Glomerular expression and elevated serum Bcl-2 and Fas proteins in lupus nephritis: preliminary findings

Programmed cell death (apoptosis) is involved in glomerular injuries leading to glomerulonephritis. Bcl-2 and Fas are proteins that promote cell survival and death, respectively. This study tests the hypothesis that lupus nephritis is associated with alterations of Bcl-2 and Fas protein expression. Thirty-six patients with lupus nephritis and 10 controls (normal individuals) were included in this study. Bcl-2 and Fas positive cells were examined in kidney biopsies by immunohistochemistry. Bcl-2 and Fas serum levels were evaluated by enzyme-linked immunosorbent assay (ELISA). In the glomeruli of normal kidneys, Bcl-2 and Fas proteins were completely absent. In lupus nephritis patients, glomerular expression of Bcl-2 and Fas was seen in mesangial cells (1.3 +/- 0.1 and 2.0 +/- 0.1 for Bcl-2 and Fas, respectively). Similarly, a statistically significantly higher Bcl-2 (217.1 +/- 85.9) and Fas (767.9 +/- 271) serum levels were found in lupus patients compared to controls (148.6 +/- 87, 550.3 +/- 91 for Bcl-2 and Fas, P < 0.05). A direct correlation between serum Bcl-2 and Fas and chronicity index was also found. Compared to normal controls, lupus nephritis is associated with glomerular expression and elevated serum levels of Bcl-2 and Fas proteins. These findings suggest possible roles for Bcl-2 and Fas in glomerular injury during evolution of lupus nephritis. The diagnostic, prognostic and therapeutic ramifications of our findings are open to further investigation.

The fas and fas ligand pathways in liver allograft tolerance

The Fas and Fas ligand (Fas/FasL) pathways may play a central role in cytotoxicity or immunoregulation in liver transplantation. Here, in an attempt to examine the role of Fas/FasL on drug-free tolerance, we measured mRNA levels of Fas/FasL in livers by reverse transcriptase-polymerase chain reaction (RT-PCR), and also protein levels of Fas/FasL in livers by immunohistochemistry and in serum by dot blot assay. PVG recipients bearing DA livers showed serious rejection between post-operative (POD) days 7 and 14, but this rejection was naturally overcome without any immunosuppression. Fas gene and protein products were expressed on almost every cell in livers taken from naive rats, and at any time point in both syngeneic and allogeneic orthotopic liver transplantation (OLT) rats. In contrast, FasL mRNA in DA livers was detectable at POD 2, peaked at POD 14, and declined at POD 63 in allogeneic OLT (DA-PVG). Although the FasL gene was detectable in isografts at POD 14, its expression was much lower than in allografts. The time course and localization of FasL expression indicated that the expression of FasL gradually switched from infiltrating cells to hepatocytes when the rejection was naturally overcome and tolerance was induced in this OLT model. Soluble Fas could constitutively be detected at any time point in the serum of the tolerogenic OLT (DA-PVG) rats and was not diminished during the rejection phase. Soluble FasL peaked at POD 14 in allogeneic OLT, while sFasL was significantly lower in the serum of normal and syngeneic OLT rats. These findings suggest that the Fas and FasL pathways, including soluble forms, may contribute to the control of the immune response in this drug-free tolerance OLT model.

Clinical implications of circulating soluble Fas and Fas ligand in patients with acute myocardial infarction

BACKGROUND

Apoptotic cell death is the major form of myocardial damage produced by coronary ischemic events.

OBJECTIVE

To assess whether circulating levels of soluble Fas (sFas), an inhibitor of apoptosis, and sFas ligand, an inducer of apoptosis, in patients with coronary artery disease are greater than normal.

METHODS

Forty-seven patients [acute myocardial infarction (AMI) in 17, old myocardial infarction (OMI) in 15, stable angina in 15] and 10 normal control subjects participated in this study. Serum levels of sFas and sFas ligand in all patients were measured, and cardiac catheterizations were performed.

RESULTS

Serum levels of sFas were greater than normal only in patients with AMI (4.6 +/- 1.6 ng/ml); the levels were significantly higher than those in patients with OMI (2.1 +/- 0.6 ng/ml) and stable angina (2.2 +/- 0.5 ng/ml), and in normal subjects (2.0 +/- 0.6 ng/ml; P < 0.0001). However, there was no difference among serum levels of sFas ligand for all groups. For patients with AMI, there was no significant correlation between serum levels of sFas and peak levels both of plasma creatine phosphokinase and of plasma myosin light chain type I as clinical indexes of infarct size. However, there were significant correlations between serum levels of sFas and both pulmonary artery wedge pressure (r = 0.767, P = 0.0003) and left ventricular end-diastolic pressure (r = 0.629, P = 0.03).

CONCLUSIONS

Circulating sFas increases in concentration in relation to the severity of hemodynamic conditions in patients with AMI, but it is independent from size of infarct. Therefore, circulating sFas could play an important role as the marker of pathophysiologic conditions associated with cardiomyocyte apoptosis in AMI.

A high serum soluble Fas/APO-1 level is associated with a poor outcome of aggressive non-Hodgkin's lymphoma

Soluble Fas (sFas) in the serum is believed to be able to inhibit apoptosis of lymphocytes. It has been reported that the serum sFas level is increased in various diseases, including malignant lymphoma and systemic lupus erythematosus. We studied the association between sFas and the prognosis of patients with aggressive non-Hodgkin's lymphoma (NHL). Compared with normal controls, the serum sFas level was increased significantly in patients with aggressive NHL and adult T cell leukemia/lymphoma. Among patients with aggressive NHL, the complete remission rate was significantly decreased in the subgroup having high serum sFas levels. Both the overall survival rate and the disease-free survival (DFS) rate were significantly lower for this subgroup than for patients with low serum sFas levels. The 5-year survival rates estimated by the Kaplan-Meier method for patients with high and low serum sFas levels were 27.6% and 68.3%, respectively (P = 0.0001). The 5-year DFS rates estimated for patients with high and low serum sFas levels were 44.7% and 71.9%, respectively (log-rank test: P = 0.0023, and generalized Wilcoxon test: P = 0.0014). Among patients with a low and low-intermediate risk group according to the International Prognostic Index (IPI), the 5-year survival rates for low and high serum sFas subgroups were 72.8% and 42.0%, respectively, showing a significant difference (Wilcoxon test: P = 0.0163, log-rank test: P = 0.0115). Among patients with a high-intermediate and high risk group, the 5-year survival rates for low and high serum sFas subgroups were 51.6% and 17.4%, respectively, again showing a significant difference (Wilcoxon test: P = 0.0001, log-rank test: P = 0.0002). Multivariate analysis of a series of prognostic factors, including the five used to calculate the IPI, showed that the serum sFas level was an independent prognostic factor for the overall survival. Based on these results, a serum sFas level of 10 ng/ml or more can be considered to indicate a poor prognosis in patients with advanced NHL, and this finding may be useful for developing strategies for further treatment.

Increased serum levels of soluble Fas in progressive B-CLL

Clinical progression of B-cell chronic lymphocytic leukemia (B-CLL) depends on survival and accumulation of leukemic cells, regulated in part by physical cell contact and soluble molecules. Here we have studied the Fas/FasL system in relation to clinical progression in B-CLL. Serum levels of soluble Fas (sFas) and FasL (sFasL) were determined by ELISA in 43 progressive and 40 non-progressive B-CLL patients and in 21 control individuals. Correlation between sFas serum levels and clinical progression, stage and survival were statistically analyzed. We found high levels of sFas in B-CLL sera correlated with disease progression (p<0.01). In addition, higher sFas levels were found in patients in stages II, III and IV in comparison to patients in stage 0 (p<0.05, p<0.01, p<0.03, respectively). Survival was significantly shorter for patients with > or =6 ng/ml sFas serum levels, although a multivariate analysis did not show sFas to be a significant independent prognostic factor. Fresh B-CLL cells showed only low levels of membrane expression, which were not correlated to sFas levels in serum. In vitro activation of B-CLL cells increased Fas expression, as reported earlier, and induced cells to release sFas into the supernatant. In conclusion, our results indicate that sFas in serum may be a useful parameter for the prediction of clinical progression in B-CLL.

Mononuclear leukocyte apoptosis and inflammatory markers in patients with chronic kidney disease

BACKGROUND/AIM

Increased apoptosis along with enhanced inflammation has been reported in hemodialysis and pre-dialysis patients. However, there is limited information at which stage during the progression of chronic kidney disease (CKD) the balance between pro- and anti-apoptotic mechanisms is disturbed and inflammatory response is activated. The aim of this study was to investigate possible alterations in apoptotic and inflammatory markers during CKD (stages 1-4) progression and the probable interactions between them.

METHODS

In a cross-sectional study, 152 steady-state CKD outpatients (83 males, 55%) with mean estimated glomerular filtration rate 46 (29-76) ml/min/1.73 m(2) were studied. Apoptosis was assessed in peripheral blood mononuclear cells by estimating Bcl-2 expression, annexin V-propidium iodine staining and serum soluble Fas (sFas) and Fas-ligand. Serum levels of C-reactive protein, tumor necrosis factor-α (TNF-α), interleukin-6 and plasma levels of fibrinogen were measured as markers of inflammation.

RESULTS

Bcl-2 expression was found to decrease significantly in both lymphocytes and monocytes from CKD stage 1 to 4. In contrast, the activity of sFas increased significantly and so did the levels of TNF-α and fibrinogen. The majority of these alterations occurred as soon as patients entered stage 3 of CKD. A multivariate regression analysis demonstrated that CKD remained a significant predictor of the aggregate of the assessed markers.

CONCLUSIONS

Apoptosis appeared to increase across CKD stages 1-4, and this was associated with increased proinflammatory activity.

Alteration of Fas and Fas ligand expression during human visceral leishmaniasis

Several studies in murine systems have suggested a role of apoptosis in the pathogenesis of leishmaniasis. However, the role of apoptosis in visceral leishmaniasis in man has not been explored. In this study, we show that patients with visceral leishmaniasis demonstrate significant dysregulation of Fas and Fas ligand. Levels of soluble Fas (sFas) and soluble Fas ligand (sFasL) were elevated in plasma of patients with active visceral leishmaniasis (VL) and individuals co-infected with VL-HIV-1 compared to healthy controls. The levels of sFas and sFasL were normalized 6 months after successful treatment. In VL patients, the expression of membrane bound Fas, and to a lower extent FasL, were up-regulated on Leishmania donovani-infected spleen cells, the site of parasite multiplication. Expression of Fas and FasL on peripheral blood mononuclear cells was within normal range, probably reflecting that the blood is not a normal site of L. donovani infection. Furthermore, this is suggested by the finding that in vitro infection of macrophages with L. donovani up-regulated Fas expression on the surface of infected cells and enhanced the levels of sFasL in supernatants from infected cultures. How this dysregulation may affect the pathogenesis of human visceral leishmaniasis is discussed.

Variations in the serum concentrations of soluble Fas and soluble Fas ligand in Vietnamese patients infected with hepatitis B virus

Earlier studies of both chronic hepatitis B and C virus (HBV and HCV) patients have shown a strong correlation between the soluble membrane Fas (sFas) and Fas protein expression on hepatocytes. The serum concentrations of sFas and soluble Fas ligand (sFasL) was examined in both healthy and HBV-infected Vietnamese patients to determine their relationship with the outcome of HBV infection. Patients with chronic rather than acute HBV had significantly higher amounts of sFas and sFasL, whilst the highest concentrations of both molecules were detected in those with malignant forms of HBV infection. sFas and sFasL concentrations tended to increase with a profile that paralleled the progression from asymptomatic to acute through chronic to malignant states, most markedly in the case of sFas. The sFas:sFasL ratio highlighted the relative predominance of sFas in those with acute and chronic HBV compared with asymptomatic or severe forms. In patients with hepatocellular carcinoma (HCC) a significant correlation was also observed between sFasL and alpha-feto protein (AFP) levels. The results indicate that sFas and to a lesser extent sFasL levels are to some degree associated with clinical progression in HBV infection.

Effects of interferon-gamma and tumour necrosis factor-alpha on CD95/Fas ligand-mediated apoptosis in human blood eosinophils

Many cells, including eosinophils, express CD95 (Fas), a surface receptor that mediates apoptosis when ligated by specific antibodies or its natural ligand, Fas ligand (FasL). As apoptosis may play an important role in the regulation of tissue eosinophilia, factors that modulate eosinophil sensitivity to apoptosis are of great interest. It has previously been shown that interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) together increase CD95 surface expression on eosinophils. However, the functional consequences of this increase in CD95 expression have not been demonstrated in detail. We therefore investigated whether the increase in CD95 expression mediated by IFN-gamma/TNF-alpha indeed translates into increased, FasL-mediated apoptosis of eosinophils. For this purpose, purified eosinophils from normal donors were incubated with different concentrations of FasL and induction of apoptosis was assessed by annexin-V/propidium iodide assay. Unlike Jurkat cells, which became apoptotic within 2 h after incubation with FasL, an increase in eosinophil apoptosis could first be dedicated after 6 h incubation with FasL. Prestimulation with IFN-gamma/TNF-alpha for 24 h significantly enhanced FasL-induced apoptosis in eosinophils. This increase in CD95/FasL-mediated apoptosis was correlated with an IFN-gamma/TNF-alpha-mediated increase in CD95 expression. From these findings we conclude that the combination of IFN-gamma and TNF-alpha enhances CD95 expression, which results in an increase in FasL-mediated apoptosis of eosinophils in vitro.

Comparison of the activation status of tumor infiltrating and peripheral lymphocytes of patients with adenocarcinomas and benign hyperplasia of the prostate

BACKGROUND

The presence of lymphocytic infiltration in prostate carcinomas has been shown to have prognostic relevance. However, it is not yet clear if this infiltrate represents a tumor-specific activated cell population or not. Therefore, the aim of the present study was to characterize the activation status of freshly isolated tumor infiltrating lymphocytes (TIL) from prostate carcinomas (PCa) and benign hyperplasia (BPH) with respect to the mRNA expression of cytokines and apoptotic factors.

METHODS

TIL were isolated from mechanically disaggregated tumor material by gradient centrifugation. The cells of the interphase were depleted from epithelial cells with anti-human epithelial antigen magnetic beads and then CD3(+)- lymphocytes were selected with magnetic beads against this determinant. In these pure lymphocyte preparations the mRNA expression of IL-1, IL-10, IFN-gamma, TNF-alpha, Fas and Fas ligand was determined by using a semiquantitative RT-PCR. Contamination with tumor cells was excluded by a PCR for PSA and PSMA.

RESULTS

The CD3(+)-TIL from 21 patients with PCa and 20 patients with BPH expressed significantly higher levels of IL-10- and Fas ligand-mRNA compared to the autologous CD3(+)- PBL, whereas the expression of IL-1-, TNF-alpha- and Fas-mRNA was not different in either cell population. In contrast, the mRNA levels of IFN-gamma were significantly higher only in the CD3(+)-TIL from the carcinomas but not from the BPH compared to autologous CD3(+)-PBL.

CONCLUSIONS

Since high levels of IFN-gamma have been reported to be produced by specifically lytic lymphocytes, our results suggest the presence of specifically activated TIL in the prostate carcinomas but not in the BPH, whereas inflammatory activated TIL are present both in the carcinomas and the BPH.

Do elevated levels of serum-soluble fas contribute to the persistence of activated lymphocytes in systemic lupus erythematosus?

Systemic lupus erythematosus (SLE) is characterized by generalized immune activation. Part of this might be explained by a decreased rate of apoptosis, possibly related to elevated levels of soluble Fas (sFas) which can inhibit Fas mediated apoptosis of lymphocytes. In order to substantiate the relation between levels of sFas and lymphocyte activation in SLE we monitored sFas levels, lymphocyte activation and disease activity in 25 SLE patients. SLEDAI scores were registered and sera were assayed for sFas levels by an enzyme-linked immunosorbent assay. Flow cytometry was used to monitor the state of activation of lymphocyte subsets. Eighteen healthy, age-matched volunteers served as controls. Soluble Fas levels were elevated in SLE patients (n=25) compared to healthy controls (n=18, P=0.002). Soluble Fas levels correlated with SLEDAI scores (r=0.45, P=0.02). Levels of sFas correlated with the percentages of activated B cells defined as CD20(+)CD38(+) cells (r=0.47, P=0.009). Percentages of CD20(+)CD38(+) cells were increased in quiescent SLE compared to healthy controls (P=0.003). The expression of activation markers on CD4(+) T lymphocytes (IL-2R, P=0.04; HLA-DR, P=0.01) and CD8(+) T lymphocytes (HLA-DR, P=0.007) was also increased in quiescent SLE compared to controls. Activation markers on all lymphocyte subsets tended to increase further during disease activity. No correlation was observed between percentages of activated T lymphocyte subsets and levels of sFas. In conclusion, soluble Fas levels are increased in SLE patients and correlate with disease activity as measured by the SLEDAI score and B and T cell subsets are activated even during quiescent SLE. Serum levels of sFas correlate with percentages of activated B cells but not with that of activated T cells.

Serum apoptosis markers related to liver damage in chronic hepatitis C: sFas as a marker of advanced fibrosis in children and adults while M30 of severe steatosis only in children

Background

Liver biopsy represents the gold standard for evaluating damage and progression in patients with chronic hepatitis C (CHC); however, developing noninvasive tests that can predict liver injury represents a growing medical need. Considering that hepatocyte apoptosis plays a role in CHC pathogenesis; the aim of our study was to evaluate the presence of different apoptosis markers that correlate with liver injury in a cohort of pediatric and adult patients with CHC.

Methods

Liver biopsies and concomitant serum samples from 22 pediatric and 22 adult patients with CHC were analyzed. Histological parameters were evaluated. In serum samples soluble Fas (sFas), caspase activity and caspase-generated neoepitope of the CK-18 proteolytic fragment (M30) were measured.

Results

sFas was associated with fibrosis severity in pediatric (significant fibrosis p = 0.03, advanced fibrosis p = 0.01) and adult patients (advanced fibrosis p = 0.02). M30 levels were elevated in pediatric patients with severe steatosis (p = 0.01) while in adults no relation with any histological variable was observed. Caspase activity levels were higher in pediatric samples with significant fibrosis (p = 0.03) and they were associated with hepatitis severity (p = 0.04) in adult patients. The diagnostic accuracy evaluation demonstrated only a good performance for sFas to evaluate advanced fibrosis both in children (AUROC: 0.812) and adults (AUROC: 0.800) as well as for M30 to determine steatosis severity in children (AUROC: 0.833).

Conclusions

Serum sFas could be considered a possible marker of advanced fibrosis both in pediatric and adult patient with CHC as well as M30 might be a good predictor of steatosis severity in children.

Soluble Fas (CD95) is a prognostic factor in patients with metastatic breast cancer undergoing high-dose chemotherapy and autologous stem cell transplantation

The Fas/Fas ligand (FasL) system plays an important role in cellular apoptosis and is involved in cancer cell death induced by the immune system and anticancer drugs. Increased serum levels of soluble Fas (sFas) are associated with a number of different disease states and with tumor progression and metastasis in patients. In this study, we examined the plasma levels of sFas in 94 women with metastatic breast cancer undergoing high-dose chemotherapy (HDCT) treatment with autologous stem cell transplantation (ASCT) using a quantitative enzyme-linked immunosorbent assay (ELISA) method. Thirty-one patients (31/94, 33%) had plasma sFas levels greater than the optimum cut point of 1.90 ng/ml (median 2.47, range 1.98-13.54 ng/ml) and were designated as sFas positive. Sixty-three patients (63/94, 67%) had sFas levels below 1.90 ng/ml (median 1.14, range 0.47-1.89 ng/ml). In univariate analysis, patients with sFas-positive status, HER-2 overexpression, and the presence of liver metastases had a significantly shorter time to disease progression (PFS) and significantly decreased overall survival (OS). Multivariable analysis (Cox proportional hazards model) for PFS determined that sFas status significantly predicted disease progression (p = 0.004) with an adjusted hazard ratio (HR) of 2.0 (95% CI, 1.3-3.3). HER-2 status and liver metastases were also significant independent predictors of disease progression (p < 0.001) for both. sFas level was also an independent prognostic factor for OS with an adjusted HR of 2.0 (p = 0.006; 95% CI, 1.2-3.4). HER-2 status and liver metastases also remained highly significant independent prognostic factors for OS (HER-2: p < 0.001, HR 2.3, and liver metastases: p = 0.001, HR 2.7). In conclusion, these results suggest that plasma levels of sFas may be a valuable clinical prognostic factor in predicting outcome (PFS and OS) for patients with metastatic breast cancer undergoing HDCT with ASCT.

Soluble and membrane isoforms of Fas/CD95 in fresh adult T-cell leukemia (ATL) cells and ATL-cell lines

Fas, also designated as Apo-1 and CD95, is a cell membrane receptor (mFas) involved in apoptotic cell death. A soluble form (sFas) lacking the transmembrane domain due to alternative splicing has been isolated. Abnormal expression of sFas and mFas is likely to be involved in lymphoproliferative disorders and auto-immune diseases. Adult T-cell leukemia (ATL) caused by human T-cell-leukemia virus type-1 (HTLV-1) is well known to be a T-cell neoplasm with strong mFas expression, suggesting a role of Fas in the pathology of the disease. We examined protein and mRNA expression of the 2 isoforms of Fas in fresh ATL cells and ATL cell lines. In general, mFas was strongly expressed in ATL cells, and sFas levels in sera were high, especially in malignant ATL. However, expression of the isoforms in some cases of ATL varied; there was no mFas expression on the cell surface and sFas levels were high in serum. In contrast, all ATL cell lines examined showed strong mFas expression and scarce production of sFas in the supernatant, corresponding to strong expression of full-length Fas mRNA and weak to negative expression of alternatively spliced mRNA lacking the transmembrane domain. Our findings indicate that the mode of expression of Fas isoforms in ATL cells is not always homogenous and that Fas may play a role in the malignant behavior and oncogenesis of ATL.

Relationship between plasma levels of cardiac natriuretic peptides and soluble Fas: plasma soluble Fas as a prognostic predictor in patients with congestive heart failure

BACKGROUND

Cardiac natriuretic peptides may induce apoptosis in myocytes; however, the relationship between plasma levels of cardiac natriuretic peptides and those of soluble Fas (sFas) and tumor necrosis factor (TNF)-alpha remains unknown in patients with congestive heart failure (CHF).

METHODS AND RESULTS

We measured plasma levels of sFas and TNF-alpha and those of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), norepinephrine, and endothelin 1 in 96 patients with CHF (ejection fraction < 45%). The patients were monitored for 3 years. Plasma levels of sFas and TNF-alpha increased with the severity of CHF. There was no significant correlation between sFas plasma levels and those of ANP and BNP. Cox proportional hazard analysis showed that high levels of sFas (P = .009) and BNP (P < .0001) and a low ejection fraction (P = .019) were independent significant prognostic predictors.

CONCLUSIONS

There is no significant correlation between cardiac natriuretic peptide and sFas levels in plasma. Plasma sFas is a useful prognostic marker independent of neurohumoral factors, suggesting that immune activation and/or apoptosis play a significant role in the pathogenesis of CHF.

Fas antigen (CD95) and hematopoietic progenitor cells

We investigated the expression of an apoptosis associated antigen (Fas) (CD95) on hematopoietic progenitor cells. Freshly isolated CD34+ cells from bone marrow did not express Fas. However, interferon-gamma (IFN-gamma) and/or tumor necrosis factor-alpha (TNF-alpha) induced dose-dependent expression of both Fas mRNA and Fas protein on the surface of CD34+ cells after 48 hours of serum-free culture. TNF-alpha-induced Fas expression was mediated by p55-TNF-alpha receptor. Induced Fas was functional as it could transduce apoptotic signals in response to anti-Fas monoclonal antibody (MoAb). The Fas-defective 1pr mice are reported to have abnormally radio-resistant hematopoietic stem cells. Consequently, we also investigated the relation between Fas and ionizing radiation. Human CD34+ cells expressed Fas following low-dose ionizing radiation in a dose-dependent fashion. Fas induced on CD34+ cells mediated apoptosis in response to anti-Fas MoAb. We evaluated the expression of Fas and Bel-2 on CD34+ hematopoietic progenitor cells expanded in vitro. CD34+ cells isolated from bone marrow were cultured with hematopoietic growth factors for 7 days. Approximately half of the freshly isolated CD34+ cells expressed Bel-2. CD34+ cells cultured with hematopoietic growth factors gradually became positive for Fas and rapidly lost Bel-2 expression. Furthermore apoptosis was induced in the cultured CD34+ population in response to anti-Fas MoAb. Thus, functional Fas can be induced on hematopoietic progenitor cells in vitro by negative hematopoietic regulators, ionizing radiation, as well as positive hematopoietic regulators. The Fas system is thought to play an important role at the level of hematopoietic progenitor cells in both physiologic and pathologic conditions.

Involvement of IL-18 and soluble fas in patients with postoperative hepatic failure

We measured the levels of tumor necrosis factor alpha (TNF-alpha), interleukins (IL)-6 and -18, and soluble Fas (sFas) in 11 patients with postoperative hepatic failure and assessed whether IL-18-mediated apoptosis is involved in the onset of liver dysfunction. The serum TNF-alpha, IL-18, and sFas levels were significantly higher in patients with sepsis as a complication than in those without sepsis. The TNF-alpha and IL-18 levels were significantly higher in nonsurvivors than in survivors. Significant correlations were observed between TNF-alpha and IL-6, between TNF-alpha and IL-18, and between TNF-alpha and sFas levels. These results showed that Fas-mediated hepatocyte apoptosis functions as an important mechanism responsible for the onset of postoperative hepatic failure in humans. They especially suggested that IL-18 and TNF-alpha function both as apoptosis-promoting factors and as apoptosis-inhibiting factors, depending on the conditions to which hepatocytes are subjected.

Anti-CD95 (APO-1/Fas) autoantibodies and T cell depletion in human immunodeficiency virus type 1 (HIV-1)-infected children

Advanced stages of HIV-1-infection are characterized by progressive CD4+ T cell depletion. Peripheral T cells from HIV-1+ donors show accelerated apoptosis in vitro. The CD95 (APO-1/Fas) receptor/ligand system is involved in this process. To further study deregulation of the CD95 system in peripheral T cells during HIV-1-infection, we measured CD95-expression on CD4+ and CD8+ T cells together with serum levels of soluble CD95 (sCD95) and anti-CD95 autoantibodies in HIV-1+ children and healthy controls. Anti-CD95 levels in HIV-1+ children were significantly elevated when compared to uninfected controls, whereas serum levels of sCD95 were not different. In HIV-1+ children, CD95-expression on CD4+ and CD8+ T cells increased with age. A strong correlation between depletion of CD4+ cells in vivo and increase in CD95-expression on CD4+ T cells was observed. In contrast, such a correlation was not found for CD8+ T cells. A negative correlation between anti-CD95 autoantibody levels and CD4+ T cell counts, that was predicted by multiple linear regression analysis of pooled data, was found in individual patients observed longitudinally by repeated measurements. Since anti-CD95 autoantibodies isolated from HIV-infected adults have previously been shown to induce apoptosis of sensitive target cells in vitro, we speculate that the interaction of these antibodies with CD95-positive and CD95-sensitive T cells in vivo might be involved in progressive T cell loss during HIV-1-infection.

Differential expression of Fas system apoptotic molecules in peripheral lymphocytes from patients with Graves' disease and Hashimoto's thyroiditis

OBJECTIVE

To examine whether the Fas system apoptotic molecules are differentially expressed in Graves' disease (GD) and Hashimoto's thyroiditis (HT), the two opposite phenotypes of autoimmune thyroid disease (AITD).

DESIGN

The expression of Fas and Fas ligand (FasL) on peripheral CD4 and CD8 lymphocytes, and non-lymphoid immune cells as well as their soluble forms in serum from untreated patients with GD and HT were evaluated.

METHODS

Flow cytometry was performed for the study of peripheral immune cells from 70 newly diagnosed patients with AITD (55 with HT and 15 with GD) and 20 controls. ELISA was used for the measurement of soluble Fas (sFas) in serum samples from a subgroup of 35 AITD patients.

RESULTS

An increase in the proportion of CD4 and CD8 cells expressing Fas was found in both GD and HT, albeit with some differences, when compared with controls. Importantly, in GD patients, the intensity of Fas expression on CD4 and CD8 lymphocytes was reduced and sFas levels in serum were simultaneously increased when compared with HT patients and controls.

CONCLUSIONS

The Fas system apoptotic molecules appear to be differentially expressed on peripheral lymphocytes in the two opposite phenotypes of AITD.

Serum soluble Fas levels in ovarian cancer

OBJECTIVE

To determine the value of serum soluble Fas levels as a prognostic marker for survival of women with ovarian cancer and as a discriminator between benign and malignant adnexal masses.

METHODS

Serum soluble Fas levels were measured with an enzyme-linked immunosorbent assay in 52 women with ovarian cancer, 30 women with benign ovarian cysts, and 35 healthy women.

RESULTS

Median serum soluble Fas levels in women with ovarian cancer, women with benign ovarian cysts, and healthy women were 3.7 (range 1.6-14.5), 2.3 (range 1.3-4.1), and 1.5 ng/mL (range 0.1-5.6), respectively (P <. 001). A univariate logistic regression model showed a significant influence of serum soluble Fas and CA 125 levels on the odds of presenting with ovarian cancer versus benign cysts (P <.001 and P =. 001, respectively). In a multivariable logistic regression model for soluble Fas and CA 125, both markers showed a statistically significant influence on the odds of presenting with ovarian cancer versus benign cysts (P =.01 and P =.01, respectively). Increased pretreatment serum soluble Fas levels were associated with shortened disease-free and overall survival (P =.002 and P =.001, respectively). A multivariable Cox regression model identified serum soluble Fas levels as a significant prognostic factor for disease-free and overall survival, independent of tumor stage (P =. 04 and P =.03, respectively).

CONCLUSION

Soluble Fas levels might be useful as a discriminator between benign ovarian cysts and ovarian cancer, adding to the information obtained with the use of the established tumor marker CA 125. Pretreatment serum soluble Fas levels also might be an independent prognostic factor for disease-free and overall survival.

Increased apoptosis of peripheral blood mononuclear cells in patients with perennial allergic asthma/rhinitis: relation to serum markers of apoptosis

BACKGROUND

The goal of our study was to examine spontaneous and stimulated apoptosis of peripheral blood MNC from allergic patients, sensitized to Der p I antigen as compared to cells from non-atopic subjects. Furthermore we aimed to investigate which populations of mononuclear cells (lymphocytes, monocytes) undergo the apoptosis and to determine relations between apoptosis and serum levels of sFas/APO-1, ICE/caspase-1 or TNF-alpha.

METHODS

The study included 17 patients with perennial, allergic asthma and/or allergic rhinitis [6 male and 11 female; mean age 29,5 years; (range 15-49)]. Apoptosis was assessed by fluorescence technique and confirmed by flow-cytometric method and DNA ladder. Serum levels of sFas, ICE/caspase-1 or TNF-alpha were determined by immunoassays (ELISA).

RESULTS

Apoptotic index of unfractionated mononuclear cells (MNC) and lymphocytes (but not monocytes) were significantly higher in allergic patients as compared to non-allergic subjects after 48 and 72 hours of culture (p<0.05). Incubation of cells with ConA (10 microg/ml) resulted in a significant increase in the proportion of apoptotic cells in all populations once the apoptotic index for MNC and lymphocytes (but not monocytes) was again significantly higher in allergic as compared to non-allergic subjects after 24, 48 and 72 hour of culture. In allergic patients, mean serum sFas level, was significantly lower then in non-allergic group (mean value 624.8 pg/ml +/- 25.67 versus 802.0 pg/ml +/- 31.91; p = 0.003) and in both groups sFas level correlated inversely with apoptosis of MNC. The mean ICE/caspase-1 concentration was significantly higher in sera of allergic patients as compared to non-allergic group (mean value 27.71 pg/ml +/- 3.79 vs 23.54 pg/ml respectively; p<0.01). ICE/caspase-1 levels in allergic patients correlated with apoptotic index of mononuclear cells (r = 0.57; p<0.001).

CONCLUSIONS

An increased spontaneous and mitogen-induced apoptosis of MNC from peripheral blood of atopic patients as well as different serum levels of sFas and ICE/caspase-1 correlating with apoptosis, suggest different regulation of apoptotic process in peripheral blood mononuclear cells of patients with allergic asthma and/or rhinitis.

Serum levels of apoptosis-related molecules in patients with multiple sclerosis and human T-lymphotropic virus Type I-associated myelopathy

We evaluated the presence of soluble Fas (sFas), Fas ligand (sFasL), and Bcl-2 in the sera of patients with multiple sclerosis (MS) or human T-lymphotropic virus type I (HTLV-1)-associated myelopathy (HAM) using an enzyme-linked immunosorbent assay (ELISA). Patients with MS in the active phase had higher sFas and Bcl-2 levels than had controls (sFas, p < 0.005; Bcl-2, p < 0.05) or patients in the inactive phase (p < 0.05). In addition, significantly increased serum levels of sFas were found in patients with HAM (p < 0.005). Interestingly, levels of sFasL in sera from patients with HAM and MS in the active stage were higher than those from controls or from patients with MS in the inactive stage or from other inflammatory neurologic diseases (OIND), although this was not statistically significant. These results suggest that serum sFas, sFasL, and Bcl-2 may play an important role in the pathogenesis of MS and HAM.

Serum concentration of soluble Fas in patients with autoimmune thyroid diseases

Fas is an apoptosis-signaling receptor molecule found on the surface of a number of cell types. Malfunction of the Fas system accelerates autoimmune diseases, whereas its exacerbation may cause tissue destruction. Soluble Fas (sFas) molecule lacks the transmembrane domain due to alternative splicing and blocks Fas-mediated apoptosis. This study investigated serum levels of sFas in autoimmune thyroid diseases. Serum levels of sFas were determined by enzyme-linked immunosorbent assay in 46 patients with Graves' disease, 32 patients with Hashimoto's thyroiditis, 14 patients with silent thyroiditis, and 24 normal controls. Compared with normal subjects (1.43+/-0.37 ng/mL), sFas was increased in thyrotoxic patients with Graves' disease (1.89+/-0.47 ng/mL, p < 0.001), and was decreased in patients with Graves' disease in remission (1.02+/-0.41 ng/mL, p < 0.001) and in euthyroid patients with Hashimoto's thyroiditis (0.97+/-0.25 ng/mL, p < 0.0001), but was normal in hypothyroid patients with Hashimoto's thyroiditis and in thyrotoxic patients with silent thyroiditis. Thus, changes in serum levels of sFas could not be explained by changes in serum thyroid hormones, although sFas concentration correlated with free thyroxine (r = 0.692, p < 0.0001). Also, the levels of sFas significantly correlated with the activities of TSH receptor antibody in Graves' disease (r = 0.671, p < 0.0001). Increased sFas in Graves' disease suggests increased expression of alternatively spliced Fas mRNA variant that produces sFas protein and decreased of cell surface expression of Fas, and may induce thyroid cell growth and production of TSH receptor antibody by protecting against apoptosis of thyroid cells and autoreactive B cells. Decreased sFas in Hashimoto's thyroiditis suggests decreased Fas mRNA variant and increased full-length Fas mRNA and membrane Fas, and may induce destruction of thyroid cells by promoting apoptosis of thyroid cells.

Increased circulating soluble form of Fas in patients with dilated cardiomyopathy

To examine the prognostic role of the circulating soluble form of Fas (sFas), circulating sFas levels were measured in 33 patients with dilated cardiomyopathy (DCM) and 12 age-matched normal control subjects (NC) using an enzyme-linked immunosorbent assay (ELISA). Circulating sFas levels in DCM were significantly higher than those in NC (2.42+/-1.02 vs 1.66+/-0.20 ng/ml, p=0.015). Patients with DCM were stratified into 2 groups [group I (n=15): sFas > or =2.06 ng/ml; group II (n=18): sFas <2.06 ng/ml] on the basis of the mean value plus 2SD of circulating sFas level in NC. The circulating sFas level was significantly increased in relation to the severity of heart failure and correlated positively to left ventricular end-diastolic pressure in DCM. However, there were no significant differences in left ventricular dimension between the 2 groups. There were 5 deaths from worsening heart failure in group II, but there were no deaths in group I during the follow-up period. In conclusion, circulating sFas levels were increased in patients with DCM. Circulating sFas levels are increased in proportion to the severity of heart failure and may provide prognostic information independent of left ventricular geometry.

Coronary heart disease, hypertension, and angiotensinogen gene variants in Indian population

Gene encoding components of the renin angiotensin system (RAS) have been implicated with the increased risk of cardiovascular disease (CVD). Two variants of the angiotensinogen (AGT) gene, M235T and T174M, have been shown to be associated with increased risk of hypertension. In the present study, we examined the association of these two polymorphisms and their synergistic interaction with the angiotensin I-converting enzyme (ACE) deletion homozygote genotype (D/D) on subjects with coronary heart disease (CHD) and hypertension. We studied 131 healthy individuals, 141 angiographically verified CHD patients, and 159 hypertensive subjects. The identification of the ACE and AGT gene polymorphisms was carried out using a PCR-based restriction endonuclease digestion method. There was no significant difference in the distribution of the M235T and T174M variants between the two test groups and the control group. Association was also not seen when analysis was carried out in patients when subgrouped according to the extent of the severity of the disease. In addition, the risk was not restricted to subjects carrying the D allele of the ACE gene and T235T of AGT. M235T and T174M variants do not contribute to the increased risk of CHD or hypertension in the Indian population.