Total urinary polyphenols and longitudinal changes of bone properties. The InCHIANTI study.

The aim of this study was to evaluate the association of levels of urinary total polyphenols considered as a proxy measure of polyphenol intake, with longitudinal changes of bone properties, in the InCHIANTI study. Dietary intake of polyphenols appears to be associated with future accelerated deterioration of bone health. INTRODUCTION: Polyphenols, micronutrients ingested through plant-based foods, have antioxidant and anti-inflammatory properties and may contribute to osteoporosis prevention. We evaluated associations of high levels of urinary total polyphenols (UTP), a proxy measure of polyphenol intake, with longitudinal changes of bone properties in a representative cohort of free-living participants of the InCHIANTI study. METHODS: The InCHIANTI study enrolled representative samples from the registry list of two towns in Tuscany, Italy. Baseline data were collected in 1998 and follow-up visits in 2001 and 2004. Of the 1453 participants enrolled, 956 consented to donate a 24-h urine sample used to assess UTP, had dietary assessment, a physical examination, and underwent a quantitative computerized tomography (pQCT) of the tibia. From pQCT images, we estimated markers of bone mass (BM), diaphyseal design (DD), and material quality (MQ). Mixed models were used to study the relationship between baseline tertiles of UTP with changes of the bone characteristics over the follow-up. RESULTS: At baseline, higher levels of UTP were positively correlated with markers of BM, DD, and MQ. Compared with lower tertile of UTP, participants in the intermediate and highest tertiles had higher cortical bone area, cortical mineral content, and cortical thickness. However, participants in the intermediate and highest UTP tertiles experienced accelerated deterioration of these same parameters over the follow-up compared with those in the lowest UTP tertile. CONCLUSIONS: Dietary intake of polyphenols estimated by UTP and dietary questionnaire was associated with long-term accelerated deterioration of bone health. Our study does not support the recommendation of increasing polyphenol intake for osteoporosis prevention.

Exploratory study on immune phenotypes in Alzheimer's disease and vascular dementia.

BACKGROUND AND PURPOSE: The differentiation of Alzheimer's disease (AD) dementia from vascular dementia (VaD) and mixed-type dementia (mixed dementia) requires stepwise analysis and usually occurs late in the disease process. Early diagnosis and therapy monitoring would benefit greatly from the identification of biomarkers of neurodegeneration, especially blood biomarkers. To this end, the aim of the present pilot study was to investigate differences in the distribution of peripheral T-cell populations in patients with AD compared to VaD and mixed dementia. METHODS: Flow cytometry was performed on blood samples from 11 patients with AD, six with VaD and six with mixed dementia, as well as 17 healthy control subjects (HCs). CD4+ and CD8+ T cells were typed for expression of CD45, CD27, CD28, CD25, FoxP3, CCR4 and CCR6; the other leukocytes were also assessed. Functionally, immune cell uptake of the ß-amyloid (Aß) toxic fragment (Aß1-42 ) was also evaluated. RESULTS: A higher proportion of CD4+CD28- memory T cells and a reciprocal reduction of CD4+CD28+CD27+ naïve T lymphocytes was detected in all patient groups relative to controls. Significantly fewer CD4+CD25+FoxP3 regulatory T cells were present in patients with VaD, and significantly more CCR6+ and CCR4+ CD4+ T cells in those with AD. Higher CCR6+ T-cell frequencies were also present in patients with mixed dementia, potentially due to the inflammation and immune cell chemoattraction triggered by Aß. CONCLUSIONS: The present study was a comprehensive investigation comparing different kinds of dementia, revealing differentially expressed peripheral markers that are potentially useful for early AD, VaD and mixed dementia diagnoses, and that would assist in proper treatments for these disparate diseases. Validation is now required.

Allergooncology: an expanding research area.

The relationship between allergic diseases and cancer is a very controversial topic, widely discussed in the last decades. Many studies have demonstrated inverse association between allergy and cancer, but others have reached neutral conclusions or have indicated a positive role of allergy in the development of cancer. However, either inhibiting or favoring, many cells and molecules relevant in the allergic process play a role in tumorigenesis. On the one hand, activated immune cells, like classically activated macrophages "M1", activated dendritic cells, IL-33 and amphiregulin stimulated Innate Lymphoid Cells (ILC2), Th1, IFN-γ producing T CD8+ and B lymphocytes have inhibitory effects on tumorigenesis and tumor progression. On the other hand, tolerogenic immune cells, like alternatively activated macrophages "M2" (M2a, M2b and M2c), tolerogenic dendritic cells, ILC3, T regulatory and B regulatory lymphocytes, while inhibiting allergic sensitization and response, appear to favour carcinogenesis. Furthermore, M2 subtypes macrophages (M2a, M2b), IL-25 stimulated ILC2 and Th2 lymphocytes have a role both in inducing allergic reactions and in favouring cancer progression. In addition, mast cells, pivotal cells in allergy, have a different effect of tumorigenesis based on their location - they can promote cancer progression or inhibit it. Finally, eosinophils have shown a prevalent tumoricidal function mediated by α-defensins, TNF-α, granzymes A and IL-18. Better understanding the role of various cells on carcinogenesis can help in developing new strategies (diagnostic, therapeutic and of follow up) against tumor.

Occupational allergy: is there a role for nanoparticles?

All fields of industry are applying nanotechnologies for the development of advanced materials, there¬fore at present the number of workers exposed to nanosized materials are significantly increasing. Unfortunately, protective equipment for nanoparticles (NPs) is of uncertain efficacy so the risk of noxious effects, in particular allergic sensitization, on workers gives many concerns. At the same time, studies of allergic physiopathology demonstrated that the lack of prevention and treatment could result in invalidating dis¬eases that, in case of professional etiology, might imply removal from the job and compensation. Therefore, a deeper knowledge of the role of NPs in inducing allergic diseases is mandatory to implement the risk assessment and preventive measures for nanosafety in the workplace. The possibility that NPs favor, ex¬acerbate or directly induce allergy is being suggested by recent experimental investigations in cellular and animal models. Unfortunately, studies are heterogeneous and few data have received experimental confir¬mation, lacking reproducibility. What comes to attention is the uncertainty about the real plausibility of the observed experimental effects, as there are only a few reported cases of allergy onset or exacerbation for workers exposed to NPs. However, the potential for NPs to induce, favor or exacerbate allergies seems possible even though not completely demonstrated. This should be a greater incentive to carry out appro¬priate epidemiological studies that are lacking and really needed.

Lipid transfer protein sensitization: reactivity profiles and clinical risk assessment in an Italian cohort.

BACKGROUND: Nonspecific lipid transfer proteins (nsLTPs) represent a major cause of systemic food allergic reactions in the Mediterranean area. This study investigate hierarchical patterns and cluster relationships of IgE sensitization to different nsLTPs, and the relationship to clinical allergy in a large Italian cohort. METHODS: A total of 568 nsLTP-positive subjects after IgE ImmunoCAP-ISAC microarray analysis with Ara h 9, Art v 3, Cor a 8, Jug r 3, Pla a 3, Pru p 3 and Tri a 14 allergens were studied. IgE inhibition experiments were carried out with mugwort and plane tree pollen extracts. RESULTS: Eighty-two per cent of nsLTP-positive participants (94% if <6 years old) were Pru p 3(pos) , and 71% were Jug r 3(pos) . Participants who reacted to >5 nsLTPs reported a higher incidence of food-induced systemic reactions. Only Art v 3 and Pla a 3 (mugwort and plane tree nsLTPs, respectively) were associated with respiratory symptoms, and a correlation was observed between sensitization to pollen and plant food nsLTPs, particularly between Pla a 3 and tree nut/peanut nsLTPs. Co-sensitization to Par j 2 and PR-10 or profilin pan-allergens was associated with a lower prior prevalence of severe food-induced reactions. In inhibition assays, plane and mugwort pollen extracts inhibited 50-100% of IgE binding to food nsLTPs in microarrays. CONCLUSIONS: Testing IgE reactivity to a panel of nsLTP allergens unveils important associations between nsLTP sensitization profiles and clinical presentation and allows the identification of novel cluster patterns indicating likely cross-reactivities and highlighting potential allergens for nsLTP immunotherapy.

CD8+ T lymphocytes provide helper activity for IgE synthesis in human immunodeficiency virus-infected patients with hyper-IgE.

Increased levels of serum IgE and eosinophilia have been described in human immunodeficiency virus (HIV) infection, almost exclusively in patients with CD4+ cell count < 200 cells/microliters. IgE production is regulated by CD4+ T helper type 2 (Th-2) lymphocytes, producing interleukin 4 (IL-4) and expressing a ligand for the B cell-specific CD40 molecule (CD40 ligand [L]). A shift to a Th-2-like pattern of cytokine secretion has been postulated to be associated with progression toward acquired immunodeficiency syndrome (AIDS). We studied three AIDS patients with very high levels of IgE and almost complete depletion of CD4+ lymphocytes, suggesting that IgE synthesis could not be driven by CD4+ cells. IgE in vitro synthesis by cells from such patients was, however, inhibited by anti-IL-4. We show that both CD8+ T cell lines and the majority of CD8+ T cells clones derived from these patients produce IL-4, IL-5, and IL-6 in half of the cases together with interferon gamma (IFN-gamma). 44% of CD8+ T cell clones expressed a CD40L, and the supernatants of the clones were capable of inducing IgE synthesis by normal B cells costimulated with anti-CD40. CD8+ T cells in these patients therefore functionally mimic Th-2 type cells and may account for hyper-IgE and eosinophilia in the absence of CD4+ cells. The presence of such CD8+ cells may also provide a source of IL-4 directing the development of predominant Th-2 responses in HIV infection.

Kounis Syndrome as First Manifestation of Allergic Sensitization.

Mast cells are abundant in the heart, among myocardial fibers, around coronary arteries, within arterial intima and intramural vessels, and in atherosclerotic plaques. Their mediators can be released during anaphylaxis and be responsible for acute coronary syndrome. This condition has been described as Kounis syndrome (KS). We report three cases of acute myocardial ischemia, which fulfill the definition for KS. In Cases 1 and 2, the association of intense chest pain with acute urticaria after an allergenic contact (wasp sting and betalactam antibiotic administration, respectively) was suspected to be an attack of angina related to an allergic reaction. No signs of an allergic reaction were observed in Case 3, but only the history of a wasp sting suggested its relationship to loss of consciousness and heart ischemia when hypersensitivity to venom was ascertained. These cases strongly recommend measurement of anaphylactic biomarkers, such as tryptase, during acute coronary syndromes to detect the possible involvement of an allergic reaction. Conversely, measurement of cardiac biomarkers during anaphylaxis, even without obvious signs of myocardial ischemia, might identify patients at risk of myocardial injury.

The "You Are Not Alone" care program for liver transplantation.

Current clinical practice is based on the principles of efficacy, appropriateness, efficiency, quality, and safety. Compliance with these tenets requires experienced medical and nursing staff, and active participation of patients and their families in the planned therapeutic program. To match patients' expectations on quality and safety of care and spur active participation in the transplant care process, we set up an integrated, multiphase, multidisciplinary care program devoted to liver transplantation (LT) candidates, engrafted patients, and their families: the "Non Sei Solo" care program (You Are Not Alone). The basic principle of the care program was that, to provide efficient and effective education to their patients, health care professionals need to learn how to teach and what to teach, acquire successful communication skills, and monitor the process of education. The methodology encompassed 5 distinct phases: phase 1, exploration of patients' needs, by means of a questionnaire devoted to waitlisted and engrafted patients and their care givers; and phase 2, creation of 16 patient-oriented educational brochures directed to patients and their families. Once created, the educational brochures were presented, discussed, and amended during a consensus meeting involving all transplantation nurses and physicians (phase 3). To acquire the necessary skills and ease communication with patients, the transplantation nurses, physicians, surgeons, and anesthesiologists attended a 6-month counseling course under the tutorial of an expert counselor (phase 4). Finally, in June 2007 the program started officially with monthly meetings with patients and their families, guided hospital tours on patient request, and activation of a toll-free phone number to provide support to patients and answer their questions.

An IL-15 dependent CD8 T cell response to selected HIV epitopes is related to viral control in early-treated HIV-infected subjects.

In some early-treated HIV-positive patients, Structured Treatment Interruption (STI) is associated to spontaneous control of viral rebound. Thus, in this clinical setting, we analyzed the immunological parameters associated to viral control. Two groups of early treated patients who underwent STI were retrospectively defined, according to the ability to spontaneously control HIV replication (Controller and Non-controller). Plasma cytokine levels were analyzed by multiplex analysis. CD8 T cell differentiation was determined by polychromatic flow cytometry. Antigen-specific IFN-gamma production was analyzed by ELISpot and intracellular staining after stimulation with HIV-peptides. Long-term Elispot assays were performed in the presence or absence of IL-15. Plasma IL-15 was found decreased over a period of time in Non-Controller patients, whereas a restricted response to Gag (aa.167-202 and 265-279) and Nef (aa.86-100 and 111-138) immunodominant epitopes was more frequently observed in Controller patients. Interestingly, in two Non-Controller patients the CD8-mediated T cells response to immunodominant epitopes could be restored in vitro by IL-15, suggesting a major role of cytokine homeostasis on the generation of protective immunity. In early-treated HIV+ patients undergoing STI, HIV replication control was associated to CD8 T cell maturation and sustained IL-15 levels, leading to HIV-specific CD8 T cell responses against selected Gag and Nef epitopes.

Frailty in the elderly: the physical dimension.

Frailty may be considered as a vulnerable status, which can precede the onset of overt disability. Operational definitions of frailty vary widely according to the conceptual framework: some authors consider frailty in a broad sense, which encompasses the physical, social, cognitive, psychological dimensions and comorbidity, whereas others define the syndrome more restrictively, mainly on the basis of performance parameters, such as gait speed, grip strength and physical activity. All these definitions are provided of a high predictive value for adverse outcomes, such as disability, hospitalization and mortality. Sarcopenia (i.e. the reduction of muscular mass and function) plays a predominant role in the pathogenesis of frailty. Among the factors responsible for sarcopenia (such as proinflammatory cytokines, low growth hormone and testosterone levels, increased production of oxygen free radicals, malnutrition and reduced neurological drive), immobility and lack of exercise have a preponderant role. Therefore, the diagnosis of frailty is mandatory for the early identification of a subset of elderly subjects at high risk, which can receive benefit from rehabilitation. A self-report and objective evaluation of physical performance are the best indicators of frailty in elderly subjects, a poor performance suggesting the need of an early and proper intervention. Structured exercise programs are effective in contrasting the progression of frailty, but an healthy and active lifestyle may be sufficient for delaying the onset of disability. In conclusion, there is clear evidence for prescription of exercise within the mainstream of the medical practice, rather than as an optional adjunct to standard care of the oldest old, given the public health implication of frailty, whose prevalence is going to increase in western populations.

Role of Anti-Inflammatory Cytokines on Muscle Mass and Performance Changes in Elderly Men and Women.

OBJECTIVES: Investigate the presence of a correlation between systemic inflammatory profile of community-dwelling individuals and the loss of muscular mass and performance in old age over a 4.5y follow-up, focusing on the role of anti-inflammatory cytokines in muscular changes in elderly. DESIGN: Longitudinal clinical study. SETTING: Subjects were randomly selected from lists of 11 general practitioners in the city of Verona, Italy. PARTICIPANTS: The study included 120 subjects, 92 women and 28 men aged 72.27±2.06 years and with BMI of 26.52±4.07 kg/m2 at baseline. MEASUREMENTS: Six minutes walking test (6MWT), appendicular and leg fat free mass (FFM) as measured with Dual Energy X-ray absorptiometry, were obtained at baseline and after 4.5 years (4.5y) of mean follow-up. Height, weight, body mass index (BMI), and circulating levels of TNFα, IL-4, IL-10, and IL-13 were evaluated at baseline. RESULTS: A significant reduction of appendicular FFM, leg FFM and 6MWT performance (all p<0.001) was observed after 4.5 y follow-up. In a stepwise regression model, considering appendicular FFM decline as dependent variable, lnIL-4, BMI, baseline appendicular FFM, lnTNFα and lnIL-13 were significant predictors of appendicular FFM decline explaining 30.8% of the variance. While building a stepwise multiple regression considering leg FFM as a dependent variable, lnIL-4, BMI and leg FFM were significant predictors of leg FFM decline and explained 27.4% of variance. When considering 6MWT decline as a dependent variable, baseline 6MWT, lnIL-13 and lnTNFα were significant predictors of 6MWT decline to explain 22.9% of variance. CONCLUSIONS: Our study suggest that higher serum levels of anti-inflammatory markers, and in particular IL-4 and IL-13, may play a protective role on FFM and performance maintenance in elderly subjects.

Frailty of older age: the role of the endocrine--immune interaction.

The so-called demographic transition has changed the age structure of the population worldwide, with profound effects on societal organization. The growing number and percentage of old and very old people has compelled the scientific community to focus on age related diseases and peculiar consequences of aging itself such as disability and frailty. Understanding the pathophysiology of frailty, a syndrome characterized by a reduced functional reserve and impaired adaptive capacity that results from cumulative declines of multiple subsystems, and causes increased vulnerability to adverse outcomes, is a major topic in aging research. Aging processes induce multiple changes in the hormones network (menopause, andropause, somatopause and adrenopause), in the immune system, and can modulate their efficiency and effectiveness in determining a response to stressors. These triggering events can unmask frailty in older people. Starting from these assumptions, we analyzed the relationship of the endocrine and immune networks in aging and in the different domains that are characteristically associated with the frailty syndrome, such as disability and sarcopenia, as well as in diseases related to aging such as Alzheimer's dementia and Congestive Heart Failure.

Sarcopenia: age-related skeletal muscle changes from determinants to physical disability.

Human aging is characterized by skeletal muscle wasting, a debilitating condition which sets the susceptibility for diseases that directly affect the quality of life and often limit life span. Sarcopenia, i.e. the reduction of muscle mass and/or function, is the consequence of a reduction of protein synthesis and an increase in muscle protein degradation. In addition, the capacity for muscle regeneration is severely impaired in aging and this can lead to disability, particularly in patients with other concomitant diseases or organ impairment. Immobility and lack of exercise, increased levels of proinflammatory cytokines, increased production of oxygen free radicals or impaired detoxification, low anabolic hormone output, malnutrition and reduced neurological drive have been advocated as being responsible for sarcopenia. It is intriguing to notice that multiple pathways converge on skeletal muscle dysfunction, but the factors involved sometimes diverge to different pathways, thus intersecting at critical points. It is reasonable to argue that the activity of these nodes results from the net balance of regulating mechanisms, as in the case of the GH/IGF-1 axis, the testosterone and cortisol functions, the pro- and anti-inflammatory cytokines and receptors. Both genetic and epigenetic mechanisms operate in regulating the final phenotype, the extent of muscle atrophy and reduction in strength and force generation. It is widely accepted that intervention on lifestyle habits represents an affordable and practical way to modify on a large scale some detrimental outcomes of aging, and particularly sarcopenia. The identification of the molecular chain able to reverse sarcopenia is a major goal of studies on human aging.

Long-term evaluation of T-cell subsets and T-cell function after HAART in advanced stage HIV-1 disease.

OBJECTIVES: Evaluation of immunological reconstitution after 2 years of highly active antiretroviral therapy (HAART) in AIDS patients. DESIGN: Previous data showed the effectiveness of HAART but conflicting evidence of immune reconstitution has been found in severely immunocompromised patients. Therefore, T-cell subsets and functions were analysed during 24 months of HAART in 21 AIDS patients (mean baseline CD4 cell count, 20 x 10(6)/l). METHODS: Subjects were tested at baseline and after 4, 12 and 24 months of therapy for clinical symptoms and the following investigations were carried out: plasma HIV RNA, T-cell subsets and lymphoproliferative responses to mitogens (phytohaemagglutinin, anti-CD3), and recall antigens (Candida mannoprotein, tetanus toxoid and recombinant glycoprotein 160). RESULTS: Increase in body weight, improvement of Karnofsky's score and reduction of opportunistic infections were observed. All patients showed an initial increase in the CD4 memory subset, whereas naive CD4 cells consistently increased only after 1 year. The magnitude of immune recovery was stronger in patients showing a significant reduction in viral load. However seven out of 21 patients who did not reach a sustained suppression of viral load showed also an increase in T-cell subsets. The majority of patients recovered lymphoproliferative responses to mitogens, whereas only four subjects showed a functional response to Candida mannoprotein. No patients showed a response to HIV recombinant glycoprotein 160 or tetanus toxoid. CONCLUSIONS: The immune recovery observed is slower and not complete in severely immunocompromised patients. Our data suggest that HAART may be continued also in the absence of a significant HIV RNA decrease if alternative drugs are not available.

Deregulation of the CD95/CD95L system in lymphocytes from patients with primary acute HIV infection.

OBJECTIVE: To analyze the role of CD95/CD95 ligand (CD95L) expression and functionality in peripheral blood lymphocytes (PBL) during primary, acute HIV syndrome (AHS) and in the subsequent period. PATIENTS: Twelve patients were studied during the acute phase of the viral infection and most were followed for some months. METHODS: Cell culture and cytotoxicity assays based upon 51Cr release and flow cytometry were used to evaluate cell killing via CD95 molecule, flow cytometry to assess surface antigens, enzyme-linked immunosorbent assay (ELISA) for the determination of soluble CD95 and CD95L plasma levels, quantitative competitive (QC) reverse transcription polymerase chain reaction (RT-PCR) with an original RNA competitor for the analysis of CD95L mRNA expression and QC RT-PCR for determining plasma viral load. RESULTS: The analysis of PBL during this phase revealed that almost all cells, including CD8 T cells with a virgin phenotype, B lymphocytes and natural killer cells displayed CD95 molecules on the plasma membrane. Activation of CD95 on the surface of isolated lymphocytes by anti-CD95 monoclonal antibodies or binding to CD95L induced rapid apoptosis. However, CD95L mRNA was not expressed in PBL from these patients and was poorly inducible. Soluble CD95 was found in the plasma of all patients, but only in a few at high levels, even some months after seroconversion. In contrast, soluble CD95L was detected in only one patient, this occurring after the symptomatic period. For 10 of the 12 patients, expression of CD95 on the cell membrane or in the plasma did not correlate with the plasma viral load, which varied widely from patient to patient. Further, plasma levels of soluble CD95 were not altered by decreased lymphocyte activation or by efficient antiretroviral therapy. CONCLUSIONS: In patients experiencing an acute, primary HIV infection, a prolonged deregulation of the CD95/CD95L system may exist, which is probably not entirely related to virus production but may contribute to the pathogenesis of the disease. The hypothesis can be put forward that a complex balance exists between proapoptotic events (increase in CD95 expression), probably triggered by the host as a method to limit viral production, and antiapoptotic events (decrease in CD95L expression) probably triggered by the virus as a way to increase its production and survival.

IgG anti-IgE from atopic dermatitis induces mediator release from basophils and mast cells.

IgG antibodies containing anti-IgE activity isolated from a patient with atopic dermatitis (H-aIgE) induced mediator release from human basophils and mast cells isolated from skin and lung tissues. The release of histamine was calcium- and temperature-dependent and did not involve cytotoxicity. There was an excellent correlation (r = 0.88; p less than 0.001) between the maximum percent histamine release from human basophils induced by rabbit anti-IgE (R-aIgE) and H-aIgE. H-aIgE was approximately 30 times more potent than R-aIgE in inducing mediator release from human basophils, skin, and lung mast cells. H-aIgE specifically desensitized human basophils to a subsequent challenge with both H-aIgE and R-aIgE. Lactic acid removal of IgE from human basophils blocked the releasing activity of both R-aIgE and H-aIgE. Passive sensitization with hyperimmune sera or purified IgE myeloma restored the response of basophils to both R-aIgE and H-aIgE. IgE purified from three different myeloma patients concentration-dependently blocked the histamine releasing activity of both R-aIgE and H-aIgE.

Extremely low frequency pulsed electromagnetic fields increase interleukin-2 (IL-2) utilization and IL-2 receptor expression in mitogen-stimulated human lymphocytes from old subjects.

The effects of the exposure of mitogen-stimulated human lymphocytes from aged subjects to low-frequency pulsed electromagnetic fields (PEMFs) were studied by measuring the production of interleukin-2 (IL-2) and the expression of IL-2 receptor. PEMF-exposed cultures that presented increased [3H]thymidine incorporation showed lower amounts of IL-2 in their supernatants, but higher percentages of IL-2 receptor-positive cells and of T-activated lymphocytes. Taken together, these data suggest that PEMFs were able to modulate mitogen-induced lymphocyte proliferation by provoking an increase in utilization of IL-2, most likely acting on the expression of its receptor on the plasma membrane.

CD45 isoforms expression on CD4+ and CD8+ T cells throughout life, from newborns to centenarians: implications for T cell memory.

CD4+ and CD8+ peripheral blood T lymphocytes show mutually exclusive expression of CD45RA or CD45R0, two isoforms of the common leukocyte antigen that seem to recognize so-called virgin/unprimed and memory/activated T cells. The expression of these isoforms has been studied by three colour cytofluorimetric analysis on CD4+ or CD8+ peripheral blood CD3+ cells from 22 healthy centenarians, analyzed in a context of 202 healthy donors 0-110 years old. An age-related unbalance of virgin and memory cells was found between CD4+ and CD8+ subsets. As expected, at birgh 95-99% of the CD3+ lymphocytes expressed the CD45RA isoform. A rapid increase of CD45R0+ cells was observed in the first 2-3 decades of life, this phenomenon being much more pronounced on CD4+ cells. Subsequently, the increase of the 'memory' compartment was much less rapid, so that in centenarians a consistent reservoire of CD45RA+ among CD4+ cells was still present (about 20%). In these exceptional individuals the percentage of CD45RA+ cells among CD8+ T lymphocytes was even higher (about 50%), and only slightly lower than that of young donors (about 55-60%). Thus, the main changes occurred at a different rate in CD4+ (about 20%). In these exceptional individuals the percentage of CD45RA+ cells among CD8+ T lymphocytes was even higher (about 50%), and only slightly lower than that of young donors (about 55-60%). Thus, the main changes occurred at a different rate in CD4+ and in CD8+ T cells, at an age of between 0 and 30 years, when the thymus is still functionally active. Interestingly, no difference in the usage of CD45 isoforms was observed within T cells bearing four different V beta-T cell receptor (TCR). The significance of this age-related unbalance is unknown. However, the presence of a great number of CD45RA+ T lymphocytes within the CD4+ and the CD8+ T cell subsets even in the peripheral blood of centenarians poses the problem of their origin (thymus? extrathymic sites?), of their functional role and of their lifespan. Moreover, the data on centenarians suggest that they may represent a very selected population where a slowing of immunosenescence occurs.

Chemokines, sTNF-Rs and sCD30 serum levels in healthy aged people and centenarians.

Several lines of evidence point to a profound remodelling of the cytokine network in healthy elderly subjects, with decreased type-1 cytokine production (IL 2) and a shift to type 0 and 2. We have also observed an increase of proinflammatory cytokines (IL-1, IL-6, TNF-alpha) in vitro, and an increase of circulating stem cell factor in vivo. In this setting, we studied changes of chemokines (MCP-1 and RANTES) with aging, as well as other molecules, namely, sTNF-RI and sTNF-RII, and the soluble form of the CD30 molecule (sCD30), involved in the pro- and antiinflammatory cytokine balance. The subjects enrolled in the study belonged to three different selected healthy groups of young, aged and centenarians. The presence of rheumatoid factor (RF) and antinuclear antibodies (ANA) was simultaneously assessed. The results show that MCP-1 serum levels were higher in the healthy aged and lowest in the young, while RANTES increased exclusively in centenarians. Only centenarians had autoantibodies (ANA and RF). sTNF-RI and sTNF-RII were significantly elevated in healthy old subjects compared to the young, and even higher in selected centenarians compared to the other age groups. sCD30 serum levels were significantly raised in centenarians compared to the young, despite absence of circulating CD30+ cells in the peripheral blood of the whole study population. No relationship among serum values of these different members of the TNF-R family was found, despite a strong correlation for sTNF-RI and sTNF-RII in all groups. We hypothesize that the increased chemokine levels in aged people, and raised sCD30 levels in centenarians, may reflect a general shift towards type 0/2 cytokines in normal aging, which may be responsible, at least in part, for the appearance of circulating autoantibodies without definite clinical consequences at advanced age.

Solid phase radioimmunoassay for detection of circulating food protein antigens in human serum.

A two site solid phase radioimmunoassay for detection of common food antigens is described. Bovine serum albumin, beta-lactoglobulin and ovalbumin can be detected in normal human serum at levels ranging from 0.1 to > 1000 ng/ml; sensitivity is not impaired by the presence of low levels of antibodies. Thirty min to 3 h after oral intake of milk, beta-lactoglobulin could be detected in the sera of 3 normal individuals, at a concentration of 0.1-3 ng/ml. This assay should prove useful in assessing the importance of macromolecular absorption in food allergy and in other gastrointestinal diseases.