Is sensitization to furry animals an independent allergic phenotype in nonoccupationally exposed individuals?

BACKGROUND: Patients sensitized to common pets (cat, dog) frequently display an immunoglobulin (Ig) E-mediated response to allergens from other animals. OBJECTIVE: To evaluate whether individuals sensitized to common pets might be at higher risk of developing allergic sensitization to other mammalian allergens. METHODS: The study population comprised 900 consecutive patients (300 individuals sensitized to different allergens including those of cat and dog [group AL, 300 sensitized to allergens other than those derived from cat and dog [group B], and 300 nonsensitized individuals [group C, controls]). All patients underwent a physical examination, an interview (clinical history, pet ownership, possible exposure data), and skin prick test (SPT) with a standard panel of allergens including cat, dog, horse, rabbit, rat, mouse, guinea pig, hamster, and cow. RESULTS: A significant difference in allergic sensitization to mammalian allergens was observed in groupA compared with group B (respectively, 244 vs. 17). No sensitization was found in group C. CONCLUSION: Since sensitization to pet allergens increases the risk of developing allergy to other furry animals, we suggest performing SPTs with several mammalian allergens to identify allergic sensitization and thus prevent future exposure in individuals who are highly sensitized and environmentally exposed to common pets.

Children passive smoking jeopardises the efficacy of standard anti-allergic pharmacological therapy, while sublingual immunotherapy withstands.

BACKGROUND: The association between genetic predisposition and environmental risk factors such as passive smoke in determining respiratory allergies is still uncertain; even less is known about the role played by passive smoking in influencing the success of therapy for rhinitis and allergic asthma. OBJECTIVE: The purpose of this prospective, randomised study was to determine whether passive smoking influences the outcome of therapies in paediatric patients with allergic respiratory diseases. METHODS: The study included 68 children (mean age 11.51 years; range: 5-17) suffering from perennial rhinitis and intermittent asthma monosensitised to Dermatophagoides. Thirty-four subjects were exposed to daily passive smoking in their families, 34 were not. The two groups have been then randomised to receive continuous treatment with cetirizine or SLIT for three years. RESULTS: There were 3/34 (8.8%) dropouts in the SLIT arm and 4/34 (11.7%) in the cetirizine arm. After three years, the patients exposed to passive smoking showed higher nasal eosinophilia, a worse clinical-symptomatic and pharmacological score with a worsened bronchial reactivity and functional indices of persistent asthma, regardless of how they had been treated. Nevertheless, SLIT prevented the worsening of all the clinical parameters more than the antihistamine alone either among the children exposed to smoking or not. CONCLUSIONS: Exposure to passive smoking in children suffering from respiratory allergies due to Dermatophagoides decreased the clinical response to both drug therapy and SLIT. Nonetheless, while the children submitted to drug therapy worsened or did not show any significant improvement, the ones treated with SLIT improved.

Efficacy and safety of sublingual immunotherapy with grass monomeric allergoid: comparison between two different treatment regimens.

BACKGROUND: Sublingual immunotherapy (SLIT) with monomeric carbamylated allergoid proved to be well tolerated, safe and effective in patients with respiratory allergy. Standard administration regimens are expected to require a long time before clinical benefit can be appreciated. We investigated whether pre-seasonal and perennial regimens differently affect the clinical efficacy of grass pollen SLIT. METHODS: Adult patients with allergic rhino-conjunctivitis with/without mild intermittent asthma due to grass pollen were included into this open prospective study and randomised to receive SLIT with a continuous regimen (Group 1: 1,000 AU/week for the entire study period) or a pre-seasonal regimen (Group 2: 5,000 AU/week for 10 weeks/year for 2 years), or on demand drug therapy alone (Group 3) for two years. At entry (November 2005), at the end of the first and second pollen season, a Visual Analogue Scale (VAS) was used to assess patients' well-being. Symptom score and drug consumption were evaluated during the seasons. Methacholine challenge was performed at study entry and conclusion. Adverse events were recorded along the whole study duration. RESULTS: Thirty-two patients were divided into Group 1 (n = 10), Group 2 (n = 11) and Group 3 (n = 11). A significant VAS improvement was observed in both SLIT groups, after the first and second pollen season, compared to baseline and to Group 3 (p < 0.05). Less symptoms and need for medications resulted during the second season (p < 0.05). No relevant variations in bronchial hyper-reactivity have been observed between the three groups. Only 2 patients experienced local or mild reactions in SLIT groups. CONCLUSION: Both pre-seasonal and continuous regimen of SLIT with monomeric allergoid turned out effective and safe, suggesting that a pre-seasonal course with 5,000 AU/week for 10 weeks may represent a convenient option in patients with grass pollen allergic rhinitis with/without mild intermittent asthma. Further research is urgently needed to consolidate these preliminary evidences.

Sublingual allergoid immunotherapy: a new 4-day induction phase in patients allergic to house dust mites.

Sublingual immunotherapy with monomeric allergoid (allergoid SLIT), given according to the standard scheme, has proved effective and safe in many clinical trials. However, its build-up phase requires a long time ranging from 16 days to 14 weeks. This study therefore investigated whether, with a four-day up-dosing, the same benefit could be achieved in a shorter time. Thirty rhinitic and/or asthmatic patients (16 M and 14 F, mean age 36+/-8.2 years) allergic to house dust mites (HDM) with or without other sensitizations were randomized to allergoid SLIT or standard drug therapy. The build-up phase lasted four days. The first day the patients took a 300 AU tablet, the second day two 300 AU tablets, the third day three 300 AU tablets and the fourth day four 300 AU tablets. The total amount taken during the up-dosing was 3000 AU. Patients were then treated for 12 months at the dosage of 2000 AU/week (total amount of allergen: 104,000 AU/year). The symptom score and drug consumption were recorded from November to February on monthly diary cards. At baseline and after 12 months a Visual Analogue Scale (VAS) was used to rate the patients? well-being. Skin prick test reactivity was evaluated before and after the 12-month treatment in both groups using 10 mg/mL histamine as reference. VAS scores rose significantly (about 45%) in both groups in comparison to baseline (p=0.001). In addition, there was a significantly greater reduction of the global symptoms score (about 52%) - but not in drug consumption - in the SLIT group in comparison to controls (p=0.0004). The SLIT group showed a highly significant reduction (about 39%) in skin prick test reactivity (p=0.000003) while the control group remained unchanged (p=0.5226). No severe adverse events were observed. Even with this short four-day up-dosing, the allergoid SLIT proves to be safe. In addition, it is already effective in patients allergic to HDM after 12 months, and significantly reduces allergen-specific skin reactivity.

Monomeric allergoid intragastric administration induces local and systemic tolerogenic response involving IL-10-producing CD4(+)CD25(+) T regulatory cells in mice.

The efficacy of sublingual immunotherapy, at present one of the treatments of choice for respiratory allergy, relies on the tolerance induced by oral mucosa-associated immune system; however, the gut-associated lymphoid tissue (GALT: Peyers patches and isolated lymphoid follicles) and mesenteric lymph nodes could also be involved, being stimulated by the ingested part of the allergen extract. The aim of the present study is to assess whether the exposure of the allergen exclusively to the GALT induces a tolerogenic response. For this purpose, mice were sensitized with ovalbumin or Par j 1 allergens. The corresponding gastric-resistant monomeric allergoids were then administered via orogastric gavage. After treatment, all mice were tested for: serum IgE, in vitro Th1 and Th2 cytokine release by allergen-stimulated peripheral blood lymphocytes, CD4(+)CD25(+) and CD4(+)CD25(+)IL-10(+) T cells in Peyers patches, mesenteric lymph nodes and spleen. Compared to the control, sensitized groups showed higher levels of serum IgE, lower frequency of CD4+CD25+IL-10+ T cells, at all sites, and higher amounts of in vitroreleased IL-4, IL-6 and TNF-alpha. Compared to the sensitized groups, higher frequency of CD4(+)CD25(+)IL-10(+) T cells was observed in the spleen of both Par-j 1 and OVA sensitized/treated groups and, only for ovalbumin-treated mice, in the Peyers patches and mesenteric lymph nodes, IgE and in vitro cytokines were significantly lower and equivalent to the control group. The results give the first evidence that the intragastric-restricted administration of gastric-resistant allergens restores local and peripheral tolerance in allergen-sensitized mice.

The clinical efficacy of a sublingual monomeric allergoid at different maintenance doses: a randomized controlled trial.

Sublingual immunotherapy is widely recognized as a viable treatment for allergic rhinitis and asthma, but the optimal dosage is still under debate, especially with modified allergens. We assessed the clinical effects of a monomeric allergoid across 3 different maintenance doses in mite-monosensitized patients with rhinitis and intermittent asthma. Eighty-nine patients allergic to HDM were randomized to 3 maintenance doses of monomeric allergoid (Lais, Lofarma) or medications only. All the patients recorded their symptoms and rescue drug consumption in a diary card from November to February. Additionally, nasal eosinophil count, spirometry and methacholine bronchial challenge were performed at the beginning of the study and after 3 years. The symptom scores showed a clear improvement in all the three active arms versus baseline and versus the controls, irrespective of the dose. Likewise, a similar improvement versus baseline was seen for nasal inflammation and bronchial hyperreactivity. The SLIT with monomeric allergoids produces clinically significant results across a wide range of doses. The absence of significant side effects, even at high doses, is probably due to their low level of allergeni city.

Oral hyposensitization to nickel induces clinical improvement and a decrease in TH1 and TH2 cytokines in patients with systemic nickel allergy syndrome.

Some patients with nickel (Ni) allergic contact dermatitis suffer from systemic (intestinal or cutaneous) symptoms after ingestion of Ni-rich foods and experience symptoms reduction with low-Ni diet, a condition termed Systemic Ni Allergy Syndrome (SNAS). We aimed at evaluating whether oral administration of low nickel doses improved clinical conditions and modulated immunological aspects of SNAS, without significant side effects. Thirty-six SNAS patients were enrolled. Treatment started after 1-month of low-Ni diet and consisted in an incremental oral NiOH dose phase (0.3ng to 1.5 microg/week) followed by a 12-months maintenance phase (1.5 microg/week). Randomly, twenty-four patients added Ni therapy to low-Ni diet and 12 remained with diet alone. All patients were allowed rescue medications (antihistamines and topical steroids). After 4 months, Ni-rich foods were gradually reintroduced. In vitro allergen-driven IL13, IL5 and IFN-gamma release by peripheral blood mononuclear cells was evaluated before and after treatment. Twenty-three patients receiving NiOH and the 12 control patients completed the study. Evaluation of SNAS clinical severity (by VAS and drug consumption) showed a significant difference in favor of NiOH-treated patients compared to controls. Twenty of 23 patients in the NiOH group and none in the control group tolerated Ni-rich food reintroduction. Release of all studied cytokines in culture supernatants was significantly lower after NiOH treatment. In conclusion NiOH is effective in reducing symptoms and drug consumption in SNAS and is able to modulate inflammatory parameters.

Respiratory allergy induced by exclusive polysensitization to serum albumins of furry animals.

In this report we describe un unusual case of exclusive allergic sensitization to furry animals, as a possible study model to speculate about different modalities ofsensitization to allergens of common and less common mammalian species. A 27-year-old woman referred in our Allergological Centre for the occurrence of conjunctival and severe respiratory symptoms after contact with several animals such as cats, dogs, rabbits, horses, cows etc. Patient underwent clinical and anamnestic evaluation including a detailed information on the modality of exposure to different furry animals. Skin-prick-test (SPT) was performed with our routine panel of commercial standardized extracts (Lofarma Laboratories, Milan, Italy). Some animal allergenic extracts (rabbit, horse, rat, mouse, cavia, cow and hamster) have been tested by SPT one week after the routine SPT A blood sample was taken for measurement of total IgE and specific IgE (CAP System, Phadia, Uppsala, Sweden) as well as Immunoblotting procedures. The results of in vivo and in vitro procedures revealed allergic sensitization only to animal-derived allergens. Total IgE were 59.3 kU/L. Immunoblotting showed a specific IgE-mediated sensitization of the patient to cow's, rabbit's and horse's serum albumins (SA). In conclusion, our case report confirms the role of SA as cross-reacting agent in allergic sensitization to furry animals. This finding suggests to perform SPTs to several furry animal allergens in all individuals with high level of allergic sensitization to common pets (cats and/or dogs) in order to identify allergy to other animals and consequently to avoid future exposures at risk.

Clinical and immunological correlates of pre-co-seasonal sublingual immunotherapy with birch monomeric allergoid in patients with allergic rhinoconjunctivitis.

Sublingual immunotherapy is safe and efficacious in the treatment of patients with allergic rhinitis. The clinical and biological efficacy of modified allergens (allergoids) has not been fully clarified. We investigated in birch allergic patients the effect of a pre-co-seasonal sublingual immunotherapy regimen with a modified allergen extract on clinical parameters and on T cell proliferation and regulatory cytokine production (IL-10, TGF-beta). We found that during the birch pollen season symptoms and drug usage scores were 30 and 40 percent improved, respectively, in treated versus control subjects (p<0.0001 for both comparisons) whereas well days were 23.5 (33 percent) versus 16.9 (23 percent) (p=0.0024), respectively. Bet v 1 allergen specific proliferation decreased (p = 0.0010), whereas IL-10 transcription increased (p=0.0010) in treated, but not in control patients. Moreover, TGF-beta transcription was increased, although not significantly (p=0.066), following immunotherapy. Thus, sublingual immunotherapy with modified allergen in birch-allergic subjects was safe, clinically efficacious and associated with the reduction of allergen-specific proliferation and with the increased production of the IL-10 regulatory cytokine.

Efficacy, safety and tolerability of sublingual monomeric allergoid in tablets given without up-dosing to pediatric patients with allergic rhinitis and/or asthma due to grass pollen.

The efficacy and safety of monomeric allergoid (Lofarma, Milan) have been demonstrated in adults but very few studies have examined it in children. This study therefore investigated the efficacy and safety of this sublingual immunotherapy (SLIT) at the dosage of 1000 AU five times a week without any up-dosing. Forty allergic children (17 M and 23 F, mean age 7 years, range 4-16 years), 16 with rhinitis and 24 with rhinitis and asthma, were randomized to SLIT or drug therapy. All the patients were sensitized to grass; some were also sensitized, though to a lesser extent, to Parietaria, Olea and Betulaceae. The patients were treated pre-/co-seasonally for two years. A visual analogue scale (VAS) was used at baseline and at the end of the first and second pollen seasons to rate the patients' well-being. The VAS score was significantly higher after both the first and the second year of treatment in the SLIT group than in the controls (p<0.05). It improved in comparison to baseline only in the active group. All 40 children tolerated the therapy very well. The monomeric allergoid at the dosage of 5000 AU/week thus appears to have a good efficacy and safety profile in children.

Date palm pollen allergoid: characterization of its chemical-physical and immunological properties.

BACKGROUND: Date palm (DP) pollen can cause allergic symptoms in people living in different countries. Specific immunotherapy with allergenic extracts by subcutaneous route is effective to cure allergic people. However, the risk of side effects has led to explore safer therapeutic modalities. The aim of our work was to evaluate IgE cross-reactivity between DP and autochthonous palm (European fan palm, EFP) pollen extracts, to chemically modify DP extract with potassium cyanate in order to obtain an allergoid, and to characterize it. METHODS: By radioallergosorbent test inhibition, immunoblotting (IB) and skin prick test, in vitro and in vivo allergenic activities of native and modified DP extracts were compared. By SDS-PAGE and IB, we compared the protein profile and IgE-binding capacity of both native and modified DP, as well as of EFP extracts. By IB inhibition, IgE cross-reactivity of native DP and EFP extracts was evaluated. By ELISA, the capacity of modified DP-induced IgG to react with native DP extract was determined. RESULTS: Radioallergosorbent test inhibition, IB and skin prick test results demonstrated that modified DP was significantly less allergenic than native DP extract. The SDS-PAGE profile showed that potassium cyanate treatment of DP extract did not alter the molecular weight of its components. In addition, no difference was observed between native DP and EFP extracts. Subsequent IB inhibition data evidenced the existence of a strong IgE cross-reactivity between native DP and EFP extracts. ELISA results indicated that the administration of modified DP in mice was able to induce specific IgG also recognizing native DP extract. CONCLUSIONS: Modified DP extract (allergoid) seems to be a good candidate for immunotherapy of patients affected by specific allergy.

Early cytokine modulation after the rapid induction phase of sublingual immunotherapy with mite monomeric allergoids.

The influence of different treatment schedules of sublingual immunotherapy (SLIT) in activating IL-10-producing T-cells, crucial in inducing allergen-specific tolerance, is not completely understood. The present work was designed to evaluate allergen driven interleukin release by mononuclear cells in the early phase of SLIT, after application of different induction schemes. Twenty mite-allergic patients were enrolled, 10 (group A) treated with a traditional 98 day induction scheme and 10 (group B) with a 16 day scheme with monomeric allergoid vaccine. At the end of the induction phase, the cumulative doses taken by group A and group B patients were equivalent to 50.5 and 50.3 microg of mite group 1 allergens, respectively. The release of Th1-, Th2- and Treg-related interleukins was assessed in culture supernatants of 5 microg/ml Der-p1-stimulated mononuclear cells, isolated before and after the induction phases. No relevant treatment-related side effects were observed. Interleukin release was similar in the two groups at the enrolment. Non-stimulated and Der p 1 stimulated release of studied cytokines was similar in the two groups at enrolment. Der p 1 stimulation significantly increased IL-10 release (p<0.0002) after treatment in group B patients, and this effect was higher (p=0.05) compared to group A patients. Furthermore, at the end of SLIT induction TNF-alpha, IL-4 and IFN-gamma production were reduced in group B patients (p<0.05, p=0.062 and p=0.060, respectively). The rapid induction scheme of sublingual immunotherapy induces an early immune suppression more effectively than the slower one. The rapid induction scheme should be the preferential way to start sublingual immunotherapy, particularly when monomeric allergoids are utilized.

Sublingual immunotherapy for allergic respiratory disease in elderly patients: a retrospective study.

BACKGROUND: Very few studies have evaluated the effects of sublingual immunotherapy (SLIT) in elderly adults with either rhinitis or bronchial asthma. The aim of this study was to ascertain whether SLIT is effective in these patients. METHODS: One hundred and sixty seven patients (aged 18-65 years) with persistent rhinitis and mild asthma, selected from 573 subjects allergic to house-dust mites, were treated with either standard chronic pharmacotherapy or SLIT plus drugs on demand. Monthly symptom/drug scores, respiratory function, methacholine (MCh) challenge and eosinophil count were scheduled at the beginning and end of the study. RESULTS: We analysed two age groups (18-28 years, 49 patients) and 55-65 years, 40 patients). There were no differences between the groups at baseline but MCh sensitivity was lower in the older patients. At the end of treatment, SLIT achieved improvement in all variables (p< 0.001) in both age groups, but the global symptoms were lower in the younger patients (p=0.0002). There were also fewer new sensitizations in the SLIT groups (p=0.03) than in the "control"patients given standard pharmacotherapy, but with no relation to age. Asthma became worse only in the control groups, regardless of age. CONCLUSIONS: SLIT reduces symptoms, drug consumption and the progression of the disease in both young and elderly subjects allergic to house-dust mites, with persistent rhinitis and mild bronchial asthma.

Purified protein derivative of Mycobacterium tuberculosis and excretory-secretory antigen(s) of Toxocara canis expand in vitro human T cells with stable and opposite (type 1 T helper or type 2 T helper) profile of cytokine production.

A large series of T cell clones (TCC) specific for purified protein derivative (PPD) of Mycobacterium tuberculosis (total 60) or Toxocara canis excretory/secretory (TES) antigen (total 69) were established from the peripheral blood of two healthy individuals and analyzed for their profile of cytokine production in response to stimulation with either the specific antigen or the polyclonal activator phorbol myristate acetate plus anti-CD3 antibody. Under both these experimental conditions, the great majority of PPD-specific TCC secreted IL-2 and IFN-gamma but not, or limited amounts of, IL-4 and IL-5. In contrast, most TES-specific TCC secreted IL-4 and IL-5 but not, or limited amounts of, IL-2 and IFN-gamma. PPD-specific TCC that failed to secrete IL-4 and IL-5, and TES-specific TCC that failed to secrete IL-2 and IFN-gamma, were found to lack transcripts for IL-4 and IL-5, or for IL-2 and IFN-gamma, respectively. During the course of the study, over a 6-mo period, the functional phenotype of both TES- and PPD-specific TCC was repeatedly assessed and remained constant. These data demonstrate that T cells with stable Th1 or Th2 functional pattern exist not only in mice but also in humans and suggest that in the course of natural immunization certain infectious agents preferentially expand T cell subsets with stable and definite profile of cytokine production.

Safety, tolerability and efficacy of sublingual allergoid immunotherapy with a 4-day shortened build-up phase.

BACKGROUND: Sublingual specific immunotherapy (SLIT) with monomeric allergoid has shown to be safe and effective the studies performed so far. The build-up phase, however, is rather time consuming mainly if performed with the conventional schedule of 14 weeks. AIMS OF STUDY: We evaluated the possibility of shortening and simplifying this phase, through a new build-up scheme of only 4 days, as well as the persistence of the allergoid SLIT efficacy after 12 months. METHODS: Thirty-nine patients (26 M, 13 F, mean age 20.5 years, range 6-49) with a history of moderate/severe rhinitis with or without mild asthma due to perennial and/or seasonal allergens entered the study. The posological schedule, adopting only 1,000 AU tablets, was the following: 1/2 tablet the 1st day; 1/2 table twice the second day; 1/2 table plus 1 table the 3rd day, 1 tablet twice the 4th day; 1 tablet twice weekly from the 5th to the 365th day (maintenance therapy). RESULTS: Only two mild adverse reactions occurred during the initial phase which disappeared with the prosecution of the treatment. During the maintenance therapy no adverse event was observed. Symptoms improved consistently and drug consumption was reduced in most of the patients. CONCLUSIONS: The 4-day shortened build-up phase resulted to be safe, well tolerated and effective, already after one year of treatment.

[Occupational allergic IgE-mediated disease from Boletus edulis: case report]. / Patologia allergica IgE-mediata di origine professionale da Boletus edulis: descrizione di un caso clinico.

BACKGROUND: Fungal components can cause allergic symptoms either through inhalation, ingestion or contact. Allergic disease from occupational exposure to Boletus edulis (BE) has only seldom been reported. OBJECTIVES: Report on a female worker who developed respiratory and skin symptoms from occupational exposure to BE in selecting and packing dried mushrooms. She never had symptoms after eating mushrooms. METHODS: An environmental study was performed by personal air samplings and settled dust collection. The RAST-inhibition procedure was used to detect BE allergen potency in collected dust. The subject underwent clinical evaluation, spirometry, skin prick-tests, RAST methacoline and specific inhalation challenge with BE extract. A follow-up study was made 2, 4 and 8 months after the first evaluation and after cessation of exposure. RESULTS: BE allergens were found in the settled dust. Clinical examination showed eczema on the face and hands. The worker had hyper-eosinophilia, bronchial hyper-responsiveness to methacoline, no allergy to common inhalants and foods, positive prick-test and RAST for BE. The specific inhalation challenge induced broncho-constriction. At follow-up we observed a progressive clinical and functional improvement. CONCLUSIONS: Our data show that BE can induce cutaneous and respiratory symptoms from occupational exposure to dried mushroom dusts. The pathogenesis is an IgE-allergy. Our patient had no symptoms from ingestion, which supports the hypothesis that respiratory allergy is due to mushroom antigens that differ from those involved in food-related allergic reactions.

cDNA cloning, expression and primary structure of Par jI, a major allergen of Parietaria judaica pollen.

A 659 bp cDNA clone** coding for an allergen of Pj pollen has been isolated from a lambda gt11 library, and its DNA sequence determined. The cDNA insert showed an open reading frame of 429 bp coding for an allergenic protein of 14,866 Da and a deduced amino acid sequence containing 143 residues. The expressed recombinant protein represented the major allergen Par jI since it reacted with 95% of the sera from Pj-allergic patients (n = 22) and with two Par jI-specific monoclonal antibodies. No similarity with other known DNA and protein sequences has been detected.

Evaluation of allergenic potency by REAST inhibition. A new tool for the standardization of allergenic extracts.

The potency of allergenic extracts can be determined in vitro by RAST inhibition, and this has become the preferred method for the standardization of allergens. A disadvantage of this technique is the impossibility of obtaining data about allergens bound to the solid phase, i.e., the counterpart of the inhibiting extract. The REAST (reverse enzyme allergosorbent test) is based on the capture of IgE by a specific antibody bound to microtiter wells, the reaction of captured IgE with biotinylated allergen and the development of a colour reaction by subsequent addition of streptavidin-peroxidase and chromogenic substrate. The addition of an allergen extract in a dose-response fashion competes with the biotinylated allergen and inhibits the test. In the present study REAST inhibition has been evaluated with Dermatophagoides pteronyssinus, Parietaria judaica and mixed grass pollen extracts. The correlation of REAST inhibition with RAST inhibition and both intra-assay and inter-assay reproducibility have been evaluated. REAST inhibition is a potentially valuable new tool for the standardization of allergenic extracts.

Modified par j I allergen from P judaica pollen and its rate of absorption in rats.

Polymerized allergens (allergoids) have been introduced in the immunotherapy of allergic disease in order to reduce the risk of side effects. However, their high molecular weight can be a limit, particularly when they are administered by a route involving passage through the mucosal barrier. We describe a simple procedure aimed at developing an original modified allergen with significantly less allergenic potential (intended as human IgE-binding capacity) but preserving the monomeric nature of the molecule. Par j I, the major allergen of Parietaria judaica pollen, was purified by a combination of monoclonal antibodies and affinity chromatography. Par j I allergen was then modified by reaction with potassium cyanate (KCNO), and compared with the native allergen to evaluate its allergenic potency (RAST-inhibition) and molecular weight (SDS-PAGE). Modified allergen showed significantly lower allergenic potency but kept its original molecular weight, making it particularly suitable for buccal (sublingual) administration. To study the adsorption profile, modified Par j I was radiolabeled and administered intravenously and sublingually to normal rats. The prospects for clinical application of the modified allergen are discussed.

Dot immunobinding assay as a new diagnostic test for human hydatid disease.

Bovine and human hydatid antigens collected from hepatic cysts and characterized by SDS-PAGE immunoblotting show similar patterns. The bovine hydatid antigen has been used to develop a simple and fast in vitro diagnostic assay for human hydatidosis. This method, named HA-DIA (hydatid antigen dot immunobinding assay), consists of incubation of a serum sample with a textile colloidal dye (pink) and a nitrocellulose stick to which the hydatid antigen has been bound. The presence of parasite-specific antibodies leads to dyeing of the stick reactive area, and a coloured spot appears. HA-DIA sensitivity and specificity have been studied in comparison with RAST-IgE and ELISA-IgG by testing 17 sera of patients with hydatid disease and 36 control sera from patients affected with other parasitic and non-parasitic diseases. HA-DIA showed positive results in all the patients' sera and in none of the control sera. Correlation with ELISA--IgG and RAST-IgE was significant. HA-DIA has been demonstrated to be of good predictive value, allowing a speedy diagnosis of hydatid disease. In view of its simplicity, not requiring any laboratory instruments, it is particularly suitable for large-scale field screening.