Allergenic cross-reactivity among peach, apricot, plum, and cherry in patients with oral allergy syndrome: an in vivo and in vitro study

BACKGROUND

Oral allergy syndrome in response to fruits and vegetables frequently occurs as clusters of hypersensitivity to members of the same botanical family, for which the immunologic basis lies in a number of common allergens, most of them still unidentified.

OBJECTIVE

This study was designed to assess the in vivo and in vitro cross-reactivity between fruits of the Prunoideae subfamily (i.e., peach, cherry, apricot, and plum) and to identify their major allergens and the cross-reactivity of the peach extract with grass and birch pollen.

METHODS

The in vivo study was conducted by skin prick tests and open food challenges with fresh fruits in 23 patients with oral allergy syndrome for peach and positive skin prick test and RAST results for the other Prunoideae. In vitro sodium dodecylsulfate-polyacrylamide gel electrophoresis was followed by immunoblotting and immunoblotting-inhibition.

RESULTS

A 13 kd component was identified as the only major allergen common to all the Prunoideae, the other major allergens were found at 14 kd in peach and at 30 kd in cherry. Immunoblotting inhibition showed wide cross-reactivity within the Prunoideae, whereas grass and birch pollen partially inhibited the peach blotting.

CONCLUSIONS

Clinical cross-reactivity to Prunoideae is essentially due to a common 13 kd IgE-binding component, which seems to be the most important major allergen of this subfamily, not shared with grass and birch pollen.

Effects of nedocromil sodium on bronchospasm and HS-NCA release induced by allergen inhalation in asthmatic patients

The aim of this study was to assess the ability of nedocromil sodium (NS) to prevent the immediate asthmatic reaction and the increase in the serum level of heat stable neutrophil chemotactic activity (HS-NCA) induced by antigen inhalation. In a double-blind, cross-over study, 13 atopic subjects affected with seasonal asthma underwent a bronchial provocation test with a preselected dose of grass pollen allergen (enough to cause a decrease of > or = 20% in FEV1:FEV1 PD20) after pre-treatment with 4 mg NS or placebo. Serum samples were withdrawn from 11 subjects for HS-NCA determination. After NS administration the decrease in FEV1 was significantly less than after placebo administration at all time points after challenge (2 min P = 0.0004; 7 min, P = 0.0005; 17 min P = 0.0002 and 27 min P = 0.0005). The percentage increase in HS-NCA was significantly higher after placebo than after NS inhalation, both 10 (P = 0.0048) and 20 (P = 0.0068) min after challenge. Our study confirms previous investigations, showing that NS inhibits the immediate asthmatic response to allergen inhalation in atopic, asthmatic subjects and moreover it shows that this drug prevents in vivo the increase of the serum HS-NCA. This last finding has not been previously reported.

A double-blind, placebo-controlled study of immunotherapy with an alginate-conjugated extract of Parietaria judaica in patients with Parietaria hay fever

A double-blind, placebo-controlled study was conducted to evaluate the efficacy and safety of immunotherapy (IT) with a partially purified alginate-conjugated extract of Parietaria judaica (Conjuvac Parietaria, Dome/Hollister-Stier) in patients suffering from rhinoconjunctivitis caused by Parietaria pollen. Eighteen patients (10 women, 8 men, mean age 35 years) received active treatment and 17 (10 women, 7 men, mean age 42.5 years) received placebo. Actively treated patients had significantly lower nasal symptom/medication scores (running nose P = 0.0087 and sneezing P = 0.048) during the Parietaria pollen season. Significant decreases in specific skin (P < 0.01), nasal (P < 0.05), and conjunctival (P < 0.01) reactivity to the Parietaria extract and significant increases of specific IgG (P < 0.001), IgG1 (P < 0.001), and IgG4 (P < 0.001) in actively treated patients, but not in placebo, were found. IT was well tolerated, the active extract inducing five mild systemic reactions (four rhinitis and one urticaria) and placebo two (rhinitis). A significant correlation was found between low skin reactivity and high specific IgG (P = 0.0002) and IgG4 (P = 0.036). These findings indicate that IT with a partially purified P. judaica extract is an effective and safe treatment for Parietaria pollen allergy. The correlation between low immediate skin reactivity and high specific IgG and IgG4 suggests that, at least in the studied cutaneous model, these antibodies may exert a blocking effect.

Lymphocyte subsets and natural killer cell activity in healthy old people and centenarians

The contribution of the immune system to healthy aging and longevity is still an open question. For this reason, several immune parameters (T, B, and natural killer [NK] cell subsets; non-major histocompatibility complex [MHC]-restricted cytotoxic activities, ie, natural and redirected killing [RDK] activities) were studied in a total of 138 healthy subjects of different ages, from 4 to 106 years of age, including 26 centenarians. The major age-related modifications were the following: (1) a decrease in the absolute number of T lymphocytes (CD3+), involving both CD4+ and CD8+ subsets, accompanied by a marked concomitant increase in the number of activated T cells (CD3+, HLA-DR+); (2) a marked decrease in the number of B lymphocytes (CD19+); and (3) an increase in the number of cells with markers of NK activity and of T lymphocytes able to mediate non-MHC-restricted cytotoxicity. These modifications linearly progressed with age and centenarians followed the trend, suggesting that their immune system did not escape the aging process. However, other immunohematologic parameters (number of red blood cells, platelets, and leukocytes) and important immune functions, such as cytotoxic activities (NK and RDK cell activities), were well preserved throughout life until the last decades of life. Unexpectedly, in apparently healthy middle-aged subjects, a decrease of cytotoxic activities was observed in comparison with those of both young controls and centenarians. In conclusions, our data suggest that in centenarians some immune responses are kept at a high level of efficiency, likely contributing to their successful aging. However, this selected group of people does not escape the aging process, as shown by the progressive derangement of a variety of immune parameters.

IgE-mediated allergy from vegetable allergens

Allergy to fresh fruits and vegetables is IgE-mediated. Its main clinical features are local, such as oral pruritus and swelling of lips and tongue but systemic symptoms such as urticaria, asthma, or anaphylactic shock may occur. Clinical associations with allergic rhinitis due to cross-reactive antigens of pollens and foods are frequent.

Increased cytokine production in mononuclear cells of healthy elderly people

The production of cytokines during aging, except interleukin (IL)-2, has been neglected in humans. We measured the in vitro production of IL-6, tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma and IL-1 beta by peripheral mononuclear cells from selected healthy young (mean age 26.8 years) and aged (mean age 80.2 years) subjects. Significant increases of IL-6, TNF-alpha and IL-1 beta levels were found in mitogen-stimulated cultures from aged donors, occurring at 24 to 72 h after stimulation. No significant differences were observed for IFN-gamma production. Proliferative capability of cells stimulated with PHA was not impaired in aged subjects. Since the amounts of all cytokines studied were similar in unstimulated cultures from young and aged subjects, and also serum levels of TNF-alpha did not differ, these data indicate that the cellular machinery for the production of these cytokines is well preserved in aging, and also that cells from old people are able to up-regulate their production in response to appropriate stimuli. The increases in cytokine synthesis were not dependent on changes in the number of monocytes, nor were they related to the significant rise of CD45RO+, and the concomitant decrease of CD45RA+, occurring in both CD4+ and CD8+ lymphocytes from aged subjects. The increased production of pro-inflammatory cytokines by stimulated mononuclear cells of healthy aged subjects may be relevant to several aspects of age-associated pathological events, including atherosclerosis, osteoporosis, fibrosis and dementia.

Early phenotypic activation of circulating helper memory T cells in scleroderma: correlation with disease activity

OBJECTIVES

The differential expression of several accessory/activation molecules (CD26, CD29, CD45RA, CD25, MLR4, HLA-DR) on peripheral blood CD4+ and CD8+ T lymphocytes in patients with scleroderma was compared with that in controls and patients with other connective systemic diseases to look for evidence of the involvement of T cells in the disease process of scleroderma.

METHODS

The two colour expression of surface molecules by circulating T cells was analysed with a panel of monoclonal antibodies and flow cytometry in 17 patients with scleroderma, 10 patients with systemic lupus erythematosus, and five patients with rheumatoid arthritis, and the results compared with those for 10 normal controls. The two colour T CD4+ phenotype was further compared between patients with active and quiescent disease in these patients with scleroderma. The coexpression of surface molecules by CD4+ T cells was also analysed by three colour flow cytometry in eight patients with scleroderma.

RESULTS

Patients with scleroderma showed increased CD4+CD26+ and CD4+CD25+ percentages and absolute numbers and decreased CD8+CD29+ percentages compared with controls. Moreover, a significant correlation between the higher CD4+CD26+ T cell percentage and absolute cell numbers with disease activity was observed. Most of the CD4+ peripheral blood T cells from patients with scleroderma showed the CD26+CD45RA- phenotype by three colour flow cytometry analysis.

CONCLUSIONS

The distinctive pattern of early helper memory T cell activation in these patients with rapidly evolving scleroderma supports the role of a T cell mediated mechanism in the progression of scleroderma.

Cytofluorimetric identification of two populations of double positive (CD4+,CD8+) T lymphocytes in human peripheral blood

Two different subsets of CD4+,CD8+ T lymphocytes have been identified in peripheral blood collected from normal subjects and from patients with different diseases. The subpopulations differed in the degree of CD4 and CD8 antigen expression. Hence, it was possible to distinguish by cytofluorimetric analysis cells with a low (dim) or with a high (bright) fluorescence intensity after the staining with anti-CD4 or anti-CD8 mAbs. CD4+dim,CD8+bright lymphocytes were found in patients with EBV-infectious mononucleosis and were present for less than a month. CD4+bright,CD8+dim T cells were observed in neoplastic patients as well as in healthy subjects and were continuously present in similar percentages over a long period of time (at the moment, about 3 years). Both the subpopulations expressed CD2, CD3, CD5 antigens and had an alpha beta-TCR, but did not express CD1a or CD7. Only CD4+dim,CD8+bright cells expressed HLA-DR antigen and the activation marker CD38, while only CD4+bright,CD8+dim lymphocytes expressed CD56 and CD57 molecules. The hypothesis may be put forward that these two subsets represent an effort of the immune system to cope with different requirements, i.e., of viral or neoplastic origin, while it is not clear the meaning of these cells in healthy subjects.

Oral challenge with alternative nonsteroidal antiinflammatory drugs (NSAIDs) and paracetamol in patients intolerant to these agents

The reliability and safety of the oral challenge procedure were evaluated in the diagnosis and prevention of intolerance to nonsteroidal anti-inflammatory drugs (NSAIDs). 112 NSAID-intolerant patients were submitted to oral challenge with aspirin (acetylsalicylic acid), dipyrone, paracetamol, imidazole-hydroxybenzoate or nimesulide to confirm historic intolerance and to evaluate tolerance to other NSAIDs. A significant correlation was demonstrated between history of intolerance and the results of oral challenge in aspirin-intolerant patients (p < 0.001). Of 237 challenges with various NSAIDs and paracetamol in 101 patients, 19 challenges were positive and 2 patients developed anaphylactic shock. The ratio of positive: total challenges with alternative NSAIDs and paracetamol were as follows: 7 of 83 for paracetamol, 2 of 49 for imidazole-hydroxybenzoate and 0 of 30 for nimesulide. On the basis of these results, nimesulide was evaluated as an alternative NSAID in a second group of 284 NSAID-intolerant patients. Challenge with nimesulide elicited a positive response in 14 patients (in 6 patients the response was delayed), although adverse reactions were mild in all instances. In conclusion, a positive history of intolerance to a given NSAID is a sufficient reason to contraindicate its use even for diagnostic purposes, e.g. oral challenge. Oral challenge should therefore be restricted to the assessment of the tolerability of alternative NSAIDs. In the present study nimesulide appeared to be the safest currently available alternative in patients with NSAID intolerance.

Changes in circulating B cells and immunoglobulin classes and subclasses in a healthy aged population

The study of 87 adults of different ages, including 15 centenarians, selected for their healthy status, showed that profound changes of humoral immunity occur throughout life. In particular, a statistically significant age-related increase of the serum level of immunoglobulin classes (IgG and IgA but not IgM) and IgG subclasses (IgG1, 2 and 3, but not IgG4) was detected. A parallel age-related decrease of circulating B cells was also observed. The hypothesis of a complex derangement of B cell function and/or compartmentalization with age is put forward, together with the proposal that healthy centenarians (as representative of successful ageing) may be helpful in identifying the physiological age-related modifications of the immune system.

Selective deficiency of CD4+/CD45RA+ lymphocytes in patients with ataxia-telangiectasia

Several immunological abnormalities have been observed in ataxia-telangiectasia (AT), the most consistent being defects of immunoglobulin isotypes, decreased T-cell numbers, and reduced proliferative responses to mitogens. We examined the distribution of T lymphocytes expressing distinctive surface Ag characteristic of "naive" (CD45RA+) and "memory" (CD29+, CD45RO+) T cells, in both CD4+ and CD8+ (bright and dim) lymphocytes from 13 AT patients, compared with healthy age-matched controls. We found that, irrespective of age, patients with AT had a severe deficiency of CD4+/CD45RA+ lymphocytes. This decrease accounted for the reduction of total CD4+ cells, since the absolute numbers of memory CD4+ cells were not significantly different in AT and in controls. Functional tests revealed poor proliferative responses to phytohemagglutinin and normal responses to soluble Ag (tetanus toxoid) in AT patients. These data fit with the distribution of naive and memory cells, which are known to respond predominantly to mitogens or to recall Ag, respectively. CD45RA molecules were normally expressed on CD8+ lymphocytes. This rules out a generalized defect of regulation or differential splicing as the cause of defective expression of CD45RA on CD4+ cells. The selective deficiency of CD4+CD45RA+ may provide a cellular basis for some functional T-cell abnormalities of AT patients. Furthermore, it might practically serve for an early, or even prenatal, diagnosis of this disease.

ACTH-like molecules in gastropod molluscs: a possible role in ancestral immune response and stress

The presence of immunoreactive ACTH molecules on phagocytic cells from the freshwater snails Planorbarius corneus and Lymnaea stagnalis was shown by cytofluorimetric analysis. The role of ACTH in phagocytosis and in the release of biogenic amines, two biological responses that may be taken as ancestral types of immune response and stress, respectively, has also been evaluated. ACTH markedly increased the phagocytosis of Staphylococcus aureus by P. corneus haemocytes and caused the release of biogenic amines from such cells into the serum. These data, as well as tracing the ancestral physiological role of ACTH, favour the hypothesis that immune and neuroendocrine systems share a common evolutionary origin.

A multicentric study on sensitivity and specificity of a new in vitro test for measurement of IgE antibodies

The sensitivity and specificity of the Pharmacia CAP System, a new in vitro assay for measuring IgE antibodies, were evaluated in a multicentric study on 286 allergic patients and 243 normal subjects. Sensitivity was 95.5%, with results significantly better than RAST for some allergens, and specificity was excellent, 98.1%.

Preferential expression of V beta 6.7 domain on human peripheral CD4+ T cells. Implication for positive selection of T cells in man

The peripheral T cell receptor repertoire is mainly controlled by the processes of positive and negative selection occurring in the thymus. Studies in normal or transgenic mice have provided compelling evidence for both negative and positive selection. Negative selection is characterized by partial or total disappearance from the periphery of T cells expressing certain C beta regions, which are normally present in the thymus. Positive selection is chiefly characterized, in the periphery, by an imbalanced ratio between CD4+ and CD8+ T cells expressing a given V domain. To date little information concerning positive and negative selection has been available in man. We studied the distribution of 4 V beta domains on CD4+ and CD8+ peripheral T cells of 34 healthy individuals with a wide age-range (0-96 years). One of the V beta domain studied, V beta 6.7, is preferentially expressed on CD4+ compared to CD8+ T cells (p greater than 0.001). No significant differences were observed using the other V beta domain-specific monoclonal antibodies (V beta 5.2-5.3, 8 or 12). These results provide evidence that a process of thymic education, similar to that described in murine animal models, may also take place in man.

Age-related expansion of functionally inefficient cells with markers of natural killer activity in Down's syndrome

Peripheral blood lymphocyte subsets of two groups of patients affected by Down's syndrome (DS), ie, 28 children and nine adults of relatively advanced age (greater than 34 years), were investigated and compared with those of age- and sex-matched healthy controls (13 children and 20 adults). Particular attention was devoted to cells with markers of natural killer (NK) activity. Double- and triple-color cytofluorimetric analysis was used to better characterize the phenotypic features of the different subsets. Apart from a reduced number of T lymphocytes (CD3+) in DS children and of B lymphocytes (CD19+) in both DS groups, the major alteration we found was a marked age-related increase of the percentage of cells bearing markers associated with NK activity, such as CD16, CD56, and CD57. These DS cells were apparently severely defective as far as their function was concerned, because NK activity was significantly reduced in comparison with age-matched controls, but still capable of responding to cytokines such as interleukin-2, interferon-beta, and interferon-gamma, and to the modulation of lytic activity exerted by the anti-CD16 monoclonal antibody. On the whole, our data stress the importance of studying DS subjects of different ages to fully appreciate the immunologic derangement characteristic of this syndrome.

A double-blind study of hyposensitization with an alginate-conjugated extract of Dermatophagoides pteronyssinus (Conjuvac) in patients with perennial rhinitis. II. Immunological aspects

In a 2-year double-blind placebo controlled study an immunological evaluation was carried out on 33 patients (15 males, 18 females, mean age 29.2 years) with mite-induced perennial rhinitis who were submitted to specific immunotherapy (IT) with an alginate-conjugated extract of D. pteronyssinus. The behaviour of IgE, IgG, IgG1 and IgG4 antibodies specific to D. pteronyssinus and its major allergen Der p1 was characterized by assessment of their changes in serum, and changes in IgG in nasal secretions during the treatment. The placebo-treated patients did not show any significant variation in the levels of specific antibodies, while in the actively treated patients we found: a statistically significant decrease (P less than 0.005) of specific IgE, a statistically significant increase of specific IgG (P less than 0.005), IgG1 (P less than 0.005) and IgG4 (P less than 0.005) in serum and a statistically significant increase (P less than 0.001) of specific IgG in nasal secretions. The IgG response showed an early relative predominance of the IgG1 subclass and a late absolute predominance of IgG4 subclass, that confirmed the model of IgG4 restriction in prolonged allergen stimulation. No correlation was found between immunological and clinical data.

Inhibition of poly(ADP-ribosyl)ation does not prevent lymphocyte entry into the cell cycle

The enzyme poly(ADP-ribosyl)transferase (ADPRT) becomes activated soon after a mitogenic stimulus is applied to lymphocyte cultures. It has also been reported that ADPRT inhibitors prevent cell proliferation when added to cultures at the same time as the mitogen. While this has been ascribed to the need to seal physiologically present DNA strand breaks before cells enter S phase, the presence of DNA strand breaks in quiescent human lymphocytes has been recently questioned. We demonstrate here that non-toxic concentrations of ADPRT inhibitors do not affect lymphocyte blastization and proliferation, as measured by thymidine incorporation and cytofluorimetry. We therefore suggest that ADPRT activation is required for late functions which are not needed for cell cycle progression.

Comparison of results of skin prick tests (with fresh foods and commercial food extracts) and RAST in 100 patients with oral allergy syndrome

One hundred adult patients with a history of oral allergy syndrome (OAS) after ingestion of fruits and vegetables, 77 patients with hay fever and 13 with skin prick tests and RAST positive to pollens but without seasonal symptoms, and 32 normal nonallergic control subjects, had Phadebas RAST and skin prick tests with commercial extracts (CSPT) and with fresh foods (FFSPT) to assess the reliability of these three tests. Sensitivity was better with FFSPT for carrot, celery, cherry, apple, tomato, orange, and peach; better with CSPT for peanut, pea, and walnut; and better with RAST for hazelnut. Specificity, negative predictive value, and positive predictive value of the three tests were determined for apple, carrot, hazelnut, orange, pea, peanut, and tomato. Specificity in the patient groups ranged between 40% (pea) and 100% (apple) for CSPT, between 61% (peanut) and 87% (carrot) for RAST, and between 42% (carrot) and 93% (peanut) for FFSPT. However, all tests were negative in the control group. Thus, false positive results may result from cross-reactivity with pollen allergens. The diagnostic accuracy of these tests in the population with OAS proved comparable for peanut, carrot, hazelnut, and pea. FFSPT proved more sensitive than CSPT or RAST in confirming a history of OAS to certain alimentary allergens, such as apple, orange, tomato, carrot, cherry, celery, and peach.

A double-blind study of hyposensitization with an alginate conjugated extract of D. pteronyssinus (Conjuvac) in patients with perennial rhinitis. 1. Clinical aspects

The efficacy of hyposensitization with a standardised extract of Dermatophagoides pteronyssinus (D. pteronyssinus) conjugated to alginate and containing known amounts of antigen P1 (Conjuvac) was tested in a double blind, placebo controlled, multi-centre study in 66 adult patients with perennial rhinitis. Patients received 11 weekly injections of increasing concentrations of Conjuvac containing from 56 x 10(1) to 448 10(3) IU D. pteronyssinus or placebo injections of the alginate diluent to some of which 5 micrograms of histamine has been randomly added. This was followed by 15 monthly injections of Conjuvac or placebo. The severity of nasal blockage, sneezing and rhinorrhoea was recorded twice daily in a diary and visual analogue assessments (VAS) made at each clinic visit. Nasal provocation testing (NPT) was performed with increasing concentrations of the same extract of D. pteronyssinus as used in the hyposensitization injections, and changes in nasal airways resistance measured by passive anterior rhinomanometry. VAS was recorded and NPT was performed on entry to the study and after the fifth, ninth and final monthly injection. Conjuvac injections were well tolerated. Large local reactions (greater than 5 cm) occurred within 30 min in only 1% of patients but later in 23%. No systemic reactions or anaphylaxis occurred within 30 min of injections, but urticaria or worsening of asthma and rhinitis was reported later in 3% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

The oral allergy syndrome

We have studied 262 patients suffering from hay fever and oral allergy syndrome after fruit and vegetable ingestion. The history and the results of RAST and skin test for pollen showed a contemporary presence of systemic and local symptoms in most of the patients; a close connection between age of onset of hay fever and oral allergy syndrome; a frequent association between allergy to some pollens and some vegetables, such as between apple, carrot, pear, cherry with birch pollen and tomato, melon, watermelon with grass pollen.