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.

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.

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.

Existence, multiplicity and stability of endemic states for an age-structured S-I epidemic model.

We study an S-I type epidemic model in an age-structured population, with mortality due to the disease. A threshold quantity is found that controls the stability of the disease-free equilibrium and guarantees the existence of an endemic equilibrium. We obtain conditions on the age-dependence of the susceptibility to infection that imply the uniqueness of the endemic equilibrium. An example with two endemic equilibria is shown. Finally, we analyse numerically how the stability of the endemic equilibrium is affected by the extra-mortality and by the possible periodicities induced by the demographic age-structure.

On the formulation of epidemic models (an appraisal of Kermack and McKendrick).

The aim of this paper is to show that a large class of epidemic models, with both demography and non-permanent immunity incorporated in a rather general manner, can be mathematically formulated as a scalar renewal equation for the force of infection.

Unreliable measurement of basophil maximum leukotriene release with the Bühlmann CAST 2000 enzyme-linked immunosorbent assay kit.

The Bühlmann CAST 2000 enzyme-linked immunosorbent assay is a potentially useful assay for measuring sulfidoleukotrienes released in vitro by allergen-challenged basophils. However, we observed that the positive-control reagent yielded positive signals in cell-free systems. These false-positive results depended on using a mouse anti-FcepsilonRI monoclonal antibody and were prevented by degranulation-inducing reagents other than mouse monoclonal antibodies.

Predictive value of anti-cell and anti-human immunodeficiency virus (HIV) humoral responses in HIV-1-exposed seronegative cohorts of European and Asian origin.

Unconventional immune responses have been demonstrated in individuals who, despite repeated exposure to human immunodeficiency virus (HIV) infection, remain seronegative. As environmental exposure to pathogens and genetic background may modulate immune responses differentially, one Italian and two Asian populations of HIV-1-exposed seronegative individuals were studied. In serum samples from each group, IgG to CCR5, IgG to CD4 and IgA to gp41 were measured, which were previously described as markers of unconventional immunity in HIV-exposed seronegative Caucasians. Given the importance of conformational epitopes in virus-cell interactions, IgG to CD4-gp120 complex was also measured. It was found that markers of HIV exposure were present in all populations studied. HIV-specific humoral responses (IgA to gp41 and IgG to CD4-gp120 complex) were extremely significant predictors of HIV exposure (P<0.0001 in both cases), whereas the predictive values of anti-cell antibodies (anti-CCR5 and anti-CD4) varied between populations. Evidence is provided for the correlation of these differences with route of exposure to HIV and level of natural antibodies to cross-reactive microbial antigens. In conclusion, exposed seronegative individuals of ethnically different origins display similar signs of HIV-dependent unconventional immunity. A specific relevance must be attributed to different innate and acquired factors.

Genetic and cytogenetic studies in patients with intersexuality or infertility.

A total of 198 patients has been investigated from the genetic and cytogenetic points of view. Chromosomal aberrations were probably responsible for 8 and genic causes for 11 of the 24 cases of intersexuality. Among 96 infertile males the prevalence of abnormal karyotypes was significantly higher in azoospermic (34%) as compared to oligospermic (9%) individuals. However, if persons with hypogonadism or Klinefelter's signs are not considered, the frequency of abnormal karyotypes decreases and the difference between azoospermic and oligospermic men becomes non-significant (19% and 7%, respectively). Genic factors may be the cause of sterility in about one-fourth of these males. Chromosome causes were identified in 29 and abnormal genes postulated in 9 of the 78 sterile females. Among the more rare karyotypes found, the following were considered in more detail: 45,X/46,X,i (Yp) (observed among the intersex patients); 46,X,r (Y), and 46,XY,t(2;8) (2p12 leads to pter::8 pter) (both found among the infertile males). Y/F ratios were calculated for 47 azoospermic, 40 oligospermic and 30 control individuals; the differences between their means were statistically non-significant.

GM1 gangliosidosis: clinical and laboratory findings in eight families.

GM1 Gangliosidosis is an autosomal recessive genetic disorder due to deficiency of the lysosome enzyme beta-galactosidase, with consequent tissue accumulation of glycolipids, oligosaccharides, and especially GM1 ganglioside. In the present paper we report the clinical and laboratory findings obtained for eight families starting from eight index cases exhibiting the childhood form of the disease. The total number of cases in these families may be as high as 14, thus causing GM1 gangliosidosis to be the inborn metabolic error most frequently diagnosed in our service. Hypotonia, neuromotor retardation, hepatosplenomegaly, macrocephaly, and hydrocele are some of the most frequent clinical findings. The disease evolves towards convulsions and bronchopneumonia, leading to patient death generally during the first half of the second year of life. The presence of vacuolated lymphocytes, alterations of the lumbar vertebrae, and cherry spots on the retina were observed in almost all patients. When tested for inborn metabolic errors, all patients gave normal results, a fact that may have confused and delayed diagnosis. Diagnosis was made by urine oligosaccharide chromatography and confirmed by beta-galactoside measurement in peripheral blood leukocytes. This method proved to be accurate also for the detection of heterozygotes, which permitted post-mortem diagnosis in two families. The authors speculate that increased fetal loss and tendency towards macrosomy may be possible characteristics of the disease, suggest that testing for vacuolated lymphocytes be used as a screening method, and propose that urine oligosaccharide chromatography be included in the routine screening for inborn metabolic errors.

Proximal trisomy 14q: report of a case and review of the literature.

Descreve-se uma crianca do sexo feminino com trissomia parcial do 14. O cariotipo 47,XX, + der(14), t(9;14) (p24;q24)mat e o resultado da disjuncao meiotica 3:1 na mae heterozigota 46,XX, t(9;14) (9qter-9p24: :14q24-14qter;14pter-14 a 24: 9p24-pter), que teve dois abortos espontaneos previos.E feita uma revisao dos casos ja descritos discutindo-se as semelhancas clinicas