Poor in vitro maturation and pro-inflammatory cytokine response of dendritic cells in children at genetic risk of type 1 diabetes

Type 1 diabetes (T1D) has been associated with an aberrant maturation of dendritic cells (DC). We studied the maturation of monocyte-derived DC in children with newly diagnosed T1D and in healthy children with genetic risk for T1D. Peripheral blood monocytes from children with newly diagnosed T1D (n = 12; mean age 13.2 years), children with human leukocyte antigen (HLA)-risk genotype of T1D (n = 7; mean age 12.7 years) and healthy children (n = 14; mean age 11.2 years) were in vitro differentiated into DC. Expression of HLA-DR, CD80/86 and CD11c and secretion of interleukin (IL)-12, tumor necrosis factor (TNF)-alpha, IL-6 and IL-10 were measured using flow cytometry. Lower percentage of DC expressed CD11c and HLA-DR, and decreased production of TNF-alpha was found in children with newly diagnosed T1D and in children at genetic risk when compared to healthy children. Children with risk genotype also had decreased IL-12 production by DC. Children with T1D and children at genetic risk of T1D appear to have similar aberrancies in the maturation of DC, which may predispose to beta-cell autoimmunity.

A prospective and multicenter safety-monitoring study of a short up-dosing schedule of immunotherapy with a mass-units-standardized extract of mites

A prospective, multicenter pharmacovigilance study was carried out to evaluate the safety of a new 7-dose treatment schedule of subcutaneous immunotherapy as opposed to the conventional 13 doses normally recommended. The study was carried out in 14 centers and included 261 patients (children and adults) with respiratory allergic disease due to sensitization to mites (Dermatophagoides pteronyssinus and/or farinae). A total of 2290 doses were administered under the direct supervision of the participating specialists. One hundred and ten reactions in 63 patients (24.1%) were recorded, representing 4.8% of the total doses administered. Most of the reactions (98) were local. Only 12 were systemic (0.5% of the administered doses) and occurred in 10 patients (3.8% of the sample). Ten reactions reverted quickly with rescue medication. The maintenance dose had to be lowered in one patient and another patient was withdrawn from the study after suffering two asthmatic crises after two consecutive doses. In view of the results obtained, we can conclude that the new schedule shows an acceptable tolerance profile and does not present a greater risk of reactions than the conventional scheme of 13 doses using an identical extract. Moreover, the new schedule represents substantial savings in the number of doses and visits required to reach the maintenance dose.

Cat allergen-induced cytokine secretion and Fel d 1-immunoglobulin G immune complexes in cord blood

BACKGROUND

We have recently obtained evidence for the presence of immune complexes (IC) in cord blood from allergic and non-allergic mothers. Such complexes could conceivably provide the fetus with the initial trigger for the priming of the T cell system already in utero.

OBJECTIVE

To relate the presence of Fel d 1-IgG IC to T cell cytokine production in cord blood mononuclear cells (CBMCs) after stimulation with cat allergen.

METHODS

CBMC obtained from babies of 15 allergic and 22 non-allergic mothers were cultured in the presence of cat allergen. The production of IFN-gamma, IL-5, IL-10 and IL-13 was determined by ELISA. Furthermore, IgG1 and IgG4 antibodies to cat allergen in cord blood samples were measured by ELISA. A more sensitive ELISA was used to measure Fel d 1-IgG IC.

RESULTS

The prevalence and levels of IC were similar in cord blood from children of allergic and non-allergic mothers. The production of IL-5, IL-10. IL-13 and IFN-gamma by CBMC was not influenced by maternal atopy, but IFN-gamma was less commonly detected in samples with IC. There was no association between the presence of IC and any other cytokines. The levels of IgG1 and IgG4 antibodies were similar in both groups, and tended to be associated with the presence of IC.

CONCLUSION

Immune complexes in cord blood may represent a normal mechanism for inducing primary immune responses, as the responses in babies from allergic and non-allergic mothers were largely similar. Low levels of IFN-gamma seems to be related with the presence of IC in cord blood.

Contribution of the gasoline distribution cycle to volatile organic compound emissions in the metropolitan area of Mexico City

Gasoline distribution in the metropolitan area of Mexico City (MAMC) represents an area of opportunity for the abatement of volatile organic compound (VOC) emissions. The gasoline distribution in this huge urban center encompasses several operations: (1) storage in bulk and distribution plants, (2) transportation to gasoline service stations, (3) unloading at service stations' underground tanks, and (4) gasoline dispensing. In this study, hydrocarbon (HC) emissions resulting from breathing losses in closed reservoirs, leakage, and spillage from the operations just listed were calculated using both field measurements and reported emission factors. The results show that the contribution of volatile HC emissions due to storage, distribution, and sales of gasoline is 6651 t/year, approximately 13 times higher than previously reported values. Tank truck transportation results in 53.9% of the gasoline emissions, and 31.5% of emissions are generated when loading the tank trucks. The high concentration of emissions in the gasoline transportation and loading operations by tank trucks has been ascribed to (1) highly frequent trips from distribution plant to gasoline stations, and vice versa, to cope with excessive gasoline sales per gasoline station; (2) low leakproofness of tank trucks; and (3) poor training of employees. In addition, the contribution to HC evaporative and exhaust emissions from the vehicles of the MAMC was also evaluated.

Significance of human papillomavirus in sinonasal papillomas

Recent investigations have suggested human papillomavirus (HPV) to be involved in the development of sinonasal papillomas (SNP). Forty-three patients operated for SNP were studied to determine the prevalence of HPV-DNA sequences in these tumours and to evaluate their value as a prognostic parameter. The original sections of all cases were reviewed and reclassified according to the WHO. Paraffin blocks available from 37 patients were subjected to in situ hybridization (ISH) and polymerase chain reaction (PCR). Histology revealed 34 cases of inverted papilloma (IP) (79 per cent), five cases of exophytic papilloma (EP) (12 per cent) and four cases of columnar cell papilloma (CCP) (nine per cent). Recurrences developed in seven of 41 patients (17 per cent), and malignancy occurred in four of 43 patients (nine per cent). HPV was detected in four of 37 specimens (11 per cent) both by ISH and PCR. In particular, HPV-11 was found in three lesions (two EP, one IP) (eight per cent), and HPV-6b was detected in one lesion (one EP) (three per cent). Our findings suggest a possible role for HPV in the pathogenesis of exophytic papillomas. As no correlation was found to malignancy and recurrence of disease, screening for HPV seems not to be useful as a prognostic parameter.

Detection of Fel d 1-immunoglobulin G immune complexes in cord blood and sera from allergic and non-allergic mothers

It is an established fact that T-cell responses of fetal origin to inhalant allergens are present in most cord blood samples. These immune responses could be explained by trans-placental passage of peptides, either as free antigens or in complexes with immunoglobulin G (IgG), providing the fetus with a trigger for priming the T-cell system already present in utero. The aim of this study was to investigate the presence of the major cat allergen, Fel d 1, in complexes with IgG in cord blood and maternal sera. Serum samples from 75 mothers (38 allergic, 37 non-allergic), and cord blood from their infants, were investigated for the presence of Fel d 1-IgG immune complexes (ICs) by using an amplified enzyme-linked immunosorbent assay (ELISA). Three monoclonal antibodies to Fel d 1 were used for coating. The specificity of the method was confirmed by inhibition experiments. ICs of Fel d 1-IgG were detected in the sera of 45% allergic and 49% non-allergic mothers, and in, respectively, 34% and 41% of their infants. Therefore, neither the prevalence nor the level of ICs were affected by maternal allergy. Low levels of trans-placentally transferred ICs can provide the fetus with a singal for the priming of T-cell responses to inhalant allergens. However, this is not necessarily related to allergic disease.

[Significance of human papillomaviruses (HPV) in sinonasal papillomas]

The present study comprises 43 patients with sinonasal papillomas operated on between 1990 and 1997 at the ENT Department, University Hospital of Zurich. Histology showed 5 cases of exophytic papilloma (EP) (12%), 34 cases of inverted papilloma (IP) (79%) including 4 cases of associated carcinoma (9%), and 4 cases of columnar cell papilloma (CCP) (9%). Recurrence developed in 6 of 41 patients (2 EP, 4 IP) (15%). HPV was detected in 4 of 37 specimens (11%) both by in situ hybridization (ISH) and polymerase chain reaction (PCR). HPV-11 was found in 3 lesions (2 EP, 1 IP), whereas HPV-6b was detected only in one lesion (1 EP). Altogether 3 of 5 EP (60%), one of 29 IP (3%) and one of 6 recurrent papillomas (1 EP) (17%) tested positive for HPV. Our findings suggest a possible role for HPV in the pathogenesis of exophytic papilloma. As no correlation was found with associated malignancy and recurrence of disease, screening for HPV seems not to be useful as a prognostic parameter.

Detection of IgA antibodies to cat, beta-lactoglobulin, and ovalbumin allergens in human milk

BACKGROUND

The relationship between the development of allergy during infancy and breast-feeding remains controversial. This controversy may be due to individual variations in the composition of human milk. Antibodies to food antigens to which the mother is commonly exposed are present in the milk, but their relationship to allergy is still unknown. IgA antibodies to inhalant allergens have not been previously detected.

OBJECTIVE

Our purpose was to analyze secretory IgA antibody levels to cat, beta-lactoglobulin, and ovalbumin allergens in colostrum and mature milk in relation to maternal allergy.

METHODS

Colostrum and samples of mature milk were obtained after 1 and 3 months of lactation from 53 nursing mothers (17 allergic and 36 nonallergic mothers) and were analyzed for total secretory IgA levels by ELISA and secretory IgA antibodies to cat, beta-lactoglobulin, and ovalbumin by an enzyme-amplified ELISA. The specificity of the assays was confirmed by inhibition experiments.

RESULTS

Secretory IgA to cat, beta-lactoglobulin, and ovalbumin allergens were detected in colostrum as well as mature milk. The levels of secretory IgA to ovalbumin were lower in colostrum from allergic mothers with P =.016, whereas the levels to beta-lactoglobulin and cat were similar in the 2 groups. IgA antibodies to ovalbumin were detected in 94% of the colostrum samples from allergic and in all samples from nonallergic mothers, in 82% and 96%, respectively at 1 month, and 53% and 65% at 3 months. Fewer samples had detectable secretory IgA antibodies to beta-lactoglobulin than to ovalbumin and cat, and only 33% and 10% of the samples from the allergic and nonallergic mothers, respectively, remained positive at 3 months. All the allergic mothers had detectable IgA to cat in colostrum, whereas 83% and 73% of the samples were positive at 1 and 3 months. The corresponding numbers were 93%, 81%, and 81% in the nonallergic mothers (not significant).

CONCLUSION

Even a low level of exposure of the mucosa (eg, by inhalant allergens) can induce antibody secretion into the milk, both in allergic and nonallergic mothers.

Human milk polyunsaturated long-chain fatty acids and secretory immunoglobulin A antibodies and early childhood allergy

The possible protective effect of breast milk against atopic manifestations in infancy, i.e. atopic eczema and food allergy, has been controversial for the last decades. Besides the methodological problems, differences in the composition of human milk could explain these controversies. The aim of this study was to investigate the composition of polyunsaturated fatty acids (PUFA) and secretory immunoglobulin A (S-IgA) levels to food proteins (ovalbumin and beta-lactoglobulin) and an inhalant allergen (cat) in milk from mothers of allergic and non-allergic children. Blood samples were obtained at birth and at 3 months from 120 children. Skin prick tests were performed at 6, 12 and 18 months, and the development of atopic diseases was assessed in the children. Breast milk samples were collected from their mothers at birth and monthly during the lactation period. Milk PUFA composition was measured by gas chromatography, and enzyme-linked immunosorbent assay (ELISA) was used to measure total S-IgA, anti-cat S-IgA, anti-ovalbumin S-IgA, and anti-beta-lactoglobulin S-IgA. Allergic disease developed in 44/120 children (22/63 children of allergic mothers and 22/57 children of non-allergic mothers). Lower levels of eicosapentaenoic acid, C20:5 n-3 (EPA), docosapentaenoic acid C22:5 n-3 (DPA), and docosatetraenoic acid C22:4 n-6 (DHA) (p < 0.05 for all) were found in mature milk from mothers of allergic as compared to milk from mothers of non-allergic children. The total n-6:total n-3 and the arachidonic acid, C20:4 n-6 (AA):EPA ratios were significantly lower in transitional and mature milk from mothers of allergic children, as compared to milk from mothers of non-allergic children. The PUFA levels in serum of allergic and non-allergic children were largely similar, except for higher levels of C22:4 n-6 and C22:5 n-6 (p < 0.05 for both) and a higher AA:EPA ratio in serum phospholipids in the former group (p < 0.05). Changes in the levels of milk PUFA were reflected in changes in PUFA serum phospholipids, particularly for the n-6 PUFA. The AA: EPA ratio in maternal milk was related, however, to the AA:EPA only in serum from non-allergic children, while this was not the case in allergic children. The levels of total S-IgA, anti-cat S-IgA, anti-ovalbumin S-IgA, and anti-beta-lactoglobulin S-IgA in milk from mothers of allergic, as compared to non-allergic, children were similar through the first 3 months of lactation. Low levels of n-3 PUFA in human milk, and particularly a high AA:EPA ratio in maternal milk and serum phospholipids in the infants, were related to the development of symptoms of allergic disease at 18 months of age. The milk PUFA composition influenced the composition of PUFA in serum phospholipids of the children. We also showed that the lower levels of colostral anti-ovalbumin S-IgA and lower total S-IgA in mature milk from atopic mothers did not influence the development of allergic disease in the children up to 18 months of age. The findings indicate that low alpha-linolenic acid, C18:3 n-3 (LNA) and n-3 long-chain polyunsaturated fatty acids (LCP) 20-22 carbon chains, but not the levels of S-IgA antibodies to allergens, are related to the development of atopy in children.

[Value of brief questionnaires in predicting smoking cessation in primary care]

OBJECTIVES

1. To study the factors predicting the giving-up of tobacco and to correlate the categories in the Smoker's Aid Programme (SAP) with levels of motivation and dependency, using brief questionnaires. 2. To find the annual percentage in the "winners" category, using the SAP methodology.

DESIGN

Prospective, observational, intervention study without a control group of a random sample of smokers attending primary care clinics.

SETTING

Four urban health centres in Zaragoza and Barcelona.

INTERVENTIONS

Systematic intervention on smokers in the change phase (SAP category). Use of questionnaires on motivation/dependency and of biochemical checks that they had actually given up.

PATIENTS

362 patients of whom 288 smokers (79.5%) took part. Average age was 40.85 (SD: 15.7). 60.8% were males.

MEASUREMENTS AND MAIN RESULTS

21.4% of the smokers had tobacco-related pathology. The number of previous attempts to give up smoking was 1.6 (SD: 2.9) Patients smoked an average of 13.4 cigarettes for 22.2 years (SD: 15.7). Average age at start of consumption was 17 (SD: 4.7). Initial motivation on the Richmond Test was 4.78 (SD: 3.2); and average dependency according to the modified Fagerström Test (TFm) was 0.6 (SD: 0.7). The number of SAP interventions was 1.9 (SD: 2.9). By the end 15.6% of the patients had achieved "winner" status, which was confirmed in 95.6% of them by the biochemical test. The logistic regression model confirmed that the factors predicting giving up tobacco were age, the initial levels of motivation and the initial number of cigarettes.

CONCLUSIONS

The short tests of motivation (Richmond) and, to a lesser extent, dependency (TFm) were good predictors of giving up tobacco and can be recommended in primary care.

Biologic activity of Dermatophagoides siboney and Blomia tropicalis allergens in exposed and unexposed mite-allergic individuals. Effect of patient selection on the biologic standardization of mite extracts

BACKGROUND

This study aimed to investigate the influence of patient selection criteria, i.e., mite-allergic individuals exposed and not exposed to Dermatophagoides siboney and Blomia tropicalis, on the biologic activity of mite extracts. Determination of the potency of mite extracts in vivo requires selection of patients with a clinical history of mite allergy. In Scandinavia, there are some anamnestic criteria for mite allergy, whereas in the tropics, where patients are continuously exposed to high levels of mites, selection of patients with mite allergy by clinical history is difficult.

METHODS

A total of 210 Cuban asthmatics with continuous symptoms, and 43 Swedes with a clinical history of mite allergy were investigated. Skin prick tests were performed with D. siboney, D. pteronyssinus, D. farinae, B. tropicalis, Acarus siro, Lepidoglyphus destructor, and Tyrophagus putrescentiae extracts. For analysis of the biologic activity of mite extracts, Cuban patients were divided into four groups: 1) all patients skin-test-positive to mites 2) patients positive to mites, but not to other inhalant allergens 3) patients reacting most to the mite species analyzed 4) patients reactive only to mites and reacting most to the mite species analyzed. The biologic potency was calculated according to the Nordic Guidelines.

RESULTS

Due to cross-reactivity between mites, Swedish mite-sensitive patients, with a clear clinical history of mite allergy, but not exposed to D. siboney and B. tropicalis, were more skin reactive to these mites than were Cubans. The estimated potency increased gradually to >200% in group 4. In group 1 Cubans, the reactivity to all mites but B. tropicalis was lower than that in mite-sensitive Swedes.

CONCLUSIONS

According to the influence of patient selection criteria on the estimation of the potency of mite extracts, the determination of the biologic activity of allergenic extracts in subjects without a clear-cut clinical history should be replaced by new methods when available.

Blood recirculation in malfunctioning catheters for haemodialysis

Venous catheters are increasingly used for chronic haemodialysis, with dual lumen catheters being the most commonly used as blood recirculation (REC%) is relatively low. The aim of this study was therefore to evaluate blood recirculation in dual lumen catheters, both well-functioning and malfunctioning, with reversed lumens. In our study, blood recirculation in well-functioning catheters with standard lumens is similar to that found in previous studies. However, when lumens are reversed, blood recirculation increases significantly (6.7 +/- 4 vs 19 +/- 11%, p < 0.001). REC% in malfunctioning catheters (10.8 +/- 2%) was higher than normal function (p < 0.05) but lower than reversed flow in normal catheters (p < 0.01). Therefore, inadvertent reversal of lumens in a well-functioning catheter increases REC% in a significant manner, thus worsening haemodialysis efficiency. We conclude that, in inflow failure catheters, lumens can be reversed because REC% is acceptable. However, inadvertent reversal of lumens in a well-functioning catheter increases REC% to a level which may compromise the adequacy of haemodialysis.

Circulating cat allergen and immune complexes in cat-allergic children

BACKGROUND

The first encounters with allergens seem to influence the development of allergy. Food antigens have been detected in sera as free antigens and in complexes with IgG but less is known about the presence of inhalant allergens.

OBJECTIVE

To investigate the presence of the major cat allergen Fel d 1, either as free allergen and/or in complexes with IgG and IgE antibodies in sera from atopic children.

METHODS

Serum samples from 33 cat allergic asthmatic children, 7-17 years old, and 15 non-allergic controls were investigated for the presence of Fel d 1 by ELISA (detection limit 0. 13 microg/L). To detect immune complexes (IC), the IgG fraction from Fel d 1 positive sera was purified by affinity chromatography. Purified and non-absorbed material was then analysed for allergen content and specific IgG antibody levels. Immune complexes with Fel d 1 IgE were detected by coupling anti-Fel d 1 MoAb to paramagnetic particles.

RESULTS

Fel d 1 was detected (0.15-1.8 microg/L) in 23 of the 33 patients (70%) but not from any of the controls. Eighteen samples contained IgE-Fel d 1 IC and two of four tested samples contained Fel d 1 in the IgG fraction. Electrophoresis and Western blotting of IgG purified material using anti-Fel d 1 MoAb corroborated the presence of IgG-Fel d 1 IC.

CONCLUSION

Free-circulating inhalant allergen and IC with allergens may contribute to maintaining immune responsiveness and sensitivity.

Cross-reactivity between Dermatophagoides siboney and other domestic mites. II. Analysis of individual cross-reacting allergens after SDS-PAGE and Western blotting inhibition

BACKGROUND

Dermatophagoides siboney (Ds) cross-reacted with other mite allergens in mite-allergic patients. The aim of this study was to investigate the cross-reactivity between individual allergens responsible for this cross-reactivity.

METHODS

The inhibition of IgE binding to Ds allergens was investigated by non-reducing SDS-PAGE and Western blotting. Nitrocellulose membranes were incubated with a pool of sera from mite-sensitive asthmatics, after the addition of serial dilutions of D. farinae (Df), D. pteronyssinus (Dp), D. microceras (Dm), Lepidoglyphus destructor (Ld), Tyrophagus putrescentiae (Tp), Acarus siro (As) and Blomia tropicalis (Bt). N-terminal amino acid sequences and amino acid analysis of the purified major allergens, Der s 1, 2 and 3, were performed after transfer to polyvinylidene difluoride membranes.

RESULTS

The inhibition was higher with Df(86%), Dp (54%) and Dm (49%) extracts than with Ld (20%), Tp (11%), As (18%) and Bt (6%). The dose-response inhibition showed a diverse pattern for the individual allergens. Despite the high cross-reactivity between the pyroglyphid mites, some proteins of Ds were less inhibited, e.g. by the Df and Dp 80-kD protein, and by the Dm and Dp 52-, 37-, 30- and 14-kD allergens. The 65-, 62-, 37- and 30-kD proteins were always inhibited more than 50% by all the mite extracts at the maximum concentration used. The 80-, 52-, 43-, 27- and 14-kD proteins cross-reacted to a lesser extent. Individual allergens of Ds were much less inhibited by non-pyroglyphid mites. However, at the highest concentration, Ld also inhibited most of the Ds allergens. All the ten selected allergens were inhibited to some extent by the heterologous mite extracts. The N-terminal sequences of Der s 1, 2 and 3 allergens showed higher homology to Df and Dm than to Dp. The homology of the group 2 allergens was higher than that of the group 1 allergens.

CONCLUSION

The individual allergens of Ds were more similar to Df and Dm than to Dp. There was a limited and variable cross-reactivity with non-pyroglyphid mites. No single allergen was unique for Ds.

Atopic dermatitis today

This review focuses on recent literature regarding atopic dermatitis (AD). New insights in epidemiology, diagnostic criteria, quality of life measures, provocative factors, patophysiology and therapy will be highlighted. New diagnostic criteria for AD set by the UK working party allow easier epidemiologic studies to cope with this increasingly prevalent disease. Immunomodulating therapy with cyclosporine holds promise in the treatment of refractory AD.

Purification and IgE binding capacity of Der s 3, a major allergen from Dermatophagoides siboney

BACKGROUND

Sensitization to the house dust mite Dermatophagoides siboney has been demonstrated in asthmatic patients. Previously, Dermatophagoides siboney group 1 and group 2 allergens, named Der s 1 and Der s 2, respectively, have been purified.

OBJECTIVES

The aim of this study was to purify and to study the IgE reactivity of 30 kDa component, suspected to correspond to group 3 allergens.

METHODS

The protein was purified by affinity chromatography using anti-Der f 3 monoclonal antibodies and semi-preparative SDS-PAGE. The IgE binding capacity of the purified fractions was tested with sera from 106 mite-sensitive asthmatic patients using a modified chemiluminiscent method.

RESULTS

Affinity chromatography resulted in fractions containing the 30 kDa component which was further purified to homogeneity by SDS-PAGE. Seventy-three per cent of the sera showed IgE reactivity to this protein, indicating that it is a major allergen. The protein also reacted with anti Der f 3 polyclonal antibodies and had tryptic activity. There were differences in the reactivity to Der s 3 according to the age of the patients.

CONCLUSION

Based on the frequency of IgE reactions and the reactivity with antibodies directed to Der f 3, it is proposed to name this 30 kDa allergen from D. siboney, Der s 3.

Sensitization to Dermatophagoides siboney, Blomia tropicalis, and other domestic mites in asthmatic patients

Mite species adapted to warm, humid climates are commonly found in house dust in the tropics. In Cuba, Dermatophagoides pteronyssinus, D. siboney, and Blomia tropicalis are the most common and abundant mite species in house dust. To investigate the pattern of sensitization of Cuban asthmatic patients to common mite species, we skin-prick-tested (SPT) 148 patients with a clinical history of asthma and possible mite allergy, and determined specific IgE antibodies against mite allergens (D. pteronyssinus, D. farinae, D. siboney, B. tropicalis, Acarus siro, Lepidoglyphus destructor, Tyrophagus putrescentiae, and Glycyphagus domesticus). The prevalence of positive SPT was high to D. siboney (88%), D. pteronyssinus (87%), A. siro (85%), B. tropicalis (85%), and D. farinae (83%). The largest skin reactions were obtained with D. siboney and B. tropicalis extracts. The skin test response to the D. siboney extract correlated to those of D. farinae, D. pteronyssinus, B. tropicalis, and A. siro. The highest IgE levels were found to Dermatophagoides species and B. tropicalis. IgE to D. siboney and B. tropicalis were found in 97% and 96% of the patients, respectively. The prevalence of specific IgE to the other mites studied varied from 46 to 65%. D. siboney and B. tropicalis are important sensitizers among asthmatic patients in Cuba.

Characterization of allergenic components from house dust mite Dermatophagoides siboney. Purification of Der s 1 and Der s 2 allergens

BACKGROUND

Allergic reactions to house dust mites of the genus Dermatophagoides play an important role in the pathogenesis of asthma and other atopic diseases. Dermatophagoides siboney has been described as a species from Cuba. Together with D. pteronyssinus and Blomia tropicalis, it is frequently found in house dust from homes of asthmatics.

OBJECTIVES

The aim of this study was to investigate the allergenic composition from the house dust mite D. siboney.

METHODS

The characterization of D. siboney extract was performed by SDS-gPAGE and immunoblotting. Purification of individual components was performed by affinity chromatography.

RESULTS

At least 16 components between 13 and 98 kDa stained by Coomassie Blue were found. Using a panel of 35 sera from atopic mite sensitive patients 13 components reacted to different extent with patient IgE. Two components, 25 and 14 kDa, bound to specific IgE strongly and frequently, i.e. 80 and 91% of the patients, respectively. Affinity chromatography using crossreacting monoclonal antibodies to group 1 and 2 allergens resulted in purified preparations of 25 and 14 kDa proteins, which showed IgE-binding with the majority of the human sera when tested by immuno-dot.

CONCLUSION

Based on the IgE binding profile of D. siboney and on the capacity to react with crossreacting monoclonal antibodies for groups 1 and 2, it is proposed to name these two allergens, 25 and 14 kDa, Der s 1 and Der s 2, respectively.

Crossreactivity between Dermatophagoides siboney and other house dust mite allergens in sensitized asthmatic patients

BACKGROUND

The role of Pyroglyphid mites in IgE-mediated sensitization has been well established. Although mites belonging to the genus Dermatophagoides dominate in the acarofauna of domestic dust, non-pyroglyphid mites might also be of clinical importance. In Cuba, Dermatophagoides siboney is found in dust coexisting with D. pteronyssinus and Blomia tropicalis. Dermatophagoides farinae is not found. Storage mites, such as Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescentiae, might also be present.

OBJECTIVES

The aim of this study was to investigate the allergenic relationships among the mites present in the environment of allergic patients in Cuba.

METHODS

The crossreactivity between an extract of D. siboney and the above mentioned six mites was studied by specific IgE inhibition, using sera of mite-sensitive patients after incubation with serial dilutions of D. siboney.

RESULTS

The inhibitory effect of D. siboney extract was more pronounced against D. farinae, 91%, than against D. pteronyssinus, 62%. Specific IgE to B. tropicalis, A. siro, L. destructor and T. putrescentiae were inhibited to a much lesser extent, i.e. between 47 and 58%. The correlation between IgE to D. siboney and IgE to D. pteronyssinus and D. farinae was of 0.92 and 0.90, respectively. A weaker correlation was found between D. siboney and L. destructor (0.7), A. siro (0.67), B. tropicalis (0.54) and T. putrescentiae (0.51).

CONCLUSION

Thus, D. siboney seems to be most closely related to D. farinae.

Parvalbumin and calbindin-D28k immunocytochemistry in human neocortical epileptic foci

Serial sections of cortical resection of 30 patients suffering from drug-resistant epilepsy were processed for parvalbumin and calbindin-D28k immunocytochemistry to determine local circuit neuron populations. Our findings indicate that there is not a simple mechanism to explain neocortical epileptic foci. On the basis of the present results it can be suggested that: (1) reduced percentage of local circuit neurons in the vicinity of neoplasms may account for a decreased intracortical inhibition. (2) Abnormal morphology and distribution of local circuit neurons may result in abnormal cortical inhibition in patients with focal cortical dysplasia, and, probably, in other focal migrational disorders, including neuronal nests in the white matter. (3) Increased percentages of immunoreactive local circuit neurons and fibers in focal neocortical necrosis (cavernous angiomas), diffuse hypoxic encephalopathy, and hippocampus in patients with temporal lobe epilepsy due to mesial sclerosis, may play a role in epilepsy. These neurons can be activated by reduced excitatory inputs, or they may establish abnormal synaptic contacts with other inhibitory neurons. (4) Lack of consistent morphologic abnormalities in the neocortex of patients with temporal lobe epilepsy, and in patients with cryptogenetic frontal lobe epilepsy, suggests that electrically abnormal neocortical foci in these cases are probably epiphenomena.