Marfan syndrome and aortic involvement: a narrative review

Marfan syndrome (MFS) is a systemic connective tissue disease that commonly and most severely affects the ocular, skeletal, and cardiovascular systems. The aim of the manuscript is to review the aortic involvement and complications in MFS, including aortal dissection, thoracic aortic aneurysm, abdominal aortic aneurysm, and acute aortic syndrome. Dissecting thoracic aortic aneurysm and progressing aortic root enlargement are the major causes of MFS morbidity and mortality. Guidelines on aortic disease endorsed by the American College of Cardiology, and the American Heart Association recommend the measurement of the external and internal aortic diameters perpendicular to the axis of blood flow when Computed Tomography, or Magnetic Resonance Imaging, or Cardiac Echography are performed. The pathophysiology, diagnosis, prevention, and medical and surgical treatments of MFS associated with aortic complications are reported in this narrative review. Development and strengthening of centers specialized in cardiovascular diseases and MFS, together with an improvement in the knowledge of its pathogenesis through genetics and proteomics investigations, can ameliorate the prognosis of this disease.

New York Heart Association class and pulmonary artery pressure as prognostic factors of interstitial lung disease survival

OBJECTIVE

The aim of this study was to evaluate New York Heart Association (NYHA) class and systolic pulmonary artery pressure (sPAP) as survival predictors in major interstitial lung diseases (ILD) including idiopathic pulmonary fibrosis (IPF), non-specific interstitial pneumonia (NSIP) and hypersensitivity pneumonitis (HP) and in other ILD like granulomatosis with polyangiitis (GPA).

PATIENTS AND METHODS

We analyzed survival, NYHA class, sPAP, and Octreoscan uptake index (UI) in 104 ILD patients (59 IPF, 19 NSIP, 10 HP and 16 GPA; median age 60.5 years) all referred to a single centre.

RESULTS

Median survival was 68 months, with 1- and 2-year survival of 91% and 78%, respectively. Survival was lower among IPF and NSIP vs. HP and GPA patients (p=0.01). NYHA class 3-4 was more frequent among IPF (76.3%) vs. NSIP patients (31.6%; p<0.001). HP and GPA had NYHA class 1-2. NYHA class was negatively associated with survival (class 1=90.3 months vs. class 3=18.3 months and class 4=5.1 months; p=0.001). sPAP was >55 mmHg in 76.3% of patients with IPF and 35-55 mmHg in 63.2% of patients with NSIP. Patients with HP and GPA had sPAP < 55 mmHg. Among patients with IPF, NYHA and sPAP were negatively associated with survival (p<0.01) both showed a parallel trend. High-resolution computed tomography and survival were worse among IPF and NSIP vs. HP and GPA patients (p<0.001). Octreoscan UI was <10, 10-12, and >12 in IPF, NSIP, HP and GPA, respectively. Octreoscan UI was negatively associated with survival (p=0.002).

CONCLUSIONS

NYHA class and sPAP are comparable ILD survival predictors. NYHA class is correlated with worse prognosis for IPF and NSIP vs. HP and GPA patients.

New York Heart Association class associated with imaging is a prognostic mortality risk predictor in interstitial lung diseases

OBJECTIVE

Mortality risk factors as forced vital capacity, diffuse lung capacity for carbon monoxide, and 6-minutes' walk test were studied in clinical trials monitoring patients affected by interstitial lung diseases (ILD). However, these parameters showed scarce accuracy. Our aim was to identify New York Heart Association (NHYA) class, in association with high resolution computed tomography (HRCT) and somatostatin receptor scintigraphy (Octreoscan), as a prognostic mortality risk factor in ILD patients.

PATIENTS AND METHODS

Study population comprised 128 ILD patients (78 Males and 50 Females). Histological diagnosis was usual interstitial pneumonia (UIP), non-specific interstitial pneumonia (NSIP) and granulomatous lung disease in 59, 19 and 50 patients, respectively. Patients were monitored by NYHA class, HRCT and Octreoscan at baseline and every 3 years up to a 10-year follow up. Overall survival was calculated from the date of diagnosis until death or last follow-up update. Statistical analysis was performed using Kaplan-Meier, log-rank test (LRT), multivariate analysis with Cox proportional hazard regression model, and log-likelihood ratio test.

RESULTS

Overall median survival was 89.3 months (7.4 years) with the poorer survival rate observed in UIP patients. NYHA class came out as a reliable prognostic mortality risk factor in each group of patients and prognosis was progressively worse with NYHA class increase (LRT p<0.001). A strong correlation was found between NYHA class and age, CT-score, and Octreoscan in UIP patients (p<0.001).

CONCLUSIONS

The determination of NYHA class can therefore be recommended as an additional prognostic mortality risk factor in ILD patients.

Evaluation of membrane-bound and soluble forms of human leucocyte antigen-G in systemic sclerosis

Systemic sclerosis (SSc) is a complex disease characterized by immune dysregulation, extensive vascular damage and widespread fibrosis. Human leucocyte antigen-G (HLA-G) is a non-classic class I major histocompatibility complex (MHC) molecule characterized by complex immunomodulating properties. HLA-G is expressed on the membrane of different cell lineages in both physiological and pathological conditions. HLA-G is also detectable in soluble form (sHLA-G) deriving from the shedding of surface isoforms (sHLA-G1) or the secretion of soluble isoforms (HLA-G5). Several immunosuppressive functions have been attributed to both membrane-bound and soluble HLA-G molecules. The plasma levels of sHLA-G were higher in SSc patients (444·27 ± 304·84 U/ml) compared to controls (16·74 ± 20·58 U/ml) (P < 0·0001). The plasma levels of transforming growth factor (TGF)-β were higher in SSc patients (18 937 ± 15 217 pg/ml) compared to controls (11 099 ± 6081 pg/ml; P = 0·003), and a significant correlation was found between TGF-β and the plasma levels of total sHLA-G (r = 0·65; P < 0·01), sHLA-G1 (r = 0·60; P = 0·003) and HLA-G5 (r = 0·47; P = 0·02). The percentage of HLA-G-positive monocytes (0·98 ± 1·72), CD4⁺ (0·37 ± 0·68), CD8⁺ (2·05 ± 3·74) and CD4⁺ CD8⁺ double-positive cells (14·53 ± 16·88) was higher in SSc patients than in controls (0·11 ± 0·08, 0·01 ± 0·01, 0·01 ± 0·01 and 0·39 ± 0·40, respectively) (P < 0·0001). These data indicate that in SSc the secretion and/or shedding of soluble HLA-G molecules and the membrane expression of HLA-G by peripheral blood mononuclear cells (PBMC) is clearly elevated, suggesting an involvement of HLA-G molecules in the immune dysregulation of SSc.

Surface trap mediated electronic transport in biofunctionalized silicon nanowires

Silicon nanowires (SiNWs), fabricated via a top-down approach and then functionalized with biological probes, are used for electrically-based sensing of breast tumor markers. The SiNWs, featuring memristive-like behavior in bare conditions, show, in the presence of biomarkers, modified hysteresis and, more importantly, a voltage memory component, namely a voltage gap. The voltage gap is demonstrated to be a novel and powerful parameter of detection thanks to its high-resolution dependence on charges in proximity of the wire. This unique approach of sensing has never been studied and adopted before. Here, we propose a physical model of the surface electronic transport in Schottky barrier SiNW biosensors, aiming at reproducing and understanding the voltage gap based behavior. The implemented model describes well the experimental I-V characteristics of the device. It also links the modification of the voltage gap to the changing concentration of antigens by showing the decrease of this parameter in response to increasing concentrations of the molecules that are detected with femtomolar resolution in real human samples. Both experiments and simulations highlight the predominant role of the dynamic recombination of the nanowire surface states, with the incoming external charges from bio-species, in the appearance and modification of the voltage gap. Finally, thanks to its compactness, and strict correlation with the physics of the nanodevice, this model can be used to describe and predict the I-V characteristics in other nanostructured devices, for different than antibody-based sensing as well as electronic applications.

General surgery, translational lymphology and lymphatic surgery

A wide clinical experience in General Surgery has brought about a remarkable knowledge about lymphatic disorders both primary and secondary ones. Diagnostic and histopathological studies of lymphatic diseases allowed to better understand etiological aspects and pathophysiological mechanisms responsible of complex clinical features correlated to lymphatic dysfunctions. Translational lymphologic basic and clinical researches permitted to improve therapeutical approaches both from the medical and surgical point of view. Thus, strategies of treatment were proposed to prevent lymphatic injuries, to avoid lymphatic complications and to treat lymphatic diseases early in order to be able even to cure these pathologies.

Immunoglobulin production pattern is allergen-specific in polysensitized patients

Allergic rhinitis (AR) is characterized by Th2 polarized immune response, such as increased IL-4 and reduced IFN-gamma production, and by a functional defect of T regulatory cells. This impaired immune response profile influences the pattern of immunoglobulin production in allergic patients. Therefore, the aim of this study is firstly to investigate the allergen-specific IgE, IgG, IgG4, and IgA serum level pattern in polysensitized AR patients with the same skin prick test positivity to some pollen allergens. Secondly, this study aims at relating immunoglobulin (Ig) values with some clinical and immunological parameters. Eighty polysensitized patients with AR were enrolled. Serum allergen-specific IgE, IgG, IgG4, and IgA for mites, Parietaria, grasses, and birch, TGF-beta and sHLA-G were determined by the ELISA method. Allergic symptoms and drugs use were also assessed. Allergen-specific IgE, IgG, IgG4, and IgA serum levels were significantly different for each tested allergen (p=0.0001). There was a significant correlation between IgE levels and allergy severity, whereas IgA had an antagonistic behaviour, considering mite-specific immunoglobulins. In conclusion, the present study provides the first evidence that immunoglobulin production pattern depends on the specificity of the allergenic response.

Anti-TNF-α Inhibitors: A New Therapeutic Approach for Inflammatory Immune-Mediated Diseases: An Update upon Efficacy and Adverse Events

The ongoing progresses in the knowledge of the pathogenic mechanisms of various inflammatory or immune-mediated diseases and the availability of innovative biotechnological approaches have lead to the development of new drugs which add to conventional treatments. TNF-α inhibitors (Infliximab, Adalimumab and Etanercept) have demonstrated efficacy either as monotherapy or in combination with other anti-inflammatory or disease modifying anti-rheumatic drugs (DMARDs). The efficacy and safety profile of the TNF-α inhibitors can be considered, in general, as a class effect. Nevertheless, some differences may exist among the three agents. In this paper, we will briefly review the indications for the use of the three TNF-α inhibitors, the pre-treatment considerations and the reported adverse events.

Prospective evaluation of a prevention protocol for lymphedema following surgery for breast cancer

Lymphedema is a common complication of axillary dissection and thus emphasis should be placed on prevention. Fifty-five women who had breast-conserving surgery or modified radical mastectomy for breast cancer with axillary dissection were randomly assigned to either the preventive protocol (PG) or control group (CG) and assessments were made preoperatively and at 1, 3, 6, 12 and 24 months postoperatively. Arm volume (VOL) was used as measurement of arm lymphedema. Clinically significant lymphedema was confirmed by an increase of at least 200 ml from the preoperative difference between the two arms. The preventive protocol for the PG women included preoperative upper limb lymphscintigraphy (LS), principles for lymphedema risk minimization, and early management of this condition when it was identified. Assessments at 2 years postoperatively were completed for 89% of the 55 women who were randomly assigned to either PG or CG. Of the 49 women with unilateral breast cancer surgery who were measured at 24 months, 10 (21%) were identified with secondary lymphedema using VOL with an incidence of 8% in PG women and 33% in CG women. These prophylactic strategies appear to reduce the development of secondary lymphedema and alter its progression in comparison to the CG women.

Soluble HLA-G and HLA-A,-B,-C serum levels in patients with allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) is characterized by Th2-polarized immune response. Soluble HLA (sHLA) molecules play an immunomodulatory activity. So far, however, no study investigated them in AR.

OBJECTIVE

The aim of this study was to evaluate sHLA-G and sHLA-A,-B,-C serum levels in AR patients with pollen allergy and in a group of healthy controls.

METHODS

Forty-nine AR patients were enrolled. A group of healthy nonallergic subjects was considered as control. sHLA-G and sHLA-A,-B,-C serum levels were determined by immunoenzymatic method. The study was conducted during the winter, such as outside the pollen season.

RESULTS

Allergic patients had significantly higher levels of both sHLA-G (P < 0.0001) and sHLA-A,-B,-C (P = 0.011) molecules than normal controls. Moreover, there was a significant relationship between these two soluble molecules (r = 0.69) in allergic patients.

CONCLUSION

The present study provides the first evidence that both sHLA-G and sHLA-A,-B,-C serum levels are significantly increased in AR patients with pollen allergy.

Haplotypes of the human RET proto-oncogene associated with Hirschsprung disease in the Italian population derive from a single ancestral combination of alleles

The RET proto-oncogene is the major gene involved in the complex genetics of Hirschsprung disease (HSCR), or aganglionic megacolon, showing causative loss-of-function mutations in 15-30% of the sporadic cases. Several RET polymorphisms and haplotypes have been described in association with the disease, suggesting a role for this gene in HSCR predisposition, also in the absence of mutations in the coding region. Finally, the presence of a functional variant in intron 1 has repeatedly been proposed to explain such findings. Here we report a case-control study conducted on 97 Italian HSCR sporadic patients and 85 population matched controls, using 13 RET polymorphisms distributed throughout the gene, from the basal promoter to the 3'UTR. Linkage disequilibrium and haplotype analyses have shown increased recombination between the 5' and 3' portions of the gene and an over-representation, in the cases studied, of two haplotypes sharing a common allelic combination that extends from the promoter up to intron 5. We propose that these two disease-associated haplotypes derive from a single founding locus, extending up to intron 19 and successively rearranged in correspondence with a high recombination rate region located between the proximal and distal portions of the gene. Our results suggests the possibility that a common HSCR predisposing variant, in linkage disequilibrium with such haplotypes, is located further downstream than the previously suggested interval encompassing intron 1.

Increased levels of interleukin-10 in saliva of Sjögren's syndrome patients. Correlation with disease activity

The aim of the study was to determine the levels of interleukin (IL)-10, IL-2, IL-4, and interferon-gamma in the saliva of patients with Sjögren's syndrome and to correlate them with laboratory and clinical parameters of disease activity. The levels of IL-2, IL-4, IL-10, and interferon-gamma were measured in salivary samples, obtained directly from the Stenone duct of 14 Sjögren's syndrome patients and 26 healthy controls by ELISA. A significant elevation of IL-10 was found in salivary fluids of Sjögren's syndrome patients compared with healthy controls (P=0.007). Elevated interferon-gamma levels were found in some patients. IL-2 and IL-4 were undetectable in all saliva samples. In patients, IL-10 levels significantly correlated with the degree of xerophthalmia and xerostomia (P=0.02 and P=0.01, respectively) and with the erythrocyte sedimentation rate (P=0.006). Our data suggest that elevated IL-10 levels are detectable in the saliva of Sjögren's syndrome patients and correlate with the severity of the disease.

Sublingual specific immunotherapy reduces PBMC proliferations

BACKGROUND

Subcutaneous specific immunotherapy has been demonstrated capable of inducing T regulatory response. There is few evidence concerning immunological changes induced by sublingual immunotherapy.

OBJECTIVE

The aim of this study was to evaluate T cell proliferation in subjects successfully treated with SLIT for HDM.

METHODS

PBMCs were isolated from patients after at least 3 years of successful HDM SLIT and from matched untreated allergic and healthy control subjects. After 3 and 6 days of in vitro stimulation with PHA, Candida albicans, Dermatophagoides farinae, grasses, Parietaria judaica, and cat, proliferation.

RESULTS

Subjects treated with SLIT showed significant reduction of proliferation induced by Candida albicans, Parietaria, and grasses in comparison with untreated atopics (p=0.0002, 0.0033, and 0.009 respectively).

CONCLUSION

This pilot study confirms reduced T cell proliferation in allergic subjects treated with SLIT.

Modifications of immunological and neuro-endocrine parameters induced by antiorthostatic bed-rest in human healthy volunteers

AIM

Space flight has profound effects on immunological and neuroendocrine parameters. Microgravity plays a major role in the induction of these changes. The aim of the present study was the evaluation on ground of the effects induced by antigravitary posture on immune and neuroendocrine functions.

METHODS

Eight healthy male volunteers (mean age 24+/-1 years) were maintained in antigravitary posture (-10 degrees) for 72 hours. Four of them were also maintained in supine posture for 72 hours as controls. The following immunological and neuroendocrine parameters have been analysed: peripheral white blood cells count, CD11b integrin expression and H(2)O(2) production by neutrophils, lymphocyte and monocyte phenotype, intracytoplasmic cytokine (IFN-gamma, TNF-alpha and IL-4) pattern, lymphocyte proliferation to mitogens and antigens, cortisol, ACTH, catecholamines, GH, LH, prolactin and testosterone plasma levels.

RESULTS

In subjects maintained in antigravitary posture, norepinephrine, dopamine, cortisol, ACTH, GH and prolactin plasma levels increased whereas H(2)O(2) production by neutrophils, lymphocyte proliferation, NK cells number and intracytoplasmic IFN-g expression decreased. No significant modifications were observed in subjects maintained in supine posture.

CONCLUSION

The results of this study indicate that several neuroendocrine and immunological parameters are modulated by a prolonged antigravitary posture on ground and may negatively affect astronauts defenses against pathogens during space flights.

Rescue of human RET gene expression by sodium butyrate: a novel powerful tool for molecular studies in Hirschsprung disease

BACKGROUND

The RET gene encodes a tyrosine kinase receptor involved in different human neurocristopathies, such as specific neuroendocrine tumours and Hirschsprung disease (HSCR). Gene expression is developmentally regulated and the RET transcript is undetectable in most adult cells, including lymphocytes. The impossibility of performing functional studies on RET mRNA has to date limited the detection and characterisation of an indefinite proportion of gene anomalies that cannot be identified by conventional DNA genomic screening in HSCR cases.

AIMS

Development of a protocol suitable to activate RET expression in RET negative cell lines and therefore to investigate directly RET mRNA, extending the conventional gene mutation analysis to detection of splicing anomalies and impaired expression of the RET gene.

METHODS

The effect of sodium butyrate (NaB), a histone deacetylase inhibitor, on rescuing RET expression was tested by one round of reverse transcription- polymerase chain reaction from total RNA of treated lymphoblasts from both HSCR patients and control individuals.

RESULTS

Analysis of RET expression was possible by NaB treatment of RET negative cells, such as lymphoblasts. This treatment allowed us to detect impaired RET expression as well as a splicing defect in two HSCR patients previously believed to be devoid of any gene abnormality.

CONCLUSIONS

The full application of the proposed protocol in most of the unexplained HSCR cases will allow us to establish the precise role of RET not only in causing but also in predisposing to HSCR pathogenesis.

[Liposomal Amphotericin B for treatment of acute phase and secondary prophylaxis of visceral leishmaniasis in a HIV positive patient]

The authors describe a clinical case of an HIV+, HBV+ and HCV+ 46-year-old male patient, with a history of drug abuse of intravenous heroin, admitted to their attention for high remittent fever (39 C), weight loss and severe dysphonia. The increasing severity of dysphonia had required a fiberlaryngoscopic examination which allowed a diagnosis of hypertrophy of vocal chords. The Wright-Giemsa stain performed on vocal chord biopsy evidenced Leishmania infantum. The same protozoon was subsequently also revealed in bone marrow aspirate. The patient underwent a course of therapy with Amphotericin B deoxycolate (0.5 mg/kg) which had to be interrupted due to insurgence of diffuse petechiae and switched to Amphotericin in cholesterinic suspension (2.5 mg/kg every 21 days). After three months, insurgence of high fever related to the infusion induced the start of therapy with liposomal Amphotericin B (3 mg/kg every 28 days) which led in 4 weeks to a complete clinical remission. Prophylaxis with liposomal Amphotericin B is continuing and remission has persisted for 40 months. This case report shows the importance of liposomal Amphotericin B therapy in order either to obtain clinical remission of visceral leishmaniasis or, in secondary prophylaxis, to reduce the risk of the disease's recurrence.

Long-term treatment of patients affected by systemic sclerosis with cyclosporin A

The aims of the present study were: 1) to verify the tolerability of long-term, low-dose treatment of patients affected by systemic sclerosis with cyclosporin A; 2) to analyze the clinical outcome of treated patients in relationship to skin, esophageal, lung, kidney and microvascular organ involvement. Nine patients affected by diffuse systemic sclerosis were treated for periods ranging from 3 to 5 years with cyclosporin A at a dosage of 2.5 mg/kg/day. Cyclosporin A treatment was variably associated or not with treatments for Raynaud's phenomenon (pentoxiphylline, defibrotide, low-dose heparin, prostacyclin analogues) in relationship to the needs of single patients. We report on patient clinical evaluations performed every year and including plicometry, esophageal pH-manometry, pulmonary spirometry, renal duplex Doppler sonography, echocardiography as well as nailfold videocapillaroscopy. The results of single tests were converted into scores. The existence of statistically significant differences between baseline mean scores and mean scores after 1, 2 and 3 years of therapy was analyzed. All patients tolerated cyclosporin A well, and no definitive withdrawals from the study were observed. Hypertricosis appeared in 3 patients, and 1 patient interrupted treatment for 6 months because of the onset of pneumonitis. No alterations of blood pressure and renal functionality were detected. Statistically significant reduction of all analyzed mean scores was observed after 2 and/or 3 years of cyclosporin A treatment with respect to baseline. The overall results suggest an encouraging clinical effect for low-dose, long-term cyclosporin A treatment in systemic sclerosis. Satisfactory tolerability and clinical improvement were observed in all the patients consecutively treated for at least 3 years.

In vitro immunosuppressive activity of soluble HLA class I and Fas ligand molecules: do they play a role in autologous blood transfusion?

BACKGROUND

The immunomodulatory effects of allogeneic blood transfusion may contribute to a poor prognosis in patients with cancer who are undergoing surgery, and clinical trials have been carried out to investigate whether these patients would benefit from autologous blood donation. As the immunomodulatory effects of allogeneic blood transfusion have been related to soluble molecules released from residual WBCs during storage, the in vitro immunomodulatory activity of soluble molecules detected in supernatants from stored autologous blood was evaluated.

STUDY DESIGN AND METHODS

Blood was donated by four healthy volunteers. Packed WBC-reduced RBCs were obtained and stored for 30 days, and supernatants were collected. FFP and serum were also obtained. The concentration of soluble molecules was determined by immunoenzymatic assays. The in vitro immunomodulatory activity of undiluted blood component supernatant was assessed by antigen-specific cytotoxic T-cell activity and mixed lymphocyte reactions in autologous combinations and by apoptosis induction in Fas+ cells.

RESULTS

The concentrations of soluble Fas-ligand and HLA class I molecules were higher in packed RBCs than in WBC-reduced RBCs, FFP, and serum. Undiluted supernatants of packed RBCs strongly inhibited functional assays and induced apoptosis in Fas+ cells. The immunomodulatory effects were correlated with the amount of soluble Fas ligand and HLA class I molecules.

CONCLUSION

The results of the present study are comparable with those already reported in allogeneic blood components, and they indicate that undiluted supernatants of autologous blood components may exert immunosuppressive effects in vitro.

Impairment of CD8+ T suppressor cell function in patients with active systemic lupus erythematosus

Alteration of T cell suppression function has been recognized in patients with systemic lupus erythematosus (SLE). Recently, CD8(+) T suppressor lymphocytes (CD8(+) Ts) have been generated in vitro by incubating purified CD8(+) T cells with IL-2 and GM-CSF. Using this method, we generated CD8(+) Ts from patients affected by SLE. No major differences were found in the CD8(+) Ts phenotype between SLE patients and healthy subjects. CD8(+) Ts from SLE patients with active disease did not inhibit the anti-CD3 mAb-induced proliferation of autologous PBMC, whereas CD8(+) Ts from SLE patients in remission exerted an inhibitory activity comparable to normal subjects. The inhibitory effect of CD8(+) Ts cells was neither mediated by cytotoxic activity nor by apoptosis induction. Two cytokines, IFN-gamma and IL-6, were found to be responsible for the function of CD8(+) TS: In fact, counteraction of CD8(+) Ts suppression activity was obtained by blocking IFN-gamma with a specific Ab or by inhibiting CD8(+) Ts-mediated IL-6 secretion by an antisense oligonucleotide. Interestingly, CD8(+) Ts from SLE patients showed a peculiar cytokine pattern characterized by an impaired secretion of IL-6 and an increased secretion of IL-12. Thus, it appears that an altered balance between inhibitory (IL-6) and stimulatory (IL-12) cytokines might be responsible for the functional impairment of CD8(+) Ts in SLE patients.

Soluble HLA class I/CD8 ligation triggers apoptosis in EBV-specific CD8+ cytotoxic T lymphocytes by Fas/Fas-ligand interaction

In the present study, we report that allogeneic soluble HLA class I (sHLA-I) molecules isolated from serum induce apoptosis on EBV-specific CD8(+) Fas(+) cytotoxic T lymphocytes (CTL). CTL apoptosis is induced by the binding of sHLA-I molecules to CD8 and its extent depends on the time of incubation with sHLA-I molecules. Apoptosis is triggered by the interaction of Fas(+) CTL with soluble Fas-ligand, which is released following the binding of sHLA-I antigens to CD8 molecules. These results suggest that sHLA-I molecules may regulate immune responses by inducing apoptosis in virus-specific CTL.

Nuclear run-on assay using biotin labeling, magnetic bead capture and analysis by fluorescence-based RT-PCR

In this report, we present a fluorescence-based approach to the assessment of cellular gene expression and transcription rates. Nuclear run-on was performed by supplying biotin-16-UTP to nuclei, and labeled transcripts were bound to streptavidin-coated magnetic beads. Total cDNA was then synthesized by means of random hexamer primed reverse transcription of captured molecules. To monitor transcript abundance in cDNA, both from nuclear run-on and total RNA, we propose a semiquantitative PCR approach based on the use of fluorescent primers.

Soluble beta2-mu-associated and beta2-mu-free HLA class I heavy chain serum levels in interferon-alpha nonresponder chronic hepatitis C patients. Markers of immune activation, and response to antiviral retreatment

The serum levels of soluble beta2-mu-associated and beta2-mu-free HLA class I heavy chains were determined in 28 interferon-alpha nonresponder chronic hepatitis C patients retreated with interferon-alpha plus ribavirin and in 70 healthy subjects. The baseline levels of beta2-mu-associated and beta2-mu-free HLA class I heavy chains were significantly higher in patients than in healthy controls (P = 0.001). The levels of beta2-mu-associated HLA class I heavy chains significantly increased in responder patients with respect to nonresponders at the third month of treatment (P = 0.03). At the sixth month of treatment and after 6 months of follow up the levels of beta2-mu-associated HLA class I heavy chains decreased in responder patients and increased in nonresponders. The levels of beta2-mu-free HLA class I heavy chains showed only minor changes during and after treatment. We suggest that the determination of hepatitis C virus RNA levels combined with soluble beta2-mu-associated HLA class I heavy chains, as a marker of immune activation, could identify interferon-alpha non responder chronic hepatitis C patients most likely to respond to a retreatment with interferon-alpha plus ribavirin.

Soluble HLA class I and Fas ligand molecules in blood components and their role in the immunomodulatory effects of blood transfusions

It has been known for many years that blood transfusions may have immunomodulatory effects, however an ultimate explanation of this phenomenon is lacking. In the present paper we report that the concentrations of soluble HLA class I (sHLA-I) and soluble Fas ligand (sFasL) molecules in supernatants of blood components which contain elevated numbers of residual donor leukocytes, like red blood cells and random-donor platelets, are significantly higher than in other blood components. Elevated amounts of sFasL molecules are also found in some commercial immunoglobulin preparations. sHLA-I and sFasL molecules in blood components and in immunoglobulin preparations are biologically active in vitro as they inhibit mixed lymphocyte responses and cytotoxic T cell activity in allogeneic and autologous combinations and induce apoptosis in Fas-positive cells. If these results are paralleled in vivo the amount of sHLA-I and sFasL molecules should be taken into account in clinical practice in order to select the blood component and the immunoglobulin preparation which could induce the desired immunomodulatory effect in the recipient.

Hepatitis G virus infection in intravenous drug users with or without human immunodeficiency virus infection

BACKGROUND/AIMS

To evaluate the HGV infection prevalence in a group of intravenous drug users with or without human immunodeficiency virus coinfection.

METHODOLOGY

We studied 57 patients (48 males and 9 females) who were either previous or still ongoing intravenous drug users. Thirty-seven patients were HIV+ve, 55 patients were anti-HCV+ve and 3 patients were HBsAg chronic carriers. Patient sera were tested for HGV-RNA, anti-E2, qualitative and quantitative HCV-RNA as well as for HCV genotypes. Moreover, the ALT level was checked in the serum sample of each patient.

RESULTS

We found a high prevalence (35/57; 61.4%) of HGV infection in our patients. HGV-RNA was detected in 16 out of the 57 intravenous drug users (28%). In particular HGV-RNA was positive in 12 out of the 37 HIV+ve patients (32.4%) and in 4 out of the 20 HIV-ve patients (20%). Anti-E2 were detected in 19 out of the 57 patients (33.3%) with greater prevalence among HIV-ve subjects (12/20; 60%) compared to HIV+ve group (7/37; 18.9%). This resulting difference was statistically significant (P < 0.05). All HGV-RNA+ve/anti-E2+ve patients were anti-HCV/HCV-RNA+ve and none of our patients were anti-E2+ve/HGV-RNA+ve at the same time. Significant differences were not found between HGV-RNA+ve and HGV-RNA-ve patients as far as clinical and virological data are concerned.

CONCLUSIONS

The prevalence of HGV infection in intravenous drug users proved to be high especially in the HIV+ve group. Moreover HGV was associated with HCV in all our cases. The actual clinical impact of HGV infection remains unclear since HGV does not seems to influence the biochemical, virological or histological alterations caused by HCV infection.

Increased beta2-microglobulin-free HLA class I heavy chain serum levels in the course of immune responses to viral antigens and to mismatched HLA antigens

Besides being present in serum in association with beta2-mu, HLA class I heavy chains are also present in serum as beta2-micro-free moieties. The increase in serum levels of beta2-micro-associated HLA class I heavy chains in conditions associated with an activation of the immune system have prompted us to measure the serum levels of beta2-mu-free HLA class I heavy chains in the course of immune responses to viral antigens and to mismatched histocompatibility antigens. The serum level of beta2-mu-free HLA class I heavy chains, like that of beta2-mu-associated HLA class I heavy chains was significantly increased in patients affected by advanced HIV-1 infection or by chronic hepatitis C (CHC). In the latter group of patients an association was found between a reduction in the beta2-mu-free HLA class I heavy chain serum level and response to therapy with interferon alpha and ribavirin. Moreover, the beta2-mu-free HLA class I heavy chain serum level was increased more than that of beta2-mu-associated HLA class I heavy chains during episodes of liver ischemia following liver transplantation and in the course of acute graft rejection and of acute graft-versus-host-disease (GVHD) after allogeneic bone marrow transplantation (BMT). These results suggest that the serum levels of beta2-mu-free and beta2-mu-associated HLA class I heavy chains are independently regulated. Furthermore, beta2-mu-free HLA class I heavy chain serum level may be a useful marker to monitor response to therapy in CHC patients and the clinical course of liver and bone marrow grafts.

Soluble human MHC class I molecules induce soluble Fas ligand secretion and trigger apoptosis in activated CD8(+) Fas (CD95)(+) T lymphocytes

In the present study, we have evaluated the apoptotic effect of soluble human MHC class I (sHLA-I) antigens on CD8(+) T lymphocytes. sHLA-I antigens and beta(2)-microglobulin-free HLA class I heavy chains, isolated from serum, induced apoptosis on phytohemagglutinin-activated CD8(+) T lymphocytes in autologous and allogeneic combinations. The extent of CD8(+) T cell apoptosis depends on the degree of activation, time of incubation with sHLA-I antigens and amount of sHLA-I antigens added to the cultures. Apoptosis is induced by the interaction of Fas (CD95)(+) cells with soluble Fas ligand which is released following binding of sHLA-I antigens to CD8 molecules. These results suggest that sHLA-I antigens may regulate immune responses by inducing apoptosis in activated CD8(+) T cells.

[The immunomodulatory effect of blood transfusions and intravenous immunoglobulins: the role of the soluble molecules of the Class-I major histocompatibility complex and of the Fas ligand]

Allogeneic blood transfusions may have immunomodulatory effects including improved allograft acceptance and increased risk for cancer recurrence or post-operative bacterial infections. These effects are associated with the presence of leukocytes in transfused blood and are reduced by pre-storage leuko-reduction. However, the precise mechanism of this effect has not yet been elucidated. We report that the concentrations of soluble major histocompatibility complex class I and soluble Fas-ligand molecules are significantly higher in supernatants of blood components containing elevated numbers of residual donor leukocytes, such as red blood cells and random-donor platelets, than in other blood components. Elevated amounts of soluble Fas-ligand molecules are also found in some intravenous immunoglobulin preparations. Soluble molecules detected in blood components and in immunoglobulin preparations are biologically active in vitro. In fact, they inhibit mixed lymphocyte responses and cytotoxic T cell activity in allogeneic and autologous combinations and induce apoptosis in Fas-positive cells. These results should be taken into account in clinical practice to select the blood component or the immunoglobulin preparation in order to induce or prevent an immunosuppressive effect in the recipient.

Decreased surface antigen density on lymphocytes of elderly humans

The aim of our study was to analyze some poorly investigated and controversial aspects of senescent lymphocyte phenotype and functions. We examined 100 healthy aging individuals, divided into 4 age groups, and 30 young controls, correlating lymphocyte responsiveness to mitogenic stimulation with membrane phenotypic pattern and surface molecular densities of the main functional lymphoid markers. Stability of values in the period of study was established. No age-related differences in the parameters evaluated were detected among aging subjects. Phytohemagglutinin-induced lymphocyte proliferation was found severely impaired (about halved) in all elderly individuals with respect to controls. There was no significant difference between elderly group and controls in CD2, CD3, CD4, CD8, CD19, CD25 and HLA-DR antigen distribution. CD56 positive cell percentages were slightly decreased in the elderly groups. In apparent correlation with reduced lymphocyte responsiveness, CD2, CD3, CD4 and CD8 molecular densities, to different extents, were found relevantly (about 1 to 3-fold) lower in all aging groups than in controls. We could not ascertain if those antigens were poorly synthesized, defectively transported to membrane or shed in excess. However, we suggest that decreased surface molecular densities of antigens involved in functional processes of immune responses may be responsible for an abnormal costimulatory pattern during lymphocyte activation, leading to apoptotic rather than proliferative signals in a greater proportion of cells than normal.

Cyclosporin A and iloprost treatment of systemic sclerosis: clinical results and interleukin-6 serum changes after 12 months of therapy

OBJECTIVES

The main aim was to analyse the long-term therapeutic effects on systemic sclerosis (SSc) patients of treatment with either (i) iloprost alone or (ii) low-dose oral cyclosporin A (CyA) associated with iloprost. A secondary aim was to analyse interleukin-6 (IL-6) serum levels in SSc patients before and after 1 yr of treatment.

METHODS

A clinical trial was performed in which 20 consecutive SSc patients were alternately randomized into two homogeneous groups receiving either monthly i.v. iloprost (1 ng/kg/min in 6 h i.v. infusion, for 5 consecutive days, 1 week per month) (Group I) or low-dose CyA (2.5 mg/kg/day) associated with iloprost administration (Group II). IL-6 concentrations were evaluated by ELISA in the sera of each patient before and after 1 yr of therapy and in 20 healthy subjects.

RESULTS

After 1 yr of therapy, a significant improvement of skin (P=0.008), microvascular (P=0.004) and oesophageal (P=0.05) morphological and functional parameters was observed only in Group II patients. Furthermore, after 1 yr of treatment, a significant reduction (P=0.007) of IL-6 serum concentration was observed only in Group II patients.

CONCLUSIONS

Collectively, our data suggest that the combination of low-dose CyA with iloprost administration may be of clinical utility in SSc and that a mechanism of action of CyA in SSc may include the decrease in IL-6 production.

Possible differences in the mechanism(s) of action of different glucocorticoid hormone compounds

Different glucocorticoid hormones (GCH) show differences in the intensity and in the kinetics of their immunomodulating activity. The mechanism(s) of action of GCH is under investigation, but is has been noted that they exert immune activity via the genomic pathway. We have studied the effects of prednisone (PDN), deflazacort (DFC), and dexamethasone (DXM) on the production of cytokines (IL-2, IL-6, TNF-alpha, IL-10) by peripheral T lymphocytes, and the effects on the inhibition of NF-kB DNA binding activity by activated Jurkat cell line. The data obtained show that the three GCH molecules exert an immunosuppression on cytokine production by T lymphocytes and a strong decrease in the nuclear translocation of NF-kB in Jurkat cells; moreover, (a) not all the cytokines investigated were affected, and not with the same intensity, by the three GCH and (b) DXM inhibited the binding activity of NF-kB less than that of DFC and PDN. These data are in agreement with the concept that different GCH compounds might differ in their binding and affinity properties, tissue-specific metabolism, and interaction with transcription factor.

Immune regulatory properties of corticosteroids: prednisone induces apoptosis of human T lymphocytes following the CD3 down-regulation

Glucocorticoid hormones (GCH) induce apoptosis in PHA-primed peripheral blood T lymphocytes (PBL) and down-regulate membrane-bound proteins involved in the immune response. We have analyzed whether GCH are able to affect the expression of the TCR-associated molecules CD3, CD4, and CD8 on PBL-PHA, and whether the modulation of those receptors is related to the GCH-driven apoptosis of the PBL-PHA. Lymphocytes were cultured with PHA or with PHA plus prednisone (PDN) 10(-3), 10(-6), and 10(-9) M. Then expression of CD2, CD3, CD4, CD8, and CD56 antigens was studied by cytofluorimetric assay using propidium iodide (PI) staining and annexin procedure, and by gel electrophoresis of low molecular weight DNA. PDN, at a pharmacological concentration (10(-6) M), was able to inhibit the CD3 expression on T cells. The kinetics of CD3 decrement and of apoptosis show that the down-regulation of CD3 molecules precedes DNA fragmentation and that the cells lacking CD3 are those prone to PDN-induced apoptosis. The inhibition of CD3 is not related to a transcriptional or posttranscriptional phenomenon, because both PBL-PHA and PBL-PHA-PDN expressed the same amount of intracytoplasmic CD3 molecule. PDN also induced a down-regulation of the CD4 and CD8 molecules that resulted sooner in more intense CD8. In vitro PDN is able to induce apoptosis in PBL-PHA through a down-regulation of CD3 molecules.

Beta2-micro-free HLA class I heavy chain levels in sera of healthy individuals. Lack of association with beta2-micro-associated HLA class I heavy chain levels and HLA phenotype

We have applied a double-determinant immune assay (DDIA) to measure soluble beta2-microglobulin (beta2-micro)-free HLA class I heavy chains in serum. The mean concentration of beta2-micro-free HLA class I heavy chains in serum from 120 healthy subjects was 0.21+/-0.24 microg/ml. The individual serum levels of beta2-micro-free HLA class I heavy chains had a wide distribution, did not seem to be related with HLA phenotype, were stable over time and did not change with age. The serum levels of soluble beta2-micro-free HLA class I heavy chains did not correlate with those of soluble beta2-micro-associated HLA class I heavy chains, suggesting that their release is independently regulated. Three forms of soluble beta2-micro-free HLA class I heavy chains, with apparent molecular masses of 44, 39 and 37-35 kD, respectively, circulate in human serum. These results provide a useful background to assess the serum level of soluble beta2-micro-free HLA class I heavy chains in pathological conditions and to evaluate their putative immunoregulatory function.

Soluble HLA class I, HLA class II, and Fas ligand in blood components: a possible key to explain the immunomodulatory effects of allogeneic blood transfusions

The immunomodulatory effect of allogeneic blood transfusions (ABT) has been known for many years. However, a complete understanding of the effects of ABT on the recipient's immune system has remained elusive. Soluble HLA class I (sHLA-I), HLA class II (sHLA-II), and Fas ligand (sFasL) molecules may play immunoregulatory roles. We determined by double-determinant immunoenzymatic assay (DDIA) sHLA-I, sHLA-II, and sFasL concentrations in different blood components. sHLA-I and sFasL levels in red blood cells (RBCs) stored for up to 30 days and in random-donor platelets are significantly (P <.001) higher than in other blood components and their amount is proportionate to the number of residual donor leukocytes and to the length of storage. Blood components with high sHLA-I and sFasL levels play immunoregulatory roles in vitro as in allogeneic mixed lymphocyte responses (MLR) and antigen-specific cytotoxic T-cell (CTL) activity, and induce apoptosis in Fas-positive cells. These data suggest that soluble molecules in blood components are functional. If these results are paralleled in vivo, they should be taken into account in transfusion practice. Blood components that can cause immunosuppression should be chosen to induce transplantation tolerance, whereas blood components that lack immunosuppressive effects should be preferred to reduce the risk of postoperative complications and cancer recurrence.

Double-stranded deoxyribonucleic acid binds to HLA class II molecules and inhibits HLA class II-mediated antigen presentation

CD4+ T cells proliferating in response to purified double-stranded deoxyribonucleic acid (dsDNA) have been recently demonstrated in peripheral blood mononuclear cells of patients with systemic lupus erythematosus. Their activation was inhibited by anti-HLA class II (HLA-II) monoclonal antibodies; thus, the existence of a molecular interaction between dsDNA and HLA-II is conceivable. In this report we show that dsDNA specifically bind to HLA-II. After preincubating cells with purified dsDNA or synthetic oligonucleotides, dsDNA was detected on the cell membrane and in the lysates of HLA-II+ but not of isogenic HLA-II- cell lines. We demonstrate that dsDNA binding inhibits that of a specific peptide to HLA-II. Mixed lymphocyte reaction and antigen-specific T cell proliferation were inhibited by the preincubation of stimulator cells or antigen-presenting cells with dsDNA. These results suggest the existence of a novel mechanism of down-modulation of the CD4+ T cell function generated by lack of stimulation due to the HLA-II presenting molecules being "occupied" by dsDNA.

Immunoregulatory role of soluble HLA molecules: a new skin for an old subject?

The available evidence suggests that measurement of the level of total sHLA-1 antigens and of donor-derived and recipient-derived allospecificities as well as the characterization of their variants in recipient's serum may provide useful information to differentiate graft rejections from infections in allograft recipients. Moreover, a significant progress has been made in our understanding of the functional properties of sHLA-I antigens in serum and of their potential role in the modulation of immune responses. If these preliminary results will be confirmed, then sHLA-I antigens are likely to become important reagents to monitor and treat graft recipients.

Downregulation of HLA class I antigen expression in CD4+ T lymphocytes from HIV type 1-infected individuals

The expression of HLA class I antigens is downregulated in CD4+ T cells following in vitro HIV-1 infection. We determined whether the expression of HLA class I antigens is downmodulated in peripheral blood lymphocytes (PBLs) of HIV-1-positive subjects and whether this defect correlates with disease progression. A cohort of 62 HIV-1-seropositive individuals in different stages of disease was studied. Among these, four subjects were evaluated at yearly intervals for 6 years. The expression of HLA class I, HLA class II, and CD38 antigens was analyzed in PBLs and in CD4+ and CD8+ T lymphocyte subpopulations. The percentage of HLA class I-positive cells and the membrane density of HLA class I antigens were significantly lower in PBLs from HIV-1-positive individuals than in PBLs from HIV-negative controls, proportionally decreased with disease progression, and significantly correlated with the decrease in CD4+ T lymphocytes. Furthermore, the percentage of HLA class I-positive cells and the membrane density of HLA class I antigens were significantly lower in CD4+ T lymphocytes from AIDS patients with respect to CD4+ T lymphocytes from HIV-negative controls and to CD8+ T lymphocytes from HIV-negative controls and AIDS patients. By contrast, the expression of HLA class II and CD38 antigens was upregulated in CD4+ and CD8+ T lymphocytes from HIV-1-positive subjects. The defective expression of HLA class I antigens could impair the lysis of HIV-infected CD4+ cells by virus-specific HLA class I-restricted cytotoxic T lymphocytes and contribute to the progression of disease.

Soluble HLA class I and class II molecule levels in serum and cerebrospinal fluid of multiple sclerosis patients

Increased concentrations of soluble HLA class I and class II molecules (sHLA-I and sHLA-II) have been observed in infectious, inflammatory, and autoimmune diseases. Because autoimmune mechanisms are considered to play a role in the pathogenesis of multiple sclerosis (MS), we decided to dose sHLA-I and sHLA-II in serum and cerebrospinal fluid (CSF) of MS patients comparing their concentrations with those observed in serum and CSF of patients with other neurologic diseases (OND) without evidence of neuroradiologic involvement of central nervous system (CNS) and in serum of healthy donors. The serum concentrations of sHLA-I were higher in both MS and OND patients than in healthy donors (P < 0.05) whereas sHLA-II serum concentrations were lower in MS patients than in both OND patients and healthy donors (P < 0.01). Detectable amounts of sHLA-II were observed in the CSF of 45% of MS patients and in CSF of only 6% of OND patients (P < 0.001). In MS patients a significant correlation between sHLA-I serum and CSF concentrations was observed (P < 0.01), whereas sHLA-II serum and CSF levels did not correlate. In conclusion, alterations of sHLA-I and sHLA-II serum and CSF concentrations are present in MS patients and could be involved in the induction of enhanced susceptibility to develop MS or in MS pathogenesis.