CD34+ hemopoietic precursor and stem cells traffic in peripheral blood of celiac patients is significantly increased but not directly related to epithelial damage severity.

Celiac disease (CD) is a chronic inflammatory enteropathy of the small bowel resulting from a local TH1-mediated reaction to wheat gliadins and barley, rye and oat prolamins with the development of auto-antibodies to transglutaminases. As well as for other chronic inflammatory diseases, genetic background and environmental factors participate to pathogenesis. An increased traffic of CD34+ hemopoietic precursor and stem cells (HPC) has been reported in peripheral blood (PB) of subjects with allergic diseases that share in their pathogenesis immuno-mediated reactions, genetic and environmental factors. The aim of the present work was to investigate the CD34+ cell traffic and H2/H1 polarization of lymphoid T-cell lineage, in the peripheral blood of subjects with CD, by means of flow-cytometric techniques. Group A of control was of 20 healthy subjects, aged 5 to 58 years. Study population (Group B) was of twenty-eight patients, all females aged 13 to 70, receiving firstly a CD diagnosis at the SS Annunziata Hospital Digestive Physiopathology Out-standings' by means of clinical, serologic and small intestinal biopsy findings. Peripheral CD34+ HPCs were significantly increased in Group B (median value 0.16) when compared with Group A (median value 0.03) (p 0.0001) but did not correlate either with anti-transglutaminase (tTG) antibody levels (IgA: p 0.226; IgG: p 0.810) or with histological damage severity (p 0.41) that, on the contrary, was significantly related with anti-tTG IgA antibodies (p 0.027). Celiac circulating CD3+CD4+ lymphocytes expressed a chemokine-receptor pattern Th2-skewed in all but three patients investigated. Concluding, the CD34+ HPC highly increased peripheral traffic observed in celiac disease appears more related to a basic and emerging as common defect shared by chronic inflammatory diseases than to the gliadin-specific Th1 local reactions. Data are consistent with a potential NFkappaB deficiency and consequent prevalence of apoptotic versus survival programs leading to excessive cell-death; to replace lost cells a supplementary bone-marrow derived precursors supply, further to that physiologically provided by the gut stem cell "niches" that are cryptopatches, could be required.

Increased CD34+ cell peripheral traffic appears to be an unique feature of the allergic inflammation.

Evidence has been cumulated during the last years concerning the immaturity of the cells involved in the local and systemic aspects of allergic inflammation. Hematopoietic precursors (HPC) are mobilized from the bone matrix as multipotent cells or, more often, as progenitors that, after the initial white-lineage commitment reach through the peripheral blood (PB) their final destinations constituted by the target organs of allergy. Although several studies have investigated the CD34+ cells traffic and location at the level of the inflamed peripheral mucosae in allergic populations, limited information is available on their behaviour on the time-course of infectious diseases. The current study thus was designed to asses the peripheral traffic of CD34+ HPC during the infectious inflammation. To this end CD34+ HPCs have been enumerated, by flow-cytometric techniques, in PB of 24 adult healthy beings (Group A), 24 adult subjects with symptomatic extrinsic allergy (Group B) and in PB of 24 adult patients hospitalised for febrile infectious pathology (Group C). CD34+ cell values ranged 0.01-0.08% with a median of 0.03 in Group A. In Group B values ranged 0.17-0.75% with a median of 0.28 and in Group C values ranged 0.00-0.12% with a median of 0.07. Variance analysis test among the three groups was statistically significant (p<0.001) supporting the conclusion that CD34+ HPC mobilizing and increased peripheral traffic is an unique feature of the allergic inflammation.

T-cell receptor Vbeta repertoire in mite-allergic subjects after sublingual immunotherapy.

Sublingual immunotherapy has been recognized as an alternative to injected immunotherapy for the treatment of allergic diseases. Even if compelling clinical evidence supports such a view, few studies are available on its mechanisms of action. This study was carried out to investigate the peripheral lymphocyte Vbeta repertoire of subjects with mite-allergic respiratory allergy who were either not treated or treated for 2 years with mite-specific sublingual immunotherapy. The T-cell receptor Vbeta distribution was studied by flow-cytometric techniques in three subject groups. Group A (untreated) included 19 subjects with symptomatic, mite-allergic, low to moderate asthma and/or rhinitis. Group B (treated) was made up of 10 asymptomatic subjects treated for 2 years with mite-specific sublingual-swallow immunotherapy for low to moderate asthma and/or rhinitis. Group C (controls) included 10 healthy subjects. The Vbeta usage was investigated with monoclonal antibodies specific to the diverse beta segments V3, V5a, V5b, V5c, V6a, V8a, V8b and V12a. The comparison between the group A and group C repertoires showed a lower expression (p < 0.05) of the beta V8b+ T-cell subset. The group B repertoire, when compared with group A, showed a significantly greater usage of the beta V5a (p <0.05), 8a (p <0.05) and 12a (p <0.01) segments. The significantly lower expression of beta V8b observed in the symptomatic untreated group was not present in the group that was asymptomatic after treatment. The oligoclonal expansion observed in the treated group was consistent with the development of suppressor T-cell and/or of Th1 clones but not with deletion mechanisms of induced tolerance.

Specific sublingual immunotherapy in atopic dermatitis. Results of a 6-year follow-up of 35 consecutive patients.

BACKGROUND: allergen-specific immunotherapy has proved to be effective in selected patients with IgE-mediated respiratory allergic diseases, and alternative routes of administration are being studied. Atopic Dermatitis (AD) is currently regarded as an allergic inflammatory disease. METHODS: we conducted a cohort study to evaluate the safety and effectiveness of sublingual-swallow immunotherapy (SLIT) in selected patients with allergic (extrinsic) AD. Thirty-five patients, 16 suffering from AD without respiratory allergic symptoms (Group A) and 19 with AD associated to mild asthma and/or rhinitis (Group B), were enrolled in the study. The severity of the skin lesions (eczema) was scored on a 0 to 4 scale (and subsequently related to the more recent SCORAD Index), where 0 indicated complete healing of the eczema and 4 indicated maximal spread of the lesions. Only patients with an eczema score of 1 to 3 were started on allergen-specific SLIT for 36 months. Eczema scores, symptoms and side effects were recorded every two months during the first 2 years and then after 36 months. After SLIT was completed, all patients attended 3 yearly follow-up visits to evaluate the long-term effects of the treatment. All patients followed a set of rules designed to control for identified confounding variables. All patients received ketotifen during the first 3 months of SLIT. RESULTS: only the complete disappearance of skin lesions (score 0) was considered to indicate effectiveness. In Group A this was observed in 12.6% of the patients after 6 months of SLIT, in 31,2% after 12 months and 68.8% after 24 months. In Group B, eczema disappeared in 0% after 6 months, in 36.8% after 12 months and 73.7% after 24 months. No patients in Group A developed asthma during SLIT, and 1 patient developed asthma 3 years after immunotherapy had ended. Three focal reactions consisting of 2 cases of mild eczema and one case of diarrhoea were recorded. One case of urticaria, due to violation of the administration schedule was the only systemic reaction observed. No life-threatening reactions appeared at any time of the study. CONCLUSIONS: the outcomes obtained, taken into account the limitations of the study design, suggest that sublingual allergen-specific immunotherapy for the treatment of the extrinsic form of Atopic Dermatitis is safe and well tolerated by patients, and may favourably affect the natural course of the disease.

CD34+ cells in peripheral blood of healthy human beings and allergic subjects: clue to acute and minimal persistent inflammation.

BACKGROUND: There is compelling evidence that hemopoietic precursor cells (HPC) play a crucial role in establishing cellular inflammation in allergic diseases. Increased levels of circulating CD34+ HPC committed to the myeloid lineage have been extensively reported in allergic rhinitis, asthma and eczema, whereas CD34+ cells have been identified within the cellular infiltrates of tissues, at peripheral sites of inflammation. METHOD: We conducted a pilot study to evaluate CD34+ traffic in the peripheral blood of 22 consecutive patients (13 men and nine women; mean age 28.9 years), independently of treatment. The patients presented rhinitis, asthma, eczema, urticaria and adverse food reactions of suspected allergic origin. Allergic reactions were extrinsic in 18 patients and intrinsic in four. In 12 patients who underwent sublingual specific immunotherapy, CD34+ cells were quantified at enrollment (T0), one year later (T1) and two years later (T2). The severity of symptoms was graded on a five-point scale (0 = absence of symptoms and 4 = severe symptoms). Twenty healthy human subjects (10 men and 10 women; mean age 24.5 years) were evaluated as controls. To obtain information about the total amount of circulating HPC, independently of the lineage commitment (Lin+/-) and the degree of differentiation (CD34bright/dim), we used a modification of the Milan protocol of peripheral blood CD34+ cell estimation. The cells were analyzed using a BD FACScan or FACSCalibur and the results were expressed as the percentage of positive cells. RESULTS: CD34+ cell traffic in the control group was very low since all values were < 0.10 (median value: 0.03 %). Values in the patient group were increased in both extrinsic and intrinsic forms with a median value of 0.25 % (interquartile range: 0.13- 0.33 %). The relationship between CD34+ traffic and the severity score was highly significant (Spearman's rho = 0.954; test of Ho: CD34; independent score: Pr > t = 0.000). CONCLUSIONS: The data reported herein suggest that the method employed is effective in assessing acute allergic inflammation, as well as minimal persistent inflammation underlying an asymptomatic clinical condition. Evaluation of CD34bright/dim peripheral traffic, if confirmed by the outcomes of a multicenter study currently being planned together with traditional study of circulating IgE, could be a reliable non-invasive laboratory tool for monitoring allergic inflammation.

IgE responses to Dermatophagoides pteronyssinus native major allergens Der p 1 and Der p 2 during long-term specific immunotherapy.

We investigated by ELISA the IgE response to whole extract of the house-dust mite Dermatophagoides pteronyssinus (Dp) and to the native major allergens, Der p 1 and Der p 2, in sera from 18 adult patients (group A) with Dp-allergic asthma before (t0) and 1, 2, 3, and 4 (t1-t4) years after subcutaneous specific immunotherapy (SIT). A qualitative reduction (P = 0.05) of the IgE responses to Dp and Der p 2 was observed from t1 to t4, but a highly statistical significant decrease appeared at t3 (P < 0.01). With regard to Der p 1 IgE values, the immunotherapy induced a significant decrease (P < 0.01) at t3, but not before. In group A, the IgE responses to Der p 1 and Der p 2 were not correlated at t0 (rs = 0.31; P = 0.21) but were correlated at t3 (rs = 0.78; P = 0.001). We also examined sera from 14 adult patients (group B, same SIT schedule as group A) who were without respiratory symptoms at the end of the third year (t3) of Dp SIT. At this time (t3), there were no significant differences in Der p 1 and Der p 2 IgE levels between group A and group B.

Mite antigens enhance ICAM-1 and induce VCAM-1 expression on human umbilical vein endothelium.

Although sublingual allergen-specific immunotherapy has been proved to be effective in the treatment of allergic diseases, controversy surrounds the means by which such a local therapy can induce systemic immunological changes. Adhesion molecules are critical in the regulation of leukocyte traffic. It has been hypothesized that allergenic extract, administered locally, may induce an up-regulation of the mucosal vessel vascular adhesion molecules (CAMs) resulting in local recruitment of circulating inflammatory cells. In the present study we investigated whether the mite antigens, Der p1 and Der p2, can modulate CAM expression of human endothelial cells (HEC). To do this, slices of whole human umbilical cord vein underwent short-term (8 hours) cultures in the presence or absence of mite antigen (baseline, unstimulated controls). Cryostatic sections of the specimens were then evaluated immunohistochemically for expression of intercellular adhesion molecule (ICAM-1) and vascular cell adhesion molecule (VCAM-1) molecules. The results revealed that while Der p1 is capable of significantly up-regulating ICAM-1 and VCAM-1 on HEC, Der p2 antigen moderately up-regulates ICAM-1 expression but is ineffective in modulating VCAM-1. Although preliminary, these results clearly support the hypothesis that at least some of the effects of sublingual immunotherapy may derive from inflammatory cell recruitment at the site of allergen release.