Serum Levels Of IFN-gamma Research Articles

Assessment of Neutrophil Apoptosis Ex Vivo in Hepatosplenic Patients with Neutropenia Pre and Post Splenectomy

The pathophysiology of neutropenia seen in patients with schistosomiasis or hepatitis C infection that complicates the course of liver disease is poorly understood. We evaluated the neutrophil apoptosis before and after splenectomy to clarify the role of apoptosis and splenomegaly in the occurrence of neutropenia. Neutrophils were isolated from 23 hepato-splenic patients with neutropenia, 8 hepatosplenic patients with normal neutrophil counts, 7 patients who were post splenectomy, and a further ten normal control subjects. These were cultured for 24 h and the time course of neutrophil apoptosis was assessed by determination of Annexin V and propidium iodide binding by flow cytometry. Fas and Bcl2 expression were determined on fresh neutrophils using flow cytometry. Levels of tumor necrosis factor alpha, interleukin 3, and gamma interferon were evaluated using an immunosorbent assay.Neutrophil apoptosis was minimal in the fresh neutrophils, however, cultured neutrophils exhibited significantly greater apoptosis in neutropenic patients when compared to non-neutropenic patients (P=0.01 at 4 h and P<0.05 at 24 h) and control group (P<0.01 at 4 h and 24 h). After splenectomy, the percentage of neutrophil apoptosis declined to the normal control levels (P>0.05). Fas and Bcl2 expression on neutrophil were significantly higher in the neutropenic group as compared to normal controls (P<0.05, P=0.01 respectively). Serum TNF alpha, IL-3, and IFN gamma levels were not significantly different in all studied groups.In conclusion: Neutrophils from neutropenic hepatosplenic patients exhibit markedly accelerated apoptosis, which is normalized after splenectomy. Thus increased neutrophil apoptosis may in part be responsible for the occurrence of neutropenia.

Serum Levels of IL-4, IL-10, IL-12, IL-13 and IFN-gamma in Behçet's disease.

Behçet's disease (BD) is an inflammatory disease of unknown etiology. Although its pathogenesis is not fully understood, recent studies have suggested that immunological abnormalities and neutrophil hyperfunction may be involved in its etiology and pathophysiology. The immune system in BD can be characterized as a divergent cytokine production profile of the mixed Th1/Th2 cell type. In this study, we investigated the levels of interleukin (IL)-4, IL-10, IL-12, IL-13 and interferon-g in the sera of patients with BD, in comparison with recurrent aphthous stomatitis and healthy controls, to determine the Th1/Th2 profile of the disease. The levels of IL-4, IL-10 and IL-13 were found to be high in active BD patients, and IL-12 and interferon-gamma levels were lower in active BD patients than in inactive BD, recurrent aphthous stomatitis, and control patients.

Hepatitis B core antigen is a potent inductor of interleukin-18 in peripheral blood mononuclear cells of healthy controls and patients with hepatitis B infection.

Clearance of hepatitis B virus infection (HBV) infection implies a polyclonal vigorous T-helper 1 (Th1) and cytotoxic T-lymphocyte (CTL) response. Interleukin-18 (IL-18), a monokine that shares functional abilities with IL-12, is a potent inductor of interferon-gamma (IFN-gamma) by Th1 and natural killer (NK) cells. However, the role and regulation in HBV infection of IFN-gamma have not been defined. This study therefore sought to determine hepatitis B core antigen (HBcAg)-mediated regulation of IL-18 production in peripheral blood mononuclear cells (PBMCs) from healthy controls (HC) and patients with chronic hepatitis B (CHB) or acute hepatitis B (AHB); 31 HC, 27 patients with CHB and 8 patients with AHB infection were included in the study. HBcAg-mediated induction of IL-18 was determined by quantitative reverse transcription-polymerase chain reaction (RT-PCR) and specific enzyme-linked immunosorbent assay (ELISA). HBcAg induced IL-18 gene transcription and dose-dependent secretion of mature IL-18 protein in HC, CHB, and AHB. HBcAg-dependent IL-18 levels were abrogated by inhibition of Caspase-1, but not by blockade of CD40-CD154 interaction. Serum levels of IFN-gamma correlated inversely with viremia in patients with CHB (rho = - 0.54, P < 0.05), but not with serum levels of IL-12 or IL-18. Interestingly, in PBMCs of HBeAg-negative patients, HBcAg induced significantly higher amounts of IL-18 than in those of HBeAg-positive patients. A variant, lacking the histone-like arginine-rich domain, did not induce IL-18 in either HC or CHB in vitro. Taken together, these results indicate that HBcAg induces IL-18 secretion by induction of Caspase-1. Differential regulation in HBeAg-negative and positive patients suggests an important role of IL-18 in CHB infection.

Effect of long-term administration of rebamipide on Helicobacter pylori infection in mice.

It has been suggested that chronic, persistent, uncontrolled inflammations in the stomach could provide the basic step for the beginning of carcinogenesis. One of the potential clinical applications of rebamipide is the inhibition of the immunoinflammatory response in gastric mucosa imposed by Helicobacter pylori. To determine the implications of long-term rebamipide treatment in H. pylori infection, we studied the underlying moleculo-pathological changes in gastric lesions in mice infected with H. pylori (SS1 strain), following this treatment. C57BL/6 mice were sacrificed 24 and 50 weeks after H. pylori infection, respectively. Colonization rates of H. pylori, degree of gastric inflammation and other pathological changes including atrophic gastritis and metaplasia, serum levels of IL-1beta, TNF-alpha, IFN-gamma and IL-10, mRNA transcripts of various mouse cytokines and chemokines, and NF-kappaB binding activities, and finally the presence of gastric adenocarcinoma were compared between an H. pylori infected group (HP), and an H. pylori infected group administered with long-term rebamipide-containing pellet diets (HPR). Serum levels of IL-1beta, IFN-gamma and TNF-alpha, the gastric mucosal expression of ICAM-1, HCAM and MMP, and transcriptional regulation of NF-kappaB-DNA binding were all significantly decreased in the HPR group compared with the HP group. An RNase protection assay showed, in the rebamipide administered group, significantly decreased mRNA levels of apoptosis-related genes such as caspase-8, FasL, Fas, TRAIL and various cytokines genes such as IFN-gamma, RANTES, TNF-alpha, TNFR p75, IL-1beta. In the experiment designed to provoke gastric cancer through MNU treatment with H. pylori infection, the incidence of gastric carcinoma was not different in either group. However, long-term administration of rebamipide showed the advantage of decreasing precancerous lesions like chronic atrophic gastritis and showed molecular evidence of attenuation of proliferation. The long-term administration of rebamipide should be considered in the treatment of H. pylori since it demonstrated molecular and biological advantages like a lessening of gastric inflammation and a possible chemopreventive effect.

Stimulation of hematopoiesis by the Fms-like tyrosine kinase 3 ligand restores bacterial induction of Th1 cytokines in thermally injured mice.

Patients with large burn injuries are susceptible to opportunistic infections due to impaired functions of multiple effector cells of innate immunity and acquired immunity, including macrophages, dendritic cells (DC), natural killer (NK) cells, and T cells. The ability of a host to produce Th1 cytokines, such as gamma interferon (IFN-gamma) and interleukin-12 (IL-12), upon infectious challenge is also impaired after burn injury. Stimulation of hematopoiesis, to regenerate new immune cells, may be an effective strategy for improving resistance to infections after severe burn trauma. Fms-like tyrosine kinase 3 ligand (Flt3L) is a hematopoietic cytokine that stimulates the expansion and differentiation of NK cells and DC. Using a mouse model, we tested the hypothesis that Flt3L treatments after burn injury stimulate the production of functional effector cells of innate immunity and restore appropriate Th1 cytokine responses to Pseudomonas aeruginosa, a common source of pneumonia and wound infections in burn victims. Flt3L increased splenic cellularity in sham (uninjured) and burned mice and increased the numbers of NK cells (DX5(+)) and DC (CD11c(+)). In response to P. aeruginosa, significant increases in the serum IFN-gamma levels and the numbers of splenic IFN-gamma-producing DC, NK cells, and T cells were observed in Flt3L-treated burned mice compared to the values obtained for untreated burned mice. The splenic levels of IL-12 and IL-15 mRNAs and the IL-12 and IL-15 receptors were also increased. In addition, Flt3L treatment restored the ability of splenic cultures prepared from burned mice to produce IFN-gamma and IL-12 after in vitro challenge with P. aeruginosa. Flt3L may have potential for restoring NK cell and DC functions and improving immunity after burn injury.

Serum interferon-γ is associated with longitudinal decline in lung function among asthmatic patients: the Normative Aging Study

Cytokines are important mediators of the asthmatic response. A retrospective pilot study showed that serum levels of interleukin (IL)-5 and interferon (IFN)-gamma were related to lung function decline among asthmatic patients over the preceding 3 years. To confirm these findings, we tested the hypothesis that serum cytokines are associated with longitudinal lung function decline. We conducted a prospective, longitudinal study of 25 asthmatic and 50 nonasthmatic men (median age, 63 years; range, 45 to 80 years) participating in the Normative Aging Study. All study subjects completed two consecutive triennial examinations, including spirometry, methacholine challenge testing, allergy skin testing, and phlebotomy. Serum levels were measured for IL-4, IL-5, IL-6, IL-8, IL-10, and IFN-gamma. Among asthmatic patients, a higher initial serum level of IFN-gamma was associated with a greater rate of decline of forced expiratory volume in 1 second (FEV1; beta = -67 mL/year per log increase in serum IFN-gamma, P = 0.04) and, to a lesser extent, of FEV1/forced vital capacity ratio (beta = -0.91%/year per log increase in serum IFN-gamma, P = 0.07) after adjusting for age, smoking status, and baseline level of lung function. Serum IL-5 level was associated with a rate of decline in FEV1 of borderline significance (beta = -61 mL/year per log increase in serum IL-5, P = 0.08) among asthmatic patients. These relationshipswere not observed among nonasthmatic patients. Serum levels of IFN-gamma are associated with subsequent rate of change in lung function among asthmatic patients in this cohort of middle-aged and older men, and may be useful as biologic markers of risk for accelerated lung function decline in population studies.

Altered intracellular expression of the chemokines MIP-1alpha, MIP-1beta and IL-8 by peripheral blood CD4+ and CD8+ T cells in mild allergic asthma.

The ability of chemokines to regulate Th1 and Th2 responses suggests a role in the pathogenesis of atopic disorders such as allergic asthma where Th2 response dominance has been observed. Although the impact of allergic asthma on local chemokine production in the lung has been the subject of investigation, little is know about the influence of disease progression on peripheral chemokine production. We now report use of whole blood culture and flow cytometry to assess the influence of mild allergic asthma on peripheral T-cell chemokine expression. Study participants included patients with mild allergic asthma (n = 7) and nonasthmatic controls (n = 7). Following in vitro stimulation of peripheral venous blood with phorbol 12-myristate acetate (PMA) and ionomycin, flow cytometry was used to estimate the percentage of CD4+ and CD8+ T cells producing a number of chemokines, including macrophage inflammatory proteins MIP-1alpha and MIP-1beta, RANTES (regulated on activation, T-cell expressed and secreted), monocytic chemotactic protein-1 (MCP)-1, and interleukin (IL)-8, or the cytokines interferon (IFN)-gamma and IL-4. Serum levels of MIP-1alpha, MIP-1beta, RANTES, MCP-1, IL-8, IFN-gamma and IL-4 were also assessed by quantitative ELISA. Intracellular expression of MIP-1beta by CD4+ and CD8+ T cells from allergic asthmatics was significantly reduced in comparison to that observed for nonasthmatics (median = 2.29% (1.75-3.50) vs 4.57% (3.38-6.64), P = 0.05; 14.20% (13.18-17.88) vs 44.10% (30.38-48.70), P = 0.01). Similarly, intracellular expression of MIP-1alpha by CD8+ T cells from allergic asthmatics was also significantly lower (3.67% (1.17-5.42) vs 17.10% (4.97-20.43), P = 0.05). Conversely, IL-8 expression by both CD4+ and CD8+ T cells from allergic asthmatics demonstrated significant enhancement (9.93% (7.77-11.28) vs 4.14% (3.61-7.11), P = 0.05; 8.40% (6.97-10.04) vs 4.98% (3.37-6.08), P = 0.05). Examination of intracellular IFN-gamma and IL-4 revealed no significant difference in the expression of either cytokine by CD4+ T-cells from allergic asthmatics and nonasthmatics. In contrast, expression of IFN-gamma was significantly reduced in CD8+ T-cells from allergic asthmatics (24.60% (21.08-32.50) vs 48.40% (41.50-55.28), P = 0.01). The occurrence in mild allergic asthma of peripheral T-cell chemokine expression suggestive of a diminished Th1 response, coinciding with marginal change in cytokine profiles indicative of a Th2 response bias, confirms the importance of chemokine involvement in the etiology of allergic asthma. The ability to use whole blood culture to estimate chemokine expression in T cell subsets may ultimately provide a practical means to evaluate disease status and to monitor early intervention therapies which target chemokines.

Serum cytokine profiles associated with clinical presentation in Vietnamese infected with hepatitis B virus.

An ineffective cytokine response is thought to be one of the reasons for the failure to suppress hepatitis B virus (HBV) replication and to eliminate the virus. We investigated the serum levels of interleukin (IL)-6, IL-10, IL-12, and interferon (IFN)-gamma in HBV-infected Vietnamese patients to determine whether they were related to the outcome of HBV infection. Samples from a total of 154 HBV-infected patients with well-characterised clinical profiles and 56 healthy controls were assessed. Serum IL-6 levels, which were inversely correlated with transaminase levels, were highest in patients with liver cirrhosis (LC) and hepatocellular carcinoma (HCC) and lowest in those with either asymptomatic (ASYM), acute or chronic HBV, and thus, represented the best marker of HBV-related clinical progression. Compared with the healthy control group, serum IL-12 was uniformly elevated in all HBV-infected patients apart from those with ASYM infections, implying no impairment of production of this cytokine in HBV-infected individuals. Serum IL-10 and IFN-gamma levels, however, were uniformly low and showed no association with clinical presentation. Cytokine profiles were not influenced by the presence of hepatitis B e antigen (HbeAg). Serum IL-6 and IL-12 but not IL-10 and IFN-gamma are associated with the clinical presentation in HBV-infected Vietnamese patients.

Effects of oxymatrine on the serum levels of T helper cell 1 and 2 cytokines and the expression of the S gene in hepatitis B virus S gene transgenic mice: a study on the anti-hepatitis B virus mechanism of oxymatrine.

Oxymatrine has been shown to have a remarkable inhibitory activity to hepatitis B virus (HBV) infection with a hepatitis B virus e antigen (HBeAg) serum conversion rate of approximately 45%. In order to explore the anti-HBV mechanism of oxymatrine, the effects of oxymatrine on serum levels of T helper (h)1 cytokines (interferon (IFN)-gamma and interleukin (IL)-2) and Th2 cytokines (IL-4 and IL-10), and the expression of S gene in HBV S gene transgenic mice were studied. Each transgenic mouse was either injected with oxymatrine or saline intraperitoneally once a day for 30 days. Serum levels of IFN-gamma, IL-2, IL-4 and IL-10 were quantitated and compared to the data before the treatment. The expression of HBV S gene in transgenic mice was analyzed at the DNA, mRNA and protein levels. The serum levels of IFN-gamma in transgenic mice before or after oxymatrine treatment were 3.108 +/- 3.172 and 11.059 +/- 6.971 pg/mL, respectively. In contrast, serum levels before and after oxymatrine treatment for IL-4 were 29.045 +/- 13.235 and 13.024 +/- 9.002 pg/mL, respectively (P < 0.001). The serum levels of IL-2 in the control (saline injection) and oxymatrine-treated mice were 1.070 +/- 0.447 and 5.537 +/- 2.887 pg/mL, respectively (P < 0.0001); and that of IL-10 were 97.226 +/- 73.306 and 33.607 +/- 23.154 pg/mL, respectively (P < 0.01). No significant differences were observed in the expression of HBV S gene in the transgenic mice at the DNA, mRNA and protein levels before or after oxymatrine treatment. The fact that Th1 cytokines are increased while Th2 cytokines are decreased suggests that oxymatrine treatment triggers the change of immune response to hepatitis B infection in transgenic mice, which leads to improved HBV inhibitory activities. The study can help us better understand the mechanisms of the anti-HBV drug, oxymatrine, and how it has potential as an application in clinical chronic hepatitis B treatment.

Association of cytokine responses with disease severity in infants with respiratory syncytial virus infection

To explore the relationship between cytokine responses and severity of respiratory syncytial virus (RSV) infection in infants. Intracellular interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) expression in peripheral blood CD3+ and CD8+ lymphocytes was measured by four-colour flow cytometry. Serum IL-12, IL-4 and IFN-gamma levels were also determined by enzyme-linked immunosorbent assay. The frequency of IL-4 and IFN-gamma expression in CD3+CD8- cells was the same in RSV-infected, non-RSV-infected and control infants and in those with RSV bronchiolitis or RSV pneumonia, indicating that no Th2 predominance exists in the acute phase of RSV infection and RSV bronchiolitis. Furthermore, RSV-infected infants had a more frequent IFN-gamma expression in CD3+CD8+ cells than controls, and they also showed a much lower serum IL-4/ IFN-gamma ratio because of decreased IL-4 and elevated IFN-gamma, the latter being most prominent in RSV bronchiolitis. The serum IL-12 level in RSV-infected infants was the same as in control infants, while those with non-RSV infections had a much higher level. Serum IL-12, IFN-gamma and frequency of IFN-gamma expression in CD3+CD8+ cells in mild RSV infection were much higher than in controls, while no difference existed between severe cases and controls. Type 2 cytokine predominance was not found in the acute phase of RSV infection and RSV bronchiolitis, but both were accompanied by enhanced production of IFN-gamma and a much higher serum IFN-gamma level than in healthy controls, especially in those with RSV bronchiolitis, suggesting a role in causing airway obstruction. IFN-gamma and IL-12 may also play a protective role in RSV infections by diminishing viral replication, and high levels of IL-12 and IFN-gamma may be associated with lessening of the severity of infection.

Mycobacterium bovis BCG-infected mice are more susceptible to staphylococcal enterotoxin B-mediated toxic shock than uninfected mice despite reduced in vitro splenocyte responses to superantigens.

Type 1 T-cell responses against intracellular pathogens play a crucial role in mediating protection. We examined whether the induction of a strong type 1 T-cell response during a chronic bacterial infection influences responses to superantigens capable of inducing acute shock. Intravenous infection of mice with Mycobacterium bovis BCG appeared to induce a progressive anergy towards staphylococcal enterotoxin B (SEB) and towards antigen preparation of BCG (BCG-Ag) itself, based on diminished gamma interferon (IFN-gamma) production by SEB- and BCG-Ag-stimulated splenocytes from infected mice. In contrast to these in vitro results, injection of SEB into BCG-infected mice led to a dramatic increase in the serum IFN-gamma levels and the death of infected but not of control mice. In vitro hyporesponsiveness towards SEB and BCG-Ag occurred only with unfractionated splenocyte cultures, as purified T cells from infected mice produced higher levels of IFN-gamma. Hyporesponsiveness towards SEB and BCG-Ag in unfractionated splenocyte cultures was not due to suppressive antigen-presenting cells (APCs), as APCs from infected mice stimulated higher levels of IFN-gamma from purified T cells. The diminished IFN-gamma levels observed with bulk splenocytes appear to be due to changes in the T-cell-to-APC ratio that result in a decreased proportion of T cells, coupled to reduced proliferative responses and an increased susceptibility of effector T cells to activation-induced cell death in vitro. Our results indicate that the reported phenomena of T-cell anergy during mycobacterial infection may be an in vitro consequence of the development of a strong type 1 response in vivo.

Role of Interleukin-18 and T-helper Type 1 Cytokines in the Development of Mycoplasma pneumoniae Pneumonia in Adults

Interleukin (IL)-18 is a proinflammatory cytokine, originally termed interferon (IFN)-gamma-inducing factor, which promotes T-helper type 1 (Th1) cytokine responses. We recently reported that serum IL-18 levels were elevated in children with Mycoplasma pneumoniae pneumonia (MP). In this study, we investigated the contribution of IL-18 to the infection and assessed the Th1 cytokine response to pulmonary involvement in adults. We investigated the clinical course, pulmonary involvement, and serum levels of IL-18, IFN-gamma, IL-12p40, and soluble IL-2 receptor (sIL-2R) in 21 patients with acute-stage MP and in 21 age- and sex-matched control subjects. Significantly (p < 0.001) increased serum IL-18 (median, 248 pg/mL [range, 89 to 441 pg/mL] vs. median, 126 pg/mL [range, 47 to 217 pg/mL]) and sIL-2R (median, 617 U/mL [range, 410 to 1,032 U/mL] vs. median, 425 U/mL [range, 268 to 601 U/mL]) were found in patients with MP as compared with healthy control subjects, and there was a tendency toward increased serum IFN-gamma and IL-12p40. Circulating IL-18 values had a positive correlation with serum sIL-2R levels (r = 0.62, p = 0.028) and the number of affected pulmonary lobes (sigma = 0.61, p = 0.024), but not with the serum levels of antibodies to M pneumoniae, IFN-gamma, or IL-12p40. Serum IL-18 and sIL-2R values in severe cases were significantly higher (p < 0.03) than those in mild cases. IFN-gamma and sIL-2R levels in four patients with pleural effusion were significantly (p < 0.05) higher than those in the other 17 subjects. Serum levels of IL-18 were raised during the acute phase of MP. We suggest IL-18 and Th1 cytokines may play a significant role in the immunopathologic responses in MP.

Serum cytokine levels do not correlate with disease activity and severity assessed by brain MRI in multiple sclerosis.

Chronic and acute dysregulation of the cytokine network has been described in multiple sclerosis (MS). Inflammatory lesions in the central nervous system of MS patients can be assessed by brain magnetic resonance imaging (MRI). This study has been performed to investigate whether changes of cytokines correlate with morphological changes as determined by MRI. We included 46 patients with relapsing-remitting MS in the study. The serum concentrations of tumor necrosis factor-beta (TNF-beta), TNF receptor-1 (TNFR-1; 55 kDa) and TNFR-2 (75 kDa), interleukin-4 (IL-4), interleukin-10 (IL-10) and interferon-gamma (IFN-gamma) were measured by enzyme linked immunosorbent assay in all patients. Each parameter was correlated with clinical findings and brain MRI parameters. We measured both the number (lesion load) and cumulated area (disease burden) of all lesions on brain MRI. In addition, the number and cumulated area of those lesions showing signs of activity [Gadolinium (Gd)-enhancement, perifocal edema] were determined. A non-significant trend (P < 0.05) was found only for the correlation of serum IFN-gamma levels and the number of active MRI lesions showing both Gd-enhancement and perifocal edema in the subgroup of patients (n=21) with active lesions. When corrected for multiple comparisons, this correlation was not significant anymore, as it was above the corrected P-value of 0.001. We could not observe any further correlation of cytokine levels and MRI parameters. However, TNF-beta serum levels were significantly (P < 0.05) elevated in the patient subgroups with higher number of lesions and disease burden, respectively. Our data show that the determination of serum levels of the investigated cytokines and cytokine receptors is not useful as a tool to determine subclinical disease activity and severity as assessed by brain MRI.

Monitoring of urine nitric oxide (NO) related substrates and immunological competence in hematological malignancy.

It has been reported that concentrations of neopterin in the urine are changed according to the host immunological conditions. In the present study, we measured urinary concentration of neopterin in patients with malignant hematological disorders and investigated the relationship between urinary neopterin levels and laboratory indices for cellular immunity. Urine neopterin levels were correlated with serum sIL-2R levels in the patients with malignant lymphoma, and inversely correlated with lymphocyte reactivity with ConA in the patients with acute myelocytic leukemia. However, no significant correlation was observed between urine neopterin levels and lymphocyte reactivity with phytohemagglutinin and pokeweed mitogen, CD4/8 ratio, CD56+ 16+ subset or serum IFN-gamma levels. In the patients with malignant lymphoma, parallel changes in serum sIL-2R and urine neopterin were observed. The presented results suggest that urine neopterin levels are related to the activation of T cells in malignant lymphoma.

Serum gamma-interferon-inducing factor (IL-18) and IL-10 levels in patients with acute hepatitis and fulminant hepatic failure.

The aim was to determine the role of T-helper (Th)1/Th2 cytokine responses in the clinical outcome of patients with acute liver injury. The serum levels of the cytokines, interleukin (IL)-18, gamma-interferon (IFN-gamma), IL-10 and IL-4 were measured in 20 fulminant hepatic failure (FHF), 18 acute hepatitis (AH), 30 chronic viral hepatitis and 20 liver cirrhosis (LC) patients. Thirteen cases were from the intensive care unit (ICU) and there were 21 healthy volunteers. Immunohistochemical staining of liver biopsies for IL-18 expression was also performed. Serum IL-18 levels in patients with FHF were significantly more elevated than in patients with other liver diseases, ICU cases and healthy volunteers. Furthermore, serum IFN-gamma levels in patients with FHF were also significantly higher than in patients with chronic viral hepatitis, LC and healthy volunteers. We found a positive correlation between the levels of IL-18 and IFN-gamma. However, no relationship was observed between these and clinical outcome. In immunohistochemical staining, CD68+ macrophage cells and IL-18-positive cells were observed in portal zones. Elevated serum IL-10 levels were restricted to patients presenting with FHF, and were significantly higher in surviving cases (P < 0.01). Furthermore, serum IL-10 levels, but not IL-4 levels, were inversely correlated with serum total bilirubin concentrations (P = 0.045) and the death rate (p) outlined in Japan (P = 0.030). These results suggest that IL-18 and IFN-gamma are involved in the pathogenesis of acute hepatic injury in humans, and that, in particular, elevated serum levels of IL-10 may be predictive of improved outcomes for these patients.

Cytokine detection in HIV-1/HHV-8 co-infected subjects.

In a previous work we have evaluated some immunologic and haematologic parameters of HIV-1 positive subjects co-infected with HHV-8. A worsening of these values were generally described in these patients as compared with those HIV-1 positive, but negative for HHV-8. Now we have studied the influence of HHV-8 co-infection of HIV-1 positive subjects on the production of some cytokines to make clear the question of its role in the immuno-deregulation of the above-mentioned subjects. In particular we have analysed serum levels of IL-4 and IL-10, Th2 type T cells cytokines, IFN-gamma, an indirect marker of Th1 cells activation and IL-18, a cytokine produced by monocytic-macrophagic cells, which is able to induce IFN-gamma production and Th1 T lymphocytes activation. No significant differences were found as regards the IFN-gamma serum levels (92.1 +/- 24.3 pg ml(-1) in the case of HIV-1 positive/HHV-8 negative subjects and 96.0 +/- 17.4 pg ml(-1) in those HIV-1 positive/HHV-8 positive). In healthy subjects the mean level of this cytokine was 17.6 +/- 5.2 pg ml(-1) (significant difference with both the former values at p < 0.001). Moreover IL-4 and IL-10, which were undetectable in healthy individuals, showed the following values in HIV-1 positive/HHV-8 negative subjects: 31.9 +/- 2.7 pg ml(-1) and 119.8 +/- 85.1 pg ml(-1) respectively and in HIV-1 positive/HHV-8 positive subjects: 30.4 +/- 4.8 pg ml(-1) and 69.4 +/- 65.3 pg ml(-1) (not significant differences). In contrast IL-18 reached a mean level of 1001.2 +/- 360.5 pg ml(-1) in HIV-1 positive/HHV-8 negative subjects, but showed a significant reduction in HIV-1 positive/HHV-8 positive subjects (737.6 +/- 284.3 pg ml(-1) --> p < 0.05) and presented very low levels in healthy individuals (21.3 +/- 30.3 pg ml(-1)). Moreover a significant correlation (-0.984 --> p < 0.001) was noticed between IL-18 reduction in HIV-1 positive subjects co-infected with HHV-8 and the degree of positivity of HHV-8. These data suggest that HHV-8 co-infection has no influence on the switch Th1 --> Th2 in HIV-1 positive subjects, but is able to reduce IL-18 production, useful for Th1 subset restoration.

Phase 1 study of interleukin-12 in combination with rituximab in patients with B-cell non-Hodgkin lymphoma

Rituximab is a chimeric murine/human monoclonal antibody that binds to CD20 on B lymphocytes. Although binding of the Fab domain may induce apoptosis, the Fc domain recruits immune effector functions to mediate cell lysis. Interleukin-12 (IL-12) facilitates cytolytic T-cell responses, enhances the lytic activity of natural killer (NK) cells, and induces the secretion of interferon gamma (IFN-gamma) by both T and NK cells. Therefore, the hypothesis was considered that combining IL-12 with rituximab would augment the immune-mediated cell lysis induced by rituximab. A phase 1 study of IL-12 in combination with rituximab was conducted in 43 adults with B-cell lymphoma to determine the optimal immunologic dose of this combination. Rituximab was administered at a dose of 375 mg/m(2) by intravenous infusion weekly for 4 weeks, and IL-12 was given subcutaneously twice weekly. The starting dose of IL-12 was 30 ng/kg and this was escalated to 500 ng/kg. Constitutional symptoms and liver enzyme elevations at 500 ng/kg of IL-12 were dose limiting. A greater than 20-fold increase in the serum levels of IFN-gamma and a 2.5- to 5-fold increase in inducible protein 10 (IP-10) levels was seen at IL-12 doses of 100 ng/kg or greater. Objective responses occurred in 29 of the 43 patients (69%), with 8 of 11 complete responses seen at IL-12 doses of 300 ng/kg or greater. The optimal immunologic dose of IL-12 in combination with rituximab was determined to be 300 ng/kg subcutaneously twice weekly starting on day 2. These data suggest that IL-12 and rituximab is an active combination and further studies of this combination in B-cell non-Hodgkin lymphoma are warranted.

Serum IFN-gamma and IL-10 levels are associated with disease progression in non-obese diabetic mice.

The goal of the present study was to determine whether cytokines in the peripheral blood of naive NOD mice correlate with the disease process and thereby would provide a marker for monitoring disease activity. Female NOD mice (5, 10 and 14-16 weeks of age) were investigated in a cross-sectional study. In the group of 14-16-week-old mice, non-diabetic and diabetic mice were analysed as different subgroups. The Th1 cytokine (IFN-gamma) and the Th2 cytokine (IL-10) were quantified in serum by sandwich enzyme-linked immunosorbent assay (ELISA). Pancreatic mRNA for IFN-gamma and IL-10 was determined by reverse transcriptase-polymerase chain reaction (RT-PCR) from the same animals. Serum levels of IFN-gamma were initially low but increased with age in NOD mice, reaching the highest levels at diabetes onset (p<0.002 compared to 10 weeks). A similar rise was noted in IFN-gamma gene expression in pancreatic lesions. In contrast, an early peak of serum IL-10 levels was observed in non-diabetic NOD mice (10 weeks) at a stage where non-destructive insulitis occurs. With increasing age a continuous loss of IL-10 until progression towards diabetes was observed. The pancreatic IL-10 mRNA expression correlated with serum IL-10 changes. As a consequence, the ratio of IFN-gamma/IL-10, reflecting the Th1/Th2 balance in the serum, was significantly increased in diabetic compared to non-diabetic NOD mice (p<0.005). These results demonstrate, for the first time, that an increased Th2 pattern in the non-diabetic stage preceding a Th1 shift is associated with the development of diabetes in naive NOD mice. Serum cytokines correlate with disease progression and pancreatic cytokine expression during prediabetes. Soluble cytokines measured in the periphery are therefore promising surrogate markers of diabetes development.

Inhibition of IL-12 synthesis of peripheral blood mononuclear cells (PBMC) stimulated with a bacterial superantigen by pooled human immunoglobulin: implications for its effect on Kawasaki disease (KD).

The aim of this study was to further assess the role of pooled human immunoglobulin (PHIG) on cytokine production from PBMC stimulated with a bacterial superantigen. Human PBMC were cultured with Streptococcus pyrogenic exotoxin A (SPE-A) with or without PHIG and several proinflammatory cytokine levels of culture supernatants were measured. Serum cytokine levels of KD patients before and after PHIG therapy were also examined. PHIG greatly reduced the production of IL-12, interferon-gamma (IFN-gamma) and other cytokines from SPE-A-stimulated PBMC, while exogenous IL-12, but neither IL-1 nor tumour necrosis factor-alpha (TNF-alpha), restored IFN-gamma production inhibited by PHIG. Although PHIG partially adsorbed SPE-A, its inhibitory effect on cytokine production was not played by anti-SPE-A antibody. Although purified CD4+ T cells cultured with human HLA-DR-transfected mouse L cells and SPE-A could not effectively produce IFN-gamma, they produced large amounts of IFN-gamma if exogenous IL-12 was introduced. KD patients in the acute phase had higher levels of serum IFN-gamma than did controls and patients with bacterial infection. Although IL-12 levels of children with or without KD were not significantly different, IL-12 levels of children were much higher than those of adults. However, serum levels of IL-12 of KD patients were transiently but significantly decreased by PHIG therapy and IFN-gamma amounts subsequently reverted to basal levels thereafter. These findings indicate that PHIG inhibits IL-12 production of SPE-A-activated monocytes and thereby decreases IFN-gamma synthesis by T cells and suggest that inhibition of IL-12 and IFN-gamma production is an important part of the mechanisms underlying PHIG therapy on KD.

The effects of interleukin-10 depletion in vivo on the immune response to Porphyromonas gingivalis in a murine model.

The immune response to Porphyromonas gingivalis in the mouse abscess model is known to be dependent upon CD4 T-cell activation and the regulatory role of cytokines. The role of interleukin-10 (IL-10) in this mouse model was examined in vivo. One-week-old, female BALB/c mice were divided into 4 groups. Groups 1 and 2 were given intraperitoneal (i.p.) injections of phosphate buffered saline (PBS) weekly for 5 weeks. Group 3 was given an i.p. injection of rat immunoglobulin. Group 4 was injected with rat anti-IL-10 antibodies. At week 6, group 1 was sham-immunized with PBS, and groups 2, 3, and 4 were injected with P. gingivalis lipopolysaccharide (Pg-LPS) weekly for 2 weeks. One week after the final immunization, delayed-type hypersensitivity (DTH) was assessed by footpad swelling to Pg-LPS. The level of serum antibodies to Pg-LPS and IFN-gamma (IFN-gamma) was determined by enzyme-linked immunosorbent assay. Dorsal abscess formation induced by the injection of viable P. gingivalis was examined daily for 30 days. The footpad swelling of the anti-IL-10-treated group (group 4) was significantly higher than that of groups 1 to 3. Similarly, the serum IFN-gamma level in group 4 was much higher than that of the other experimental groups. There was no significant difference in serum IgG antibodies to Pg-LPS in any of the experimental groups. However, the level of IgM antibodies in group 4 mice was significantly lower than that in groups 2 and 3. In addition, serum IgG1 was suppressed in group 4 mice, while IgG2a antibodies were raised. However, there was no difference observed between the levels of IgG2b and IgG3 antibodies in any group of mice. The lesions in sham-immunized mice (group 1) persisted for 30 days, and those in group 2 and 3 were undetected by day 18 and 20, respectively. In sharp contrast, lesions in group 4 had healed completely by day 13. This study has shown that IL-10 depletion in vivo in P. gingivalis LPS-induced immune response in mice led to an elevated DTH response, an increase in serum IFN-gamma levels, and raised levels of IgG and IgG2a antibodies. Treatment with anti-IL-10 antibodies resulted in suppressed IgG1 and IgM responses and a more rapid healing of abscesses than in non-IL-10-depleted mice. These results suggest that IL-10 depletion in Pg-LPS-induced immune response in mice may lead to a Th1-like immune response and provide strong protection against a subsequent challenge with live P. gingivalis in an abscess model.