (P < 0.01) spirometric improvement over the 12-h monitoring period, when compared to the spirometric improvement after placebo, but while formoterol induced a dose-dependent increase of the FVC, FEV1 and FEF50, this was not the case for salmeterol. In fact, 75 micrograms salmeterol did not produce a further improvement of these parameters. Mean peak bronchodilation, expressed as the increase in FEV1 over baseline values, occurred 2 h after inhalation of the three doses of salmeterol, and 1 h after inhalation of the three doses of formoterol. A comparison of 50 micrograms salmeterol with 12 micrograms or 24 micrograms formoterol (clinically recommended doses), showed that improvement of FEV1 after salmeterol was statistically (P < 0.05) higher than that after the two doses of formoterol, although the mean peak bronchodilations were similar. This was because salmeterol has a longer duration of action than formoterol. These data demonstrate that salmeterol is equally effective as, but longer-acting than, formoterol at clinically recommended doses in patients suffering from COPD, with severe airway obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergenic pollens in the southern Mediterranean area

In the Mediterranean area there are characteristic climatic conditions (mildness of winter, summer dryness, etc.) that facilitate the growing of a typical vegetation with production of allergenic pollen, such as those from Parietaria and Olea europaea, very different from that of central and northern Europe. We present in this article the results of an 8-year pollen count in the atmosphere of Naples, Italy. The pollen content was examined with a volumetric spore trap (Lanzoni VPPS-2000) like that of Hirst. The results of the pollen counts were subsequently compared with results of skin tests of patients born and still living in and around Naples to determine the pollinosis of that area. We found that the most important allergenic pollen in the Naples area is Parietaria, with very long-lasting periods of pollination. The first period, more important, occurring from March to July, and the second period of much lower intensity, occurring from the end of August to the end of October. Pollen allergy to Parietaria was found to be present in 82.02% of pollen-allergic patients. It was followed by Gramineae (32.12%), Olea (23.11%), and Artemisia vulgaris (17.08%). These data are quite different from data of the pollinosis in northern Italy and in the northern Mediterranean area, as well as the southern coast of France, where allergic sensitization to Poaceae is the most important.

Clothing is a carrier of cat allergens

Clinical and allergologic studies have shown that sensitization to allergens derived from domestic animals (dogs and particularly cats) is an important cause of prolonged airway hyperresponsiveness with allergic respiratory symptoms and is sometimes a risk factor for bronchial asthma attacks leading to emergency department visits. 1 The major cat allergen, Fel d 1, is found universally in homes of patients with respiratory allergy induced by this animal. Significant increases in allergen levels have been detected after simply allowing the cats to leave their holding cages and move about the room. However, Fel d 1 is also present in dust samples from homes and public places where a cat has never been kept. 2 Consequently, not only direct exposure to cats but also indirect contact may be responsible for an allergic sensitization. In fact, many patients who are allergic to cats do not have this animal in their homes. In this trial, to determine whether clothing could be responsible for dispersal of cat allergen, concentrations of Fel d 1 have been quantified in dust samples from clothes of subjects with and without a cat or a dog in their homes.

Effects of serotonin on airways: recent developments

Serotonin (5-hydroxytryptamine, 5-HT) is an endogenous autacoid that can modulate activity in visceral sensory nerves. It produces complex physiologic actions within the cardiopulmonary system by interacting with both vascular and airway smooth-muscle 5-HT receptors (51). Although the role of 5-HT in humoral control of airway tone is not known, several interactions between this monoamine and the lung have been described. 5-HT is actively transported by the pulmonary endothelial cells where it is metabolized by monoamine oxidase, perhaps accounting for an affinity site on the outer layer of the mitochondria (112). Radio autographic localization has confirmed that pulmonary endothelial cells are the site of 5-HT uptake (112).

A double‐blind, placebo‐controlled trial of local nasal immunotherapy in allergic rhinitis to Parietaria pollen

We assessed the efficacy and safety of local nasal immunotherapy (LNIT) using an extract in macronized powder form of Parietaria pollen, a very important allergenic plant in the Mediterranean and other parts of the world. Twenty‐six patients aged 13–37 years, with seasonal allergic rhinitis to this pollen, were enrolled in a double‐blind placebo‐controlled trial, carried out from autumn 1991 to the end of June 1992. They were selected on the basis of a positive skin‐prick test, radioallergosorbent test (RAST) and intranasal challenge to Parietaria antigen. Patients were randomly divided into two groups of 13; the first group was given Parietaria antigen, and the second placebo. We recorded mean weekly symptom scores and drug consumption for 17 weeks during the pollen season in the year 1992, and specific serum‐IgE and IgG levels. Three patients in the active group withdrew from the study because of bronchial symptoms. A significant difference was observed in mean weekly nasal symptom scores, in drug consumption and in specific nasal threshold to Parietaria allergenic extract in the treated and control groups. No difference was observed in serum IgE and IgG levels. Serum IgE levels rose significantly only in the control group after the pollen season. This study indicates that LNIT may be a useful alternative to traditional subcutaneous immunotherapy in patients with allergic rhinitis.

European allergenic pollen types

SummaryPollen data have been collected from 66 stations, situated in 19 European countries thanks to the initiative of both the Working Group «European Aeroallergen Network» (of the Int. Assoc. of Aerobiology) and the Subcommittee «Aerobiology of inhalant allergens» of the European Academy of Allergology and Clinical Immunology. Volumetric data over periods of 3 to 5 years (up to 1988) were included, and 15 both aerobiologically and allergologically relevant taxa were selected. Geographically adjacent stations were grouped together into regions looking at the peak period of the airborne grass-pollen presence. The result is a collection of 21 regional European pollen calendars, some of which are covering several countries (e.g. «Western Europe»), others are applicable only to a part of one country (e.g. «Southern Italy»).Comparing the calendars, general features are the South-to-North delay shift in the appearance of tree-pollen types in Spring, and the reverse shift for the weed-pollen types in late summer. The presence ofAmbrosia pollen in the air in several parts of Central Europe is clearly shown.

A study on airborne allergenic pollen content of the atmosphere of Naples

In this paper we describe the results of volumetric sampling of the airborne allcrgenic pollen content of the Naples atmosphere. These studies have been carried out continuously since 1 May 1979 until 31 December 1981 utilizing a Burkard volumetric spore trap.

Thunderstorm-related asthma: what happens and why

The fifth report issued by the Intergovernmental Panel on Climate Change forecasts that greenhouse gases will increase the global temperature as well as the frequency of extreme weather phenomena. An increasing body of evidence shows the occurrence of severe asthma epidemics during thunderstorms in the pollen season, in various geographical zones. The main hypotheses explaining association between thunderstorms and asthma claim that thunderstorms can concentrate pollen grains at ground level which may then release allergenic particles of respirable size in the atmosphere after their rupture by osmotic shock. During the first 20–30 min of a thunderstorm, patients suffering from pollen allergies may inhale a high concentration of the allergenic material that is dispersed into the atmosphere, which in turn can induce asthmatic reactions, often severe. Subjects without asthma symptoms, but affected by seasonal rhinitis can also experience an asthma attack. All subjects affected by pollen allergy should be alerted to the danger of being outdoors during a thunderstorm in the pollen season, as such events may be an important cause of severe exacerbations. In light of these observations, it is useful to predict thunderstorms and thus minimize thunderstorm‐related events.

Immunotherapy with Alpare in patients with respiratory allergy to Parietaria pollen: a two year double-blind placebo-controlled study.

Allergy to Parietaria judaica pollen causes significant morbidity in many areas of the world. In addition to rhinitis, patients who are allergic to this pollen have a high incidence of asthma. The pollinating season is long, making this particular allergy challenging for clinicians to treat. This study was designed to determine if immunotherapy with an alum adsorbed partially purified Parietaria extract (Alpare Parietaria) containing a targeted maintenance dose of 12 500 BUs was effective in decreasing rhinitis symptoms in patients allergic to Parieiaria. Using a double‐blind placebo‐controlled technique 36 patients received placebo or active extract for 2 years. Twenty (11 placebo and nine active) completed the 2 year study. Efficacy of treatment was evaluated by determining changes in skin reactivity, visual analog scores, diary symptom scores and end of study assessments. Reactions were monitored as well. Skin‐test suppression was marginally significant in the actively treated group after 1 year and showed even more significant suppression after the second year. Nasal block, rhinorrhoea and sneezing all were significantly decreased in the active group. The nasal provocation test did not show a significant change after 1 year, in either group, but after 2 years of treatment the active group did show significant improvement. Although almost all patients in the actively treated group experienced local reactions, the incidence of systemic reactions was not different between the two groups. In conclusion, immunotherapy with this extract at this dose was effective in ameliorated rhinitis symptoms in patients allergic to Parietaria judaica.