Looking for ALPS: The value of a combined assessment of biochemical markers

BACKGROUND

Autoimmune lymphoproliferative syndrome (ALPS) is a rare primary immune disorder caused by defect of the extrinsic apoptotic pathway. The current diagnostic criteria combine clinical features and typical biomarkers but have not been the object of clear international consensus.

METHODS

We conducted a retrospective study on pediatric patients who were investigated for autoimmune cytopenia and/or lymphoproliferation at the CHU Sainte-Justine Hospital over 10 years. Patients were screened using the combination of TCRαβ+ CD4- CD8- "double negative" (DN) T cells and soluble plasmatic FAS ligand (sFASL).

RESULTS

Among the 398 tested patients, the median sFASL and DN T cells were 200 ng/mL and 1.8% of TCRαβ+ T cells, respectively. sFASL was highly correlated with vitamin B12 levels. We identified five patients diagnosed with ALPS for whose sFASL and vitamin B12 levels were the more discriminating biomarkers. While ALPS diagnostic criteria had high sensibility, their predictive value remained low.

CONCLUSION

sFASL level can efficiently discriminate patients with ALPS when using the appropriate thresholds. Our study highlights the need for an international consensus to redefine the place and threshold of biological biomarkers for ALPS diagnosis.

Patients with hepatocellular carcinoma that die during the first year of liver transplantation have high blood sFasL concentrations

BACKGROUND

Fas ligand (FasL) is one ligand that activates extrinsic apoptosis pathway. High expression in lymphocytes of FasL have been found in patients with acute rejection of liver transplantation (LT). No high blood concentrations of soluble FasL (sFasL) have been found in patients with acute LT rejection; however, the samples size of those studies was small.

AIM

To determine whether patients with hepatocellular carcinoma (HCC) that dead during the first year of LT have higher blood sFasL concentrations previously to LT that those who that remain alive in a study of higher sample size.

METHODS

Patients underwent LT due to HCC were included in this retrospective study. Serum sFasL levels prior to LT were measured and one-year LT mortality was registered.

RESULTS

Non-surviving patients (n = 14) showed higher serum sFasL levels [477 (269-496) vs 85 (44-382) pg/mL; P < 0.001] than surviving patients (n = 113). Serum sFasL levels (pg/mL) were associated with mortality (OR = 1.006; 95%CI = 1.003-1.010; P = 0.001) independently of age of LT donor in the logistic regression analysis.

CONCLUSION

We report for the first time that HCC patients who die within the first year of HT have higher blood sFasL concentrations prior to HT than those who remain alive.

Plasma Levels of sFas-sFasL and FASL Gene Expression Are Associated with Tuberculosis

Apoptosis of macrophages infected by Mycobacterium tuberculosis via Fas-FasL is an important immune mechanism against infection. This study investigated the association of tuberculosis (TB) with the presence of the polymorphisms FAS -670A/G and FASL -124A/G, the levels of sFas and sFasL, and the gene expression of FASL and cytokines. Samples of 200 individuals diagnosed with TB and 200 healthy controls were evaluated. Real-time PCR (genotyping and gene expression) and ELISA (dosages of sFas, sFasL, IFN-γ, and IL-10) tests were performed. There was no association of FAS -670A/G and FASL -124A/G polymorphisms with TB. The TB group exhibited high plasma levels of sFas and reduced plasma levels of sFasL (p < 0.05). The correlation analysis between these markers revealed a positive correlation between the levels of sFas and sFasL, sFasL and FASL expression, and between sFas and FASL expression (p < 0.05). In the TB group, there was a positive correlation between FASL expression and IFN-γ levels and higher levels of IL-10 compared to IFN-γ (p < 0.05). High levels of sFas and reduced levels of sFasL and FASL expression may contribute to the inhibition of apoptosis in infected cells and represent a possible bacterial resistance resource to maintain the infection.

Mortality prediction of patients with spontaneous intracerebral hemorrhage by serum soluble Fas ligand concentrations

BACKGROUND

A study of patients with spontaneous intracerebral hemorrhage (SIH) found a higher content of Fas ligand in the perihematomic brain area compared to healthy brain areas. The objective of this study was to analyze whether blood soluble Fas ligand (sFasL) concentrations could be used to estimate the prognosis of SIH patients.

METHODS

Observational and prospective study performed in five Spanish Intensive Care Units. Patients with severe supratentorial SIH, defined as Glasgow Coma Scale (GCS) <9, were included. Serum sFasL levels were determined at the time of diagnosis of severe SIH. Mortality at 30 days was the end-point study.

RESULTS

Surviving SIH patients (n = 41) compared to nonsurvivors (n = 38) showed lower serum sFasL levels (p < 0.001). The area under curve of mortality prediction for serum sFasL levels was 0.79 (95% CI = 0.70-0.89; p < 0.001). Multiple logistic regression analysis found an association of serum sFasL concentrations with 30-day mortality (ORo = 1,034; 95% CI = 1,010-1,058; p = 0,006) after controlling for midline shift, early hematoma evacuation, and intracerebral hemorrhage score.

CONCLUSIONS

The capability of serum sFasL to predict SIH patient mortality is the main novel finding of our study.

ABBREVIATIONS

APACHE II: Acute Physiology and Chronic Health Evaluation; aPTT: activated partial thromboplastin time; FIO₂: fraction of inspired oxygen; GCS: Glasgow Coma Scale; ICU: Intensive Care Unit; INR: international normalized ratio; PaO₂: pressure of arterial oxygen.

High Serum Soluble Fas Ligand Levels in Non-survivor Traumatic Brain Injury Patients

PURPOSE

Soluble Fas Ligand (sFasL) is one of the main ligands that activates the apoptosis extrinsic pathway. Higher expression of FasL in brain samples and higher cerebrospinal fluid FasL concentrations in traumatic brain injury (TBI) patients than in controls have been found. However, the potential association between blood sFasL concentrations and TBI mortality has not been reported. Therefore, the objective of this study was to determine whether that association exists.

METHODS

We included patients with a severe isolated TBI, defined as < 9 points in Glasgow Coma Scale (GCS) and < 10 non-cranial aspects points in Injury Severity Score in this observational and prospective study performed in 5 Intensive Care Units. We measured serum sFasL concentrations on day 1 of TBI.

RESULTS

We found that 30-day survivor (n = 59) in comparison to non-survivor patients (n = 24) had higher GCS (p = 0.001), lower age (p = 0.004), lower APACHE-II score (p < 0.001), lower intracranial pressure (ICP) (p = 0.01), lower computer tomography (CT) findings of high risk of death (p = 0.02) and lower serum sFasL concentrations (p < 0.001). The area under the curve for mortality prediction by serum sFasL levels was of 75% (95% CI = 63%-87%; p < 0.001). In Kaplan-Meier analysis was found that patients with serum sFasL levels > 29.2 pg/mL had a higher mortality rate (Hazard ratio = 6.2; 95% CI = 2.6-14.8; p < 0.001). Multiple logistic regression analysis found an association between serum sFasL levels and mortality after controlling for GCS, age and CT findings (OR = 1.055; 95% CI = 1.018-1.094; p = 0.004), and after controlling for APACHE-II, ICP and CT findings (OR = 1.048; 95% CI = 1.017-1.080; p = 0.002).

CONCLUSIONS

The association between serum sFasL levels and 30-day mortality in TBI patients was the major novel finding of our study; however, future validation could be interesting to confirm those results.

Elevated Concentrations of Soluble Fas and FasL in Multiple Sclerosis Patients with Antinuclear Antibodies

Antinuclear antibodies (ANA) are currently considered as an epiphenomenon of apoptotic processes, possibly in control of autoreactivity in patients with multiple sclerosis (MS). Apoptosis of reactive lymphocytes by the Fas/FasL system is described as an effective control mechanism for autoreactivity in MS. We aimed to provide a context to the potential link between ANA and peripheral lymphocyte apoptosis in MS. The presence of ANA was detected in sera by immunofluorescence assay, and concentrations of sFas and sFasL were determined in the sera of 44 and cerebrospinal fluid (CSF) of 11 relapsing-remitting (RR) MS patients using cytometric bead-based array, and their association with the disease characteristics was determined. ANA were detected in the sera of 43.2% of RRMS patients, and their frequency was the highest in patients with disease duration of less than one year (88,89%). In addition, the number of experienced relapses was lower in ANA-positive patients. Concentrations of sFasL were inversely associated with patients' expanded disability status scale (EDSS) scores. Low concentrations of both soluble factors strongly discriminated patients with moderate to severe disability, from patients with mild or absent disability only in a group of patients with prolonged disease duration (>10 years). Both soluble mediators were significantly higher in ANA-positive patients. FasL concentrations were inversely associated with the number of relapses. There is a potential link between the presence of ANA and peripheral lymphocyte apoptosis mediated by Fas/FasL system in MS, whose precise role and significance needs to be determined by future mechanistic studies.

Association between serum sFasL concentrations and sepsis mortality

BACKGROUND

There are scarce data on soluble Fas Ligand (sFasL), one of the main ligands that activate the apoptosis extrinsic pathway, in septic patients. In a small study of septic children were found higher plasma sFasL levels in non-survivors compared with survivors; however, an association between blood sFasL levels and mortality controlling for sepsis severity was not stablished due to the small sample size of the study. Therefore, the main objective of this study was to determine whether there is an association between blood sFasL concentrations and mortality in septic patients controlling for sepsis severity. Methods: Septic patients were included in this observational and prospective study conducted in three Spanish Intensive Care Units. Serum samples at diagnosis of sepsis were obtained for serum sFasL levels determination.

RESULTS

Thirty-day non-surviving patients (n = 85) with respect to surviving patients (n = 151) showed higher serum sFasL levels (p<.001). Multiple logistic regression analysis found an association between serum sFasL levels and mortality (odds ratio [OR] = 1.007; 95% confidence interval [CI] = 1.003-1.010; p<.001) after controlling for age, septic shock, SOFA, INR and aPTT. The area under the curve (AUC) for mortality prediction by serum sFasL levels was of 62% (95% CI = 56-69%; p=.003). In Kaplan-Meier analysis was found that patients with serum sFasL levels >109 pg/mL had a higher mortality rate (hazard ratio = 3.6; 95% CI = 1.93-6.78; p<.001).

CONCLUSIONS

The main new finding from our study was that serum sFasL concentrations were associated with mortality in septic patients controlling for sepsis severity. Highlights Blood sFasL concentrations were higher in non-survivor than in survivor patients. There is an association between blood sFasL concentrations and mortality in septic patients. Blood sFasL concentrations could predict mortality of septic patients.

Circulating Plasma Gelsolin: A Predictor of Favorable Clinical Outcomes in Head and Neck Cancer and Sensitive Biomarker for Early Disease Diagnosis Combined with Soluble Fas Ligand

Head and neck cancer (HNC) accounts for more than 330,000 cancer deaths annually worldwide. Despite late diagnosis being a major factor contributing to HNC mortality, no satisfactory biomarkers exist for early disease detection. Cytoplasmic gelsolin (cGSN) was discovered to predict disease progression in HNC and other malignancies, and circulating plasma gelsolin (pGSN) levels are significantly correlated with infectious and inflammatory disease prognoses. Here, the plasma levels of five candidate biomarkers (circulating pGSN, squamous cell carcinoma antigen, cytokeratin 19 fragment, soluble Fas, and soluble Fas ligand (sFasL)) in 202 patients with HNC and 45 healthy controls were measured using enzyme-linked immunosorbent assay or Millipore cancer multiplex assay. The results demonstrated that circulating pGSN levels were significantly lower in patients with HNC than in healthy controls. Moreover, circulating pGSN outperformed other candidate biomarkers as an independent diagnostic biomarker of HNC in both sensitivity (82.7%) and specificity (95.6%). Receiver operating characteristic curves indicated that combined pGSN and sFasL levels further augmented this sensitivity (90.6%) for early disease detection. Moreover, higher pGSN levels predicted improved prognosis at both 5-year overall survival and progression-free survival. In conclusion, circulating pGSN could be an independent predictor of favorable clinical outcomes and a novel biomarker for the early HNC detection in combination with sFasL.

Granulocytes and monocytes apheresis induces upregulation of TGFβ1 in patients with active ulcerative colitis: A possible involvement of soluble HLA-I

Granulocyte and monocyte apheresis has been used in different immune-mediated disorders, mainly inflammatory bowel diseases. The removal of activated leukocytes and several additional immunomodulatory mechanisms have been so far suggested to explain the anti-inflammatory effects of the treatment. Recent data indicate that, during centrifugation based apheresis, sHLA-I adsorbed to plastic circuits is able to induce TGFβ₁ production in activated leukocytes. On these bases, the present study was aimed at analyzing if this model could be applied to a noncentrifugation based apheresis, such as granulocyte and monocyte apheresis. Ten patients with ulcerative colitis were enrolled. Every patient received 5 weekly apheresis treatments. Cellulose acetate beads removed from the column post-GMA were stained by fluorescent anticlass I mAb and examined by fluorescent microscope. Moreover, sFasL plasma concentration, TGFβ₁ plasma levels, and the percentage of TGFβ₁ positive neutrophils were evaluated before and immediately after each single apheresis. Immunofluorescent images revealed a homogeneous layer of a sHLA-I adsorbed to the surface of the beads recovered following the procedure. sFasL plasma concentration progressively increased both following the procedures and during inter-procedure periods. Consistently, also TGFβ₁ plasma levels and the percentage of TGFβ₁ positive neutrophils increased during the procedures with a meaningful relationship with sFasL plasma levels. Taken together, these findings suggest that the immunosuppressive effects attributed to granulocyte and monocyte apheresis might depend, at least in part, on the sensitivity of activated leucocytes to the bioactivity of sHLA-I molecules. J. Clin. Apheresis 32:49-55, 2017. © 2016 Wiley Periodicals, Inc.

Serum levels of apoptosis-related markers (sFasL, TNF-a, p53 and bcl-2) in COPD patients

INTRODUCTION

Taking into account important role of apoptosis in COPD pathogenesis, we wanted to asses the serum levels of markers involved in apoptosis regulation, including apoptosis inducers such as TNF-a, sFasL or p53 protein and apoptosis inhibitor bcl-2 and, in addition, to compare these markers with selected COPD parameters.

MATERIAL AND METHODS

In 181 patients (60 women) with COPD (age was 62.2+ 9.37 years; FEV1% 55.2 + 19.98 %) and in 29 controls (11 women), serum levels of TNF-a, sFasL, p53 and bcl-2 were evaluated by the enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

In COPD patients the mean sFasL level was 0.092 ± 0.077 ng/ml and mean TNF-a level was 2.911 ± 3.239 pg/ml. There were no differences in serum sFasL and TNF-a in COPD patients and control group. TNF-a and sFasL did not correlate with COPD parameters such as FEV₁%, BMI, RV% (percentage of predicted value of residual volume) or BODE. Although we tried to evaluate bcl-2 and p53 protein serum levels with two different tests, measurable levels of bcl-2 were only detected in 15 patients and p53 in only 3 patients. Bcl-2 values were from 0.418 to 11.423 ng/ml and p53 from 90.772 to 994.749 pg/ml.

CONCLUSIONS

We didn't observe any differences in serum levels of pro- and antiapoptotic markers in COPD patients and the control group or correlations between the markers studied and COPD parameters.

Soluble molecules in intravenous immunoglobulin: benefits and limitations

Because of its predominance, the main immunomodulatory function of IVIg is carried out by the IgG molecules; while, based on multiple studies, the immunomodulatory role of other soluble molecules in commercial IVIg products is impossible to ignore. Although the existence of these molecules and their suppressive effects on the immune response may be considered a positive contribution to the treatment of autoimmune disorders, their presence, half-life, accumulation and immunosuppressive actions in immunocompromised patients should be monitored by physicians and manufacturing companies.

Cutting edge: FasL(+) immune cells promote resolution of fibrosis

Immune cells, particularly those expressing the ligand of the Fas-death receptor (FasL), e.g. cytotoxic T cells, induce apoptosis in 'undesirable' self- and non-self-cells, including lung fibroblasts, thus providing a means of immune surveillance. We aimed to validate this mechanism in resolution of lung fibrosis. In particular, we elucidated whether FasL(+) immune cells possess antifibrotic capabilities by induction of FasL-dependent myofibroblast apoptosis and whether antagonists of membrane (m) and soluble (s) FasL can inhibit these capabilities. Myofibroblast interaction with immune cells and its FasL-dependency, were investigated in vitro in coculture with T cells and in vivo, following transplantation into lungs of immune-deficient syngeneic Rag-/- as well as allogeneic SCID mice, and into lungs and air pouches of FasL-deficient (gld) mice, before and after reconstitution of the mice with wild-type (wt), FasL(+) immune cells. We found that myofibroblasts from lungs resolving fibrosis undergo FasL-dependent T cell-induced apoptosis in vitro and demonstrate susceptibility to in vivo immune surveillance in lungs of reconstituted, immune- and FasL-deficient, mice. However, immune-deficient Rag-/- and SCID mice, and gld-mice with FasL-deficiency, endure the accumulation of transplanted myofibroblasts in their lungs with subsequent development of fibrosis. Concomitantly, gld mice, in contrast to chimeric FasL-deficient mice with wt immune cells, accumulated transplanted myofibroblasts in the air pouch model. In humans we found that myofibroblasts from fibrotic lungs secrete sFasL and resist T cell-induced apoptosis, whereas normal lung myofibroblasts are susceptible to apoptosis but acquire resistance upon addition of anti-s/mFasL to the coculture. Immune surveillance, particularly functional FasL(+) immune cells, may represent an important extrinsic component in myofibroblast apoptosis and serve as a barrier to fibrosis. Factors interfering with Fas/FasL-immune cell-myofibroblast interaction such as sFasL secreted by fibrotic-lung myofibroblasts, may abrogate immune surveillance during fibrosis. Annulling these factors may pave a new direction to control human lung fibrosis.

Transfection of apoptosis related gene Fas ligand in human hepatocellular carcinoma cells and its significance in apoptosis

AIM: To evaluate the expression of apoptosis related gene Fas ligand (FasL) in human hepatocellular carcinoma (HCC) cells HepG2 and its significance in apoptosis.

METHODS: Levels of soluble Fas ligand (sFasL) in a group of patients with hepatitis B virus (HBV)-induced chronic hepatitis, HBV-positive liver cirrhosis and HCC were evaluated. In a further study, the recombinant eukaryotic expression plasmid pcDNA3.1hisB-FasL was transfected into HCC cells HepG2 by lipofection, and then soluble FasL was examined in the supernatant of culture cells by EIA, FasL expression in HepG2 cells was detected by immuohistochemistry. After being stained by annexin V and propidium iodine, cells were passed through a flow cytometer and examined by a fluorescence microscope and a laser scanning microscope.

RESULTS: The sFasL levels were significantly lower in patients with HCC when compared to the patients with hepatitis or liver cirrhosis. In comparison with untransfected cells, the soluble FasL could be detected in the supernatant of transfected cells. FasL was expressed on the membranes and cytoplasm of transfected cells. The apoptotic cell rate was 36.30% in transfected cells, and was 11.53% in untransfected cells. Moreover, the different stage of apoptotic cells could be distinguished by annexin V and propidium iodine staining.

CONCLUSION: Fas ligand is an apoptotic pathway of HCC cells.

Short Communication: Expression of Apoptosis Regulating Factors on T Lymphocytes in Multiple Myeloma Patients

Multiple myeloma (MM) is a malignant proliferation of plasma cells in which dysregulation of programmed cell death (apoptosis) is responsible for tumor cell expansion. However some phenotypic and functional alterations of T cells in MM patients have been reported, that also can influence the plasma cell growth. The aim of the study was to assess some aspects of T lymphocyte apoptosis in MM to obtain a better understanding of the changes in the immune system in this disease. Flow cytometry was used to analyze the expression of two main regulators of apoptosis: the pro-apoptotic Fas antigen and the anti-apoptotic protein BCL-2 in patients with untreated MM and in healthy controls. ELISA was used to determine soluble Fas ligand (sFasL) serum levels in patients and control groups. We detected statistically significant higher Fas expression in patients than in controls both on CD4 and CD8 lymphocytes, but no differences in BCL-2 expression by these cells. The sFasL level was statistically significant lower in patients than in controls. Our results indicate that T cells in MM are controlled by up-regulation of Fas. The Fas/FasL system induces the killing of T cells expressing Fas antigen, what could account for the incapability of the immune system to protect host against tumor expansion.