M. Di Renzo

Extracorporeal photochemotherapy restores Th1/Th2 imbalance in patients with early stage cutaneous T‐cell lymphoma

Extracorporeal photochemotherapy (ECP) has been shown to be a potent activator of peripheral blood macrophages because it causes a marked release of macrophage‐dependent proinflammatory cytokines, and it is therefore currently considered to be a safe and non‐toxic immunomodulatory treatment. On this basis we studied the function of peripheral blood mononuclear cells (PBMC) in eight patients with early stage (Ib) cutaneous T‐cell lymphoma (CTCL), before and 1 year after ECP, together with their clinical and histological responses. In particular we evaluated in vitro phytohaemagglutinin (PHA)‐stimulated proliferation and production of interleukin‐4 (IL‐4) and interferon‐&ggr; (IFN‐&ggr;) as well as lipopolysaccharide (LPS)‐induced production of IL‐12. Before treatment we observed that PBMC of patients produced significantly higher levels of IL‐4 and lower levels of IFN‐&ggr; and IL‐12 than those of healthy control subjects. After 1 year of ECP, IL‐4, IFN‐&ggr; and IL‐12 production no longer differed from that of control subjects. Moreover, we observed a good clinical result matched by histological response. Our data confirm that early‐ stage CTCL patients show a predominantly type‐2 immune response that might be responsible for several immunological abnormalities found in this disease. We have demonstrated that ECP reverses the T‐helper type 1/T‐helper type 2 (Th1/Th2) imbalance and may therefore be considered an efficient biological response modifier.

Common variable immunodeficiency: a review.

Abstract.Common variable immunodeficiency (CVID) is the commonest symptomatic primary antibody deficiency syndrome. The predominant manifestation is hypogammaglobulinemia. CVID is characterized by recurrent bacterial infections, especially of the upper and lower respiratory airways, and is also associated with an increased incidence of autoimmune and neoplastic disorders. Most patients are diagnosed as adults and delay in the recognition of the disease is common. Several T and B cell defects have been described, although the underlying cause is still unknown.

Mechanism of action of extracorporeal photochemotherapy in chronic graft-versus-host disease

Chronic graft‐versus‐host disease (GvHD) affects 50% of long‐term bone marrow transplant survivors and remains a cause of major long‐term morbidity in these patients despite aggressive therapy. Extracorporeal photochemotherapy (ECP), considered as an effective treatment for patients with erythrodermic cutaneous T‐cell lymphoma (CTCL), has recently been used successfully in the treatment of GvHD. One of the most intriguing aspects of ECP is its ability to induce two apparently opposite effects: activation of the immune system against neoplastic cells (as in CTCL) and downregulation of the activity of T‐cell clones in autoimmune diseases (as in systemic sclerosis, systemic lupus erythematosus and pemphigus vulgaris) and autoallogeneic immune responses (as in GvHD and allograft rejection). Only a better and more complete understanding of the various mechanisms involved will enable this interesting new therapy to be made more effective and selective.

Extracorporeal photopheresis affects co‐stimulatory molecule expression and interleukin‐10 production by dendritic cells in graft‐versus‐host disease patients

Graft‐versus‐host disease (GVHD) is a major complication of allogeneic bone marrow transplantation. Extracorporeal photochemotherapy (ECP) has been introduced as an alternative treatment for GVHD refractory to conventional immunosuppressive treatment, although its mechanism of action is not yet clear. We investigated, in seven GVHD patients, the effects of ECP on dendritic cell maturation and cytokine production in an in vitro model that could mimic the potential in vivo effect of reinfusion of ECP‐treated peripheral blood mononuclear cells. The model was based on co‐culture of ECP‐treated lymphocytes with monocyte‐derived dendritic cells (DCs) of the same patient. We found that the co‐culture of ECP‐treated lymphocytes with immature DCs reduced CD54, CD40 and CD86 mean fluorescence intensity (MFI) significantly after lipopolysaccharide (LPS) stimulation, without affecting human leucocyte antigen D‐related and CD80 MFI. In the same co‐culture model, DCs produced increased amounts of interleukin (IL)‐10 when co‐cultured with ECP‐treated lymphocytes and stimulated with LPS, while IL‐12 and tumour necrosis factor‐α production were not affected. These results suggest that reinfusion of large numbers of autologous apoptotic lymphocytes is significant for the therapeutic outcome of ECP through down‐regulation of co‐stimulatory molecules on DCs, inducing non‐fully mature DCs with a low signal 2 and up‐regulation of IL‐10, which is an immunosuppressive cytokine.

Pro-inflammatory/anti-inflammatory cytokine imbalance in acute coronary syndromes

The aim of this study was to evaluate the presence of an imbalance between proinflammatory and anti-inflammatory mediators in patients affected by acute coronary syndromes (ACS). We considered two groups of 26 and 28 patients with acute myocardial infarction (AMI) and unstable angina (UA) respectively, compared with a group of 30 patients with stable angina and 30 healthy volunteers. We evaluated the production in cultured and stimulated lymphomonocytes of interferon (IFN)γ and tumour necrosis factor (TNF)α, which are well known to possess proinflammatory effects, and of interleukin (IL)10, which has been shown to have a protective anti-inflammatory activity. We also assessed the clinical characteristics of groups and, particularly, we evaluated the circulating levels of C-reactive protein (hs-CRP). We found a significant increase of IFNγ and TNFα production (P<0.01) and a significant decrease of IL10 production (P<0.05) in cultures of lymphomonocytes taken from patients with AMI and UA compared with SA patients and controls. No significant changes where found between AMI and UA patients and SA patients and controls. Circulating levels of hs-CRP were significantly increased (P<0.01) in patients with ACS compared with the other control groups. Our data showed an increased production of proinflammatory mediators in ACS that may be detectable both in circulating blood and in cell cultures where it is possible to evaluate in a better way the functional state of cells; this finding was associated with a reduced production of the antiinflammatory cytokine IL10. In conclusion, a relevant imbalance is present in ACS and this fact could contribute to plaque instability and clinical manifestations.

Extracorporeal photopheresis affects interleukin (IL)-10 and IL-12 production by monocytes in patients with chronic graft-versus-host disease.

Background  Chronic graft‐versus‐host disease (cGVHD) is a major complication of allogeneic bone marrow transplantation. Extracorporeal photopheresis (ECP) has recently been introduced as an alternative treatment for cases of cGVHD refractory to conventional immunosuppressive treatment, but its mechanism of action is not yet clear.

T cell activation and enhanced apoptosis in non-ST elevation myocardial infarction

Abstract. Recent studies have shown that inflammation plays a major role in coronary plaque destabilization and in the induction of thrombosis in acute coronary syndromes. The aim of this study was to evaluate circulating lymphocyte activation and apoptosis in patients with non-ST elevation myocardial infarction (NSTEMI) in comparison with subjects with stable angina and with age-matched healthy controls. We considered T cell subpopulations, T cell surface HLA-DR and CD69 expression (evaluated by flow cytometry), lymphomonocyte spontaneous apoptosis (evaluated by ELISA), and IL2 production (evaluated by ELISA) in peripheral blood within 6 hours of onset of NSTEMI. We also investigated Fas expression on T cells (evaluated by flow cytometry) and FasL mRNA (evaluated by RT-PCR), as well as Fas functionality. In NSTEMI patients we found a significant increase of HLADR+ CD3+ and CD69+CD4+ cells. Spontaneous apoptosis was significantly increased in NSTEMI patients in comparison with the two control groups and was associated with an increased expression of Fas, an increased susceptibility to Fas agonist (CH11), and a normal production of IL2 in cell cultures. These data suggest that the enhanced apoptosis is due to a mechanism of “active” antigen-driven death, induced by the expression of death cytokines and not by the failure of cell growth factors. We conclude that peripheral lymphocytes are activated in NSTEMI and undergo an enhanced programmed cell death due to activation mechanisms. It is likely that lymphocyte activation occurs before the onset of acute ischemia and contributes to the plaque rupture and to the myocardial ischemic insult.

Relationship between serum complement and different lipid disorders

Abstract Inflammatory and lipid factors share an important role in atherosclerosis. Recent studies showed the concomitant presence and increase of complement components and lipid both in the atherosclerotic plaque and the circulating blood. The aim of this study was to examine the relationship between the complement system and lipid disorders. We evaluated the circulating complement terminal complex C5b-9, a clear sign of complement activation, in three groups of 30 patients the first with hypercholesterolemia, the second with hypertriglyceridemia (associated with low values of HDL-cholesterol), the third with low levels of HDL-cholesterol compared with an equivalent group of matched normolipemic subjects. We found a significant increase of sC5b-9 in each group of patients compared with controls. The mean sC5b-9 level in the hypercholesterolemic population was 366.2±141.2 ng/ml (P<0.01), 395.4±118.2 ng/ml in the hypertrygliceridemic group (P<0.01), 414.8±126.4 ng/ml in the low HDL-chol subjects (P<0.01), and 182.0±40.8. ng/ml in the control group. Regression analysis showed a significant direct correlation between sC5b-9 and triglycerides (r=0.64), and a significant inverse correlation between sC5b-9, HDL-chol (r=0.74), and apo-A1 (r=0.68); no significant relationship was found between sC5b-9 and cholesterol. We suggest that complement activation is associated with the various lipid disorders and is more important in those dyslipidemic conditions in which other factors may be involved. In particular, hypertriglyceridemia may be associated with endothelial and fibrinolytic disturbances, and the decrease of HDL may induce the failure of the regulatory proteins transported by the same HDL.

Increased TNF-α production by peripheral blood mononuclear cells in patients with Krabbe's disease : effect of psychosine

Background  Inflammatory and/or immune activation occurs both in animal models (twitcher mice) and in the brain of patients with Globoid cell leukodystrophy (GLD) or Krabbes disease (KD). In this study we evaluated in vitro the cytokine profile of KD patients and the effect of psychosine, the toxic metabolite which plays a role in the demyelination process in these patients.

The in vitro effect of pidotimod on some immune functions in cancer patients

There are several reports concerning an impairment of cellular immune response in patients affected by malignant disease. The aim of this study was to evaluate the in vitro effect of Pidotimod, a synthetic biological response modifier, on some immune functions in 14 cancer patients. In particular, we showed that these subjects had a significantly reduced peripheral blood mononuclear cell (PBMC) proliferation both in response to PHA and to Con A in comparison with a group of healthy subjects. Besides, they showed a significantly reduced PBMC IL2 production, which was evaluated both through an ELISA method and a biological assay. The in vitro addition of increasing concentrations of Pidotimod (10, 25 and 50 ug/ml) was able to enhance PBMC proliferation and IL2 production significantly. However, in spite of the addition of Pidotimod, both immune functions in our neoplastic patients did not reach normal values.