Soluble Antiapoptotic Molecules and Immune Activation in Chronic Heart Failure and Unstable Angina Pectoris

Programmed myocyte cell death and activation of the immune system have been shown to occur in patients with congestive heart failure. Besides, unstable angina episodes are likely to be associated with immune activation. Our aim was to evaluate the role of changes in circulating levels of soluble Fas (sFas), suggestive of an enhanced inhibitory response to ongoing apoptosis, and soluble IL2 receptor (sIL2-R), indicative of T-lymphocyte activation, in chronic heart failure and unstable angina pectoris. Thirty patients affected by chronic heart failure (20 idiopathic and 10 ischemic cardiomyopathy) and 13 patients with unstable angina were evaluated. Twenty healthy individuals matched for age and gender were used as controls. A complete biochemical determination of indexes of myocardial damage including cardiac troponin I (cTnI) and creatine kinase (MB/CK) was performed. The results demonstrated that mean levels of sFas and sIL2-R were significantly increased in patients affected by chronic heart failure and unstable angina and were not associated with changes in renal function or with serum levels of cTnI. Highest values of sFas were found in NYHA class IV patients (IV NYHA class = 7.39 ± 0.52 vs. controls = 1.34 ± 0.12 ng/ml; P < 0.01) and more elevated in idiopathic than in ischemic cardiomyopathy (3.64 ± 0.40 vs. 1.82 ± 0.37 ng/ml; P < 0.01). Moreover, in chronic heart failure patients sFas and ejection fraction were negatively correlated (P = 0.01), whereas sFas and sIL2-R were positively correlated (P < 0.01). In unstable angina patients too, sFas and sIL2-R appeared to be correlated (P = 0.03); whereas sFas (angina group = 3.18 ± 0.39 vs. controls = 1.34 ± 0.12 ng/ml; P < 0.01) and sIL2-R (angina group = 0.46 ± 0.11 vs. controls = 0.00 UI/ml; P < 0.01) were higher in angina group than in controls. In most of the cases, the increase of sFas was associated with comparable changes in sIL2-R serum levels, indicating that the activation of Fas system is strictly associated with autoimmune–inflammatory reactions. This phenomenon, both in chronic heart failure and in unstable angina, occurs in the absence of biochemical evidences of myocardial damage and seems to parallel the activation of T cell. Soluble Fas could have a role in sustaining inflammatory response and in prolonging the detrimental effects correlated with it in chronic heart failure and angina pectoris.     

Placental site trophoblastic tumor of the mediastinum

Choriocarcinoma has been described as the most frequent subtype of mediastinal germ cell tumors showing trophoblastic differentiation. We report a unique case of a placental site trophoblastic tumor, which developed in the mediastinum of a 14-year-old boy 2 years after the resection of a mature teratoma. The recurrent tumor was composed of a grossly hemorrhagic and necrotic mass. Histologically, diffusely infiltrating large polygonal cells with focal nodular growth and a teratomatous part containing mature intestinal, respiratory, and squamous epithelium with adjacent cutaneous adnexal structures were found. The typical morphologic features included vessel wall infiltration by the neoplastic cells with fibrinoid deposits and geographic necroses within the tumor masses. Characteristic diffuse positivity for melanoma cell adhesion molecule and human leucocyte antigen G was found on immunohistochemical investigation, confirming the diagnosis of placental site trophoblastic tumor. The patient died 1 year later after polychemotherapy. The outcome of this rare tumor is similar to the reported poor clinical outcome in patients with mediastinal choriocarcinomas.     

Imbalances in serum proinflammatory cytokines and their soluble receptors: a putative role in the progression of idiopathic IgA nephropathy (IgAN) and Henoch–Schönlein purpura nephritis,and a potential target of immunoglobulin therapy?

Following recent experimental data suggesting an aggravating effect of circulating proinflammatory cytokines on the histological lesions of IgAN, we studied changes in serum proinflammatory cytokines and their soluble receptors and antagonists in patients treated with polyvalent immunoglobulins (15 with severe nephropathy who had indicators of poor prognosis: heavy proteinuria, hypertension, altered renal function and Lee's histological grade III or IV; and 14 with moderate forms of IgAN who had permanent albuminuria > 300 mg/day and < 2000 mg/day, Lee's histological grade II and a glomerular filtration rate > 70 ml/min) in comparison with healthy controls (n = 20) and patients with non-IgA nephritides (n = 50). These were measured by means of specific immunometric assays before and after 9 months of immunoglobulin therapy. Total tumour necrosis factor (TNF) serum and IL-6 levels were elevated in IgAN patients before therapy, relative to controls, and normalized after immunoglobulin therapy. Levels of soluble TNF receptor of type I (sR55) and type II (sR75) increased on immunoglobulin therapy. TNF index α-55,75 used to assess biologically available TNF-α (ratio of total TNF-α divided by levels of soluble TNF receptors sR55 and sR75) was elevated before therapy and was below healthy control values after 9 months of immunoglobulin administration. Levels of serum IL-1 receptor antagonist were low prior to immunoglobulin administration in patients with severe forms of IgAN, and normalized on therapy. Serum interferon-gamma was unmodified. The histological activity index correlated with serum total TNF-α, TNF index α-55,75 and serum IL-6 levels, whereas proteinuria correlated with serum total TNF-α and TNF index α-55,75 but not with serum IL-6. These data suggest that the overproduction of proinflammatory cytokine is unbalanced by their natural antagonists in IgAN and Henoch–Schönlein syndrome. This process may play a role in the progression of the disease and be one of the targets of immunoglobulin therapy.     

Differences in protein synthesized in vivo and in vitro by cells associated with the cerebral microvasculature. A protein synthesized in response to trauma?

A protein of molecular weight 71,000 (P₇₁) was synthesized by cells associated with the cerebral microvasculature in telencephalon slices incubated in vitro. This protein, however, was not synthesized in vivo. There was a 30 min delay in the synthesis of P₇₁ by brain slices. During this lag period a new ribonucleic acid species which was required for P₇₁ synthesis was produced in the slices. After this delay P₇₁ became a major product of protein synthesis. P₇₁ was also produced by microvasculature enriched fractions isolated from telencephalon.This protein may be involved in the initial response of the vascular system to injury.     

Elevated levels of soluble CD163 in sera and fluids from rheumatoid arthritis patients and inhibition of the shedding of CD163 by TIMP-3

The aim of the present study was to evaluate levels of soluble CD 163 in sera and fluids from rheumatoid arthritis (RA) patients and elucidate the mechanism that regulates the shedding of CD163. Levels of soluble CD163 in sera and fluids from RA patients were examined by a sandwich enzyme immunoassay and Western blotting. To determine the effects of tissue inhibitors of metalloproteinase (TIMPs) on the shedding of CD163 from monocytes/macrophages, levels of soluble CD163 in cultures of monocytes/macrophages and the expression of CD163 on monocytes/macrophages in the presence or absence of TIMPs were examined by a sandwich enzyme immunoassay and flow cytometry, respectively. The clinical marker that was most associated with serum levels of soluble CD163 was levels of CRP. TIMP-3, but not TIMP-1 or TIMP-2, inhibited the shedding of CD163 from monocytes/macrophages. It was shown that serum levels of soluble CD163 are a sensitive and reliable marker to monitor activated macrophages in synovitis from RA patients and the results imply that the responsible proteinase for the shedding of CD163 is not a member of the matrix metalloproteinases, but is likely to be a member of ADAMs.     

支气管肺炎患儿治疗前后血清SIL-2R和白三烯测定的临床意义

目的：探讨了血清可溶性白细胞介素-2受体（SIL-2R）和半胱氨酰白三烯（LTS）水平在支气管肺炎患儿治疗前后的变化及意义。方法：应用ELISA对35例支气管肺炎患儿进行了血清SIL-2R和LTS测定，并与30例正常儿作比较。结果：支气管肺炎患儿在治疗前血清SIL-2R和LTS水平非常显著地高于正常儿组（P〈0.01）。治疗后2周后血清SIL-2R和LTS水平与正常儿比较无显著性差异（P〉0．05）。结论：检测支气管肺炎患儿血清中SIL-2R和LTS水平可作为病情预后判断的重要指标。     

抗人可溶性间皮素相关蛋白单克隆抗体的制备及特性鉴定

目的:制备鼠抗人可溶性间皮素相关蛋白(SMR)的单克隆抗体(mAb),鉴定其生物学特性。方法:应用计算机通过综合预测对间皮素(MSLN)进行B-细胞表位预测。合成相应肽段并免疫BALB/c小鼠,采用杂交瘤技术制备mAb,利用免疫细胞化学和Western blot分析对所制备的mAb进行鉴定。结果:综合预测方法分析间皮素的抗原表位可能于153-162、282-292及471-481氨基酸残基或其附近,选择性合成了可能性最高的位于471-481氨基酸残基的可溶性间皮素相关蛋白表位,制备了mAb(2H10),经免疫细胞化学和Western blot分析该抗体具有较高的特异性。结论:成功地制备了鼠抗人可溶性间皮素相关蛋白的mAb(2H10),该抗体具有较高的特异性,为进一步利用ELISA对可溶性间皮素相关蛋白进行检测奠定了基础。     

Distinct modulation by interferon-gamma (IFN-γ) of CD23 expression on B and T lymphocytes of atopic subjects

The low-affinity IgE receptor (FcεRII/CD23) plays a role in IgE production. Cytokines participating in IgE synthesis also modulate CD23 expression on lymphocytes, but whether this modulation is different in atopic subjects remains unclear. We studied CD23 expression on B and T lymphocytes in 10 asthmatic patients with Dermatophagoides pteronyssinus hypersensitivity and 10 healthy non-atopic subjects. Studies were performed by flow cytometry, in phytohaemagglutinin (PHA) or IL-4-stimulated mononuclear cell cultures, alone or in the presence of IFN-γ. Soluble CD23 (sCD23) released in the culture supernatants was measured by enzyme-linked immunoassay. Both PHA and IL-4 induced the expression of CD23 on lymphocytes of atopic and non-atopic subjects. Whereas PHA increased both the percentage and mean fluorescence intensity of CD23⁺ B and T cells, IL-4 alone did not increase the percentage of CD23⁺ T cells. The effects of IFN-γ were different in both groups, since it was able to reduce the percentage of PHA-stimulated CD23⁺ T cells only in non-atopic individuals. In non-atopic subjects more than atopic, levels of sCD23 were increased in the supernatants of PHA and IL-4 cultures. These results show that the modulation of CD23 expression is different on B and T cells, and that IFN-γ acts differently in atopic and non-atopic individuals.     

Identification, in mouse macrophages and in serum, of a soluble receptor for the Fc portion of IgG (Fc{gamma}R) encoded by an alternatively spliced transcript of the Fc{gamma}RII gene

Low affinity FcR are a heterogeneous group of glycoproteinswhich exist in transmembrane (TM) as well as in soluble forms.Two membrane isoforms of the murine type II FcR, FcRilb1 andFc;Rilb2, have been described. They result from the translationof alternatively spliced premRNA, FcRilb2 lacking sequencesof the first intracytoplasmic domain (IC1). Soluble forms ofFcR (sFcR) have previously been shown to result from proteolysisof membrane receptors. We report here the identification, inmacrophages, of a mRNA derived from the FCRll gene by splicingexons encoding the TM and IC1 domains, i.e. corresponding toa TM-deleted FcRllb2 mRNA. A soluble protein possibly encodedby this mRNA was identified in macrophage supernatants. In accordancewith FcR nomenclature, we propose to name this new FcRll IsoformFcRllb3. It is the most abundant 8FcR present in serum, as comparedwith 8FcR resulting from cleavage of membrane FcR.     

Serum levels of soluble CD30 in chronic hepatitis B virus infection

There is evidence that both cellular and humoral components of the immune response are required for viral clearance to occur in chronic hepatitis B. Recent studies demonstrated that CD30 molecule, a member of the tumour necrosis factor superfamily of membrane cytokine receptors, is expressed on, and released as a soluble molecule (sCD30) by activated T cells producing T helper 2 (Th2) cytokines, which modulate antibody responses. To better characterize the immunoregulatory mechanisms in chronic hepatitis B virus (HBV) infection, sCD30 values were evaluated by an ELISA in 90 hepatitis B surface (HBsAg)-positive patients with chronic hepatitis, selected on the basis of active viral replication and biochemical activity. At presentation abnormal levels (>20 U/ml) of sCD30 were detected in 57 (63%) out of 90 patients with chronic hepatitis B, and median value was significantly higher in this group of patients compared with that of healthy HBsAg carriers (26.7 versus 10.5 U/ml, P < 0.000 05) and with normal controls (26.7 versus 3 U/ml, P < 0.000 01). Sequential studies of chronic hepatitis B did confirm the association of raised sCD30 levels with the active phase of the illness. On the other hand, a significant decrease was noted when sCD30 levels at diagnosis and after termination of HBV replication and biochemical remission of hepatitis were compared in 10 untreated patients (median, 28 U/ml at entry versus 8 U/ml at remission, P < 0.01) and in six patients responding to interferon-alpha therapy (median, 29.5 U/ml at entry versus 6 U/ml at remission, P < 0.05). The high serum sCD30 levels reported during the active phase of HBsAg-positive chronic hepatitis suggest a certain degree of immune competence of these patients, at least with respect to a Th2-type response. These data are in agreement with recent serologic surveys showing that most chronic hepatitis B patients do demonstrate ongoing humoral immune response to HBV antigens, using novel immunoassays designed to detect antibody in the presence of excess serum viral antigen. Th2 functions that mainly promote humoral immunity to HBV antigens may be critical, in association with a competent virus-specific cytotoxicity, for efficient termination of HBV replication in chronic hepatitis B.