P49 SURGICAL OPEN AORTA TRANSCATHETER VALVE IN VALVE IMPLANT FOR A MALFUNCTIONING AORTIC BIOPROSTHESIS

Background

Most cases of aortic valve bioprosthesis degenerative disease are currently best managed by transcatheter aortic valve replacement (TAVR). Compared to redo surgery, advantages of TAVR include reduced invasiveness and a minimized prosthesis gradient; however, this approach is occasionally unfeasible due to the risk for coronary flow impairment or prosthesis stent dimensions unfit to accommodate an appropriately sized device. We present a case of an open TAVR after surgical leaflets excision of a failing aortic valve bioprosthesis.

Case Summary

A 76 years old female with type 2 diabetes, hypertension and dyslipidemia was referred to our institution for a malfunctioning 21 Carpentier Edwards pericardial aortic valve bioprosthesis implanted 9 years earlier. Patient was initially considered for a valve in valve TAVR. However, because of very low–lying coronary arteries origin at preoperative CT scan we estimated substantial chances for ostia impingement when prosthesis leaflets would have been stretched out by the deploying transcatheter device (Figure 1); although feasible, conventional redo surgery with bioprosthesis excision and re–suture was not preferred because of patients age and comorbidities; risk of damaging the aortic ring and wall including coronaries emergence when dissecting out the stent of the biopsosthesis and reimplanting a new one was also evaluated. We therefore opted for an hybrid procedure. After redo median sternotomy, careful dissection of adhesions, central Cardio–Pulmonary Bypass (CPB), aortic cross clamp and antegrade cardioplegia, a transverse aortotomy was done. The prosthesis was inspected and found grossly deteriorated: leaflets only were excised leaving the stent intact (Figure 2) and a 23 Sapien3 Ultra valve was carefully deployed under direct vision. Coronary ostia were checked and found patent. Myocardial ischemia and CPB times were 61 and 85 minutes respectively. Intensive care unit stay was 2 days. After a reassuring postoperative CT scan (Figure 3), patient was discharged home 11 days after surgery.

Conclusions

We found this approach a good compromise when dealing with challenging aortic valve reoperations, as it is associated to reduced surgical complexity and potential for less morbidity and mortality compared to conventional surgery when low coronary ostia make valve in valve TAVR unachievable.

Clinical effects of preemptive intra-articular lidocaine, dexmedetomidine and lidocaine-dexmedetomidine administration in dogs undergoing arthroscopy

This study investigated the perioperative effects of preemptive intra-articular lidocaine (L group), dexmedetomidine (D group) and lidocaine-dexmedetomidine (LD group) in dogs. Physiological variables were intraoperatively recorded at 5 min intervals starting from baseline (5 min before intra-articular injection). If nociception occurred, IV fentanyl was administered. Postoperative pain was assessed using the Short Form-Glasgow Composite Measure Pain Scale. Twenty-four dogs (eight in each group) were included in this prospective, randomized, masked clinical study. In the LD group, systolic arterial pressure significantly increased at T10 (P = 0.027), T15 (P = 0.021) and T20 (P = 0.022), compared with baseline. In the D and LD groups, mean arterial pressure significantly increased at T10 (P = 0.022; 0.024), T15 (P = 0.024; 0.09) and T20 (P = 0.019; 0.021), compared with baseline and diastolic arterial pressure significantly increased at T10 (P = 0.026; 0.047), T15 (P = 0.021; 0.023), T20 (P = 0.011; 0.012) and T25 (P = 0.019; 0.027), compared with baseline. In the LD group, heart rate significantly decreased at T5 (P = 0.031), T10 (P = 0.026) and T15 (P = 0.034), compared with baseline. Atrioventricular blocks appeared more frequently in the LD group than in L and D groups (P = 0.002). Group L received more fentanyl than the D and LD groups (P = 0.03). No differences in postoperative pain score were detected (P = 0.121). These findings suggested systemic absorption of intra-articular dexmedetomidine. Intra-articular lidocaine-dexmedetomidine was associated with a greater incidence of atrioventricular blocks. Intra-articular dexmedetomidine, alone and combined with lidocaine, provided better intraoperative analgesia than lidocaine in dogs undergoing arthroscopy, although the 12 h postoperative analgesic effect of the three treatments was similar.

Soluble CD30 and Lymphocyte Activation Gene-3 (CD223), as Potential Serological Markers of T Helper-Type Cytokine Response Induced by Acellular Pertussis Vaccine

T cell responses are involved in vaccine-induced immunity to pertussis but no easy-to-monitor, serological markers are available to assess these responses. The lymphocyte activation gene-3 (CD223) molecule is present on, and released by, activated T helper (Th) 1 cells, whereas CD30 molecules have been associated with Th2 immune responses. Starting from the recent knowledge of the cytokine profile induced by pertussis vaccination, we examined the levels of soluble (s)CD223 and sCD30 proteins in child recipients of acellular pertussis (aP) and diphtheria-tetanus (DT) vaccines and in children receiving DT vaccine only, as control. The correlation of the two proteins with specific antibody and T cell responses was assessed. The main findings are: i) sCD223 and sCD30 levels are inversely related, suggesting that the two markers are the expression of different and counter-regulated T-cell responses; ii) sCD30 level correlated with induction of T cell proliferation to pertussis vaccine antigens and antibody response to pertussis toxin. Overall, sCD30 and sCD223 levels seem to be promising candidate markers to assess the induction of Th-type responses in vaccine recipients.

Serological Markers of Pulmonary Tuberculosis and of Response to Anti-Tuberculosis Treatment in a Patient Population in Guinea

The aim of the study was to evaluate serological correlates of active tuberculosis and of response to antituberculosis treatment in a cohort of HIV-negative patients with pulmonary tuberculosis studied at diagnosis and during treatment at the Service de Pneumo-Phtisiologie, Centre Hospitalier-Universitaire Ignace Deen, Conakry, Republic of Guinea. Two similar cohorts of HIV-negative healthy households of patients and healthy community controls were included in the study. Plasma samples were obtained from 168 untreated tuberculosis patients, 167 healthy household controls, and 168 healthy community controls. Serial plasma samples were also obtained from the tuberculosis patients at 2 and 8 months after initiation of chemotherapy. IgG antibody levels were measured by an enzyme-linked immunosorbent assay (ELISA) using ten purified M. tuberculosis antigens. ELISA results were analysed by comparing geometric means of data. Of the ten antigens tested, five (14kDa Ag, 19kDa Ag, AlaDH, MS, and MPT83) elicited similar antibody responses in untreated TB patients and controls. In contrast, levels of three antibodies (ESAT-6, LAM, and 38kDa Ag) were higher in untreated TB patients than in household or community controls (p < 0.0001). Levels were higher in untreated patients than in community controls also for the anti-Rv2626c antibody (p = 0.0001) and, at a lower significance level, for the anti-FdxA antibody (p < 0.025). Antibody levels against ESAT-6 and Rv2626c decreased during therapy, while antibody levels to the 38 kDa antigen and LAM increased during therapy; FdxA antibody levels did not vary with treatment. Neither severity of presentation nor chest X-ray patterns affected levels of these antibodies before treatment. In contrast, after the 8-month therapeutic course, patients who presented with moderate/severe disease had higher levels of anti-ESAT-6, anti-FdxA, and anti-38kDa antibodies than those of patients with mild disease onset. Patients with bilateral lung lesions had significantly higher anti-38kDa and anti-LAM levels, both at diagnosis and after 8-month treatment, than patients with lesions involving only one lung. Antibodies to alanine dehydrogenase and malate synthetase measured at initiation of treatment were higher in tuberculosis patients who subsequently failed therapy than in those who were cured. The main conclusions of the study are: a) plasma levels of antibodies to a number of M. tuberculosis represent serological correlates of active disease; b) these correlates are affected in an antigen-specific fashion by anti-tuberculosis treatment; c) particular serological markers may be predictive of treatment outcome.

A breaking down of the Mediterranean diet in the land where it was discovered. A cross sectional survey among the young generation of adolescents in the heart of Cilento, Southern Italy

BACKGROUND

To investigate dietary habits among young people in the Mediterranean lands, exactly where the health benefits of the Mediterranean diet (MD) were discovered by Ancel Keys.

STUDY DESIGN

A cross-sectional study design.

METHODS

A 10-items food-frequency questionnaire was administered to 1117 students in the schools of the Cilento area. Adherence to the MD was appraised according to a scale of 0-10. A logistic regression model was used to identify possible factors associated with "Following an unhealthy diet". Results were expressed as Odds Ratio with 95% confidence interval and the level of significance was set at p<0.05.

RESULTS

A percentage of 63.8 reached a score under six, indicating that the majority of the students did not respect the rules of the Mediterranean diet and only 36.2% (n. 371) exceeded a score of 6 adhering to it in varying degrees. At the logistic regression analysis smokers resulted to be affected by almost a double risk of getting away from the Mediterranean dietary pattern (OR = 1.93; CI 95% 1.44-2.57); on the contrary, those with a higher PCS12 (Physical Component Summary score) were in a lower risk to move away from the MD style (OR = 0.98; 95% CI = 0.96-0.99).

CONCLUSIONS

Despite its increasing popularity worldwide, adherence to the MD model is decreasing. The new generation of young people does not adhere to the MD pattern although they live in the lands characterized by the tradition and culture of healthy diet and where the benefits from this pattern were initially discovered. Interventions and specific education about the healthy diet may be useful to recover student's dietary patterns as in the old eating tradition.

Human Gastric Epithelium Produces IL-4 and IL-4δ2 Isoform Only upon Helicobacter Pylori Infection

Recent evidence suggests that interleukin-4 (IL-4) is related to mucosal tolerance by which an injurious immune response is prevented, suppressed or shifted to a non-injurious response. We investigated the expression of IL-4 and its splice variant isoform IL-4δ2 in gastric epithelial cells of healthy subjects and gastritis patients infected with Helicobacter pylori (H. pylori) with or without the cag pathogenicity island ( cag-PAI). IL-4 and IL-4δ2 mRNAs were evaluated in microdissected gastric epithelium and in AGS cell lines co-cultured with H. pylori B128 or SSI strains. IL-4 mRNA was consistently detected in microdissected gastric epithelial cells from healthy subjects. The IL-4 mRNA expression was low in H. pylori-infected patients, and markedly reduced in cag-PAI-positive ones. IL-4δ2 mRNA was expressed on gastric epithelium of H. pylori-infected patients, but not in healthy subjects. The IL-452 expression was lower in cag-PAI-positive than in cag-PAI-negative H. pylori infected patients. AGS cells also produced IL-4 mRNA upon SSI strain stimulation, whereas IL-4δ2 mRNA expression was detected in AGS co-cultured with either SSI or B128 strains. An inverse correlation was documented between IL-4 and IL-482 mRNA expression by microdissected gastric epithelial cells and the score of gastritis. IL-4, but not IL-452, is expressed by gastric epithelium of healthy subjects, whereas IL-452 and lesser IL-4 mRNA are detectable in the gastric epithelium of H. pylori-infected patients. Data suggest that gastric epithelial cells might regulate the balance between tolerance and immune response by the fine tuning of IL-4 and IL-4δ2 expression.

Stimulation of TH1 Response by Helicobacter Pylori Neutrophil Activating Protein Decreases the Protective Role of IgE and Eosinophils in Experimental Trichinellosis

Th2 responses seem to play an important role in defence against Trichinella spiralis (Ts). The Neutrophil Activating Protein of Helicobacter pylori (HP-NAP), that induces IL-12, and IL-23 expression and shifts to Th1 allergen-specific Th2 cells in vitro was used as an anti-Th2 agent in BALB/c mice infected with T. spiralis. The muscle larvae (ML) burden was lower ( p < 0.02) in untreated infected animals than those infected treated with HP-NAP. In both groups there was an inverse relationship between ML burden of each animal and total IgE level (controls: r −0.617, p = 0.0013 and HP-NAP-treated: r −0.678, P = 0.0001) or eosinophil count, evaluated in the same mouse on day 42 (r −0.390, P = 0.0592 and r −0.803, P = 0.0001, respectively). Inflammatory response around the nurse cell-parasite complex was significantly higher in HP-NAP-treated infected animals than in those untreated infected, on the contrary the number of eosinophils, counted around each complex was significantly lower in the first animal group. This study provides evidence of a powerful anti-Th2 activity in vivo by HP-NAP and for the partial protective effect of Th2 responses in T. spiralis infection.

Moraxella catarrhalis-specific Th1 cells in BAL fluids of chronic obstructive pulmonary disease patients

In chronic obstructive pulmonary disease (COPD) patients airway mucosa is infiltrated by macrophages and T lymphocytes, potentially reactive to pathogens. We studied the antigen-specificity and the effector functions of in vivo activated T lymphocytes isolated from BAL (Bronchoalveolar lavage) of 5 Moraxella catarrhalis (Mc)-infected and 5 Mc-non-infected COPD patients. Mc-specific T cells were detected only in BAL or peripheral blood of Moraxella catarrhalis-infected patients. The majority of BAL Mc-specific T cells expressed the T helper type 1 (Th1) cytokine profile with high cytotoxic and pro-apoptotic activity. Upon antigen stimulation, all Mc-specific T clones were able to help the immunoglobulin production by autologous B cells and the MMP (Matrix MetalloProteinase)-12 activity by monocytes. Our results suggest a role for Th1-driven response to Moraxella catarrhalis in the genesis of COPD.

Mutations in TAZ/WWTR1, a co-activator of NKX2.1 and PAX8 are not a frequent cause of thyroid dysgenesis

AIM

In 80-85% of cases, congenital hypothyroidism is associated with thyroid dysgenesis (TD), but only in a small percentage of cases mutations in thyroid transcription factors (NKX2.1, PAX8, FOXE1, and NKX2.5) have been associated with the disease. Several studies demonstrated that the activity of the transcription factors can be modulated by the interaction with other proteins, such as coactivators and co-repressors, and TAZ (transcriptional co-activator with PDZ-binding motif or WWTR1) is a co-activator interacting with both NKX2.1 and PAX8. In the present study we investigate the role of TAZ in the pathogenesis of TD.

MATERIAL AND METHODS

By Single Stranded Conformational Polymorphism, we screened the entire TAZ coding sequence for mutations in 96 patients with TD and in 96 normal controls.

RESULTS

No mutations were found in patients and controls, but we found several polymorphisms in both groups. No significant differences could be demonstrated in the prevalence of the mutations between patients and controls.

CONCLUSIONS

Our data indicate that TAZ mutations are not a cause of TD in the series of patients studied.

Plant-derived recombinant F1, V, and F1-V fusion antigens of Yersinia pestis activate human cells of the innate and adaptive immune system

Plague is still endemic in different regions of the world. Current vaccines raise concern for their side effects and limited protection, highlighting the need for an efficacious and rapidly producible vaccine. F1 and V antigens of Yersinia pestis, and F1-V fusion protein produced in Nicotiana benthamiana administered to guinea pigs resulted in immunity and protection against an aerosol challenge of virulent Y. pestis. We examined the effects of plant-derived F1, V, and F1-V on human cells of the innate immunity. F1, V, and F1-V proteins engaged TLR2 signalling and activated IL-6 and CXCL-8 production by monocytes, without affecting the expression of TNF-alpha, IL-12, IL-10, IL-1beta, and CXCL10. Native F1 antigen and recombinant plant-derived F1 (rF1) and rF1-V all induced similar specific T-cell responses, as shown by their recognition by T-cells from subjects who recovered from Y. pestis infection. Native F1 and rF1 were equally well recognized by serum antibodies of Y. pestis-primed donors, whereas serological reactivity to rF1-V hybrid was lower, and that to rV was virtually absent. In conclusion, plant-derived F1, V, and F1-V antigens are weakly reactogenic for human monocytes and elicit cell-mediated and humoral responses similar to those raised by Y. pestis infection.

The complexity of the CD4 T-cell responses: old and new T-cell subsets

The T-cell compartment of the immune system reacts to an enormous variety of antigens, including self antigens, due to its a wide repertoire of T-cell clones. Self-reactive T cells undergo a negative selection process resulting in apoptosis of T cells with high affinity for self-peptides. Self-reactive T cells escaped to negative selection are then controlled by natural T regulatory (Treg) cells. Regulation also controls excessive effector T-cell responses. Three types of effector T cells are recognized: T helper 1 (Th1) cells, which protect against intracellular bacteria; Th2 cells, which play a role against parasites; Th17 cells, which would face extracellular bacteria, but also are involved in autoimmunity. Effector T-cell polarization is determined by the complex interaction of antigen-presenting cells with naive T cells and involves a multitude of factors, including the dominant cytokine environment, costimulatory molecules, type and load of antigen presented and signaling cascades. The decision for the immune response to go in a certain direction is based not onto one signal alone, rather onto many different elements acting synergistically, antagonistically and through feedback loops leading to activation of Th1, Th2, or Th17 responses. Both Th1 and Th2 can be suppressed by adaptive Treg cells through contact-dependent mechanisms and/or cytokines.

Serological markers of pulmonary tuberculosis and of response to anti-tuberculosis treatment in a patient population in Guinea

The aim of the study was to evaluate serological correlates of active tuberculosis and of response to antituberculosis treatment in a cohort of HIV-negative patients with pulmonary tuberculosis studied at diagnosis and during treatment at the Service de Pneumo-Phtisiologie, Centre Hospitalier-Universitaire Ignace Deen, Conakry, Republic of Guinea. Two similar cohorts of HIV-negative healthy households of patients and healthy community controls were included in the study. Plasma samples were obtained from 168 untreated tuberculosis patients, 167 healthy household controls, and 168 healthy community controls. Serial plasma samples were also obtained from the tuberculosis patients at 2 and 8 months after initiation of chemotherapy. IgG antibody levels were measured by an enzyme-linked immunosorbent assay (ELISA) using ten purified M. tuberculosis antigens. ELISA results were analysed by comparing geometric means of data. Of the ten antigens tested, five (14kDa Ag, 19kDa Ag, AlaDH, MS, and MPT83) elicited similar antibody responses in untreated TB patients and controls. In contrast, levels of three antibodies (ESAT-6, LAM, and 38kDa Ag) were higher in untreated TB patients than in household or community controls (p<0.0001). Levels were higher in untreated patients than in community controls also for the anti-Rv2626c antibody (p = 0.0001) and, at a lower significance level, for the anti-FdxA antibody (p<0.025). Antibody levels against ESAT-6 and Rv2626c decreased during therapy, while antibody levels to the 38 kDa antigen and LAM increased during therapy; FdxA antibody levels did not vary with treatment. Neither severity of presentation nor chest X-ray patterns affected levels of these antibodies before treatment. In contrast, after the 8-month therapeutic course, patients who presented with moderate/severe disease had higher levels of anti-ESAT-6, anti-FdxA, and anti-38kDa antibodies than those of patients with mild disease onset. Patients with bilateral lung lesions had significantly higher anti-38kDa and anti-LAM levels, both at diagnosis and after 8-month treatment, than patients with lesions involving only one lung. Antibodies to alanine dehydrogenase and malate synthetase measured at initiation of treatment were higher in tuberculosis patients who subsequently failed therapy than in those who were cured. The main conclusions of the study are: a) plasma levels of antibodies to a number of M. tuberculosis represent serological correlates of active disease; b) these correlates are affected in an antigen-specific fashion by anti-tuberculosis treatment; c) particular serological markers may be predictive of treatment outcome.

Soluble CD30 and lymphocyte activation gene-3 (CD223), as potential serological markers of T helper-type cytokine response induced by acellular pertussis vaccine

T cell responses are involved in vaccine-induced immunity to pertussis but no easy-to-monitor, serological markers are available to assess these responses. The lymphocyte activation gene-3 (CD223) molecule is present on, and released by, activated T helper (Th) 1 cells, whereas CD30 molecules have been associated with Th2 immune responses. Starting from the recent knowledge of the cytokine profile induced by pertussis vaccination, we examined the levels of soluble (s)CD223 and sCD30 proteins in child recipients of acellular pertussis (aP) and diphtheria-tetanus (DT) vaccines and in children receiving DT vaccine only, as control. The correlation of the two proteins with specific antibody and T cell responses was assessed. The main findings are: i) sCD223 and sCD30 levels are inversely related, suggesting that the two markers are the expression of different and counter-regulated T-cell responses; ii) sCD30 level correlated with induction of T cell proliferation to pertussis vaccine antigens and antibody response to pertussis toxin. Overall, sCD30 and sCD223 levels seem to be promising candidate markers to assess the induction of Th-type responses in vaccine recipients.

Investigation of environmental and host-related risk factors for tuberculosis in Africa. II. Investigation of host genetic factors

In an accompanying paper (Am. J. Epidemiol. 2002;155:1066-73), the authors describe the design of a large multicenter study being carried out in three West African countries for investigation of the roles of environmental and host-related factors in the development of tuberculosis. In this paper, the authors review some evidence that host genetic factors play a role in susceptibility to tuberculosis. They describe the three components of the study that are designed to investigate the effect of host genetic factors on the development of tuberculosis: case-control and family-based association studies of candidate genes and analysis of affected relative pairs to screen the human genome for areas of linkage to the disease. The authors also address a number of methodological issues that arise, such as the effects of consanguinity, half-siblings, and nonpaternity. Lastly, they review opportunities to assess gene-environment interaction in the framework of the study, in light of current methodological knowledge. Consideration of these issues may be useful in the design of other studies of genetic susceptibility to infectious diseases, particularly those to be carried out in developing countries.

Investigation of environmental and host-related risk factors for tuberculosis in Africa. I. Methodological aspects of a combined design

Host-related and environmental factors for tuberculosis have usually been investigated separately using different study designs. Joint investigation of the genetic, immunologic, and environmental factors at play in susceptibility to tuberculosis represents an innovative goal for obtaining a better understanding of the pathogenesis of the disease. In this paper, the authors describe methods being used to investigate these points in a West African study combining several designs. Patients with newly diagnosed smear-positive cases of tuberculosis are recruited. The effect of host-related factors is assessed by comparing each case with a healthy control from the case's household. The role of environmental factors is estimated by comparing cases with randomly selected community controls. The frequencies of candidate gene variants are compared between cases and community controls, and results are validated through family-based association studies. Members of the households of cases and community controls are being followed prospectively to determine the incidence of "secondary" tuberculosis and to evaluate the influence of geographic and genetic proximity to the index case. This type of design raises important methodological issues that may be useful to consider in studies investigating the natural history of infectious diseases and in attempts to disentangle the effects of environmental and genetic factors in response to infection.

Atopy, intestinal helminth infection and total serum IgE in rural and urban adult Gambian communities

BACKGROUND

The rarity of atopy in traditional societies has been attributed to high parasite-driven blocking IgE concentrations. Information is lacking on the relationship between atopy, IgE and intestinal helminth infection in African populations.

OBJECTIVE

To determine the prevalence of atopy and intestinal helminth infection and to relate these to wheeze history and serum total IgE in a community sample of adults from an urban (Banjul) and a rural (Farafenni) area of the Gambia.

METHODS

Six hundred and ninety-three adults were interviewed about respiratory symptoms using a modified version of the IUTLD questionnaire, and had skin prick testing using four allergens. Stools were examined after formol-ether concentration. Total serum IgE concentration was measured in a subset of participants.

RESULTS

The prevalence of atopy (mean weal diameter > or = 3 mm) in the urban and rural area was 35.3% and 22.5% (P = 0.05); D. pteronyssinus and Mold mix being the common sensitizing allergens. Prevalence of wheeze in the previous 12 months was 4.4% and 3.5% for the urban and rural areas, respectively. Wheezing was not significantly associated with atopy. Seventeen per cent of urban and 8.2% of rural subjects had helminths detected in stools. There was an inverse association between atopy and intestinal helminth infection; 7% of atopic subjects had helminths, compared to 13% of non-atopic subjects (unadjusted odds ratio 0.51, 95%CI 0.24-1.1, P = 0.09; adjusted odds ratio 0.37, 95%CI 0.15-0.92, P = 0.03). Non-atopics had total serum IgE concentrations about 2.5 times the upper limit of the reference range in non-atopic Western populations. Geometric mean total serum IgE concentration was significantly higher among atopic subjects (570 IU/mL, IQR 91-833) than non-atopic subjects (259 IU/mL, IQR 274-1303) (P < 0.001). IgE concentration was not associated with the presence of helminth infection.

CONCLUSION

Further studies are needed to clarify why asthma is still relatively uncommon in spite of the prevalence of atopy in Gambian adults. Our data are also compatible with the idea that atopy might protect against helminth infection.

Preferential Th1 profile of T helper cell responses in X-linked (Bruton's) agammaglobulinemia

X-linked agammaglobulinemia (XLA) is a primary immunodeficiency of the B-cell compartment caused by a defective gene encoding for the tyrosine kinase (btk) essential for B cell differentiation. Affected males undergo recurrent pyogenic infections and deficient immunoglobulin production. Peripheral blood T cells from 6 XLA patients and 6 matched healthy controls were stimulated with either PHA or tetanus toxoid (TT) and T cell clones obtained were compared for their cytokine profile. In the series of PHA-induced or TT-specific CD4(+) T cell clones derived from XLA patients, the Th1 profile was predominant (63 and 65 %, respectively). Upon stimulation with TT, the proportion of activated T cells from XLA that expressed the IFN-gamma -associated LAG-3 activation molecule was higher than in control T cells (51 vs. 25 %), whereas the expression of the IL-4-associated CD30 molecule was lower (5 vs. 21 %). In a cohort of 31 XLA patients, plasma levels of soluble (s)LAG-3 and sCD30, chosen as indirect indicators of the Th1 / Th2 activity in vivo, were significantly higher and lower, respectively, than those measured in 31 healthy controls. Likewise, plasma levels of interferon-inducible protein 10 and of macrophage-derived chemokine in XLA patients were significantly higher and lower, respectively, than in healthy controls.

Neonatal bacillus Calmette-Guérin vaccination induces adult-like IFN-gamma production by CD4+ T lymphocytes

The immaturity of the neonatal immune system in mice is associated with defective IFN-gamma production and Th2-biased immune responses. In this study, infants vaccinated at birth with BCG produced similar concentrations of IFN-gamma in response to PPD and showed similar frequencies of IFN-gamma-producing lymphocytes as compared to immune adults. Infants and adults produced only low concentrations of IL-4 and IL-5. CD4+ T lymphocytes were the main source of IFN-gamma. Similar proportions of Th1 and Th0 PPD-specific T cell clones were observed in infants and adults. This study demonstrates that the human neonatal immune response to BCG is not biased towards Th2 and is characterized by the predominant production of IFN-gamma by CD4+ T lymphocytes.

Polarization of PPD-specific T-cell response of patients with tuberculosis from Th0 to Th1 profile after successful antimycobacterial therapy or in vitro conditioning with interferon-alpha or interleukin-12

The T helper (Th) 1/Th2 balance in the T-lymphocyte response to purified protein derivative (PPD) was evaluated at the clonal level in six Italian and five Gambian patients with pulmonary tuberculosis (TB) before and after antimycobacterial therapy, as well as in five Gambian and four Italian healthy immune control subjects. In untreated patients, most PPD-specific clones derived from either peripheral blood or pleural effusions showed a Th0 cytokine profile (production of both interferon [IFN]-gamma and interleukin [IL]-4/IL-5). After 6 mo of therapy and clinical healing, most PPD-specific clones showed a polarized Th1 profile (production of IFN-gamma but not IL-4/IL-5) in both Italian and Gambian patients. The Th1 polarization was less marked in Gambian than in Italian patients and failed to occur in another group of four Italian patients who experienced treatment failure. The cytokine profile observed after successful therapy in patients with TB was similar to that found in healthy control subjects. T-cell clones of undefined specificity generated from PPD-stimulated cultures showed a similar Th0/Th2 bias in Gambian individuals and Italian patients with treatment failure. The Th0/Th2-biased responses in Gambian patients before therapy could be modulated in vitro by IFN-alpha or IL-12, which induced a Th1 polarization of both PPD-specific and bystander T cells. Our data show that active TB associates with a predominant Th0 response to mycobacterial antigens that could play a role in the pathogenesis of the disease. Adjunctive immunotherapy using Th1-polarizing cytokines could increase host defense against mycobacteria and accelerate healing.

H(+),K(+)-atpase (proton pump) is the target autoantigen of Th1-type cytotoxic T cells in autoimmune gastritis

BACKGROUND & AIMS

The proton pump H(+),K(+)-adenosine triphosphatase (H(+),K(+)-ATPase) of parietal cells is the major humoral autoantigen in both human and experimental autoimmune gastritis (AIG) characterized by an inflammatory infiltrate in the gastric mucosa and loss of parietal cells. The aim of this study was to detect H(+),K(+)-ATPase-specific T cells in the gastric mucosa of patients with AIG and to define their functional properties.

METHODS

In vivo-activated T cells from the infiltrates of the gastric mucosa of 5 patients with AIG were isolated and cloned. The ability of gastric T-cell clones to proliferate and to produce cytokines in response to H(+),K(+)-ATPase, as well as their expression of B-cell help, perforin-mediated cytotoxicity, and Fas-Fas ligand-mediated apoptosis in target cells, were assessed.

RESULTS

A proportion (25%) of the CD4(+) clones from the gastric corpus of AIG patients proliferated in response to porcine H(+),K(+)-ATPase. Most of these clones (88%) showed a Th1 profile, whereas a few secreted both Th1 and Th2 cytokines. Virtually all of the H(+),K(+)-ATPase-specific clones produced tumor necrosis factor alpha and provided substantial help for B-cell immunoglobulin production, and most of them expressed perforin-mediated cytotoxicity against antigen-presenting cells and induced Fas-Fas ligand-mediated apoptosis in target cells.

CONCLUSIONS

Activation of proton pump-specific Th1 cytotoxic/proapoptotic T cells in the gastric mucosa can represent an effector mechanism for the target cell destruction in AIG.

Defective recruitment and activation of ZAP-70 in common variable immunodeficiency patients with T cell defects

We have previously identified a subset of common variable immunodeficiency (CVID) patients with defective T cell function associated with impaired activation of the TCR-dependent tyrosine phosphorylation cascade. Here we have assessed the structural and functional integrity of the principal components involved in coupling the TCR/CD3 complex to intracellular tyrosine kinases in two of these patients. We show that ZAP-70 fails to bind the signaling-competent CD3zeta tyrosine phosphorylation isoform and to become activated following TCR engagement, suggesting that defective recruitment of ZAP-70 might underlie the TCR signaling dysfunction in these patients. Determination of the nucleotide sequences encoding the intracellular domains of the CD3/zeta subunits and ZAP-70 did not reveal any mutation. Furthermore, ZAP-70 from these patients could interact in vitro with recombinant phospho-zeta, ruling out genetic defects at the immunoreceptor tyrosine-based activation motif/SH2 domain interface responsible for ZAP-70 recruitment to the activated TCR. No defect was found in expression, activity or subcellular localization of Lck, which is thought to be primarily responsible for CD3zeta phosphorylation. Hence, while the T cell defect in these CVID patients can be pinpointed to the interaction between ZAP-70 and CD3zeta, the integrity in the components of the signaling machinery involved in this process suggests that additional components might be required for completion of this step.

[Dilated thyrotoxic cardiomyopathy]

We report a case of reversible, dilated cardiomyopathy due to thyrotoxicosis, which occurred in a young male without any underlying heart disease. The patient presented a clinical picture of cardiogenic shock related to severe left ventricular dilation and dysfunction and with new-onset atrial fibrillation and very high ventricular rate. In spite of vigorous medical therapy, there was only a mild improvement of clinical and hemodynamic status and ventricular rate persisted inappropriately elevated. Subsequently, laboratory test results allowed for recognition of thyrotoxicosis (secondary to Graves's disease) and then specific thyrostatic treatment was added. There was a prompt clinical improvement and parallel, progressive reversal of left ventricular dysfunction. The patient could be converted to normal sinus rhythm and one week later was discharged in good condition. We discuss the pathophysiological mechanism for the induction of this rare form of thyrotoxic cardiomyopathy and emphasize that awareness of this possible presentation of hyperthyroidism is essential to identify patients with potentially reversible dilated cardiomyopathy.

[Reconstruction of the aortic root: midterm results]

BACKGROUND

The aim of this study was to assess mid-term results of aortic reconstruction.

METHODS

According to Dr. David's technique, 20 patients (17 males, 3 females, median age 63 years) were examined, who underwent surgery between September 1996 and August 1999. Indications for operation were aortic insufficiency with ascending aorta aneurysm in 19 patients, and acute Stanford type A dissection in 1 patient. In every patient the native valve was preserved and suspended inside a tubular prosthesis on which the coronaries were reimplanted.

RESULTS

No patient died in hospital. Follow-up (mean 13 months) was complete for all patients. One patient died of extracardiac causes. Seventeen of 19 survivors are in NYHA functional class I, the remaining 2 in class II. Nineteen patients underwent echocardiography which showed moderate aortic regurgitation in 1, mild in 6 and absent or trivial in 12. There were no instances of thromboembolism.

CONCLUSIONS

These results are encouraging and have brought us to consider aortic reconstruction a valid alternative to traditional aortic root replacement. Dr. David's technique is reproducible and reliable in the long term.

Usefulness of (13)C-urea breath test in the diagnosis of gastric helicobacter pylori infection

Helicobacter pylori chronically infects half of the human population and is associated with gastritis, peptic ulcer and gastric cancer. (13)C-urea breath test (UBT) is the main in vivo tool for the diagnosis of H. pylori infection. In this study, the safety and the accuracy of UBT were evaluated. A group of 492 dyspeptic patients was studied by UBT, the results were expressed as the difference over baseline at 30 min (DOB30). All patients were evaluated for systemic, gastrointestinal or allergic-type adverse reactions after ingestion of 75 mg (13)C-urea and citric acid in aqueous solution. The first 256 patients enrolled also underwent endoscopy and gastric biopsy. Patients positive on histology were considered infected. UBT was well tolerated and none of the 492 patients had any systemic or allergic-type adverse reaction. Among the 256 patients studied with histology, 116 were H. pylori positive on biopsies. Using 4 %o as cut-off value for DOB30,115 out of the 256 patients were positive on UBT, with only 2 false positive and 3 false negative. With this threshold, the sensitivity, specificity, and accuracy of the UBT were 97.4%, 98.5%, and 98.0%, respectively. (13)C-UBT has proven to be a safe and simple, yet accurate, test for the non-invasive diagnosis and monitoring of H. pylori infection.

Impaired T-cell regulation of B-cell growth in Helicobacter pylori--related gastric low-grade MALT lymphoma

BACKGROUND & AIMS

Neoplastic B cells of the Helicobacter pylori-related low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma are responsive to T helper cells and sensitive to withdrawal of H. pylori-induced T-cell help.

METHODS

The clonal progeny of T cells from the gastric mucosa of 5 patients with MALT lymphoma was compared with that of T-cell clones obtained from 5 H. pylori-infected patients with chronic gastritis.

RESULTS

T-cell clones were assessed for specificity to H. pylori, cytokine profile, help for B-cell proliferation, and perforin- or Fas-mediated cytotoxic regulation of B-cell growth. Twenty-eight of 165 CD4(+) gastric clones from MALT lymphoma and 33 of 178 CD4(+) clones from chronic gastritis recognized H. pylori antigens. Cytokine production was similar in the 2 series of clones. All MALT lymphoma-derived clones dose-dependently increased their B-cell help, whereas clones from chronic gastritis lost helper activity at T-to-B-cell ratios greater than 1 because of concomitant cytolytic killing of B cells. T-cell clones from MALT lymphoma had both reduced perforin-mediated cytotoxicity and poor ability to induce Fas-mediated apoptosis. These defects were limited to gastric T cells.

CONCLUSIONS

H. pylori-induced T cell-dependent B-cell activation and deficient cytotoxic control of B-cell growth may link H. pylori infection, local T-cell response, and genesis of low-grade gastric MALT lymphoma.

Phenotype and cytokine profile of Schistosoma mansoni specific T cell lines and clones derived from schistosomiasis patients with distinct clinical forms

It is essential to distinguish the role of T lymphocytes on the physiopathology associated to more severe forms of schistosomiasis and on the immunomodulation that evolves in the majority of infected people. In this study, we generated Schistosoma mansoni-specific T cell lines and clones from patients with the acute and chronic (intestinal and hepatosplenic forms) phases of disease, from former ones, and from uninfected individuals sensitized to parasite soluble antigens. T cell lines derived from nontreated acute infected donors were capable of producing IL-4 and IL-5, while cells from treated patients secreted IFN-gamma. Lines from intestinal chronic and antigen-sensitized donors preferentially produced IFN-gamma, while those from hepatosplenic patients secreted all three cytokines. The cytokine analysis of CD4+ T cell clones revealed a Th2/Th0 pattern (clones producing IL-4 and IL-5 and clones producing all three cytokines) for those derived from infected patients, while cells from antigen-sensitized donors exhibited an opposite Th1/Th0 pattern (clones producing IFN-gamma and clones producing all three cytokines). The possible role of these T cell populations on human schistosomiasis mansoni is discussed.

Defective Th1 and Th2 cytokine synthesis in the T-T cell presentation model for lack of CD40/CD40 ligand interaction

In this study, T or NK cell clones used as antigen-presenting cells (T- or NK-APC) were shown to be significantly less efficient than professional APC in inducing Th1 and Th2 cytokines by antigen-specific T cell clones. This phenomenon was not related to a limited engagement of TCR by T-APC, since comparable thresholds of TCR down-regulation were shown when antigen was presented by either T-APC or professional APC. Rather, the stimulatory T-APC weakness was due to their inability, because they are CD40-, to provide the appropriate co-stimuli to responder T cells both indirectly via IL-12, and partially via direct CD40L triggering on T cells. Indeed, the simultaneous addition of IL-12 and reagents directly engaging CD40L on responder T cells restored T cell cytokine synthesis when antigen was presented by T-APC. In addition, either IL-12 production or blocking of T cell cytokine synthesis by anti-IL-12 p75 antibodies was evident only when professional APC were used in our antigen-specific system. The down-regulation of cytokine synthesis in the system of T-T cell presentation could represent a novel mechanism of immune regulation, which may intervene to switch off detrimental Th1- or Th2-mediated responses induced by antigen presentation among activated T cells infiltrating inflamed tissues.

Human Th1 and Th2 T-cell clones are equally susceptible to infection and immortalization by human T-lymphotropic virus type I

Human CD4+ Th1 and Th2 clones were infected with human T-lymphotropic virus type I (HTLV-I) and followed up for a 12 month period in culture. PCR analysis showed that proviral DNA and viral mRNA were present in both Th1 and Th2 infected clones, throughout the entire culture period. Thus, HTLV-I exhibited neither preferential tropism nor exerted differential immortalizing activity in Th1 versus Th2 cells. All the infected clones immediately lost their antigen dependency for growth and continuously proliferated in IL-2-conditioned medium without need for additional stimulation. Infected Th1 and Th2 clones equally showed high expression of CD25, HLA-DR, CD44, CD30 and CD45RO. Infection with HTLV-I altered the cytokine profile in Th1 and Th2 clones. Both types of clones produced IL-6 and TNF-alpha. Th1 infected clones retained their ability to secrete IFN-gamma, but lost IL-2 gene expression. Th2 infected clones lost IL-4 gene expression, retained the ability to produce small amounts of IL-5 and acquired IFN-gamma expression.

Expression of the T-cell-specific tyrosine kinase Lck in normal B-1 cells and in chronic lymphocytic leukemia B cells

Src family kinases play a key role in mitogenesis. The exquisitely tissue-specific distribution of different Src family members suggests that a fine tuning of their expression might be a key prerequisite for cell homeostasis. We tested B cells from patients affected by B-cell chronic lymphocytic leukemia (B-CLL) for expression of Src family kinases. The T-cell-specific tyrosine kinase Lck was found to be expressed at significant levels in CLL B-cells. This finding could be accounted for either by ectopic expression of Lck in B-CLL or by specific expression of this kinase in normal B-1 cells, which are believed to be the normal counterpart of CLL B cells. To answer this question B cells from different sources, characterized by a different size of the B-1 subpopulation, were tested for Lck expression. The results show that Lck expression is a feature of CD5(+), B-1 cells, suggesting a potential role for Lck in the self-renewal capacity of this B-cell subpopulation and supporting the notion that B-1 cells are the subset undergoing oncogenic transformation in B-CLL. Furthermore, we show that the CD5(-), B-2 subpopulation, while normally lacking Lck expression, acquires the capacity to express Lck ectopically upon transformation by EBV.

The concept of type-1 and type-2 helper T cells and their cytokines in humans

In both mice and humans, functionally distinct helper T (Th)-cell subsets, known as Th1 and Th2 cells, are characterized by the patterns of cytokines they produce. These two polarized forms of the specific cellular immune response provide a useful model for explaining not only the different types of protection, but also the pathogenic mechanisms of several immunopathological disorders. The development of polarized Th1 or Th2 responses depends on either environmental factors, including dose of antigen, nature of immunogen and cytokines (IL-12 and interferons or IL-4) at the time of antigen presentation, or other undefined factors in the individual genetic background, mainly at level of the so-called "natural immunity". Th1-dominated responses are potentially effective in eradicating infectious agents, including those hidden within the host cells. When the Th1 response is poorly effective or exhaustively prolonged, it may result in host damage. In contrast, Th2 responses are apparently insufficient to protect against the majority of infectious agents, but can provide some protection against parasites. Th2 cells are able to make unpleasant the life of parasites in the host and tend to limit potentially harmful Th1-mediated responses. Thus, Th2 cells may be regarded as a part of down regulatory (or suppressor) mechanism for exaggerated and/ or inappropriate Th1 responses. The Th1/Th2 paradigm applied to the study of chronic inflammatory disorders or autoimmune diseases allowed to understand that a number of diseases are mediated by Th1 cells, the two clearest examples being multiple sclerosis and thyroid autoimmunity. In other disorders, Th1/Th2 polarization is less prominent, or rather Th2 responses tend to predominate, such as in systemic lupus erythematosus, progressive systemic sclerosis or allergic diseases. It is of note that in experimental models in animals, a number of diseases can be prevented by switching immune responses from Th1 to Th2 or from Th2 to Th1. Moreover, the Th1/Th2 concept suggests that modulation of the relative contribution of Th1- or Th2-type cytokines makes possible to regulate the balance between protection and immunopathology, as well as the development and/or the severity of some immunologic disorders.

Chondromalacia of the patella. Natural progression

A total of 42 cases of patellar pain in subjects aged an average of 17.2 years submitted to arthroscopy are analyzed. Femoropatellar balance, where indicated, led to resolution of disorders with full resumption of sports activity. In the remaining cases chondromalacia showed the features of an affection with a spontaneously favorable course, confirming the common orientation towards conservative treatment. Arthroscopy is effective for a correct classification of cartilaginous lesions, and it is a good instrument to use when attempting to achieve recovery of patellofemoral joint when disorders are caused by a lack of equilibrium.

Expression and role in apoptosis of the alpha- and beta-chains of the IFN-gamma receptor on human Th1 and Th2 clones

The mRNA and protein expression of the alpha- and beta-chains of IFN-gammaR were evaluated on a panel of human Th1 and Th2 clones. When cultured in IL-2-conditioned medium, both types of clones expressed mRNA for the alpha- and beta-chains, and both chains were present in the cytoplasm. Membrane expression of the alpha-chain was higher on Th2 than on Th1, whereas the beta-chain was poorly expressed on both types but increased following IL-2 withdrawal or PHA stimulation. In addition, both types of clones overexpressed MHC class I glycoproteins following IFN-gammaR triggering by exogenous IFN-gamma, although the kinetics was slower in Th1, and this exposure induced mRNA for IRF-1. When their TCR was triggered in the absence of APC, Th1 only underwent apoptosis. This activation-induced apoptosis was prevented by blocking of the alpha-chain or by IFN-gamma neutralization. Addition of IFN-gamma triggered the apoptosis of Th2 clones. Apoptosis of both types of clones was mediated by autocrine or exogenous IFN-gamma through the up-regulation of Fas-L expression, since anti-IFN-gammaR alpha mAb inhibited its expression on Th1 and exogenous IFN-gamma increased its expression on Th2. These results indicate that activated human Th1 and Th2 lymphocytes express IFN-gammaR alpha- and beta-chains and are both sensitive to signals provided by IFN-gamma. Data also suggest that IFN-gamma is critical for switching off their responses.

Different cytokine profile and antigen-specificity repertoire in Helicobacter pylori-specific T cell clones from the antrum of chronic gastritis patients with or without peptic ulcer

Helicobacter pylori (Hp) infection almost invariably results in chronic antral gastritis, but only a proportion of patients develop peptic ulcer. Some Hp strains may be more ulcerogenic than others, but some ulcerogenic mechanisms may also depend on the type of the host immune response. In this study, the antigen specificity and the cytokine profile of 53 Hp-specific CD4+ T cell clones derived from the antral mucosa of five patients with Hp-induced uncomplicated chronic gastritis (CG) were assessed and compared with those of 34 Hp-specific CD4+ T cell clones derived from six Hp-infected patients with chronic gastritis and peptic ulcer (CG-PU). The majority (28/34; 82%) of gastric Hp-specific T cell clones from CG-PU patients expressed the Th1 profile and 17 (all Th1) of the 34 clones were specific for cytotoxin-associated protein (CagA). In contrast, 34 (64%) of the 53 Hp-specific gastric T cell clones derived from CG patients were able to secrete both Th1 and Th2 cytokines (Th0 profile) and only 36% expressed a polarized Th1 profile. The majority (85%) of Hp-specific clones from CG patients recognized Hp antigens other than CagA, since 13/53 (25%) were specific for urease, 6 (11%) for VacA, 6 (11%) for HSP and 20 (38%) for other undefined Hp antigens. Results provide evidence that the type of T helper cell response against Hp may vary according to the antigen involved and suggest that a polarized Th1 response may play a role in the genesis of peptic ulcer, whereas a local Th0 response, including interleukin-4 production, may represent an individual host factor which contributes to lower the degree of gastric inflammation and prevent ulcer complication.

Uncoupling of T-cell antigen receptor and downstream protein tyrosine kinases in common variable immunodeficiency

Patients with common variable immunodeficiency (CVID) are heterogeneous in the clinical manifestations of the disease and the underlying mechanisms leading to the immunodeficiency. Although the overt defect is an impairment in B-cell function, there is increasing evidence of primary T-cell dysfunctions in a proportion of patients with CVID. We have analyzed T-cells from six CVID patients for activation of both early and late events in response to TCR triggering. The data showed that T-cells from three of six CVID patients were defective in the capacity to initiate the TCR/CD3 signaling pathway by activating intracellular tyrosine kinases, associated with impaired proliferative responses to TCR/CD3 triggering. Since both surface expression of the TCR/CD3 complex and intracellular expression of key tyrosine kinases such as p56lek and ZAP-70 were normal in these patients, our data suggest a defect in the earliest step of TCR signal transduction.

Expression and role in apoptosis of the alpha- and beta-chains of the IFN-gamma receptor on human Th1 and Th2 clones

The mRNA and protein expression of the alpha- and beta-chains of IFN-gammaR were evaluated on a panel of human Th1 and Th2 clones. When cultured in IL-2-conditioned medium, both types of clones expressed mRNA for the alpha- and beta-chains, and both chains were present in the cytoplasm. Membrane expression of the alpha-chain was higher on Th2 than on Th1, whereas the beta-chain was poorly expressed on both types but increased following IL-2 withdrawal or PHA stimulation. In addition, both types of clones overexpressed MHC class I glycoproteins following IFN-gammaR triggering by exogenous IFN-gamma, although the kinetics was slower in Th1, and this exposure induced mRNA for IRF-1. When their TCR was triggered in the absence of APC, Th1 only underwent apoptosis. This activation-induced apoptosis was prevented by blocking of the alpha-chain or by IFN-gamma neutralization. Addition of IFN-gamma triggered the apoptosis of Th2 clones. Apoptosis of both types of clones was mediated by autocrine or exogenous IFN-gamma through the up-regulation of Fas-L expression, since anti-IFN-gammaR alpha mAb inhibited its expression on Th1 and exogenous IFN-gamma increased its expression on Th2. These results indicate that activated human Th1 and Th2 lymphocytes express IFN-gammaR alpha- and beta-chains and are both sensitive to signals provided by IFN-gamma. Data also suggest that IFN-gamma is critical for switching off their responses.

Predominant T-helper 1 cytokine profile of hepatitis B virus nucleocapsid-specific T cells in acute self-limited hepatitis B

The cytokine pattern secreted by T cells on viral antigen recognition is believed to exert a profound influence on both the type of disease caused by the infecting agent and the final outcome of the viral infection. To characterize the cytokine pattern associated with spontaneous resolution of acute hepatitis B, we analyzed interferon gamma (IFN-gamma), interleukin (IL)-4, and IL-5 production by a wide series of hepatitis B virus (HBV) nucleocapsid-specific T-cell lines (34 lines) and T-cell clones (71 clones) derived from the peripheral blood of 13 patients during the acute or recovery phase of hepatitis B (2 and 7 of them were studied only in the recovery or the acute phase, respectively, and 4 during both). Most T-cell lines (67%) and clones (77%) isolated during the acute phase of infection expressed a T-helper (Th) 1 cytokine profile dominated by the production of IFN-gamma. A larger proportion (74%) of T-cell lines produced several years after resolution of hepatitis was able to secrete not only IFN-gamma, but also IL-4 and IL-5 (Th0-like cells). Results indicate that the antigen-specific fraction of peripheral blood T cells in acute self-limited hepatitis B selectively secrete Th1-type eytokines, suggesting that Th1-mediated effects may contribute not only to liver cell injury, but probably also to recovery from disease and successful control of infection.

T helper 1 effector cells specific for Helicobacter pylori in the gastric antrum of patients with peptic ulcer disease

Chronic antral gastritis following Helicobacter pylori (Hp) infection is characterized by a cellular inflammatory infiltrate whose cytokines may represent a host-dependent factor influencing the outcome of the infection. The pattern of cytokines produced by the immunologically active cells in the gastric antrum was analyzed at the mRNA level in antral biopsies from five Hp-infected patients with duodenal ulcer and three Hp-negative dyspeptic controls. T cell clones were generated from parallel antral biopsies of the same Hp-infected patients and assessed for reactivity to Hp Ags, cytokine profile, and effector functions. Antral biopsies from all Hp-infected patients showed IFN-gamma, TNF-alpha, and IL-12, but not IL-4, mRNA expression, whereas no cytokine mRNA signal was found in the mucosa of controls. A total of 24 out of the 163 CD4+ T cell clones (15%) derived from Hp-infected patients proliferated in response to a Hp lysate; 11 clones (46%) also reacted with Cag-A, 2 with Vac-A, and 1 with urease. Upon Ag stimulation, 20 out of the 24 Hp-reactive clones (83%) produced IFN-gamma, but not IL-4 or IL-5 (Th1-like), whereas 4 produced IFN-gamma, IL-4, and IL-5 (Th0-like). All Hp-specific clones secreted high levels of TNF-alpha. At low T:B cell ratio, Hp-specific clones expressed Ag-dependent helper function for B cell proliferation and Ig production, whereas at higher T:B cell ratios, 15 Th1 and 2 Th0 clones lysed Ag-pulsed autologous EBV-transformed B cells. Results provide evidence for Hp-specific Th1 effectors in the gastric antrum of Hp-infected patients, where they may play a role in the genesis of either peptic ulcer or Hp-associated gastric B cell lymphoma.

T helper 1 effector cells specific for Helicobacter pylori in the gastric antrum of patients with peptic ulcer disease

Chronic antral gastritis following Helicobacter pylori (Hp) infection is characterized by a cellular inflammatory infiltrate whose cytokines may represent a host-dependent factor influencing the outcome of the infection. The pattern of cytokines produced by the immunologically active cells in the gastric antrum was analyzed at the mRNA level in antral biopsies from five Hp-infected patients with duodenal ulcer and three Hp-negative dyspeptic controls. T cell clones were generated from parallel antral biopsies of the same Hp-infected patients and assessed for reactivity to Hp Ags, cytokine profile, and effector functions. Antral biopsies from all Hp-infected patients showed IFN-gamma, TNF-alpha, and IL-12, but not IL-4, mRNA expression, whereas no cytokine mRNA signal was found in the mucosa of controls. A total of 24 out of the 163 CD4+ T cell clones (15%) derived from Hp-infected patients proliferated in response to a Hp lysate; 11 clones (46%) also reacted with Cag-A, 2 with Vac-A, and 1 with urease. Upon Ag stimulation, 20 out of the 24 Hp-reactive clones (83%) produced IFN-gamma, but not IL-4 or IL-5 (Th1-like), whereas 4 produced IFN-gamma, IL-4, and IL-5 (Th0-like). All Hp-specific clones secreted high levels of TNF-alpha. At low T:B cell ratio, Hp-specific clones expressed Ag-dependent helper function for B cell proliferation and Ig production, whereas at higher T:B cell ratios, 15 Th1 and 2 Th0 clones lysed Ag-pulsed autologous EBV-transformed B cells. Results provide evidence for Hp-specific Th1 effectors in the gastric antrum of Hp-infected patients, where they may play a role in the genesis of either peptic ulcer or Hp-associated gastric B cell lymphoma.

Different cytokine profiles of intraphepatic T cells in chronic hepatitis B and hepatitis C virus infections

BACKGROUND & AIMS

The cytokine pattern secreted by T cells at the site of viral replication may influence the final outcome of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. The aim of this study was to assess whether a cytokine imbalance oriented toward T helper (Th) 1 or Th2-type responses may play a role in chronic hepatitis B or C.

METHODS

Production of interferon (IFN)-gamma, interleukin (IL)-4, and IL-5 by wide series of T-cell clones derived from the liver of 6 patients with chronic hepatitis B (291 clones) and 9 patients with chronic hepatitis C (260 clones) was studied. T-cell clones were generated by limiting dilution from freshly isolated mononuclear cells derived from liver tissue to give a reliable representation of the intrahepatic inflammatory infiltrates.

RESULTS

The majority of liver-infiltrating T cells in chronic hepatitis C were Th1 cells able to secrete IFN-gamma but unable to secrete IL-4 or IL-5, whereas in hepatitis B, most CD4+ and CD8+ liver T cells were ThO-like cells able to produce not only IFN-gamma but also IL-4 and IL-5.

CONCLUSIONS

The different cytokine profiles of T cells within the liver in chronic HBV and HCV infections illustrate a different behavior of the local immune response in these two infections that may have pathogenetic implications.

Immune mechanisms in the pathogenesis of inflammatory gastrointestinal disorders

The cytokine secretion profile of T cells present in the gastric antrum of Helicobacter pylori-infected patients with peptic ulcer and in the gut of patients with Crohn's disease was investigated. A type 1 T helper (Th1)-dominated response was detected in the gastric antrum of Helicobacter pylori-infected subjects with peptic ulcer by both reverse transcriptase-PCR and immunohistochemistry. By using a T-cell cloning technique, it was shown that the majority of Th 1 cells were specific for Hp antigens. A Th1 predominance, which associated with high IL-12 expression, was also found, at both clonal and immunohistochemical level, in the gut of patients with Crohn's disease. These findings suggest that the Th1/Th2 paradigm may be useful to explain the inflammatory reactions involved in the pathogenesis of some gastrointestinal disorders.

Long-lasting memory T cell responses following self-limited acute hepatitis B

The molecular and cellular basis of long-term T cell memory against viral antigens is still largely undefined. To characterize anti-viral protection by memory T cells against non-cytopathic viruses able to cause acute self-limited and chronic infections, such as the hepatitis B virus (HBV), we studied HLA class II restricted responses against HBV structural antigens in 17 patients with acute hepatitis B, during the acute stage of infection and 2.2 to 13 yr after clinical resolution of disease. Results indicate that: (a) significant T cell proliferative responses to HBV nucleocapsid antigens were detectable in all patients during the acute phase of infection and in 14/17 also 2-13 yr after clinical resolution of disease; b) long-lasting T cell responses were sustained by CD45RO+T cells, predominantly expressing the phenotype of recently activated cells; c) limiting dilution analysis showed that in some patients the frequency of HBV-specific T cells was comparable to that observed in the acute stage of infection and, usually, higher than in patients with chronic HBV infection; d) the same amino acid sequences were recognized by T cells in the acute and recovery phases of infection; and e) HBV-DNA was detectable by nested-PCR in approximately half of the subjects. to conclusion, our results show that vigorous anti-viral T cell responses are detectable in vitro several years after clinical recovery from acute hepatitis B. Detection of minute amounts of virus in some recovered subjects suggests that long-term maintenance of an active anti-viral T cell response could be important not only for protection against reinfection but also for keeping the persisting virus under tight control.

Airway eosinophilia and expression of interleukin-5 protein in asthma and in exacerbations of chronic bronchitis

BACKGROUND

An increased number of eosinophils in the bronchial mucosa has been demonstrated both in asthma and in exacerbations of chronic bronchitis.

OBJECTIVE

To investigate whether the airway eosinophilia present in asthma and in chronic bronchitis during exacerbations is associated with interleukin (IL)-5 protein expression in the bronchial mucosa.

METHODS

We obtained bronchial biopsies in 18 subjects with asthma (four intrinsic, seven extrinsic and seven occupational) and in 11 subjects with chronic bronchitis examined during an exacerbation. The findings were compared with those of bronchial biopsies from 10 subjects with chronic bronchitis examined under baseline conditions and from seven normal subjects, taken as controls. By immunohistochemistry, we assessed the expression of IL-5 protein and the number of eosinophils (EG2), mast cells (tryptase), and T-lymphocytes (CD3) in the submucosa.

RESULTS

As compared with controls, the number of eosinophils was increased to a similar degree in both asthma (P < 0.001) and in exacerbations of chronic bronchitis (P < 0.001), whereas the number of IL-5 immunopositive cells was increased significantly only in asthma (P < 0.01). No differences were observed in the number of mast cells and T-lymphocytes between the four groups of subjects examined.

CONCLUSIONS

This study shows that the degree of airway eosinophilia is similar in asthma and in exacerbations of chronic bronchitis, but only in asthma is it associated with an increased expression of IL-5 protein in the bronchial mucosa.

CKS knee prosthesis: biomechanics and clinical results in 42 cases

From 1991 to 1993 a total of 42 CKS prostheses were implanted for the following reasons: osteoarthrosis (34 cases), rheumatoid arthritis (7 cases) tibial necrosis (1 case). At follow-up obtained after 17 to 41 months the results were: excellent or good: 41; the only poor result was probably related to excessive tension of the posterior cruciate ligament. 94% of the patients reported complete regression of pain, 85% was capable of going up and down stairs without support. Mean joint flexion was 105 degrees. Radiologically the anatomical axis of the knee had a mean valgus of anatomical axis of the knee had a mean valgus of 6 degrees. The prosthetic components were always cemented. The posterior cruciate ligament was removed in 7 knees, so that the prosthesis with "posterior stability" was used. The patella was never prosthetized. One patient complained of peri-patellar pain two months after surgery which then regressed completely.

CD30 cell expression and abnormal soluble CD30 serum accumulation in Omenn's syndrome: evidence for a T helper 2-mediated condition

Omenn's syndrome (OS) is a severe immunodeficiency, characterized by clinical and laboratory features reminiscent of a T helper type-2 (Th2) response. CD30, a member of the tumor necrosis factor receptor superfamily, has been found to be preferentially expressed by human T cell clones exhibiting a Th2-line profile and function. We investigated whether there are derangement in CD30 expression in tissues, and/or abnormalities in soluble CD30 (sCD30) levels in the serum, or both, of three children with OS and one child with maternal engraftment and Omenn's-like syndrome (OLS). Large proportions of tissue-infiltrating T lymphocytes from all four patients expressed CD30, whereas in control tissues, including peripheral blood, CD30+ T lymphocytes were extremely few or absent. In addition, levels of sCD30 were abnormally increased in all patients' sera. T cell clones were generated from sorted CD30+ and CD30-peripheral blood T cells of the patient with OLS who showed unusually high numbers of circulating CD30+ T lymphocytes. Most CD4+ T cell clones derived from CD30+ cells showed a Th2-like cytokine profile, whereas the majority of clones generated from CD30-T cells were Th1. These findings support the hypothesis that Th2 cells are involved in the pathogenesis of OS. Moreover, they provide evidence that detection of CD30+ T cells in tissues, increased levels of sCD30 in biological fluids, or both, reflect the presence of immune responses characterized by prevalent activation of T cells producing Th2 cytokines.