COVID-19 lockdown, personal protective equipment, hyper-hygiene and allergy

Summary

At the beginning of SARS-CoV 2 pandemic, in the absence of "targeted" therapies, the national health authorities have introduced some measures aimed at reducing the spread of infection in the community (lockdown, social distancing, personal protective equipment (PPE), personal hygiene and disinfection of living environments). All the containment measures have led to both positive and negative effects in patients with allergic diseases. We believe that further studies should be undertaken to investigate the possible correlations between SARS-CoV-2 infection and allergy, from a broader perspective. In particular, the risk factors for the development of undesirable effects should be investigated, especially in healthcare professionals forced to use PPE and sanitizing agents for a long time. However, since the COVID-19 pandemic probably will not be short-lived, the use of such protective aids will necessarily be widespread even in the general population. Therefore, further studies on the materials used for the production of PPE and sanitizing agents would be necessary to reduce their sensitizing and, in some cases, toxic potential.

Lessons from peculiar cases of anaphylaxis: why allergists should be prepared for the unexpected

Summary

Anaphylaxis is the most severe systemic hypersensitivity reaction, it can be caused by a number of well identified triggers such as foods, drugs, stinging insects and facilitated by predisposing clinical conditions. However, sometimes anaphylaxis shows up with uncommon or peculiar characteristics which could delay diagnosis and therapeutic treatment. In this report we aimed to describe less accounted / difficult-to-approach shapes of anaphylaxis to facilitate clinicians to suspect these severe reactions even in uncommon conditions. We choose to present data on anaphylaxis regarding simulation, mode of exposure to sensitizing agents, pregnancy, exposure to animals, intimate behaviour, psychological stress and other situations.

The prevalence of sleep impairments and predictors of sleep quality among patients with asthma

BACKGROUND

Sleep is a significant dimension of daily life. However, only a few studies have examined the sleep quality of asthmatics in a real-world clinical settings.

OBJECTIVE

This study is aimed to estimate the prevalence of sleep impairments among asthmatic patients and examine the relationship between sleep quality, asthma control, rhinitis symptoms, and sociodemographic characteristics.

METHODS

The present study adopted the observational cross-sectional research design that has been designed by the Italian Respiratory Society and used valid assessments to measure the study variables.

RESULTS

Data from 1150 asthmatic patients (mean age 51.01 years ± 16.03) were subjected to analysis. 58.3% of the patients had impaired sleep quality (Pittsburgh Sleep Quality Index [PSQI] total scores > 5), and their mean PSQI score was 5.68 (SD = 3.4). A significant correlation emerged between sleep quality and asthma control (p = 0.0001) and a significant albeit weak correlation emerged between PSQI total scores and Total 5 Symptoms Score (r = 0.24, p = 0.0001). Sleep quality was significantly associated health-related quality of life [HRQoL]. (r = 0.50, p < 0.001). After exclusion of patients at risk for Obstructive Sleep Apnea Syndrome (OSAS) and Gastro Esophageal Reflux Disease (GERD), the most important determinants of PSQI score were HRQoL, In the entire sample asthma control is the strongest predictor of both sleep quality and HRQoL.

CONCLUSIONS

The results of this real-world study highlight the prevalence, impact and predictors of sleep disturbances in asthmatic patients and suggest the need for physicians to detect poor sleep quality.

Effects of a structured educational intervention in moderate-to-severe elderly asthmatic subjects

Background

Adherence to inhaled drugs is linked to patients’ satisfaction with their device, and an incorrect use can negatively affect the outcomes of asthma treatment. We speculated that this is particularly true in elderly asthmatic subjects.

Aim

We performed a national pre-post interventional multicentre study, enrolling moderate-to-severe asthmatic subjects aged ≥65 ​years treated with fixed inhaled combination drugs by dry powder inhaler (DPI) or pressurized metered dose inhaler (pMDI). Adherence and critical errors were evaluated by means of validated questionnaires at first visit (V1) and after 3–6 months (V2). At V1, subjects underwent intensive training on the correct use of their device by physical demonstration.

Results

A total of 411 asthmatics (F/M: 238/173, mean age±SD: 72 ​± ​5 ​years) participated to the study. At V1, 50% of the study subjects showed an Asthma Control Test (ACT) score ≤19 despite GINA step 3 and 4 treatment, and 40% had experienced at least one severe asthma exacerbation in the previous year. Poor adherence to treatment was recorded in 43% of subjects, and at least one error in using the device was registered in 56% of subjects. At V2, available for 318 patients, both the percentage of individuals with poor adherence and with at least one critical error significantly decreased (from 46% to 25%, and from 49% to 25%, respectively; p ​< ​0.001 for both comparisons) with a significant increase of the ACT score (from 19 ​± ​4.9 to 20 ​± ​4.0, p ​< ​0.001).

Conclusions

Asthma in the elderly is characterized by low levels of symptom control. Educational interventions are strongly advocated in this age group in order to increase adherence to treatment and inhaler techniques.

Frequency of allergic sensitization to Can f 5 in North East Italy. An analysis of 1403 ISACs 112 (Component Resolved Diagnosis) collected retrospectively

Summary

Recent studies have shown the increasing relevance of allergic sensitization to Can f 5, a prostatic kallicrein expressed in the prostate and detectable only in male dogs. The aim of the present study was to establish the frequency, level of sensitization and association with other dog allergens of Can f 5, as assessed by Component Resolved Diagnosis (CRD- ISAC 112, ThermoFisher Scientific, Uppsala, Sweden), in North East Italy. A total of 1403 CRD ISAC 112 were examined retrospectively. Five-hundred twenty subjects (37 %) had a positive IgE response to at least one of the available animal allergens. Among these 520 subjects, 268 (51.5 %) showed at least one sensitization to dog allergens. Among dog-sensitized individuals, 183 (69.02%) showed IgE against Can f 5, and 106 (57.92%) were sensitized exclusively against Can f 5. The average Can f 5 specific IgE was 8.810 ISU-E, with 77.6 % of individuals showing medium or high values of specific IgE according to manufacturer's specifications. In conclusions, our data confirmed that there is a high number of sensitized patients to Can f 5, which have a high degree of allergic sensitization. These results should be taken into account by allergists managing dog allergic patients. In fact, clinical consequences of this sensitization regard respiratory allergy (burden of rhinitis/asthma), systemic reactions (anaphylaxis during sexual intercourse from cross-reaction with human prostatic antigen), allergen immunotherapy-AIT (likely ineffective in patients with exclusive sensitization), and preventive measures (possibility to own a female dog and a likely reduction of allergen passive transport). Further studies are needed to better explore these aspects in "real life".

Should omalizumab be used in severe asthma/COPD overlap?

A large number of patients suffering from asthma or chronic obstructive pulmonary disease (COPD) can show overlapping features of both diseases. Several subjects affected by asthma-COPD overlap (ACO) may be at a severe stage, poorly responsive to triple therapy including inhaled corticosteroids, long-acting β2 agonists and muscarinic antagonists. This review tries to explore whether omalizumab can be used in poorly controlled severe ACO patients. According to the few studies available, omalizumab may improve asthma outcomes in ACO, although the magnitude of improvements may be lower in comparison to those obtained in subjects affected only by severe asthma. Omalizumab, by acting on IgE, might improve the eosinophilic pattern which is characteristic of the ACO asthma inflammation component. It can be hypothesized that a prevalence of Th1/Th17 airway inflammation pathways can modulate a lower response to anti-IgE while a Th2 pattern can lead to a higher effectiveness to omalizumab in ACO. High levels of IgE, FeNO and blood eosinophil count may be markers of a better response to omalizumab. In conclusion, on the basis of the few studies available, omalizumab could be effective in poorly-controlled severe ACO, although to a reduced extent in comparison to patients affected only by asthma.

Factors reducing omalizumab response in severe asthma

BACKGROUND

Despite adding Omalizumab to conventional therapy, several severe asthmatics still show poor disease control. We investigated the factors that may affect a reduced Omalizumab response in a large population of severe asthmatics.

METHODS

340 patients were retrospectively evaluated. FEV₁%, FVC%, Asthma Control Test (ACT), fractional exhaled nitric oxide (FENO), possible step-downs/step-ups of concomitant therapies, exacerbations, disease control levels, ICS doses and SABA use, observed at the end of treatment, were considered as a response to Omalizumab.

RESULTS

Age was an independent risk factor for a reduced response concerning FEV₁%, FVC%, ACT and for a lower asthma control. Obesity (vs normal weight) was a determinant condition for exacerbations (OR:3.114[1.509-6.424], p = 0.002), for a disease partial/no control (OR:2.665[1.064-6.680], p = 0.036), for excessive SABA use (OR:4.448[1.837-10.768], p = 0.002) and for an unchanged/increased level of concomitant asthma medications. Furthermore, obesity also reduced the response in FEV₁ (β = -6.981,p = 0.04), FVC (β = -11.689,p = 0.014) and ACT (β = -2.585, p = 0.027) and was associated with a higher FENO level (β = 49.045,p = 0.040). Having at least one comorbidity was a risk factor for exacerbations (OR:1.383[1.128-1.697], p = 0.008) and for an ACT <20 (OR:2.410[1.071-3.690], p = 0.008). Specifically, chronic heart disease was associated with both a lower ACT and FVC% whereas gastroesophageal reflux with a partial/no asthma control. Nasal polyps were a predisposing factor leading both to exacerbations and to the use of higher inhaled corticosteroids doses. Moreover, smoking habits, pollen or dog/cat dander co-sensitizations may negatively influence Omalizumab response.

CONCLUSION

Age, obesity, comorbidities, smoking habits, nasal polyps, allergic poly-sensitization might reduce Omalizumab effectiveness independently to other asthma-influencing factors.

Selection and Assessment of Laboratory Tests for the Evaluation of Liver Functional Impairment

A large number of biochemical tests is at present available for the evaluation of the different aspects of the liver function. As a consequence, the requirement of laboratory investigations is generally increasing in clinical practice. However, the usefulness of such a tendency in liver investigation is questionable: the doubt concerns both the diagnostic efficacy of new individual tests and the opportunity of a progressive increase in tests requirement.

This paper deals with the problem of selecting liver tests on the basis of their information content with respect to different aspects of liver function. The study was performed on 288 normal and pathological subjects. Two different methods were used: a classical statistical feature selection method, and a method based on the probability theory developed in the framework of the fuzzy sets theory. The ranking of the tests was based on the estimated misclassification rate.

The results obtained appear quite relevant from a practical point of view: no effective improvement in liver functional assessment is reached by using more than 3 or 4 selected tests among the many available for each of the functional aspects considered.

A reasonable compromise between diagnostic efficacy, feasibility, and costs indicates that the following groups of tests could be proposed for the functional assessment of liver diseases in clinical routine: Albumin, Pseudo-cholinesterase, and Prothrombin Time for biosynthesis and metabolism; Bilirubin, Gamma-glutamyl-transpeptidase, Bile Acids (fasting) for cholestasis; Aspartate Aminotransferase, Alanine Aminotransferase, Isocitrate-dehydrogenase, for cytolysis; Gamma-globulin, G, A and M Immunoglobulin for reactivity.

Allergic sensitization to common pets (cats/dogs) according to different possible modalities of exposure: an Italian Multicenter Study

Background

The query "are there animals at home?" is usually administered for collecting information on anamnesis. This modality to consider exposure to pet allergens constitutes a potential bias in epidemiological studies and in clinical practice. The aim of our study was to evaluate/quantify different modalities of exposure to cat/dog in inducing allergic sensitization.

Methods

Thirty Italian Allergy units participated in this study. Each centre was required to collect the data of at least 20 consecutive outpatients sensitized to cat/dog allergens. A standardized form reported all demographic data and a particular attention was paid in relieving possible modalities of exposure to cat/dog.

Results

A total 723 patients sensitized to cat/dog were recorded, 359 (49.65%) reported direct pet contact, 213 patients (29.46%) were pet owners, and 146 subjects (20.19%) were exposed to pets in other settings. Other patients were sensitized by previous pet ownership (150-20.75%) or indirect contact (103-14.25%), in 111 subjects (15.35%) any contact was reported.

Conclusions

Only 213 patients (29.46%) would be classified as "exposed to animals" and 510 (70.54%) as "not exposed" according to usual query. Our classification has shown that many "not-exposed" subjects (399-55.19%) were "really exposed". The magnitude of exposure to pet allergens at home is not related exclusively to pet ownership. These considerations should be taken into account during the planning of epidemiological studies and in clinical practice for the management of pet allergic individuals.

Allergic sensitization to common pets (cats/dogs) according to different possible modalities of exposure: an Italian Multicenter Study

Background

The query “are there animals at home?” is usually administered for collecting information on anamnesis. This modality to consider exposure to pet allergens constitutes a potential bias in epidemiological studies and in clinical practice. The aim of our study was to evaluate/quantify different modalities of exposure to cat/dog in inducing allergic sensitization.

Methods

Thirty Italian Allergy units participated in this study. Each centre was required to collect the data of at least 20 consecutive outpatients sensitized to cat/dog allergens. A standardized form reported all demographic data and a particular attention was paid in relieving possible modalities of exposure to cat/dog.

Results

A total 723 patients sensitized to cat/dog were recorded, 359 (49.65%) reported direct pet contact, 213 patients (29.46%) were pet owners, and 146 subjects (20.19%) were exposed to pets in other settings. Other patients were sensitized by previous pet ownership (150–20.75%) or indirect contact (103–14.25%), in 111 subjects (15.35%) any contact was reported.

Conclusions

Only 213 patients (29.46%) would be classified as “exposed to animals” and 510 (70.54%) as “not exposed” according to usual query. Our classification has shown that many “not-exposed” subjects (399–55.19%) were “really exposed”. The magnitude of exposure to pet allergens at home is not related exclusively to pet ownership. These considerations should be taken into account during the planning of epidemiological studies and in clinical practice for the management of pet allergic individuals.

Atlas occipitalisation associated with other anomalies in a 16th century skeleton from Sardinia (Italy)

Archaeological excavations carried out in the plague cemetery of 16th century Alghero (Sardinia) brought to light the skeleton of a male aged 35-45 years, showing anomalies of the atlas. A macroscopic and radiological study has been carried out. The first cervical vertebra is fused with the skull base, resulting in an occipitalisation of the atlas. Absence of the costal element of the left foramen transversarium, resulting in an open anterior foramen transversarium, and posterior arch defect are also observed. The atlanto-occipital junction is a complex structure, susceptible to develop different patterns of congenital defects. These anatomical variations of atlas should be considered in modern clinical practice in order to formulate a correct diagnosis and to conceive an appropriate treatment. Osteoarchaeological cases are important as, beside to ascertain the presence of congenital defects in past populations, allow an in-depth study in dry bones, which can help modern medicine in interpreting anatomical variations. We present an association of congenital anomalies of the atlanto-occipital junction, a condition rarely documented in ancient and modern human skeletal remains.

Effects of omalizumab in severe asthmatics across ages: A real life Italian experience

BACKGROUND

This retrospective study aimed at evaluating long-term effects of Omalizumab in elderly asthmatics in a real-life setting.

METHODS

105 consecutive severe asthmatics (GINA step 4-5; mean FEV₁% predicted:66 ± 15.7) treated with Omalizumab for at least 1 year (treatment mean duration 35.1 ± 21.7 months) were divided into 3 groups according to their age at Omalizumab treatment onset: 18-39, 40-64 and ≥ 65 years.

RESULTS

Comorbidities, number of overweight/obese subjects and patients with late-onset asthma were more frequent among older people. A similar reduction of inhaled corticosteroids dosage and SABA on-demand therapy was observed in all groups during Omalizumab treatment; a similar FEV₁ increased was also observed. Asthma Control Test (ACT) improved significantly (p < 0.001) in the three groups, increasing from 15 [IQR:12-18] to 24 [IQR:22-25] in younger subjects, from 14 [IQR:10-16] to 21 [IQR:20-23] in the 40-64-year-group and from 15 [IQR:12-16] to 20 [IQR:18-22] in elderly patients where improvement was lower (p = 0.039) compared to younger people. Asthma exacerbations decreased significantly after Omalizumab but the percentage of exacerbation-free patients was higher in younger people (76.9%) compared to middle aged patients (49.2%) and the elderly (29%) (p = 0.049). After Omalizumab treatment, the risk for exacerbations was lower in subjects aged 40-64 (OR = 0.284 [CI95% = 0.098-0.826], p = 0.021) and 18-39 (OR = 0.133 [CI95% = 0.026-0.678], p = 0.015), compared to elderly asthmatics. Also, a significantly reduced ACT improvement (β = -1.070; p = 0.046) passing from each age class was observed.

CONCLUSION

Omalizumab improves all asthma outcomes independently of age, although the magnitude of the effects observed in the elderly seems to be lower than in the other age groups.

Phenotyping asthma in the elderly: allergic sensitization profile and upper airways comorbidity in patients older than 65 years

BACKGROUND

Data about allergic rhinitis in elderly patients with asthma are lacking.

OBJECTIVE

To investigate the presence of rhinitis and the role of sensitization of airborne allergens in elderly patients with asthma.

METHODS

This was a multicenter cross-sectional study involving subjects at least 65 years old with asthma. Demographic features, comorbidities, and the presence of allergic respiratory disease were retrieved through interview. Skin prick tests for common allergens were performed. Associations of demographic and clinical features were evaluated in relation to asthma control and forced expiratory volume in the first second less than 80% in the total population and in the subgroup with features resembling chronic obstructive pulmonary disease.

RESULTS

Of 368 elderly subjects with asthma, 101 had features resembling chronic obstructive pulmonary disease. Rhinitis was present in 59.0% of subjects (allergic rhinitis in 47.6%), with an age of onset significantly different from that of asthma (49 ± 18 vs 57 ± 18 years). At least 1 sensitization was observed in 52.4% of subjects, more frequently for house dust mite (HDM; 31.8%). The prevalence of poorly and partially controlled asthma was higher in patients sensitized to airborne allergens (odds ratio 1.64, 95% confidence interval 1.03-2.61), in particular to HDM (odds ratio 1.73, 95% confidence interval 1.05-2.85).

CONCLUSION

Approximately 60% of elderly subjects with asthma had rhinitis, mainly allergic and often untreated, whose onset preceded asthma symptoms by a mean of approximately 10 years. Nonallergic asthma was better controlled than allergic asthma. However, HDM sensitization was greater in subjects with asthma with features resembling chronic obstructive pulmonary disease (39% vs 28%). When restricting analysis to this group, the negative role of HDM in overall asthma control (forced expiratory volume in first second and Asthma Control Test) was significant.

Role of calpain-1 in the early phase of experimental ALS

Elevation in [Ca(2+)]i and activation of calpain-1 occur in central nervous system of SOD1(G93A) transgenic mice model of amyotrophic lateral sclerosis (ALS), but few data are available about the early stage of ALS. We here investigated the level of activation of the Ca(2+)-dependent protease calpain-1 in spinal cord of SOD1(G93A) mice to ascertain a possible role of the protease in the aetiology of ALS. Comparing the events occurring in the 120 day old mice, we found that [Ca(2+)]i and activation of calpain-1 were also increased in the spinal cord of 30 day old mice, as indicated by the digestion of some substrates of the protease such as nNOS, αII-spectrin, and the NR2B subunit of NMDA-R. However, the digestion pattern of these proteins suggests that calpain-1 may play different roles depending on the phase of ALS. In fact, in spinal cord of 30 day old mice, activation of calpain-1 produces high amounts of nNOS active species, while in 120 day old mice enhanced-prolonged activation of calpain-1 inactivates nNOS and down-regulates NR2B. Our data reveal a critical role of calpain-1 in the early phase and during progression of ALS, suggesting new therapeutic approaches to counteract its onset and fatal course.

Asthma control in elderly asthmatics. An Italian observational study

BACKGROUND

The exponential increase of individuals aged >64 yrs is expected to impact the burden of asthma. We aimed to explore the level of asthma control in elderly subjects, and factors influencing it.

METHODS

A multicenter observational study was performed on consecutive patients >64 years old with a documented physician-diagnosis of asthma. Sixteen Italian centers were involved in this 6-month project.

FINDINGS

A total of 350 patients were enrolled in the study. More than one-third of elderly asthmatic patients, despite receiving GINA step 3-4 antiasthmatic therapy, had an Asthma Control Test score ≤19, with a quarter experiencing at least one severe asthma exacerbation in the previous year. Twenty-nine percent of patients (n = 101) were classified as having Asthma-COPD Overlap Syndrome (ACOS) due to the presence of chronic bronchitis and/or CO lung diffusion impairment. This subgroup of patients had lower mean Asthma Control Test scores and more exacerbations compared to the asthmatic patients (18 ± 4 compared to 20 ± 4, p < 0.01, and 43% compared to 18%, p < 0.01, respectively). Modified Medical Research Council dyspnea mMRC scores and airway obstruction, assessed on the basis of a FEV(1)/FVC ratio below the lower limit of normal, were more severe in ACOS than in asthma, without any difference in responses to salbutamol. In a multivariate analysis, the mMRC dyspnea score, FEV(1)% of predicted and the coexistence of COPD were the only variables to enter the model.

INTERPRETATION

Our results highlight the need to specifically evaluate the coexistence of features of COPD in elderly asthmatics, a factor that worsens asthma control.

Stress and corticosterone increase the readily releasable pool of glutamate vesicles in synaptic terminals of prefrontal and frontal cortex

Stress and glucocorticoids alter glutamatergic transmission, and the outcome of stress may range from plasticity enhancing effects to noxious, maladaptive changes. We have previously demonstrated that acute stress rapidly increases glutamate release in prefrontal and frontal cortex via glucocorticoid receptor and accumulation of presynaptic SNARE complex. Here we compared the ex vivo effects of acute stress on glutamate release with those of in vitro application of corticosterone, to analyze whether acute effect of stress on glutamatergic transmission is mediated by local synaptic action of corticosterone. We found that acute stress increases both the readily releasable pool (RRP) of vesicles and depolarization-evoked glutamate release, while application in vitro of corticosterone rapidly increases the RRP, an effect dependent on synaptic receptors for the hormone, but does not induce glutamate release for up to 20 min. These findings indicate that corticosterone mediates the enhancement of glutamate release induced by acute stress, and the rapid non-genomic action of the hormone is necessary but not sufficient for this effect.

Cypress pollen: an unexpected major sensitizing agent in different regions of Italy

OBJECTIVES

In this multicenter survey, we assessed the impact of sensitization to cypress in atopic patients in Italy and determined whether cypress pollen concentration changed over time.

METHODS

Allergists were required to collect the results of 100-200 consecutive skin prick tests (SPTs) performed during 2012. Seasonal symptoms were also recorded, as were airborne cypress pollen concentrations (data from the Italian Aerobiology Association) in 1998-2000 and 2010-2012.

RESULTS

We examined 2258 atopic outpatients (56% females; age, 2-84 years) sensitized to at least 1 of the aeroallergens tested (Dermatophagoides species, grass, pellitory, olive, cypress, birch, Alternaria tenuis, and dog and cat dander). We found that 62.9%, 16.1%, and 32.7% of patients living in central, northern, and southern Italy, respectively, were sensitized to cypress (P < .0001). The cypress pollen concentration peak was delayed from February to March in 1998-2000 and 2010-2012 in all 3 regions, with a shift in pollination towards spring. Patients who were monosensitized to cypress reported mainly rhinitis (90.7%-97.6%) and conjunctivitis (38.1%-100%). In polysensitized patients, the prevalence of rhinitis, conjunctivitis, and asthma increased progressively (P < .0001) from southern to northern Italy. The same trend was observed for the prevalence of reported winter symptoms typical of cypress allergy (28%-65%).

CONCLUSIONS

Today, cypress pollen is the most frequent sensitizing aeroallergen (assessed by SPT) in several areas of central Italy. Variations in the timing of the cypress pollination period may have favored this increased sensitization. Rhinitis and conjunctivitis are the predominant symptoms. The clinical impact of this allergy was poor in southern Italy and increased in central areas before reaching its peak in northern regions.

Small plasma focus as neutron pulsed source for nuclides identification

In this paper, we present preliminary results on the feasibility of employing a low energy (2 kJ, 31 kV) plasma focus device as a portable source of pulsed neutron beams (2.45 MeV) generated by nuclear fusion reactions D-D, for the "in situ" analysis of substances by nuclear activation. This source has the relevant advantage of being pulsed at requirement, transportable, not permanently radioactive, without radioactive waste, cheap, among others. We prove the feasibility of using this source showing several spectra of the characteristic emission line for manganese, gold, lead, and silver.

Sensitization to horse allergens in Italy: a multicentre study in urban atopic subjects without occupational exposure

BACKGROUND

Horses play a significant role in people's leisure time in Italy and other countries, but few data are available on IgE-mediated sensitization to horse allergens in patients without occupational exposure. We assessed, in a multicentric survey, the prevalence of horse sensitization in atopic subjects and its clinical characteristics.

METHODS

Allergists from the whole Italian territory were required to collect the results of skin prick tests from at least 100 consecutive subjects. Those patients with a positive skin test to horse dander underwent a detailed interview concerning clinical history, pet ownership and possible exposure.

RESULTS

Data from 3,235 outpatients were collected and 2,097 had at least 1 skin positivity. Among them, 113 (5.38%) were sensitized to horse dander (9 monosensitized). Thirty patients reported direct horse contact (4 owners and 26 for riding or occasional contact), 23 patients were sometimes in contact with horse owners and 60 subjects denied any direct or indirect exposure. Among 9 horse monosensitized patients, 6 had intermittent and mild rhinitis and 3 persistent moderate/severe rhinitis plus asthma. Three of them were horse owners or riders and the remaining had no contact with the animal.

CONCLUSIONS

Our data evidence that the rate of sensitization to horse dander is not negligible and probably underestimated. In susceptible, not occupationally exposed individuals, horse contact, but also indirect or no apparent exposure, may induce sensitization. We recommend inclusion of horse allergen in the routine panel for the diagnosis of respiratory allergy.

γ-Amino butyric acid (GABA) release in the ciliated protozoon Paramecium occurs by neuronal-like exocytosis

Paramecium primaurelia expresses a significant amount of γ-amino butyric acid (GABA). Paramecia possess both glutamate decarboxylase (GAD)-like and vesicular GABA transporter (vGAT)-like proteins, indicating the ability to synthesize GABA from glutamate and to transport GABA into vesicles. Using antibodies raised against mammalian GAD and vGAT, bands with an apparent molecular weight of about 67 kDa and 57 kDa were detected. The presence of these bands indicated a similarity between the proteins in Paramecium and in mammals. VAMP, syntaxin and SNAP, putative proteins of the release machinery that form the so-called SNARE complex, are present in Paramecium. Most VAMP, syntaxin and SNAP fluorescence is localized in spots that vary in size and density and are primarily distributed near the plasma membrane. Antibodies raised against mammal VAMP-3, sintaxin-1 or SNAP-25 revealed protein immunoblot bands having molecular weights consistent with those observed in mammals. Moreover, P. primaurelia spontaneously releases GABA into the environment, and this neurotransmitter release significantly increases after membrane depolarization. The depolarization-induced GABA release was strongly reduced not only in the absence of extracellular Ca2+ but also by pre-incubation with bafilomycin A1 or with botulinum toxin C1 serotype. It can be concluded that GABA occurs in Paramecium, where it is probably stored in vesicles capable of fusion with the cell membrane; accordingly, GABA can be released from Paramecium by stimulus-induced, neuronal-like exocytotic mechanisms.

Topical oropharyngeal vancomycin to control methicillin-resistant Staphylococcus aureus lower airway infection in ventilated patients

AIM

Topical vancomycin applied to the oropharynx has been shown to control carriage and lower airway infection due to methicillin-resistant Staphylococcus aureus (MRSA). We undertook a three-year prospective observational study to evaluate the effectiveness of two policies for topical vancomycin administration on oropharyngeal carriage and lower airway infection due to MRSA in patients requiring mechanical ventilation.

METHODS

All consecutive patients aged over 18 years and expected to require mechanical ventilation for more than 72 hours were enrolled. During period one, patients who were established MRSA carriers received 1 g of 4% vancomycin gel into the oropharynx four times a day until carriage was abolished. During period two, all enrolled patients received the same protocol immediately on admission, irrespective of their MRSA carrier state.

RESULTS

One hundred ninety-one patients met the entry criteria (98 in period one and 93 in period two). During period one, 40 patients developed oropharyngeal MRSA carriage; of these, 29 acquired MRSA in the unit. In contrast, MRSA carriage was not demonstrated during period two (relative risk [RR] 0.018, 95% confidence interval [CI] 0-0.29; P=0.004). Twenty-one patients from period one suffered from an Intensive Care Unit-acquired lower airway infection due to MRSA, compared with five patients from period two (RR 0.25, 95% CI 0.10-0.64, P=0.004). Vancomycin-intermediate Staphylococcus aureus and vancomycin-resistant enterococci were not isolated.

CONCLUSION

In the setting of MRSA endemicity, the prevention of MRSA carriage by topical oropharyngeal vancomycin was more effective in reducing carriage and infection of the lower airways than treatment of established carriers.

MBL2 and MASP2 gene polymorphisms in patients with hepatocellular carcinoma

The pathogenesis of hepatocellular carcinoma (HCC) is not fully understood, but the majority of patients with HCC are associated with hepatitis B virus (HBV) or hepatitis C virus (HCV) infection. Mannan-binding lectin (MBL) is a collectin that can act directly as opsonine or activate MBL-associated serine proteases (MASPs) thus initiating the antibody-independent pathway of the complement system. In our study, we analysed two MBL2 and MASP2 functional polymorphisms (MBL2 allele A/0 and MASP2 D120G) as well as MASP2 polymorphism (Y371D) responsible for an amino acidic change in the protein in 215 HCC patients (HBV-infected, HCV-infected, HBV/HCV co-infected and patients with HCC with no viral infection) and 164 healthy controls to give new insights regarding the role of these two molecules in HCC and viral infection pathogenesis. No significant association was found between MBL2 or MASP2 alleles or genotypes, neither comparing the total patients with HCC and healthy controls nor between the different groups of HCC subjects divided for type of viral infection. Also, dividing the total HCC patients group into low MBL producer (A0 and 00 genotypes) and normal producer (AA genotype) and comparing MASP2 polymorphisms in these two groups, no significant differences were found. Our data do not seem to suggest a role for MBL2 and MASP2 polymorphisms in HCC susceptibility either for HBV-HCV infection-dependent HCC or for HCC raised as a consequence of exposure to different risk factors.

The expression of innate immunity genes in Italian Crohn disease patients

Crohn' disease (CD) is a chronic idiopathic inflammatory bowel disease characterized by the interaction of both hereditary and environmental factors. Intestinal flora and pathogens such as bacteria, viruses and fungi, are thought to be the first step leading to an inflammatory status, which is subsequently amplified in genetically susceptible patients thus triggering the disease. Since the innate immune system is believed to be very important in regulating the flora of the gastrointestinal tract, we decided to study the influence of two important molecules of the innate immune system in CD. Frozen intestinal biopsies from 49 Crohn patients and 10 healthy individuals were collected at the gastroenterology unit of Children's Hospital Burlo Garofolo in Trieste and innate immunity gene expression was evaluated by using both in situ RT-PCR and quantitative PCR. We have analyzed the expression and localization of both MBL2 and DEFB1 genes in intestinal biopsies of Italian Crohn patients by in situ RT-PCR and quantitative PCR. DEFB1 is expressed equally in all subjects. Importantly, MBL2 transcripts were upregulated in CD patients compared to healthy controls. MBL2 expression in controls is normally extremely low, detectable only by quantitative PCR with a Taqman probe. We demonstrated the MBL2 and DEFB1 expression in intestinal biopsies of patients suffering from CD. Our results showed that the MBL2 gene is expressed by cells in the basal lamina, whilst DEFB1 is expressed by epithelial cells.

Selective decontamination of the digestive tract reduces bacterial bloodstream infection and mortality in critically ill patients. Systematic review of randomized, controlled trials

A systematic review and meta-analysis of randomized controlled trials (RCTs) of selective decontamination of the digestive tract (SDD) was undertaken to evaluate the impact of this procedure on bacterial bloodstream infection and mortality. Data sources were Medline, Embase, Cochrane Register of Controlled Trials, previous meta-analyses, and conference proceedings, without restriction of language or publication status. RCTs were retrieved that compared oropharyngeal and/or intestinal administration of antibiotics as part of the SDD protocol, with or without a parenteral component, with no treatment or placebo in the controls. The three outcome measures were patients with bloodstream infection, causative micro-organisms, and total mortality. Fifty-one RCTs conducted between 1987 and 2005, comprising 8065 critically ill patients were included in the review; 4079 patients received SDD and 3986 were controls. SDD significantly reduced overall bloodstream infections [odds ratio (OR), 0.73; 95% confidence interval (CI), 0.59-0.90; P=0.0036], gram-negative bloodstream infections (OR, 0.39; 95% CI, 0.24-0.63; P<0.001) and overall mortality (OR, 0.80; 95% CI, 0.69-0.94; P=0.0064), without affecting gram-positive bloodstream infections (OR, 1.06; 95% CI, 0.77-1.47). The subgroup analysis showed an even larger impact of SDD using parenteral and enteral antimicrobials on overall bloodstream infections, bloodstream infections due to gram-negative bacteria and overall mortality with ORs of 0.63 (95% CI, 0.46-0.87; P=0.005), 0.30 (95% CI, 0.16-0.56; P<0.001), and 0.74 (95% CI, 0.61-0.91; P=0.0034), respectively. Twenty patients need to be treated with SDD to prevent one gram-negative bloodstream infection and 22 patients to prevent one death.

CCR5 promoter polymorphisms and HIV-1 perinatal transmission in Brazilian children

The frequencies of four CCR5 promoter polymorphisms, and of the Delta32 deletion, have been evaluated in Brazilian HIV-1 positive (HIV+) and HIV-1 negative (HIV-) children, both born from HIV-1 positive mothers and healthy controls (HC), with the aim of investigating whether CCR5 polymorphisms could be associated to vertical transmission of HIV-1. One hundred and six HIV-1 positive children and 70 HIV-1 negative children were enrolled from impoverished areas of Recife (Brazil). We recruited also as healthy controls 104 uninfected children from the same ethnic background, matched for age and known to be not at risk for HIV-1 infection. CCR5 polymorphisms were detected by PCR amplification and direct sequencing. Although no significative divergence was found for CCR5 Delta32, CCR5-59356-C/T and CCR5-59653 C/T polymorphisms, the frequency of CCR5-59353-T/C and CCR5-59402-A/G genotypes differed among HIV+, HIV- and HC children. The presence of the CCR5-59353-TT genotype indicated a trend for increased risk of vertical transmission of HIV-1 infection in Brazilian children, while the presence of the CCR5-59402-AA genotype is suggestive for a protective effect against HIV-1 vertical transmission.

Time-course of diastolic dysfunction in different stages of chronic HCV related liver diseases

AIM

A hyperdynamic circulatory pattern in advanced liver disease is known since a long time. The first studies evaluating cardiac function in cirrhosis were performed in patients with alcoholic liver disease and thus this condition was attributed to the toxic effects of ethanol. A reduced performance of the left ventricle after physical and pharmacological strains along with an altered diastolic function has been demonstrated also in postviral cirrhosis. Many factors are involved in advanced cirrhosis whereas little is known in the earlier stages of disease.

METHODS

To this aim we have investigated patients with different stages of hepatitis C virus (HCV)-related liver disease to detect the time-course of diastolic dysfunction. An impaired relaxation and increased thickness of left ventricular walls along with an altered pattern of transmitral flow can be easily detected by means of echocardiography.

RESULTS

In chronic hepatitis diastolic function is preserved but increased thickness of left ventricle parietal walls can be detected in patients with fibrosis on liver biopsy. The typical pattern of diastolic dysfunction is observed in Child A cirrhotic patients and in Child C ascitic patients but thickness of parietal walls is more relevant in the former group. Chronic aldosterone blockade could exert favourable effects in heart remodeling suggesting a potential role of these drugs in cirrhotic cardiomyopathy.

CONCLUSIONS

The presence of increased thickness of left ventricle parietal walls in chronic hepatitis C in the precirrhotic stage point to a putative role of HCV in this heart structural abnormality that can become a co-factor in the more advanced stages of cirrhosis when portal hypertension and its deleterious effects on systemic hemodynamics, cardiac function and structure become manifest.

Eosinophils, specific hyperreactivity and occurrence of late phase reaction in allergic rhinitis

BACKGROUND

Eosinophil infiltration may be considered characteristic of nasal allergic inflammation. However, a mild inflammatory infiltrate may be present in asymptomatic subjects exposed to specific allergen.

OBJECTIVE

We investigated the relationship between inflammation, specific hyperreactivity and clinical late phase reactions in allergic subjects using the ASNC model.

METHODS

Sixty allergic subjects (aged from 18 to 47 years) were enrolled among those sensitized to pollens (n=20) and those to house dust mite with (n=20) or without (n=20) known clinical nasal LPR. All subjects were asymptomatic. TNSS and eosinophil number were assessed at baseline, 30 min (early phase) and 6 hours (late phase) after ASNC.

RESULTS

Eosinophil number was higher in LPR+ rhinitics than in other groups, at baseline and during the early and late phase (p<0.001). ATD was lower in LPR+ rhinitics than in other groups (p<0.001). In LPR+ rhinitics, at baseline there was a significant correlation between eosinophils and ATD (r=0.56, p=0.009). After allergen challenge, TNSS was significantly higher in LPR+ rhinitics than in other groups, both during early and late phase (p<0.001 for all comparisons).

CONCLUSIONS

In house dust mite sensitised subjects, LPR occurrence after allergen challenge is associated with higher inflammation and lower ATD at baseline. Therefore, in house dust mite allergy minimal persistent inflammation without symptoms can drive different clinical responses to allergen challenge.

Nasal eosinophils correlate with FEV1 in patients with perennial allergic rhinitis associated to asthma

BACKGROUND

Eosinophil inflammation is present in nasal and bronchial mucosa and a clear link between upper and lower airways exists. Our aim was to evaluate whether nasal inflammation correlates with lung function in patients with perennial allergic rhinitis associated with asthma.

METHODS

Eighty perennial allergic rhinitics with mild asthma, aged from 18 to 46 years, were enrolled. Nasal scraping and spirometry were performed in all subjects.

RESULTS

A close relationship between the nasal eosinophil number and the percentage of predicted FEV1 was demonstrated (r = -0.76; p<0.0001). CONCLUSIONS Nasal cytology may be considered a non-invasive tool to assess airway inflammation in mild asthmatics with associated allergic rhinitis.

Airway function and nasal inflammation in seasonal allergic rhinitis and asthma

BACKGROUND

Allergic rhinitis (AR) and asthma are frequently associated and characterized by a Th2-dependent inflammation. Nasal and bronchial obstruction may be objectively measured.

OBJECTIVE

The aim of this study was to evaluate the relationships among upper and lower airway function and nasal inflammation in subjects with seasonal allergic rhinitis (SAR) and asthma.

METHODS

Twenty out-patients (12 males and eight females, mean age: 23.4+3.6 years) with SAR and asthma were evaluated during the pollen season. All of them showed a moderate-severe grade of nasal obstruction. Total symptom score, rhinomanometry, spirometry, nasal lavage, and nasal scraping were obtained in all subjects. Eosinophils were counted by conventional staining; IL-4 and IFN-gamma were measured by immunoassay on fluids recovered from nasal lavage.

RESULTS

Functional parameters, i.e. nasal airflow and forced expiratory volume in 1 s (FEV(1)), were correlated with nasal eosinophils (R(2)>0.83, P<0.001). Inflammatory parameters, i.e. eosinophils were correlated with immunological parameters, i.e. IL-4 and IFN-gamma levels (R(2)=0.93, P<0.001). Nasal symptoms were correlated with nasal airflow (rho=-0.71, P< or =0.01) and eosinophils (rho=0.72, P<0.01). Nasal airflow was correlated with FEV(1) (r=0.89, P<0.0001).

CONCLUSIONS

This study demonstrates the close connection between Th2 cytokines and eosinophil infiltration in the nose. There is also clear evidence concerning the relationships between eosinophils infiltration and cytokines levels. Nasal eosinophils can be regarded as the most important predictors of upper and lower airway functions. These findings constitute first evidence of a relationship among nasal Th2-related inflammation and nasal and bronchial airflow in patients with SAR and asthma.

Cetirizine reduces cytokines and inflammatory cells in children with perennial allergic rhinitis

Cetirizine has been demonstrated able of reducing nasal inflammatory infiltration in children with allergic rhinitis and cytokine production in in vitro studies. The aim of this double-blind, placebo-controlled, and randomized study was to evaluate cytokine pattern and inflammatory cells in children with perennial allergic rhinitis, before and after treatment with cetirizine or placebo. Twenty children with perennial allergic rhinitis were evaluated, 13 males and 7 females (mean age 13.4 years). Inflammatory cells and cytokines were evaluated by scraping and nasal lavage, before and after 2-weeks administration of cetirizine or placebo. IL4 and IL8 were measured by immunoassay and inflammatory cells were counted by conventional staining. Cetirizine treatment induced a significant decrease of IL4 (p<0.01) and IL8 levels (p=0.01). A significant reduction of the inflammatory cells was detected in actively-treated children, both concerning neutrophils and eosinophils (p<0.01). Moreover, cetirizine significantly reduced nasal obstruction score (p=0.007). This study shows the cetirizine effectiveness in exerting anti-inflammatory activity by modulating cytokine pattern and by reducing inflammatory infiltration in children with perennial allergic rhinitis.

Prevention of MRSA pneumonia by oral vancomycin decontamination: a randomised trial

This study was undertaken to assess whether oropharyngeal vancomycin may control oropharyngeal carriage and lower airway infection due to methicillin-resistant Staphylococcus aureus (MRSA) acquired in the intensive care unit (ICU). Secondary endpoints were the emergence of vancomycin-resistant enterococci, vancomycin-intermediate S. aureus and vancomycin consumption. A total of 84 patients, admitted to a medical/surgical ICU and mechanically ventilated for >72 h, were randomly assigned to control (n=42) or test (n=42) group. Both groups received the protocol of selective decontamination of the digestive tract, including polymyxin E, tobramycin and amphotericin B. Patients in the test group received 0.5 g of a 4% vancomycin gel at 6-h intervals in the oropharynx. Lower airway infections due to MRSA acquired on the ICU were reduced in the test group, as was oropharyngeal carriage. Neither vancomycin-resistant enterococci nor vancomycin-intermediate S. aureus were isolated from either surveillance or diagnostic samples during the study period. The vancomycin costs were lower in the test group. This study demonstrates that oropharyngeal vancomycin, which controls intensive care unit-acquired lower airway infections and secondary carriage due to methicillin-resistant Staphylococcus aureus, is cost-effective and safe in terms of vancomycin-resistant enterococci and vancomycin-intermediate Staphylococcus aureus.

Nasal cytokine modulation by montelukast in allergic children: a pilot study

BACKGROUND

Allergic rhinitis and asthma are characterized by chronic inflammation due to a Th2 cytokine polarization. Leukotrienes receptor antagonists have been shown to be effective in both diseases.

OBJECTIVE

Aim of the study was to evaluate the modulation by the antileukotriene montelukast on Th2 and Th1 cytokines in allergic rhinitis.

METHODS

Fourteen school children affected by persistent allergic rhinitis (PAR) and exercise-induced asthma (EIA) underwent a nasal lavage before and after a two-week treatment with montelukast. A panel of cytokines, including IL4, IL13, and IFN gamma, was measured by immunoassay on nasal lavage samples.

RESULTS

Montelukast treatment induced a significant decrease of IL4 and IL13 levels (p < 0.001, for both comparisons), and a significant increase of IFN gamma (p < 0.001).

CONCLUSIONS

Montelukast treatment reversed a typical Th2 cytokine pattern (IL4 and IL13) toward a Th1 (IFN gamma) predominance in children with PAR and EIA. This effect could be considered relevant for long term allergic inflammation control and of interest when treating EIA with concomitant PAR.

Long-term cetirizine treatment may reduce new sensitisations in allergic children: a pilot study

Experimental data demonstrate that mite allergy is characterized by persistent chronic inflammation. This suggests that long-term continuous treatment may be included in the global strategy of allergy management as recently reported. Moreover, most of allergic subjects show polysensitisation. We conducted a study to investigate whether a long-term cetirizine treatment may reduce the occurence of new sensitisations in children with mite allergy. This study was initially double-blind, randomized, and placebo-controlled, with two parallel groups of 10 children with mite allergy receiving either cetirizine or placebo daily. All children could assume cetirizine as rescue medication (i.e. symptomatic treatment). After six months, parents of continuously-treated children decided to continue the treatment for 3 years. Other subjects continued to assume cetirizine on symptomatic basis. All children were prospectively followed for other 3 years. Outcome measure was skin prick test, yearly performed. Cetirizine-continuously-treated group showed a significant lower incidence of new sensitisations (p = 0.002). In conclusion, cetirizine administered daily for prolonged periods (i.e. 3 years) may decrease the development of new sensitisations in monosensitised children, showing a potential effect of tertiary prevention of allergy.

Most nosocomial pneumonias are not due to nosocomial bacteria in ventilated patients. Evaluation of the accuracy of the 48 h time cut-off using carriage as the gold standard

A prospective observational cohort study was undertaken with two endpoints: (1) to compare the time cut-off of 48h and the carrier state criterion for classifying lower airway infections in adult and paediatric long-term ventilated patients, and (2) to evaluate the potential of optimized time cut-offs for characterizing imported and ICU-acquired lower airway infections. All patients admitted to the general and paediatric intensive care units and expected to require mechanical ventilation for a period > or = 3 days were enrolled. Surveillance cultures of throat and rectum were obtained on admission and thereafter twice weekly to distinguish micro-organisms that were imported into the unit from those acquired during the stay on the unit. A total of 130 adults and 400 children were studied. In the adult population, 70% of lower airway infections were classified as ICU-acquired by the 48 h cut-off and 48% by the criterion of carriage; on the paediatric ICU the percentages were 65% and 20%, respectively. To separate imported from ICU-acquired infections, eight days was optimal in the adult population and 10 days in the paediatric population. Sensitivity, specificity, positive predictive value and negative predictive value for a time cut-off of eight days for adults were 86, 77, 80, 83%, respectively, and using 10 days for children were 87, 62, 90, 56%, respectively. The use of the 48 h cut-off rule classifies patients as having nosocomial pneumonia, when in fact the infections are commonly caused by microorganisms carried in by the patients. In contrast, using the carriage method, the proportion of lung infections due to nosocomial bacteria was relatively small and was a late phenomenon. Although in prolonging the time cut-off the difference between the two types of classification was shorter, time cut-offs were still found to be unreliable for distinguishing imported from unit-acquired lower airway infections.

Role of leukotriene receptor antagonists in the management of mild-to-moderate asthma

To date the position of Leukotriene Receptor Antagonists (LTRAs) in asthma is not yet fully established. Recent asthma guidelines consider LTRAs as 'alternative' to low doses of inhaled corticosteroids (ICS) for treatment of patients with mild persistent asthma, while in Europe LTRAs are licensed as additional therapy to ICS. Our aim in this paper is to review comparative studies between ICS and antileukotrienes in mild to moderate asthma, looking at their efficacy on asthma outcomes and on patient expectations (compliance, quality of life, and safety). Some studies report a superior efficacy of ICS, while others, in particular in patients aged < 12 years, found no differences. When considering patients' expectations LTRAs seem to be superior, with higher compliance and quality of life. Even if no differences in adverse effects have been found between ICS and LTRAs, whose safety profiles are not different from placebo, some concerns exist on long term treatment with ICS, even at low doses, in children and postmenopausal women. For this reason, even if ICS are superior to LTRAs in controlling asthma outcomes and in improving pulmonary function, in children and elderly patients LTRAs can be considered an alternative to low-dose ICS.

Fexofenadine reduces nasal congestion in perennial allergic rhinitis

BACKGROUND

Nasal congestion is the predominant symptom in perennial allergic rhinitis (PAR), and it seems to be mainly related to the late-phase inflammatory events. The present pilot study aimed to evaluate the therapeutic effect exerted by fexofenadine in patients with PAR due to mite allergy.

METHODS

This study was a parallel, double-blind, randomized, three-arm (1:1:1), placebo-controlled study. Thirty-one subjects with PAR were enrolled and received double-blind medication: fexofenadine 120 or 180 mg, or placebo, once a day for 28 days.

RESULTS

The total symptom score was reduced by fexofenadine (both dosages) at V2 (P=0.007), whereas placebo did not modify it. Nasal congestion decreased after 1 week of treatment with fexofenadine 120 (P=0.027) and 180 (P=0.01), but not with placebo (P=NS). At V3, fexofenadine (both dosages) significantly reduced nasal congestion (P=0.011 and P=0.007, respectively), by placebo did not show any significant effect.

CONCLUSIONS

This pilot study represents the first evidence of the efficacy of fexofenadine in PAR, and also the control of the nasal congestion. We suggest performing larger trials to confirm these preliminary findings.

On the functional consequences of bronchial basement membrane thickening

Reticular basement membrane (RBM) thickness and airway responses to inhaled methacholine (MCh) were studied in perennial allergic asthma (n = 11), perennial allergic rhinitis (n = 8), seasonal allergic rhinitis (n = 5), and chronic obstructive pulmonary disease (COPD, n = 9). RBM was significantly thicker in asthma (10.1 +/- 3.7 microm) and perennial rhinitis (11.2 +/- 4.2 microm) than in seasonal rhinitis (4.7 +/- 0.7 microm) and COPD (5.2 +/- 0.7 microm). The dose (geometric mean) of MCh causing a 20% decrease of 1-s forced expiratory volume (FEV(1)) was significantly higher in perennial rhinitis (1,073 microg) than in asthma (106 microg). In COPD, the slope of the linear regression of all values of forced vital capacity plotted against FEV(1) during the challenge was higher, and the intercept less, than in other groups, suggesting enhanced airway closure. In asthma, RBM thickness was positively correlated (r = 0.77) with the dose (geometric mean) of MCh causing a 20% decrease of FEV(1) and negatively correlated (r = -0.73) with the forced vital capacity vs. FEV(1) slope. We conclude that 1) RBM thickening is not unique to bronchial asthma, and 2) when present, it may protect against airway narrowing and air trapping. These findings support the opinion that RBM thickening represents an additional load on airway smooth muscle.