Depigmented and polymerised house dust mite allergoid: allergen content, induction of IgG4 and clinical response

BACKGROUND

Polymerised allergenic extracts (allergoids) are commonly used in allergen immunotherapy. Clinical efficacy and safety of these extracts have been demonstrated. Recently, allergen sequences have been identified by mass spectrometry in depigmented and polymerised (Dpg-Pol) extracts. The objectives of this study were to investigate the presence of allergens in Dpg-Pol extracts of house dust mite and to analyze the immunological changes induced by these extracts in asthmatic patients enrolled in a double-blind, placebo-controlled study.

METHODS

Dpg-Pol extracts were manufactured and vaccines with a composition of 50% Dermatophagoides pteronyssinus and 50% D. farinae (100 HEPL/ml) were prepared. Allergen composition was analyzed by mass spectrometry. Patients with asthma and rhinoconjunctivitis were treated in a 1-year, double-blind, placebo-controlled, parallel-group study with 6 up-dosing and monthly maintenance injections. Specific IgE and IgG4 titres to D. pteronyssinus, Der p 1 and Der p 2 were measured in patients' sera using the CAP system and direct ELISA experiments.

RESULTS

Sequences from the major allergens Der p 1 and Der p 2 and from other allergens were identified in native and Dpg-Pol extracts. There was a statistically significant increase in specific IgG4, a decrease in the ratio of IgE/IgG4 to D. pteronyssinus and a significant increase in specific IgG4 to Der p 1 and Der p 2 in the patients allotted to active treatment.

CONCLUSIONS

The detection of allergen sequences suggests preservation of major and minor allergens in Dpg-Pol allergoids from house dust mites. Efficacy in asthma treatment and the increase in specific IgG4 seem to be associated with the presence of major allergens in Dpg-Pol allergen extracts.

[The EPI-SCAN survey to assess the prevalence of chronic obstructive pulmonary disease in Spanish 40-to-80-year-olds: protocol summary]

BACKGROUND AND OBJECTIVES

Chronic obstructive pulmonary disease (COPD) causes considerable morbidity and mortality in Spain. The 1997 IBERPOC study, applying the old criteria of the European Respiratory Society, reported a COPD prevalence of 9.1% in the adult population of Spain. The Epidemiologic Study of COPD in Spain (EPI-SCAN) aims to determine the current prevalence of COPD in residents of Spain aged 40-80 years and to estimate changes over the past 10 years. Secondary objectives are, among others, to describe the current prevalence of smoking and changes in COPD prevalence relative to previous studies; to describe treatments received by patients, quality of life, and the BODE index (body mass index, obstruction of airflow, dyspnea, and exercise tolerance); and to measure inflammatory markers in blood and exhaled-breath condensate.

PATIENTS AND METHODS

EPI-SCAN is a population-based, cross-sectional epidemiologic study targeting the general population of Spain aged between 40 and 80 years. Participating centers were located in Barcelona, Burgos, Cordoba, Huesca, Madrid, Oviedo, Seville, Valencia, Vic, and Vigo. All subjects filled in an extensive questionnaire to collect social, demographic, and clinical information. Slow and forced spirometry tests before and after a bronchodilator test were also undertaken. Additionally, selected subjects performed a 6-minute walk test and answered generic and specific quality-of-life questionnaires, as well as an activities-of-daily-living questionnaire. Exhaled-breath condensate and blood samples were also collected from these subjects for measurement of inflammatory and other biomarkers.

Development and validation of a questionnaire to assess asthma control in pediatrics

OBJECTIVE

To develop and validate a questionnaire to assess asthma control in children (CAN).

DESIGN

Two versions of the CAN (for carers and children) were developed. Both versions were validated in an observational, prospective, multicenter study performed in 38 hospital outpatient clinics throughout Spain. Four hundred fifteen patients and their carers agreed to participate. Of these, 414 patients under 14 years old with frequent episodic or persistent (moderate to severe) asthma completed the questionnaire on 3 occasions (baseline, week 2, and week 12). For patients aged 2-8 the questionnaire was only completed by the carers, but for patients aged 9-14 the questionnaire was completed by the carers and the children. Clinician ratings of asthma control were used as a gold standard to assess the sensitivity, specificity, PPV and NPV of the new measure.

RESULTS

Evaluable responses were obtained from 215 carers for children aged 2-8 years and 199 children aged 9-14 years, and their parents. Using a questionnaire total score cut-off of 8 the patient version had a sensitivity of 76.3% and a specificity of 62.9%. For carer version these values were 73% and 69.7%, respectively. A cut point of 8 was selected to maximize the screening accuracy of the CAN questionnaire. Effect sizes in patients with clinician-rated improvements in asthma control were 0.33 and 0.57 for the carer and child versions, respectively.

CONCLUSIONS

The screening accuracy and validity of the CAN questionnaire make it suitable for use in research and clinical practice. The sensitivity and specificity were close to 70%, which is acceptable for the study objective: obtain a tool to measure the level of asthma control.

Validation of the Spanish version of the Asthma Control Test (ACT)

OBJECTIVE

Validation of the Spanish version of the Asthma Control Test (ACT).

METHODS

A total of 607 asthmatic patients were assessed. The psychometric properties of ACT were evaluated. The ACT capacity to predict the physician's assessment of asthma control was assessed using the area under the receiving operating characteristics (ROC) curve (AUC), sensitivity, specificity, and positive-negative predictive values.

RESULTS

ACT's Cronbach alpha was 0.84. The intraclass correlation coefficient was 0.85. The AUC was 0.86, with a sensitivity of 71% and a specificity of 85% for a score of < or =19.

CONCLUSIONS

The Spanish version of ACT is shown to be a reliable and valid tool for evaluating and discriminating asthma control.

Asthma control: do patients' and physicians' opinions fit in with patients' asthma control status?

The aim of this study was to determine the level of asthma control and the concordance between physicians' and patients' opinions and the real patients' situation. A total of 777 subjects (55% female) with asthma were recruited. The study comprised a 4-week follow-up period, during which subjects completed a diary recording peak expiratory flow (PEF), symptoms, and use of rescue medication. At the end, both physicians and patients rated asthma control status. The level of control was evaluated using a composite measure. Agreement among subjective assessments of asthma control by patients and physicians and objective evaluation with the composite measure was assessed through kappa scores. A total of 518 (67%) patients had "not well-controlled asthma," being the remaining "totally controlled" (8%) or "well-controlled" (25%). "Not well-controlled asthma" was more frequent in smokers (82%) than in ex-smokers (70%) or in non-smokers (62%; p=0.0002). Kappa scores between patients' and physicians' opinions and the real patients' status were 0.02 (95% CI, 0.01-0.05) and 0.07 (95% CI, 0.03-0.09), respectively. In conclusion, current level of asthma control is suboptimal for a majority (67%) of patients in Spain. Besides, asthma control is worse in smokers. Neither patients' nor physicians' opinions agree with patients' real situation. Both patients and physicians accept as normal a suboptimal status of their disease.

Effects of effervescent ranitidine on gastric pH: comparison with almagate and placebo in fasting and postprandial conditions

AIM

To compare the effect of effervescent ranitidine, almagate (magnesium carbonate-aluminium hydroxide) and placebo on gastric pH, in fasting and postprandial conditions.

METHODS

Twelve healthy volunteers underwent a gastro-oesophageal pH monitoring on three different occasions after the administration of each of the following randomly allocated treatments: almagate, effervescent ranitidine and placebo. Treatment effects were assessed in fasting and postprandial conditions. Onset and duration of alkalinization, percentage of time with pH > 4 and median gastric pH after treatments were calculated in both periods.

RESULTS

Onset of action of effervescent ranitidine was similar to almagate in fasting [median 1.2 min (IQR: 0.6-12.7) vs. 2.9 min (0.4-227.6)] and postprandial conditions [1.4 min (0.5-4.9) vs. 4.1 min (1.3-63.8)] and both were significantly faster than placebo [fasting 211.1 min (2.7-240); postprandial 240 min (175.6-240)]. The duration of action of effervescent ranitidine was statistically significant longer than almagate in fasting [235 min (105.2-239.4) vs. 19.4 min (6.7-38.8)] and postprandial conditions [171.8 min (133.2-239.5) vs. 61.3 min (44.7-91.9)]. Effervescent ranitidine was more effective than almagate in increasing the percentage of time with a pH > 4 both in fasting (73.9% vs. 7.3%) and postprandial (59.1% vs. 21.3%).

CONCLUSIONS

Effervescent ranitidine shows an effect on gastric pH as fast as almagate but provides a duration of alkalinization longer than almagate, in both fasting and postprandial conditions.

[Assessment of quality of life in lung cancer patients]

OBJETIVES

The aim of this study was to describe lung cancer patients' quality of life, measuring physical, psychological and social parameters, and general and specific symptoms of the disease using different questionnaires.

METHODS

103 primary lung cancer patients who were between 20 and 80 years old and recruited during one year were included. All patients fulfilled the generic health related quality of life (HRQoL) questionnaire SF-36 and the specific EORTC-C30. Also sociodemographic and clinical important data were collected. Differences in aspects of perceived quality of life by diagnostic group and stage were analysed.

RESULTS

The results indicate that the patients with a higher disease stage had worse perception of their quality of life in comparison with patients in a lower stage of the disease. Likewise, small cell lung cancer patients, overall, showed a worse perception of their quality of life than non-small cell lung cancer patients. These differences were shown either by generic and the specific questionnaire scores.

CONCLUSIONS

The results obtained in the study show that the SF-36 and EORTC capture the differences in the perceived quality of life in patients by diagnosis and evolution stage of the disease. All quality of life areas were already affected at the moment of the diagnosis of the disease. The scores of both questionnaires are coherent with clinical evaluation, based on the clinical stage, which support the discriminative validity of those instruments.

Selection and development of a Spanish precocious strain of Eimeria necatrix

A precocious line of Eimeria necatrix (PEN E-281/20) with an abbreviated life cycle was derived from a Spanish field strain (E-281) by repeated passages of the first shed oocysts recovered from the caecal contents of previously infected chickens. After 20 passages, the 'useful' prepatent period (time from infection to obtaining sufficient oocysts to repassage) of the parasite was reduced by 30 h (from 148 to 118 h). The earliest oocysts found in the caecal content were 114 h postinfection (hpi), on the 19th passage. The pathogenicity of the parasite was reduced in comparison with the parent strain, its immunogenicity against homologous and heterologous strains was maintained and its reproductive capacity was similar to or higher than that of the parent strain. Compared with the parent strain, the second generation of schizonts was reduced in size (reduced pathogenicity), third generation schizonts were bigger and with more merozoites (maintenance of the reproductive index) and the life cycle progressed faster from the second generation of schizonts (reduction of prepatent period). Complete second schizogony, from trophozoites to mature schizonts was observed frequently in the caeca of birds infected with both parent and precocious lines.

[Clinical and etiological features of community-acquired pneumonia in the elderly]

BACKGROUND

The aim of the present study was to know the clinical and etiologic features of community-acquired pneumonia (CAP) in elderly patients requiring hospital admission.

METHODS

A prospective study of 36 consecutive patients aged over 70 years, admitted to a general hospital was performed. Standard analytical determinations, blood cultures, and serologic studies were performed in all patients using invasive techniques: aspirative transthoracic puncture (ATP) with ultrafine needle in 35 (97%) cases, and telescopic catheter (TC) in 1 case.

RESULTS

The mean age was 79 years (range: 71-90). Twenty-two patients had received antibiotic treatment prior to admission (61%) and 17 (47%) presented chronic debilitating diseases. The clinical characteristics of CAP were "typical" with acute presentation in most. Fifteen cases (42%) were etiologically diagnosed and the most frequently isolated agents were Streptococcus pneumoniae (22%) and Haemophilus influenzae (8%). Empiric treatment was changed on the basis of isolations in 7 cases (19%). Eight patients died (22%).

CONCLUSIONS

According to our results community-acquired pneumonia in the population studied: 1) generally showed an acute presentation with "typical" characteristics, carrying a high mortality rate (22%), 2) is of bacterial etiology, with S. pneumoniae and H. influenzae being the most frequently isolated microorganisms, 3) the use of ATP in community-acquired pneumonia offers a high diagnostic effectiveness, good tolerance and low risk of complications.