Glomerular filtration rate and parathyroid hormone secretion in primary hyperparathyroidism

CONTEXT

The recent Third International Workshop on the Management of Asymptomatic Primary Hyperparathyroidism (PHPT) set 60 ml/min as the precise level of glomerular filtration rate (GFR) below which surgery is recommended because it is considered a threshold of concern in patients with PHPT.

OBJECTIVE

The aim of the study was to investigate the relationship between different stages of renal insufficiency and PTH levels in PHPT patients.

DESIGN

We conducted a cross-sectional study.

PATIENTS AND METHODS

We studied 294 consecutive PHPT patients. Biochemical evaluation included total and ionized serum calcium, phosphate, creatinine, immunoreactive intact PTH, and 25-hydroxyvitamin D3 levels in the fasting state. GFR was assessed with the Modification of Diet in Renal Disease Study formula.

RESULTS

The mean GFR of the whole group of PHPT patients was 92.3 +/- 31.6 ml/min x 1.73 m(2). The patients were divided into four groups according to National Kidney Foundation Disease Outcomes Quality Initiative (K/DOQI) guidelines: group 1 with normal or increased GRF (>90 ml/min x 1.73 m(2); n = 153); group 2 with mild decreased GFR (60-89 ml/min x 1.73 m(2); n = 90); group 3 with moderately decreased GFR (30-59 ml/min x 1.73 m(2); n = 45); and group 4 with severely decreased GFR (<30 ml/min x 1.73 m(2); n = 6). PTH levels were comparable across groups 1-3, whereas group 4 showed significantly higher PTH levels (P < 0.0001).

CONCLUSION

In our series of PHPT patients, only a severe impairment of GFR was characterized by a further PTH increase. These findings challenge the concept of a PTH elevation below the threshold of 60 ml/min of GFR.

Hypoadiponectinemia in lipodystrophic HIV individuals: a metabolic marker of subclinical cardiac damage

BACKGROUND AND AIM

To evaluate cardiovascular abnormalities in highly active antiretroviral therapy (HAART) treated HIV patients with no signs or symptoms of cardiovascular impairment, and to assess the relative role of multiple concomitant risk factors.

METHODS AND RESULTS

Forty-four consecutive HIV subjects (mean age 41+/-6 yrs) were enrolled. Inclusion criteria were HIV infection, CD4+cell count>150/ml, HAART treatment for at least 4 years. Metabolic serum levels, morphological and functional echocardiographic parameters were assessed in all subjects. Sixteen healthy age and sex matched subjects with no cardiovascular risk factors were recruited as controls. HIV patients showed increased left ventricular mass index with reduced mid-wall fractional shortening (mFS) when compared to controls (50.2+/-10.5 vs. 38.6+/-14.4, p=0.05 and 18.3+/-0.6 vs. 21.9+/-0.7, p<0.05, respectively). Twenty-nine patients were lipodystrophic (LD) and showed a longer HAART period (p=0.0004) and greater use of protease inhibitors (PI) (p=0.001). Coronary flow reserve (CFR) was significantly reduced in HIV patients as compared to controls (p<0.0001), as it was in LD subjects when compared to non-lipodystrophic ones (NLD) (p<0.001). Adiponectin concentrations were found to be significantly lower in LD subjects than in NLD ones (7.8+/-0.8 vs. 13.8+/-1.2 microg/ml, p=0.01), and showed a direct correlation with CFR. In multiple regression analysis, insulin, HDL and adiponectin accounted for 63% of CFR variations.

CONCLUSIONS

Left ventricular hypertrophy, depressed mFS and reduced CFR represent the main signs of subclinical cardiac damage in HIV subjects treated with HAART. Hypoadiponectinemia in these subjects seems to be a metabolic risk factor of cardiovascular impairment.

Flu vaccination with a virosomal vaccine does not affect clinical course and immunological parameters in scleroderma patients

Safety and efficacy of adjuvanted vaccines in autoimmune individuals raises growing clinical and scientific interest. Protection from influenza would bring particular benefits in these patients with common cardiac and respiratory impairment. This study evaluates efficacy, clinical safety and immune effects of the administration of a single dose of a virosomal flu vaccine in 46 scleroderma patients. The following parameters were evaluated before and after administration of Inflexal: clinical conditions, inflammation and autoimmunity parameters, humoral response, lymphocyte proliferation and cytokine production upon flu antigen stimulation by specific and non-specific cells. Inflexal was found effective in scleroderma patients. In no subject was worsening of clinical conditions, inflammation and immunological parameters observed.

Gastroesophageal reflux and pulmonary fibrosis in scleroderma: a study using pH-impedance monitoring

RATIONALE

Interstitial lung disease (ILD) in patients with systemic sclerosis (SSc) is associated with increased morbidity and mortality. Gastroesophageal reflux (GER) is considered a contributing factor in the pathogenesis of ILD.

OBJECTIVES

To characterize GER (acid and nonacid) in patients with SSc with and without ILD.

METHODS

Patients with SSc underwent pulmonary high-resolution computer tomography (HRCT) scan and 24-hour impedance-pH monitoring off-proton pump inhibitor therapy. The presence of pulmonary fibrosis was assessed using validated HRCT-scores. Reflux monitoring parameters included number of acid and nonacid reflux episodes, proximal migration of the refluxate, and distal esophageal acid exposure. Unless otherwise specified, data are presented as median (25th-75th percentile).

MEASUREMENTS AND MAIN RESULTS

Forty consecutive patients with SSc (35 female; mean age, 53 yr; range, 24-71; 15 patients with diffuse and 25 with limited SSc) were investigated; 18 (45%) patients with SSc had pulmonary fibrosis (HRCT score >or= 7). Patients with SSc with ILD had higher (P < 0.01) esophageal acid exposure (10.3 [7.5-15] vs. 5.2 [1.5-11]), higher (P < 0.01) number of acid (41 [31-58] vs. 19 [10-23]) and nonacid (25 [20-35] vs. 17 [11-19]) reflux episodes, and higher (P < 0.01) number of reflux episodes reaching the proximal esophagus (42.5 [31-54] vs. 15 [8-22]) compared with patients with SSc with normal HRCT scores. Pulmonary fibrosis scores (HRCT score) correlated well with the number of reflux episodes in the distal (r(2) = 0.637) and proximal (r(2) = 0.644) esophagus.

CONCLUSIONS

Patients with SSc with ILD have more severe reflux (i.e., more reflux episodes and more reflux reaching the proximal esophagus). Whether or not the development of ILD in patients with SSc can be prevented by reflux-reducing treatments needs to be investigated.

Small intestinal bacterial overgrowth in patients suffering from scleroderma: clinical effectiveness of its eradication

OBJECTIVES

After the skin, the gastrointestinal tract is the second most common target of systemic sclerosis (SSc).

AIM

Our aims were to investigate orocecal transit time (OCTT) and the presence of small intestinal bacterial overgrowth (SIBO) in SSc as a cause of intestinal symptoms.

METHODS

Fifty-five SSc patients and 60 healthy controls, sex and age matched, entered the study. Enrolled subjects completed a questionnaire for intestinal symptoms and a global symptomatic score (GSS) was calculated. OCTT and the presence of SIBO were assessed by a lactulose breath test (LBT). Patients with SIBO were treated with rifaximin 1,200 mg/day for 10 days. Finally, a second questionnaire and LBT were performed 1 month after the end of therapy.

RESULTS

The prevalence of SIBO was higher in SSc patients compared with controls (30/54 vs 4/60, respectively, P < 0.001). OCTT was significantly slower in SSc patients compared with controls (150 min, 25-75th percentile 142.5-165 vs 105 min, 25-75th percentile 90-135, respectively, P < 0.001). In patients with SIBO, the median GSS score was 8 (25-75th percentile 3.25-10.75). Eradication of SIBO was achieved in 73.3% of patients, with a significant reduction of symptoms in 72.7% of them (GSS score 2, 25-75th percentile 1-3, P < 0.05).

CONCLUSIONS

These data suggest that SIBO occurs more frequently in SSc patients than in controls. Intestinal symptoms in these patients may be related to this syndrome and its eradication seems useful to improve clinical features. OCTT is significantly delayed in SSc patients, suggesting an impairment of intestinal motility, a further risk factor for the development of SIBO.

Cardiac magnetic resonance imaging detects subclinical right ventricular impairment in systemic sclerosis

OBJECTIVE

To assess myocardial involvement in patients with systemic sclerosis (SSc) with no signs or symptoms of cardiac impairment (New York Heart Association functional class I).

METHODS

Fifty patients (45 women, 5 men, age 53.3 +/- 12.9 yrs) who did not complain of serious diseases other than SSc were recruited out of 119 consecutive patients with SSc. Thirty-three were found to have limited cutaneous SSc (lSSc) and 17 diffuse SSc (dSSc). All underwent cardiovascular magnetic resonance imaging (MRI) to determine right and left systolic and diastolic volumes and ventricular ejection fractions (RVEF and LVEF). Thirty-one healthy subjects matched for sex, age, and body surface area (BSA) were studied as controls. Diffusion lung capacity test (DLCO) and high resolution computed tomography were performed to evaluate lung involvement.

RESULTS

Disease duration between patients with lSSc (14.1 +/- 11.4 yrs) and those with dSSc (6.9 +/-4.4yrs) was found to be significantly different (p < 0.003). lSSc patients were older than those with dSSc (54.8 +/- 13.7 yrs vs 50.4 +/- 9.9 yrs, respectively; p < 0.04). Anticentromere antibodies and Scl-70 were positive in 23 (46%) and 17 patients (34%). Except for the left and right systolic volumes, all unadjusted cardiac MRI measures were significantly reduced in SSc compared to the controls (p < 0.001 and p < 0.009). These differences persisted after adjustment for subjects' height and BSA. Raw RVEF data and RVEF data matched for height and BSA were significantly reduced in dSSc patients in comparison to lSSc (p < 0.03).

CONCLUSION

Compromised RVF was found in patients with asymptomatic SSc. Unlike standard diagnostic techniques, cardiac MRI appears to be a rapid and noninvasive means of determining subclinical right myocardial involvement that is otherwise undetected in patients with SSc.

CD8+CD28− T Regulatory Lymphocytes Inhibiting T Cell Proliferative and Cytotoxic Functions Infiltrate Human Cancers

Tumor growth is allowed by its ability to escape immune system surveillance. An important role in determining tumor evasion from immune control might be played by tumor-infiltrating regulatory lymphocytes. This study was aimed at characterizing phenotype and function of CD8+ CD28- T regulatory cells infiltrating human cancer. Lymphocytes infiltrating primitive tumor lesion and/or satellite lymph node from a series of 42 human cancers were phenotypically studied and functionally analyzed by suppressor assays. The unprecedented observation was made that CD8+ CD28- T regulatory lymphocytes are almost constantly present and functional in human tumors, being able to inhibit both T cell proliferation and cytotoxicity. CD4+ CD25+ T regulatory lymphocytes associate with CD8+ CD28- T regulatory cells so that the immunosuppressive activity of tumor-infiltrating regulatory T cell subsets, altogether considered, may become predominant. The infiltration of regulatory T cells seems tumor related, being present in metastatic but not in metastasis-free satellite lymph nodes; it likely depends on both in situ generation (via cytokine production) and recruitment from the periphery (via chemokine secretion). Collectively, these results have pathogenic relevance and implication for immunotherapy of cancer.

Nonleukoreduced red blood cell transfusion induces a sustained inhibition of neutrophil chemotaxis by stimulating in vivo production of transforming growth factor-beta1 by neutrophils: role of the immunoglobulinlike transcript 1, sFasL, and sHLA-I

BACKGROUND

Red blood cell (RBC) transfusion has been linked to increased susceptibility to infections in critically ill patients and to augmented incidence of postoperative infections. The mechanisms by which transfusions can induce immunosuppression are only partially defined. Recently, it has been demonstrated that RBC supernatants inhibit neutrophil migration. Such inhibitory activity is due to transforming growth factor (TGF)-beta1 contained in the supernatants that desensitize neutrophils to subsequent chemotaxic stimulation.

STUDY DESIGN AND METHODS

In ancillary experiments, it was observed that plasma from transfused patients maintained its capacity of inhibiting neutrophil chemotaxis several days after RBC transfusion. Thus, this study was planned to investigate the mechanism(s) responsible for the prolonged inhibition of neutrophil chemotaxis observed after RBC transfusion.

RESULTS

Plasma samples obtained from subjects who underwent RBC transfusion display a capability of inhibiting neutrophil chemotaxis, which is detectable up to 15 days after the transfusion. The inhibition is related to the capacity of FasL and HLA-I molecules contained in RBC supernatants to induce in vivo TGF-beta1 synthesis by neutrophils. The induction of TGF-beta1 secretion in neutrophils by HLA-I molecules depends on immunoglobulinlike transcript 1/CD85 triggering.

CONCLUSION

The property of RBC transfusion of inducing a sustained inhibition of neutrophil chemotaxis seems to be a potential mechanism that concurs to the susceptibility to infections in patients who receive transfusions. Furthermore, our findings, showing neutrophil production of TGF-beta1 in response to FasL and HLA-I molecules, confirm that neutrophils are endowed not only with effector functions but also with immunomodulatory properties possibly involved in the regulation of inflammatory processes.

Association of -318 C/T and +49 A/G cytotoxic T lymphocyte antigen-4 (CTLA-4) gene polymorphisms with a clinical subset of Italian patients with systemic sclerosis

Systemic sclerosis (SSc) is a complex and heterogeneous autoimmune disorder with a multi-factorial pathogenesis. Like other autoimmune disorders, the possible role of specific cytotoxic T lymphocyte antigen-4 (CTLA-4) gene polymorphisms in predisposing to SSc has been hypothesized, but it remains controversial. CTLA-4 promoter (-318C/T) and exon 1 (+49 A/G) polymorphisms have been analysed in 43 Italian females with SSc and in 93 unrelated matched healthy controls by a newly designed tetra-primer amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) method. No significant association has been found with either polymorphisms.Nevertheless, SSc patients without concomitant Hashimoto's thyroiditis (HT) were carrying both the -318T allele (P = 0.031) and the +49 G allele (P = 0.076) more frequently than SSc patients with HT [defined by positivity for anti-thyroperoxidase (TPO) and anti-thyroglobulin (TGA) autoantibodies] than controls. Haplotype analysis confirms this association (P = 0.028), and suggests the predominant role of the -318T, whereas that of the +49 G, if any, seems weak. Thus, in Italian SSc patients the CTLA-4 -318C/T promoter polymorphism appears to be associated with the susceptibility to develop SSc without thyroid involvement. Larger studies are needed to confirm these findings and to clarify whether the -318C/T polymorphism is the functional responsible or whether it reflects the presence of another linked genetic element in the same chromosomal region.

Frequency of telomerase-specific CD8+ T lymphocytes in patients with cancer

Telomerase is considered a universal tumor-associated antigen (TAA) due to its high rate of expression by cancers (≈90%), and clinical trials are in progress to test the immunotherapeutical efficacy of antitelomerase immunization in patients with cancer. However, the data concerning frequency and functional activity of telomerase-specific cytotoxic T lymphocytes (CTLs) in patients with cancer are few and conflicting, although their knowledge would be mandatory to predict the efficacy of telomerase-specific immunotherapy in selected patients. We performed this study to analyze frequency and cytolytic function of circulating CD8+ T lymphocytes specific for the p540 telomerase peptide in a series of human leukocyte antigen (HLA)–A2+ cancer patients. The results show that most patients with cancer have circulating telomerase-specific CD8+ T lymphocytes, but a high frequency of telomerase-specific CTLs are present only in a fraction of them. Furthermore, CTL lines able to kill telomerase-positive tumor cells, including autologous cancer cells, can be expanded ex vivo from some, but not all, patients with cancer. In conclusion, the results of the study support the development of clinical protocols using telomerase peptides as an immunizing agent. However, they underline the necessity to study single patients immunologically before undergoing vaccination, to select the patients adequately, and to eventually adapt the immunization schedule to the patient's immunologic status.

Apoptosis of antigen-specific T lymphocytes upon the engagement of CD8 by soluble HLA class I molecules is Fas ligand/Fas mediated: evidence for the involvement of p56lck, calcium calmodulin kinase II, and Calcium-independent protein kinase C signaling pathways and for NF-kappaB and NF-AT nuclear translocation

The binding of soluble HLA class I (sHLA-I) molecules to CD8 on EBV-specific CTL induced up-regulation of Fas ligand (FasL) mRNA and consequent sFasL protein secretion. This, in turn, triggered CTL apoptosis by FasL/Fas interaction. Molecular analysis of the biochemical pathways responsible for FasL up-regulation showed that sHLA-I/CD8 interaction firstly induced the recruitment of src-like p56(lck) and syk-like Zap-70 protein tyrosine kinases (PTK). Interestingly, p59(fyn) was activated upon the engagement of CD3/TCR complex but not upon the interaction of sHLA-I with CD8. In addition, sHLA-I/CD8 interaction, which is different from signaling through the CD3/TCR complex, did not induce nuclear translocation of AP-1 protein complex. These findings suggest that CD8- and CD3/TCR-mediated activating stimuli can recruit different PTK and transcription factors. Indeed, the engagement of CD8 by sHLA-I led to the activation of Ca2+ calmodulin kinase II pathway, which eventually was responsible for the NF-AT nuclear translocation. In addition, we found that the ligation of sHLA-I to CD8 recruited protein kinase C, leading to NF-kappaB activation. Both NF-AT and NF-kappaB were responsible for the induction of FasL mRNA and consequent CTL apoptosis. Moreover, FasL up-regulation and CTL apoptotic death were down-regulated by pharmacological specific inhibitors of Ca2+/calmodulin/calcineurin and Ca2+-independent protein kinase C signaling pathways. These findings clarify the intracellular signaling pathways triggering FasL up-regulation and apoptosis in CTL upon sHLA-I/CD8 ligation and suggest that sHLA-I molecules can be proposed as therapeutic tools to modulate immune responses.

Emerging biologic drugs for the treatment of rheumatoid arthritis

This article reviews the role of emerging biologic drugs for the treatment of rheumatoid arthritis (RA). Besides anti-tumor necrosis factor (TNF)-alpha and anti-interleukin (IL)-1 agents (Infliximab, Adalimumab, Etanercept and Anakinra) whose clinical efficacy is now established, new drugs have been proposed for the therapy of rheumatoid arthritis patients not responding to conventional treatments. These approaches include the blockade of B-cell activity with anti-CD20 monoclonal antibody (Rituximab) and the inhibition of T-cell activation with fusion protein CTLA4Ig. Moreover, promising results have been obtained in animal models utilizing suppressors of cytokine signaling (SOCS) and dominant-negative TNF variants to inactivate TNF signaling.

[Nailfold videocapillaroscopy in systemic sclerosis: diagnostic and follow-up parameters and correlation with both specific serum autoantibodies and subsets of skin involvement]

INTRODUCTION

The aim of the present study was to demonstrate, by nailfold videocapillaroscopy (NVC), the existence of diagnostic and follow-up parameters of microvascular damage in systemic sclerosis (SS) (grouped in the "early", "active" and "late" NVC patterns). The presence of the different subsets of skin involvement (limSS and difSS), as well as the role of some specific serum autoantibodies in the expression of the NVC parameters were investigated.

METHODS

245 consecutive SS patients were recruited and clinical data assessed. Antinuclear (ANA), antitopoisomerase I (Scl70) and anticentromere (ACA) antibodies were investigated in all patients.

RESULTS

Giant capillaries and hemorrhages were confirmed to be the earliest NVC finding in SS (diagnostic parameters). The loss of capillaries, along with ramified capillaries and vascular architectural disorganization were validated as parameters of progression of SS microangiopathy. Really, both Raynaud's phenomenon (RP) and SS duration were detected longer in patients with the "late" than in those with the "active" or the "early" NVC pattern. Patients affected by limSS were found to have shorter disease duration, as well as showed more frequently the "early" or the "active" NVC patterns. Conversely, patients affected by the difSS showed longer disease duration and mostly the presence of the "active" or "late" NVC pattern. The Scl70 positivity was lower in the patients showing the "early" than in those with the "active" and the "late" NVC patterns, whereas no significant correlation was found between the Scl70 presence and both RP and SS duration. The ACA positivity was higher in patients showing the "early" NVC pattern, as well as in patients with longer disease duration.

CONCLUSIONS

This study confirms that the identification of distinct NVC patterns may be useful to evaluate the severity and the stage of the SS microvascular damage. The presence of the Scl70 antibodies seems related to a more rapid progression of the SS microangiopathy. On the contrary, the presence of the ACA seems to be related to a slower progression of the SS microvascular damage. The SS peripheral microangiopathy is similar as in patients with limSS, as in those affected by difSS.

Nonantigen specific CD8+ T suppressor lymphocytes originate from CD8+CD28− T cells and inhibit both T-Cell proliferation and CTL function

Nonantigen specific CD8+ suppressor T lymphocytes (CD8+ Ts) inhibit T-cell proliferation of antigen-specific T lymphocytes. The impossibility to generate in vitro these cells has been correlated with the appearance of relapses in patients affected by autoimmune diseases, suggesting the involvement of these cells in immune regulation. This study was aimed to identify circulating precursors and to characterize the phenotype and mechanism of action of CD8+ Ts. We found that CD8+ Ts can be generated in vitro from CD8+CD28- T lymphocytes, but not from CD8+CD28+ T cells. A key role in their generation is played by monocytes that secrete interleukin-10 (IL-10) after granulocyte macrophage-colony-stimulating factor (GM-CSF) stimulation. Cell-to-cell direct interaction between CD8+CD28- T cells and monocytes does not play a role in the generation of CD8+ Ts. CD8+ Ts have a CD45RA+, CD27-, CCR7-, IL-10Ralpha+ phenotype and a TCR Vbeta chain repertoire overlapping that of autologous circulating CD8+ T cells. This phenotype is typical of T lymphocytes previously expanded due to antigen stimulation. Their suppressive effect on T-cell proliferation targets both antigen presenting cells, such as dendritic cells, and antigen-specific T lymphocytes, and is mediated by IL-10. CD8+ Ts suppress also the antigen-specific cytotoxic activity of CTL decreasing the expression of HLA class I molecules on target cells through IL-10 secretion. These findings can be helpful for the better understanding of immune regulatory circuits and for the definition of new pathogenic aspects in autoimmunity and tumor immunology.

Blunted coronary flow reserve in systemic sclerosis

OBJECTIVES

We investigated whether the non-invasive determination of coronary flow reserve (CFR), as evaluated by transthoracic Doppler echocardiography, might be a potential method to detect early dysfunction of cardiovascular system in patients affected by systemic sclerosis (SSc) without clinical signs or symptoms of cardiac impairment. The possible correlations between the CFR values and the duration of the disease, specific autoantibodies and cutaneous involvement subsets were investigated.

METHODS

Forty-four consecutive patients affected by SSc were analysed. The CFR was detected in the distal left anterior descending coronary artery by contrast-enhanced transthoracic second harmonic Doppler in all SSc patients and in 16 healthy controls. CFR was assessed at rest and during hyperaemia induced by administration of adenosine at 0.14 mg/kg/min over 5 min. The CFR was calculated as the ratio between hyperaemic (peak adenosine infusion) and resting peak diastolic velocity (PdvCFR) and resting velocity time integral (VtiCFR). Past medical history was carefully investigated.

RESULTS

Both PdvCFR and VtiCFR were significantly reduced in SSc patients when compared with controls (P<0.0001). In particular, both PdvCFR and VtiCFR were significantly lower in patients with dSSc when compared with patients affected by lSSc (P<0.02 and P<0.04 respectively). No statistically significant correlation was found between CFR values and history of smoking, serum levels of cholesterol or triglycerides, blood pressure, age of patients, duration of SSc and serum autoantibody positivity for ANA, ACA and Scl70.

CONCLUSIONS

CFR is often reduced in SSc patients. CFR was lower in patients with dSSc than in those affected by lSSc. A reduced CFR value should be considered an indirect sign of heart involvement in scleroderma, but its clinical and prognostic implications need to be clarified.

IFN-γ production in human NK cells through the engagement of CD8 by soluble or surface HLA class I molecules

The engagement of CD8 on NK cell surface by either surface or soluble HLA class I (sHLA-I) molecules induces synthesis and secretion of IFN-gamma. HLA-I-mediated effects were inhibited by the covering of CD8 with specific anti-CD8 monoclonal antibodies, indicating a direct interaction of HLA-I and CD8. That CD8 ligation induces IFN-gamma production was further supported by the finding that cross-linking of CD8 led to release of IFN-gamma at similar levels to those obtained with HLA-I. The sHLA-I-induced IFN-gamma production via CD8 was strongly down-regulated by the engagement of the inhibitory isoforms of either CD94/NKG2 complex by sHLA-I-non-(A,B,C,G) (putative sHLA-E) or CD158b by sHLA-I-Cw3 allele. Ligation of CD8 did not elicit, different from other activating NK cell surface molecules such as CD16 or CD69, triggering of NK cell-mediated cytolysis. Cyclosporin A, but not concanamycin A, an H+-ATPase vacuolar inhibitor which affects perforin and granzyme release, strongly reduced the sHLA-I-mediated CD8-dependent IFN-gamma production but did not affect cytolytic activity of NK cells, suggesting that different biochemical pathways are involved. Altogether, these findings indicate that CD8 engagement by sHLA-I activates a cyclosporin A-dependent pathway leading to production and secretion of IFN-gamma which may play a role in the regulation of innate immune responses in humans.

Transforming growth factor-beta1 in supernatants from stored red blood cells inhibits neutrophil locomotion

Studies comparing transfusion and nontransfusion patients suggest an increased risk of postoperative infections in transfusion groups. Supernatants of blood components have been shown to affect the function of T lymphocytes and natural killer cells. Here, we found that supernatants from stored red blood cells (RBCs) inhibit human neutrophil migration in response to formyl peptides and stimulate neutrophil locomotion. These effects can be observed with high dilutions of RBC supernatants, such as 1:5 x 106 (vol/vol), able to trigger locomotion as well as desensitization of the cells to alternative chemoattractants. The phenomenon might be mediated by chemoattractants present in the supernatants. As RBC supernatants failed to mobilize intracellular free calcium, the chemoattractants should belong to the group of pure chemoattractants, that is, soluble Fas ligand (sFasL) and transforming growth factor-beta1 (TGF-beta1), known to act without increasing calcium levels. Recombinant TGF-beta1, but not sFasL, was found to reproduce the ability of RBC supernatants to both inhibit neutrophil response to formyl peptides and stimulate neutrophil locomotion. Moreover, TGF-beta1-immunodepleted supernatants did not display neutrophil-directed activities. Finally, RBC supernatants from RBCs stored after depletion of leukocytes were incapable of affecting neutrophil function. With neutrophils acting as a first-line antimicrobial defense, the ability, shown here, of high dilutions of RBC supernatants to inhibit neutrophil chemotaxis through TGF-beta1 may be a relevant determinant of infections in the postoperative period for transfusion patients. Consistently, the neutrophil chemotactic response to formyl peptide was inhibited by the plasma obtained from 5 transfusion patients.

[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.