Histamine release positive test associates with disease remission in chronic spontaneous urticaria: a proof-of-concept study.

SUMMARY: Background. Histamine release (HR) test has previously been shown to predict the presence of endogenous histamine-releasing factors in chronic spontaneous urticaria (CSU). Objectives and methods. Twenty CSU patients unresponsive to antihistamine treatment were enrolled in order to evaluate the correlations between HR test results and demographic features, quality of life, disease activity, clinical course, and autologous serum and plasma skin tests (ASST and APST). Results. All patients with positive HR test (9/9, 100%) had a more severe disease activity at onset (urticaria activity score, UAS > 2) when compared to negative HR test patients (5/11; p = 0.04). Quality of life questionnaire's results were not substantially different between HR positive and negative subgroups at baseline (p > 0.05), and results of HR test and ASST/APST did not co-segregate (p > 0.05). After 12 months, patients with a positive HR test had a significant reduction of disease activity (p = 0.003) whereas patients with a negative HR test did not (p > 0.05), leading to disease remission and antihistamine treatment withdrawal in 67% (6/9) of positive HR test patients versus 18% (2/11) of negative HR test patients (p = 0.027). Conclusions. Positive HR test may predict spontaneous CSU remission at 12 months.

Serum diamine oxidase activity in patients with histamine intolerance.

INTRODUCTION: Intolerance to various foods, excluding bona fide coeliac disease and lactose intolerance, represents a growing cause of patient visits to allergy clinics.Histamine intolerance is a long-known, multifaceted clinical condition triggered by histamine-rich foods and alcohol and/or by drugs that liberate histamine or block diamine oxidase (DAO), the main enzyme involved in the metabolism of ingested histamine. Histamine limitation diets impose complex, non-standardized restrictions that may severely impact the quality of life of patients. METHODS: We retrospectively evaluated 14 patients who visited allergy outpatient facilities in northern Italy with a negative diagnosis for IgE-mediated food hypersensitivity, coeliac disease, conditions related to gastric hypersecretion, and systemic nickel hypersensitivity, and who previously underwent a histamine limitation diet with benefits for their main symptoms. Serum diamine oxidase levels and the clinical response to diamine oxidase supplementation were investigated. RESULTS: We found that 10 out of 14 patients had serum DAO activity<10 U/mL, which was the threshold suggested as a cutoff for probable histamine intolerance. Moreover, 13 out of 14 patients subjectively reported a benefit in at least one of the disturbances related to food intolerances following diamine oxidase supplementation. The mean value (±SD) of diamine oxidase activity in the cohort of patients with histamine intolerance symptoms was 7.04±6.90 U/mL compared to 39.50±18.16 U/mL in 34 healthy controls (P=0.0031). CONCLUSION: In patients with symptoms triggered by histamine-rich food, measuring the serum diamine oxidase activity can help identify subjects who can benefit from a histamine limitation diet and/or diamine oxidase supplementation.Properly designed, controlled studies investigating histamine intolerance that include histamine provocation are indispensable for providing insights into the area of food intolerances, which are currently primarily managed with non-scientific approaches in Italy.

Early onset of allergic rhinitis and asthma in recent extra-European immigrants to Milan, Italy: the perspective of a non-governmental organisation.

BACKGROUND: Allergy is determined by genetic and environmental factors. People immigrating from under-developed to industrialised countries are at higher risk of developing allergic diseases and immigration is as a good epidemiological model to quantify the influence of the environment. We performed the allergological assessment of 32,555 recent immigrants from different areas of the world to a polluted metropolitan area of Northern Italy. METHODS: We evaluated time of onset of allergic rhinitis and/or asthma, sensitisations and clinical characteristics of 395 subjects (3.74 ± 2.94 yrs, mean ± SD) from four macro-areas (Asia, Africa, East-Europe, South America) arriving to Milan, Italy from June 2005 to June 2009. Data were compared with immigrants having access to the same medical facility for any medical problem and with resident Italians living in the same area. RESULTS: Immigrants with allergic rhinitis and/or asthma days since arrival in Italy correlated with number of sensitisations (p=0.0030). Moreover, personal (2.02%) or familial (2.78%) history of allergic diseases was lower in allergic immigrants as compared to allergic residents (37.77 and 29.39%, respectively; p<0.0001 for both comparisons). Finally, the frequency of allergic immigrants from South America (63.3%) was higher than expected from the overall proportion of individuals from this macro-area who sought medical help at the same facility (40.4%; p<0.0001, OR 2.289, CI 2.1670-3.255). CONCLUSIONS: Environmental factors play a relevant role in the induction of allergies in immigrants to Northern Italy. Genetics appears as a further promoting factor in the case of immigrants from South America.

Omega-5 gliadin anaphylaxis: an integrated diagnostic approach.

We report the case of a 62-year old man who presented a wheat-dependent, exercise-induced anaphylaxis (WDEIA). The case illustrates the usefulness of skin prick test not only with wheat extract, but also with native gliadin extract. Moreover we confirm the value of recombinant IgE dosage with rTri a 19 omega-5 gliadin in the diagnostic pathway of this condition.

Monoreactive high affinity and polyreactive low affinity rheumatoid factors are produced by CD5+ B cells from patients with rheumatoid arthritis.

In patients with rheumatoid arthritis (RA), circulating CD5+ B lymphocytes, but not CD5- B lymphocytes, are increased in number and size, exist in an activated state, spontaneously proliferate, and secrete Ig that binds to the Fc fragment of IgG. By constructing continuous mAb-secreting cell lines from CD5+ B lymphocytes, the properties and dissociation constants (Kd) of these antibodies were determined. Two types of rheumatoid factors (RFs) with discrete reactivities were produced. The first type is polyreactive and binds with relatively low affinity (Kd, 10(-5) mol/liter) to the Fc fragment of IgG. These antibodies are similar to those produced by CD5+ B cells from healthy subjects. The second type of RF is monoreactive and binds with higher affinity (Kd, 10(-7) mol/liter) to the Fc fragment of IgG. These latter autoantibodies are produced by CD5+ B cells of RA patients, but not healthy subjects. Long-term longitudinal studies are needed to determine the role of these two types of RFs in the pathogenesis of RA.

Antibody raised against soluble CD4-rgp120 complex recognizes the CD4 moiety and blocks membrane fusion without inhibiting CD4-gp120 binding.

We studied the humoral response of mice immunized with soluble CD4-rgp120 complex, testing polyclonal and monoclonal antibodies (mAbs) with the aim of identifying molecular changes that take place after the first interaction between human immunodeficiency virus and the cell surface. The antisera had a paradoxically high syncytia-blocking titer associated with anti-CD4 specificity, while their capacity to inhibit CD4-gp120 binding was relatively modest. One of the mAbs produced from these responders blocks syncytia formation but does not inhibit CD4 interaction with gp120. Apparently, this mAb interacts with the CD4 moiety of CD4-gp120 complex and prevents a post-binding event necessary for membrane fusion and viral infection.

Antigen-driven C-C chemokine-mediated HIV-1 suppression by CD4(+) T cells from exposed uninfected individuals expressing the wild-type CCR-5 allele.

Despite repeated exposure to HIV-1, certain individuals remain persistently uninfected. Such exposed uninfected (EU) people show evidence of HIV-1-specific T cell immunity and, in rare cases, selective resistance to infection by macrophage-tropic strains of HIV-1. The latter has been associated with a 32-base pair deletion in the C-C chemokine receptor gene CCR-5, the major coreceptor of macrophage-tropic strains of HIV-1. We have undertaken an analysis of the HIV-specific T cell responses in 12 EU individuals who were either homozygous for the wild-type CCR-5 allele or heterozygous for the deletion allele (CCR-5Delta32). We have found evidence of an oligoclonal T cell response mediated by helper T cells specific for a conserved region of the HIV-1 envelope. These cells produce very high levels of C-C chemokines when stimulated by the specific antigen and suppress selectively the replication of macrophage-tropic, but not T cell-tropic, strains of HIV-1. These chemokine-producing helper cells may be part of a protective immune response that could be potentially exploited for vaccine development.

Human lymphocytes making rheumatoid factor and antibody to ssDNA belong to Leu-1+ B-cell subset.

B lymphocytes bearing the Leu-1 cell-surface antigen (Leu-1+), the human equivalent of mouse Ly-1+ B lymphocytes, have been detected in human peripheral blood, but there is little information on their frequency and properties. Analysis by fluorescence-activated cell sorter and double immunofluorescence showed that Leu-1+ B cells are consistently present in the peripheral blood and spleens of healthy subjects and constitute 17.0 +/- 5.0% (mean value +/- standard deviation) and 17.3 +/- 3.9%, respectively, of total B cells. When purified Leu-1+ and Leu-1- B lymphocytes were transformed into immunoglobulin-secreting cells by infection with Epstein-Barr virus and the culture fluids were tested for reactivity with self-antigens, at least two important autoantibodies, antibody to the Fc fragment of human immunoglobulin G (rheumatoid factor) and antibody to single-stranded DNA, were found to be made exclusively by Leu-1+ B cells. It is concluded that the Leu-1+ lymphocytes represent a major subset of the normal human B cell repertoire and include the B cells capable of making autoantibodies similar to those found in systemic lupus erythematosus and rheumatoid arthritis.

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.

Ambient pollutants as adjuvant for allergic sensitization: the emerging role of platinum group elements.

The prevalence of asthma and allergies often observed in urban metropolitan areas as compared to rural and farm communities is still an enigma. Westernized life styles, type of farming and exposure to environmental pollutants seem to simultaneously interact in the determination of this phenotype in genetically predisposed individuals. In this scenario, we asked whether and to what extent we could single out antropogenic airborne contaminants in general, and platinum group elements in particular as relevant causal factors in the generation and in the clinical expression of allergic immune responses in exposed individuals. To this aim, we evaluated epidemiological and basic immunology studies published on peer-reviewed journals indexed in Medline on this subject. We reviewed studies focused on effect of the exposure to platinum group elements on the allergic immune response, with specific reference to our own studies, on their influence on dendritic cells and on the consequent skewing of T-helper and T-regulatory lymphocyte functions. Our laboratory contributed to generate consistent evidence supporting the notion that anthropogenic emissions in general, and platinum group elements in particular, can functionally modulate the immune response in a coordinated pro-allergic fashion. We conclude that in genetically predisposed individuals platinum group elements exert an adjuvant effect specifically leading to more severe allergic reactions.

Multiple drug hypersensivity: insight into the underlying mechanism and correlation with autoimmune diseases.

BACKGROUND: Subjects with drug hypersensitivity are sometimes simultaneously reactive to several drugs. This nosological entity is defined as multiple drug hypersensivity (MDH). Urticaria and angioedema are the commonest clinical manifestations of hypersensitivity drug reactions (HDR). These clinical signs are also pathognomonic of chronic idiopathic urticaria (CIU), whose pathogenetic mechanisms are still largely unknown. The diagnostic algorithm of CIU includes autologous serum skin test (ASST) and autologous plasma skin test (APST), which demonstrated a high positive and negative predictive value, in multiple nonsteroidal anti-inflammatory drugs (NSAIDs) intolerance. OBJECTIVE: to explore the underlying mechanism of MDH and to assess the correlation between such tests and autoimmune diseases (AD). METHODS: Twenty eight subjects with MDH referred to our Allergy/Immunology Unit were enrolled from May 2006 to May 2007. Eight healthy subjects served as controls. In addition to common diagnostic tools used in the diagnostic algorithm of MDH, enrolled subjects also underwent ASST and APST. RESULTS: Patients were predominantly female (23 female vs. 5 male; mean age 52.2 years). In 61% of cases MDH was associated with either CIU or AD. NSAIDs and antibiotics were the major causes of HIDR, both implied in 54% of subjects. The proportions of MDH-subjects with positive ASST and APST were 46.4% and 28.6%, respectively. All patients with MDH+AD+CIU (4/4) presented apositive ASST. CONCLUSIONS: In patients with MDH, ASST proved to be frequently positive, as previously described for multiple NSAIDs intolerance. In ASST-positive subjects, the activity of several drugs appears to add up FceRI-specific autoantibodies in the induction of the release of allergic mediators.

Comparison of different diagnostic products for skin prick testing.

BACKGROUND: Different in vivo methods are used to quantify the amount of allergens in products for skin prick testing. It is unclear how this impacts on the correct diagnosis of allergies. AIM OF THE STUDY: We compared the allergenic potency of three commercial extracts for skin prick testing and evaluated batch-to-batch differences within each product. METHODS: Patients with a mono-sensitization (specific IgE level > 0,70 KU/L, ImmunoCAP, Phadia) to Phleum pratense (N=21), Parietaria judaica (N=20) or Dermatophagoides pteronyssinus (N=28) were evaluated by standard skin prick testing and with the end-point dilution technique using commercial products from Stallergenes (A) (Antony, France), Lofarma Allergeni (B) (Milan, Italy) and ALK Abellò (C) (Hoersholm, Denmark). Results were expressed as mean areas of the wheal (cut-off for positive reactions: 7 mm2). RESULTS: With standard prick testing, the following differences in wheal areas were found: Phleum, C higher than B (p=0.0454); Parietaria, C higher than A (p=0.094); Dermatophagoides, C higher than A (p=0.021). With limiting dilution testing, the following differences in dilutions yielding positive skin prick tests were found: Phleum, C and B higher than A (p=0.0391 and 0.0039, respectively); Dermatophagoides, C higher than A and B (p=0.0010 and 0.0156, respectively). In the batch-to-batch comparison, mean differences between wheal areas of compared undiluted solutions did not significantly differ in any allergen tested, although in single cases large differences were observed. At the 1 to 64 dilution, agreement was significant only with Dermatophagoides from Manufacturer C (p= 0.262). At the 1 to 16 dilution, agreement was significant with Phleum from Manufacturer C (p=0.0116) and with Dermatophagoides from Manufacturer B and C (p=0.0239 and 0.0001, respectively). At the 1 to 4 dilution agreement was significant with Dermatophagoides from the three considered Manufacturers (p=0.0189, 0.0052 and 0.0077, respectively) and with Phleum from Manufacturer B and C (p=0.0336 and 0.0113, respectively). CONCLUSION: There are significant differences among commercially available diagnostic products for skin prick testing.

Natural rubber latex allergy in children: clinical and immunological effects of 3-years sublingual immunotherapy.

BACKGROUND: We previously demonstrated that one year of sublingual immunotherapy (SLIT) with natural rubber latex (NRL) was safe and efficacious in paediatric patients with NRL allergy. RESEARCH DESIGN AND METHODS: We studied 12 NRL-allergic children (age 4-15), previously assigned to the treated arm of a double-blind placebo controlled study, who received a commercial latex SLIT for three years. Adverse reactions were monitored. The primary end-point was the NRL glove-use test. As secondary end-points, skin prick test with NRL and NRL serum specific IgE were used. MAIN OUTCOMES MEASURES: No SLIT-related side effects were observed. A significant reduction of the glove-use score was observed after one-year treatment (5.1 +/- 4.2 vs. 14.8 +/- 5.7, p=0.0031). This parameter was further reduced in the second year since SLIT start (2.0 +/- 2.7, p=000007). After 3 years of SLIT all patients had a negative glove-use test (p<0.0001). Baseline wheal areas of skin prick test (6.8 +/- 2.5 mm2) were significantly reduced after 2 (5.3 +/- 1.8 mm2) and 3 years (4.0 +/- 1.8 mm2) of SLIT (p=0.039 and 0.027, respectively). Baseline values of serum specific IgE (23 +/- 34 KU/l) were significantly reduced after 3 years since SLIT start (6.4 +/- 5.0, p=0.0371). CONCLUSIONS: Three years of latex SLIT is safe and consolidates the efficacy previously observed after one year of treatment in paediatric patients.

Human monocytoid THP-1 cell line versus monocyte-derived human immature dendritic cells as in vitro models for predicting the sensitising potential of chemicals.

Immature dendritic cells (DCs) modulate differentiation markers following in vitro exposure to chemicals generating contact allergies. THP-1 is a monocytoid cell line maintaining some differentiating plasticity. In this study, human DCs and THP-1 cells were compared as in vitro models to predict contact sensitisation of chemicals with different sensitising potential. Expression of CD80 and CD86 was assessed by flow cytometry after exposure to subtoxic concentrations of potent (2,4-dinitrochlorobenzene, DNCB and p-phenylendiamine, PPD), strong (thimerosal, TMS), moderate (sodium tetrachloroplatinate, Na2PtCl4) sensitising compounds as well as of non-sensitising, irritating sodium dodecyl sulphate (SDS) as compared to a vehicle of sensitising substances (dimethyl sulphoxide, DMSO). Up-regulation of CD86 following in vitro incubation of DCs and THP-1 cells with DNCB, PPD, TMS and Na2PtCl4, but not with SDS, was observed. The CD80 membrane marker was up-regulated on DCs following in vitro incubation with DNCB and PPD, but not with TMS, Na2PtCl4. and SDS. On THP-1 cells, only DNCB up-regulated CD80 expression. In conclusion, both the cell line THP-1 and DCs are promising in vitro models for assays aiming at predicting the sensitisation potential of chemicals. THP-1 cell line is by far easier to handle and offers relevant advantages from the practical point of view.

Chromium (VI)-induced immunotoxicity and intracellular accumulation in human primary dendritic cells.

Chromium compounds, besides being occupational carcinogens, can also induce allergic contact dermatitis (ACD) and other immunomodulatory effects. In this study we investigate cell viability, uptake and intracellular distribution of chromium in human primary dendritic cells (DCs), either immature (iDCs) or driven to differentiate by a specific maturation stimulus (LPS) (mature DCs, mDCs), when exposed for 48 h to concentrations of soluble radiolabelled Na251CrO4 ranging from 5 to 0.5 microM. The modulation of the expression of membrane markers (CD80, CD86, MHC class II) correlated with the immunological functions of DCs was also measured. After 48 h of exposure the mean IC50 values in 4 donors were 36 and 31 microM in iDCs and mDC respectively, as detected by propidium iodide incorporation. Cellular uptake of chromium was nearly linear with increasing doses. At 48 h post-exposure chromium was accumulated preferentially in the nuclear and cytosolic fractions (44.1 to 66% and 13.1 to 31% of total cellular chromium, respectively). Although a high inter-individual variability was observed, an increase in the expression of CD86 and, to a lower extent, CD80 and MHC class II membrane markers was found in mDCs of single donors. These results highlight the relevance of searching for the biodistribution of trace metals in primary cells of the immune system. Moreover, they suggest that DCs differentiation markers can help in measuring the immunotoxicity of metal compounds with sensitisation potential.

Age, gender and reactivity to allergens independently influence skin reactivity to histamine.

BACKGROUND: The ability to mount an IgE response to allergens is a prerequisite for the development of positive allergen skin tests. Histamine is commonly used as a positive control in skin prick testing and provides a measure of nonspecific skin reactivity, similar to bronchial hyper-responsiveness. METHODS: To determine whether allergen responsiveness, age, gender and season of the year contribute to histamine sensitivity, 620 subjects (502 of them with at least one known sensitizing allergen and the remaining 118 non-allergic controls) were prick-tested with a panel of allergens common in the Northern Italy semi-rural area where the patients lived, and with 10 mg/ml histamine dihydrochloride. RESULTS: We found higher histamine reactivity in allergic versus control individuals (median value 23.7 versus 19.8 mm2; p=0.0497). Likewise, we found in allergic subjects a correlation between allergen responsiveness in terms of number of positive allergens at skin prick test and sensitivity to histamine (mono- sensitized versus poly-sensitized subjects: p=0.0015). Moreover older age and male sex were associated with a higher response to histamine, also when separately considering allergic subjects (p<0.0001 in both cases: correlation coefficient for age versus histamine reactivity: r=0.3408). The correlation between allergen responsiveness and sensitivity to histamine was maintained also when statistically balanced for age and sex. CONCLUSION: Allergen responsiveness, gender and age allow more accurate prediction of histamine sensitivity than either parameter alone.

Prediction of body cell mass, fat-free mass, and total body water with bioelectrical impedance analysis: effects of race, sex, and disease.

The inability to precisely estimate body composition with simple, inexpensive, and easily applied techniques is an impediment to clinical investigations in nutrition. In this study, predictive equations for body cell mass (BCM), fat-free mass (FFM), and total body water (TBW) were derived from direct measurements through use of single-frequency bioelectrical impedance analysis (BIA) in 332 subjects, including white, black, and Hispanic men and women, who were both healthy control subjects and patients infected with the human immunodeficiency virus (HIV). Preliminary studies showed more accurate predictions of BCM when parallel-transformed values of reactance were used rather than the values reported by the bioelectrical impedance analyzer. Modeling equations derived after logarithmic transformation of height, reactance, and impedance were more accurate predictors than equations using height2/resistance, and the use of sex-specific equations further improved accuracy. The effect of adding weight to the modeling equation was less important than the BIA measurements. The resulting equations were validated internally, and race and disease (HIV infection) were shown not to affect the predictions. The equation for FFM was validated externally against results derived from hydrodensitometry in 440 healthy individuals; the SEE was < 5%. These results indicate that body composition can be estimated with simple and easily applied techniques, and that the estimates are sufficiently precise for use in clinical investigation and practice.

Estimation of extracellular and total body water by multiple-frequency bioelectrical-impedance measurement.

This study evaluated a new technology of bioelectrical-impedance (BI) measurement that makes use of multiple frequencies (5, 50, and 100 kHz) for estimation of extracellular and total body water. In 36 healthy males, resistance and reactance at three frequencies were compared with extra-cellular water (ECW) and total body water (TBW) determined by isotope dilution. ECW was best predicted by resistance measured at 5 kHz, corrected for height and weight (R = 0.930, SEE = 1.94 L) whereas TBW was best predicted by resistance at 100 kHZ and weight (R = 0.947, SEE = 2.64 L). Cross-validation analysis on two randomly selected subsets (n = 18 each) indicated that the prediction equations were reproducible and valid. Thus, BI at dual frequencies is valid for determination of body-water compartments and may be useful in the nutritional assessment of patients in whom body water and hydration is of clinical concern.

Asians have lower body mass index (BMI) but higher percent body fat than do whites: comparisons of anthropometric measurements.

We studied the correlations between body mass index (BMI) and percent body fat (fat%) measured by dual-photon absorptiometry (DPA) in 445 white and 242 Asian adults aged 18-94 y. In addition, comparisons in six circumferences and eight skinfold-thickness measurements between whites and Asians were made to explain the discrepancies. Although Asians had lower BMI, they were fatter than whites of both sexes. The correlations between fat% and BMI varied by BMI and sex and race. Comparisons in anthropometry show that Asians had more subcutaneous fat than did whites and had different fat distributions from whites. Asians had more upper-body subcutaneous fat than did whites. The magnitude of differences between the two races was greater in females than in males. Prediction equations developed for each sex and race, based on BMI alone, gave SEEs ranging from 4.4% to 5.7%. All were significantly improved to the range of 3.5-4.4% when age and several skinfold-thickness measurements were added.