Serum levels of IL-6 type cytokines and soluble IL-6 receptors in active B-cell chronic lymphocytic leukemia and in cladribine induced remission

We have investigated the serum concentrations of interleukin-6 (IL-6) and two IL-6 family cytokines-oncostatin M (OSM) and leukemia inhibitory factor (LIF)-in 63 patients with B-cell chronic lymphocytic leukemia (B-CLL) and 17 healthy controls using the enzyme-linked immunosorbent assay (ELISA) method. Simultaneously, we measured the serum levels of the soluble forms of two subunits of the IL-6 receptor complex-ligand binding glycoprotein 80 (sIL-6R) and glycoprotein 130 (sgp130). The cytokines and receptors were evaluated in 25 untreated patients and 38 patients treated with cladribine (2-CdA), as well as in 17 healthy controls. We have correlated the serum levels of these proteins with Rai's clinical stage of the disease, the response to 2-CdA treatment and some hematological parameters. We have also evaluated the correlation of the IL-6 serum level with the concentration of OSM and IL-6 soluble receptors. IL-6 was measurable in 62/63 (98.4%), OSM in 20/25 (80%) of untreated and 14/38 (37.8%) of the treated patients. sIL-6R and sgp130 were detectable in all 63 patients and LIF in none of the CLL patients. IL-6 serum level in untreated patients was not significantly different as compared to its concentration in the control group (P>0.05). However, in the patients treated with 2-CdA the IL-6 level was significantly lower (P<0.02), and the lowest concentration was found in the patients with complete remission (CR; median 1.4pg/ml; P<0.02). The concentration of sIL-6R was significantly higher in untreated (median 61.8 ng/ml) and treated (median 50.1 ng/ml) CLL patients when compared to normal persons (median 41.2 ng/ml; P=0.04; P<0.001, respectively). There was no difference between the sIL-6R levels in the patients with CR and the healthy controls. In non-responders sIL-6R concentration was the highest and similar to its level in the untreated patients. OSM level was higher in the untreated patients (median 1.8pg/ml) than in the normal controls (median 0.0pg/ml; P<0.001) and in the CR patients (median 0.0pg/ml; P<0.03). The serum concentration of sgp130 was similar in the untreated (median 480 pg/ml) and treated (median 470 pg/ml) patients, as well as in the healthy persons (median 420 pg/ml; P>0.05). We have found significant positive correlation between the levels of sIL-6R and the lymphocytes count in CLL patients (p=0.423; P<0.001). In addition, sIL-6R and OSM serum concentrations correlated also with CLL Rai stage. In conclusion, the serum level of IL-6, OSM and sIL-6R, but not LIF and sgp130, are useful indicators of CLL activity.     

Serum soluble IL-2 receptor as a marker of lymphocyte activation in some autoimmune diseases. Effect of immunosuppressive therapy

Our experience regarding serum soluble interleukin-2 receptor (sIL-2R) measurement as a marker of lymphocyte activation consists of patients with autoimmune disease: 37 with systemic lupus erythematosus (SLE), 23 with autoimmune hepatitis (AIH), 74 with inflammatory bowel disease and six with Wegener's granulomatosis (WG). The influence of immunosuppressive therapy has also been assessed. Serum sIL-2R in SLE is significantly higher than in healthy controls and good correlation is found between sIL-2R and disease activity. Severity of kidney inflammation in lupus nephritis can be reflected by the increased excretion of sIL-2R. It was found that sIL-2R level significantly falls when the disease becomes clinically inactive after immunosuppressive therapy, but in many cases (up to 50%) it does not reach normal levels. The last finding suggests that lymphocyte activation may still be present even though the disease is considered inactive under clinical criteria and support the need of prolonged immunosuppression after the first signs of remission. In AIH the serum levels of sIL-2R are elevated in all patients with active disease; all cases with "highly active" disease have significantly higher concentrations than patients with "mild activity". A good correlation has been demonstrated between elevated serum sIL-2R values and anti-asialoglycoprotein receptor (ASGPR) titer (the specific marker of AIH). The follow-up study showed a significant decrease of both sIL-2R levels and anti-ASGPR titer after 3-9 month immunosuppressive therapy. The findings support that sIL-2R and anti-ASGPR titer could serve as reliable humoral markers for disease-specific activity. Compared with inactive ulcerative colitis (UC) and Crohn's disease (CD), significantly higher levels of sIL-2R were present in the serum of patients with active disease, and in inactive disease than in healthy age-matched controls. Methotrexate (MTX) therapy of patients with refractory UC resulted in sIL-2R decrease at the end of therapeutic period (20 i.m. injections of once a week 25 mg), good responders showing > 50% decrease even at 5-7 weeks of treatment. Serum sIL-2R is elevated in all six patients with WG. Contrary to anti-neutrophil cytoplasmic antibodies (ANCA), sIL-2R remains elevated above cut-off for normal range, despite clinical improvement following immunosuppressive treatment. The last observation suggests that serum sIL-2R is not a good measure of the disease activity and argue for the need of longer immunosuppressive therapy just after the first days of clinical remission.     

Relationship between circulating interleukin-10 (IL-10) with interleukin-6 (IL-6) type cytokines (IL-6, interleukin-11 (IL-11), oncostatin M (OSM)) and soluble interleukin-6 (IL-6) receptor (sIL-6R) in patients with multiple myeloma

We investigated the serum concentration of the interleukin-10 (IL-10), along with cytokines of interleukin-6 (IL-6) family (IL-6, IL-11 and oncostatin M - OSM), as well as soluble receptor for IL-6 (sIL-6R), in 121 patients with multiple myeloma (MM) and 28 healthy subjects. We studied the interactions between IL-10 and other cytokines, and the receptor. The correlation between IL-10 and some clinical and laboratory parameters associated with the disease activity were also analysed. The IL-10 was detectable in all patients with multiple myeloma and in all controls. The IL-10 concentration was significantly increased in myeloma patients compared with healthy persons (mean - 7.09 and 2.1 pg/ml, respectively) (p = 0.008). The level of IL-10 correlated positively with the advanced stage of disease estimated according to the Salmon and Durie classification (I versus III stage - p = 0.03). Higher values of IL-10 were found in patients with the light chain disease, hypercalcaemia, and correlated with the elevated concentrations of C-reactive protein (CRP). IL-6 was detected in 117 of the 121 patients and in all controls. The concentration of IL-6 was statistically increased in MM patients compared with control group (mean - 16.06 and 4.49 pg/ml, respectively) (p = 0.01). We found a positive correlation between IL-10 and IL-6 serum levels in MM patients. The relationship, expressed as Spearman's rank sum coefficient (rho = 0.249, p = 0.006) was significant. IL-11 was detected in 26 of the 121 MM patients and in 3 of the 28 healthy subjects at the mean concentration of 1.2 and 0.6 pg/ml respectively (p > 0.05). OSM was at detectable levels in 51 of the 121 patients and in only 4 of the 28 controls (mean - 3.84 and 0.1 pg/ml, p = 0. 002). The correlation between IL-10 and IL-11 levels in MM patients was not significant, but there was a strong statistical correlation between IL-10 and OSM concentrations (rho= 0.327, p = 0.0002). The serum concentration of sIL-6R was measurable in all patients and all controls (mean - 66.00 and 39.57 ng/ml respectively), but the difference between these groups was not significant. We found significant, positive correlation between the levels of IL-10 and sIL-6R (rho= 0.233, p = 0.01). In conclusion, we state that the serum concentrations of IL-10, IL-6, OSM and sIL-6R in MM patients may be a useful markers for the evaluation of the disease activity.     

Vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and soluble interleukin-2 receptor (sIL-2R) concentrations in peripheral blood as markers of pituitary tumours

Vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and soluble interleukin-2 receptor (sIL-2R) are important cytokines. They are secreted by normal pituitary glands and those with all types of adenomas and may be involved in pituitary tissue growth. The peripheral blood concentrations of VEGF, bFGF and sIL-2R in nineteen patients (17-70 years) with pituitary tumours and ten healthy subjects (23-34 years) were studied. Hypersecretion of prolactin (five cases), human growth hormone (four cases), and thyroid stimulating hormone (one case) was recorded in some patients, and the remaining subjects were diagnosed as having nonfunctional pituitary tumours. Increased peripheral blood plasma levels of VEGF (310.82 +/- 59.17 pg/ml) compared with controls (40.32 +/- 11.80 pg/ml; p < 0.01), as well as bFGF (87.27 +/- 7.58 pg/ml) versus controls (11.14 +/- 2.43 pg/ml; p < 0.001) were recorded. The levels of sIL-2R did not differ between the pituitary tumour patients (4,490.58 +/- 581.50 pg/ml) and control subjects (3,617.01 +/- 1,397.18 pg/ml; p > 0.05). The concentrations of VEGF and bFGF in the peripheral blood are useful additional markers of the presence of tumours.     

Serum concentrations of sIL-2R, IL-6, TGF-beta1, neopterin, and zinc in chronic hepatitis C patients treated with interferon-alpha

T lymphocytes and immunoregulatory cytokines play an important role in the host response to hepatitis C virus (HCV) infection. Zinc is required for a wide spectrum of immune functions, including T-cell activity. To determine the clinical significance of the cytokines sIL-2R, IL-6, TGF-beta1, neopterin, and of zinc in chronic heptatitis C virus (HCV) infection, we investigated their concentrations in the serum of 16 patients with chronic HCV infection before, during and at the end of therapy with interferon (IFN) alpha (Roferon A), and after 6 months follow-up. Elevated concentrations of sIL-2R, IL-6, TGF-beta1, and neopterin were found in the serum of all patients prior to therapy, as compared to healthy controls. sIL-2R patterns differed in responders and non-responders. While the mean concentration of sIL-2R (335.75 pg/ml) before therapy was about 40% higher in complete responders (n=4) than in controls (272.20 pg/ml), the mean concentration in non-responders (n=6) was 4-fold higher than in controls (1153.33 pg/ml). During therapy, sIL-2R levels in responders decreased by about 40%. Mean IL-6 concentrations in both complete and partial responders (n=6) decreased continuously during treatment, while mean concentrations in non-responders decreased for only a short time, and increased again after cessation of therapy. Mean levels of TGF-beta1 behaved similarly to those of IL-6. Only negligible differences in mean neopterin levels were found between responders and non-responders over the entire observation time. The mean serum zinc concentrations slightly decreased in all 3 patient groups, the greatest reduction occurring in 3 of the 4 responders. The present findings underscore the importance of the immune system in the pathogenesis of chronic HCV infection. Serum sIL-2R levels may be used as a serological marker of outcome following IFN-alpha treatment.     

SERUM CONCENTRATIONS OF sIL-2R, IL-6, TGF-β1, NEOPTERIN, AND ZINC IN CHRONIC HEPATITIS C PATIENTS TREATED WITH INTERFERON-ALPHA

T lymphocytes and immunoregulatory cytokines play an important role in the host response to hepatitis C virus (HCV) infection. Zinc is required for a wide spectrum of immune functions, including T-cell activity. To determine the clinical significance of the cytokines sIL-2R, IL-6, TGF-β1, neopterin, and of zinc in chronic heptatitis C virus (HCV) infection, we investigated their concentrations in the serum of 16 patients with chronic HCV infection before, during and at the end of therapy with interferon (IFN) α (Roferon A), and after 6 months follow-up. Elevated concentrations of sIL-2R, IL-6, TGF-β1, and neopterin were found in the serum of all patients prior to therapy, as compared to healthy controls. sIL-2R patterns differed in responders and non-responders. While the mean concentration of sIL-2R (335.75 pg/ml) before therapy was about 40% higher in complete responders (n=4) than in controls (272.20 pg/ml), the mean concentration in non-responders (n=6) was 4-fold higher than in controls (1153.33 pg/ml). During therapy, sIL-2R levels in responders decreased by about 40%. Mean IL-6 concentrations in both complete and partial responders (n=6) decreased continuously during treatment, while mean concentrations in non-responders decreased for only a short time, and increased again after cessation of therapy. Mean levels of TGF-β1 behaved similarly to those of IL-6. Only negligible differences in mean neopterin levels were found between responders and non-responders over the entire observation time. The mean serum zinc concentrations slightly decreased in all 3 patient groups, the greatest reduction occurring in 3 of the 4 responders. The present findings underscore the importance of the immune system in the pathogenesis of chronic HCV infection. Serum sIL-2R levels may be used as a serological marker of outcome following IFN-α treatment.     

Correlation of serum tumor necrosis factor-alpha,interleukin-4 and soluble interleukin-2 receptor levels with radiologic and clinical manifestations in active pulmonary tuberculosis

The precise clinical manifestations of tuberculosis are likely to result from a complex interaction between the host and the pathogen. We took serum samples from a group of patients with a variety of clinical and radiological stages of pulmonary tuberculosis in order to characterize tumor necrosis factor-alpha (TNF-alpha), interleukin-4 (IL-4) and soluble interleukin-2 receptor (sIL-2R) response. We further evaluated whether the levels of TNF-alpha, IL-4 and soluble IL-2R are related with each other, and also evaluated the levels of TNF-alpha, IL-4 and sIL-2R after anti-tuberculosis therapy and relation with radiologic scores. Forty-three inpatients with active pulmonary tuberculosis and 19 healthy controls participated in the study. Patients were divided into four categories radiologically on chest X-ray (minimal, moderate-advanced, far-advanced and with miliary infiltration). Concentrations of TNF-alpha (20.9+/-10/15.4+/-8 pg/ml) and sIL-2R (2569+/-842/1444+/-514 pg/ml) were statistically different between patients and controls (p=0.02 and p=0.0001, respectively). Before chemotherapy there was a positive correlation between TNF-alpha and sIL-2R (r=0.34), but there was no correlation between IL-4 and TNF-alpha, and between IL-4 and sIL-2R (r=-0.23 and r=-0.22). The TNF-alpha level was not statistically different in four groups before and after chemotherapy. Results of this study provided some evidence confirming the previously reported role of TNF-alpha, IL-4 and sIL 2R in the control of tuberculosis, but these cytokines were not found related with disease severity.     

Serum proinflammatory mediators at different periods of therapy in patients with multiple myeloma

Multiple myeloma (MM) is a malignant disease characterized by the clonal proliferation of plasma cells within the bone marrow. Several cytokines have been demonstrated to be involved in the control of growth, progression, and dissemination of MM. We determined serum levels of interleukin-1beta (IL-1beta), soluble interleukin-2 receptor (sIL-2R), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP) in 14 newly diagnosed MM patients. The median age of the patients was 63.4 +/- 10.8 years and all of the patients were stage III (classified according to the Durie-Salmon classification). The same parameters were measured in 15 healthy controls. In addition, we also examined the effects of vincristine-adriamycin-dexamethasone (VAD) therapy on the same parameters and mediators as well as the relationship among the parameters in the same patient groups. The serum concentrations of TNF-alpha, IL-1beta, sIL-2R, IL-6, IL-8, and CRP (18.6 +/- 3.7 pg/mL, 10.1 +/- 2.8 pg/mL, 730 +/- 220 U/mL, 11.4 +/- 3.3 pg/mL, 23.9 +/- 8.3 pg/mL, and 49.9 +/- 19.5 mg/dL, resp) were significantly higher in newly diagnosed MM patients than in healthy controls (P < .0001). All of the parameters were found to be significantly reduced after chemotherapy. In conclusion, we found that after the VAD therapy, the level of these cytokines which are thought to play an important role in the pathogenesis of MM was significantly suppressed. This is the first study demonstrating strong impact of VAD treatment on circulating mediators of sIL-2R and IL-8 levels parameters.     

Serum levels of TNF-alpha,sIL-2R,IL-6, and IL-8 are increased and associated with elevated lipid peroxidation in patients with Behçet's disease

AIM: Behçet''s disease (BD) is asystemic immunoinflammatory disorder and the aetiopathogenesis is to be specified. Cytokines play a role in immune response and in many inflammatory diseases. The aim of this case-control study is to investigate serum pro-inflammatory cytokine tumour necrosis factor (TNF)-alpha, interleukin-1beta (IL-1beta), soluble IL-2 receptor (sIL-2R), IL-6, and chemokine IL-8 levels in patients with BD. We also determined the end product of lipid peroxidation (malondialdehyde (MDA)) in BD patients as an index for oxidative stress. METHODS: A total of 37 patients (19 men, 18 women) with BD (active, n = 17; inactive, n = 20) and 20 age-matched and sex-matched healthy control subjects (11 men, nine women) included in this cross-sectional, blinded study. Serum TNF-alpha, IL-1beta, sIL-2R, IL-6 and IL-8 levels were determined by a spectrophotometer technique using the immulite chemiluminescent immunometric assay. Lipid peroxidation was evaluated by Wasowicz et aL The levels of cytokines and lipid peroxidation in the active period were compared with the inactive period of the disease. Results are expressed as mean +/- standard error. RESULTS: IL-1beta levels were below the detection limits of the assay (< 5 pg/ml) in all samples. Mean levels of MDA (8.1+/-0.7 micromol/l), sIL-2R (800+/-38 U/ml), IL-6 (12.6+/-1.1 pg/ml), IL-8 (7.2+/-0.4 pg/ml), and TNF-alpha (7.9+/-0.5 pg/ml) in active BD patients were significantly higher than those in inactive patients (4.3+/-0.5 micromol/l, p < 0.01; 447+/-16 U/ml, p < 0.001; 8.3+/-0.6 pg/ml, p = 0.006; 5.3+/-0.1 pg/ml, p < 0.001; and 5.1 0.2 pg/ml, p < 0.001; respectively) or control subjects (2.1+/-0.2 micromol/l, p < 0.001; 446+/-20 U/ml, p < 0.001; 6.4+/-0.2 pg/ml, p < 0.001; 5.4+/-0.1 pg/ml, p < 0.001; and 4.7+/-0.1 pg/ml, p < 0.001, respectively). On the contrary, only the mean IL-6 level was significantly different between inactive BD and control subjects (p = 0.02). All acute phase reactants were significantly higher in active BD than in inactive period (for each, p < 0.01). Conclusions: High levels of sIL-2R, IL-6, IL-8 and TNF-alpha indicate the activation of immune system in BD. Serum sIL-2R, IL-6, IL-8 and TNF-alpha seem to be related to disease activity. Increased lipid peroxidation suggests oxidative stress in BD and therefore tissue damage in such patients. Amelioration of clinical manifestations would be envisaged by targeting these cytokines, chemokines and lipid peroxidation with pharmacological agents.     

Acute effect of hemodialysis on serum levels of the proinflammatory cytokines

Chronic inflammation is a common feature of end-stage renal disease, which carries a heightened risk of atherosclerosis and other co-morbid conditions. Dialysis treatment per se can bring additional risk factors for inflammation, such as increased risk of local graft and fistula infections, impure dialysate or bio-incompatible membranes. Our study was designed to determine whether a hemodialysis session leads to an acute substantial alteration in the plasma levels of the proinflammatory cytokines interleukin (IL)-6, IL-1beta and tumor necrosis factor (TNF)-alpha, the T-lymphocyte activation factor soluble IL-2 receptor (sIL-2R), and an inflammation mediator and chemotactic granulocyte factor, IL-8, in end-stage renal disease patients receiving chronic intermittent HD. In this study, 21 (12 male/nine female) patients undergoing chronic hemodialysis were enrolled. The acute effect of a hemodialysis session on serum cytokine concentrations was assessed by comparison of pre-hemodialysis and post-hemodialysis determinations. Serum IL-1beta, sIL-2R, IL-6, IL-8 and TNF-alpha levels were determined with chemiluminescence enzyme immunometric assays. A significant difference was not observed for IL-1beta, IL-6, TNF-alpha, and sIL-2R concentrations in pre-hemodialysis and post-hemodialysis specimens (p>0.05). Serum median (25th-75th percentiles) IL-8 concentration was 69.4 (34.9-110.3) pg/ml before hemodialysis, and decreased to 31.5 (18.0-78.8) pg/ml following hemodialysis (p: 0.006). Clearance of IL-8 increased by 0.47+/-0.08 pg/ml for each unit increase in pre-dialysis IL-8 (p<0.001) and decreased by 5.63+/-2.59 pg/ml for each unit increase in pre-dialysis urea mmol/l (p<0.05). In conclusion, the results of our study demonstrate that a hemodialysis session markedly decreases IL-8 concentration, which is significantly affected by pre-dialysis concentrations, indicating that removal of IL-8 is a concentration gradient-dependent action, but does not change the serum levels of IL-1beta, sIL-2R, IL-6, and TNF-alpha, underlining importance of the structural characteristics of the molecules.     

Tumour necrosis factor-alpha,interleukin-2 soluble receptor and different inflammatory parameters in patients with rheumatoid arthritis

BACKGROUND AND AIMS: Although the participation of cytokines in the pathogenesis of rheumatoid arthritis (RA) seems to be unequivocal, their relationship with current serum markers of this disease is not clear. The present study analyses whether there is any correlation between the levels of tumour necrosis factor-alpha (TNF-alpha), interleukin-2 soluble receptor (sIL-2R) and the concentrations of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and beta(2)-microglobulin in a group of 21 patients with RA, all rheumatoid factor positive. METHODS: The levels of TNF-alpha and sIL-2R were analysed in association with other parameters of inflammation (ESR, CRP and beta(2)-microglobulin). RESULTS: In comparison with the control group, RA patients presented high median levels of both cytokines, TNF-alpha (6.4 pg/ml) and sIL-2R (56 pmol/L), as well as of ESR (34 mm/h), CRP (0.9 mg/dl) and beta(2)-microglobulin (1.6 mg/dl) (p < 0.01). However, only ESR levels in the RA group significantly differ from the control group (p < 0.01). No correlation was found between the inflammatory parameters. CONCLUSIONS: These results suggested that TNF-alpha and slL-2R levels are up-regulated in RA patients but did not significantly differ from the control group. Due to the chronic course of this disease, other inflammatory markers must be identified in order to provide early therapeutic strategies to these patients.     

Enhanced acute-phase response and oxidative stress in older adults with type II diabetes.

OBJECTIVE: To test whether oxidative stress could promote a systemic acute-phase response in elderly patients with type II diabetes. DESIGN AND METHODS: In a group of 30 older diabetic patients with poor glycemic control, serum levels of lipid peroxides, measured as thiobarbituric acid-reacting substances (TBARS); C-reactive protein (CRP); interleukin (IL)-6 and the soluble form of its receptor (slL-6R), were evaluated at baseline and after 2 and 3 months of therapeutic intervention. Thirty asymptomatic, untreated individuals with abnormal fasting glycemia, but otherwise healthy status, of similar age, sex, and weight served as control group. RESULTS: At baseline, glycemia (8.83 +/- 0.67mmol/l), HbA1C (8.66 +/- 0.59%), TBARS (8.68 +/- 1.21 micromol/l), CRP (16.05 +/- 3.81 mg/l) IL-6 (5.39 +/- 1.25 pg/ml) and sIL-6R (1425 +/- 492 pg/ml) were significantly higher in diabetic patients than in asymptomatic hyperglycemic individuals (p<0.001). After treatment, glycemia significantly decreased with respect to baseline values (- 9.82% after 60 days and -13.74% after 90 days), as did serum levels of TBARS (-14.05% and -21.89%, respectively), CRP (-32.71% and -43.86%), IL-6 (-23.75% and -40.63%) and sIL-6R (-34.53% and -48.49%, respectively). In diabetic patients, multiple regression showed, at each time, that TBARS and IL-6 were independently correlated with CRP, considering CRP as the dependent variable. Similar correlations were found in asymptomatic hyperglycemic subjects. CONCLUSION: These results suggest that oxidative stress might be implicated in promoting a state of low-grade systemic inflammation in elderly patients with type II diabetes.     

Serum levels of interleukin-6 type cytokines and soluble interleukin-6 receptor in patients with rheumatoid arthritis.

We investigated the serum concentrations of interleukin-6 (IL-6) and two IL-6 family of cytokines (leukaemia inhibitory factor (LIF) and ciliary neurotrophic factor (CNTF) as well as IL-6 soluble receptor (sIL-6R) using an enzyme-linked immunosorbent assay (ELISA) in 66 patients with rheumatoid arthritis (RA) and 24 healthy controls. We examined a possible association between the serum levels of these peptides and RA activity according to the Mallya and Mace scoring system and Ritchie''s index. We also evaluated the correlation between the serum levels of IL-6, LIF, CNTF and sIL-6R and duration of the disease and calculated sIL-6R/IL-6 ratio in RA patients and in the control group. IL-6 and sIL-6R were detectable in all 66 patients with RA and 24 normal individuals. LIF was also found in the serum of all patients with RA and in 16 (66.7%) normal individuals. In contrast CNTF was measurable only in 15 (22.7%) patients with RA and 24 (33.3%) normal individuals. The highest IL-6 and sIL-6R levels were found in the patients with Stages 3 and 4 of RA activity and the lowest in the control group. In contrast there were no statistically significant differences between the LIF and CNTF levels in RA patients and normal individuals. We found positive correlation between IL-6 and sIL-6R concentrations and Ritchie''s index and a lack of such correlation with LIF and CNTF. IL-6 serum level correlated positively with the disease duration, but sIL-6R, LIF and CNTF did not. Serum sIL-6R/IL-6 ratio was significantly lower in RA patients than in healthy controls. In conclusion, an increase in the serum levels of IL-6 and sIL-6R, but not LIF and CNTF concentrations, may be useful markers for RA activity.     

The clinical significance of serum soluble interleukin 2 receptor (sIL-2R) concentration in lung cancer

The activated mononuclear cells can release a soluble form of interleukin 2 receptor (sIL-2R) in the blood. Serum sIL-2R level is a sensitive and quantitative marker of circulating peripheral blood mononuclear cell activation. This molecule acts as an antagonist of IL-2-mediated responses. The present study was carried out to analyze the circulating levels of sIL-2R in lung cancer in relation to the histological type of the tumour, clinical stage, response to therapy, time survival for patients. The study included 62 patients (30 SCLC, 32 NSCLC) and 10 healthy subjects as controls. SIL-2R serum levels were measured with a sandwich enzyme immunoassay using commercial kits (ENDOGEN). The mean serum values of sIL-2R were significantly higher in cancer patients than in controls (p=0.01). There was no significant difference in relation to tumour histological type. Within the NSCLC chemotherapy group, sIL-2R mean levels observed at the end of chemotherapy were higher in the progressing patients than in the responding patients. The metastatic patients had higher levels of sIL-2R than those with locally limited disease. In the case of SCLC classified to extensive disease mean levels of sIL-2R were higher than SCLC classified to limited disease. The mean serum values of sIL-2R were significantly higher in weight loss patients than no weight ones (p=0.03). Within NSCLC group there was a correlation between sIL-2R mean levels and the age of patients (p=0.04). In SCLC group there was a correlation between levels of sIL-2R and time survival for patients (p=0.009).     

Soluble IL-2-receptor and CD8 in the serum and the periparasitic granuloma of patients with alveolar echinococcosis.

Cellular immunity plays a key role in the defence against the larva of the cestode Echinococcus multilocularis. This larva is responsible for alveolar echinococcosis (AE) of the liver, a rare parasitic disease which occurs in endemic areas including European alpine countries, Alaska, the USSR, Western China and Northern Japan. We have shown a marked decrease of the CD8+ T-cell population in the blood and we have described an infiltrate composed mainly of activated CD8+ T-cells in the liver lesions of most patients with AE. In this study, we assessed the serum level of soluble IL-2-receptor (sIL-2R) and CD8 (sCD8) in 37 patients (23 men, 14 women, mean age 59.5 yrs) with a histologically proven AE. The results, obtained using sandwich ELISA, were compared to those of healthy controls and correlated to parameters evaluating the severity of the disease. The mean serum levels of sIL-2R were significantly higher in AE patients than in controls. There was a significant correlation between sIL-2R levels and both the volume of parasitic lesions and a calculated index of severity of the disease. The mean serum levels of sCD8 did not differ significantly from the values obtained in controls. These results indicate that the infiltration of the liver by CD8+ T-lymphocytes is not associated with an increased release of sCD8 into the serum. The circulating levels of sIL-2R appear to reflect the extent as well as the severity of the disease. Immunostaining of the cells of the periparasitic granuloma suggests that the cell origin of the sIL-2R could be macrophages rather than T-lymphocytes.     

Quantitative analysis of serum IL-6 and its correlation with increased levels of serum IL-2R in HIV-induced diseases

We have devised a luminescence sandwich ELISA for the quantification of IL-6 in both sera and cell culture supernatants, which had a detection limit of 100 fg/ml of test sample. By using the luminescence sandwich-ELISA, low but measurable levels of IL-6 (9.5 pg/ml on average) were found in the sera from normal individuals. The serum levels of IL-6 were elevated in HIV-seropositive asymptomatic carriers (55.5 pg/ml on average), and the IL-6 levels were correlated with the degree of HIV-induced disease progression (AIDS-related complex 106.8 pg/ml on average and (AIDS 283 pg/ml). IL-6 immunoreactivity in the sera of AIDS patients eluted at a 25,000 m.w. major peak, which was biologically active and heat-stable, and a 500,000 m.w. minor peak in size-exclusion HPLC. Interestingly, a significant correlation was observed between the serum IL-6 levels and soluble IL-2R levels. In vitro, HIV infection of PHA-activated PBMC led to enhanced release of IL-6 into the culture supernatants. Moreover, soluble IL-2R release was markedly increased by adding exogenous IL-6, whereas it was decreased by adding the neutralizing anti-IL-6 mAb to the cultures. These results demonstrate that increased IL-6 levels are significantly associated with sIL-2R levels, and suggest a cause of the increased levels of this receptor in patients with HIV infection. Furthermore, both serum IL-6 and serum IL-2R levels in HIV infection reflect the stage of the HIV-induced disease.     

Tumour necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6) and their soluble receptors (sTNF-alpha-Rp55 and slL-6R) serum levels in systemic lupus erythematodes

We investigated a possible association between serum concentrations of tumour necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6) and their soluble receptors (sTNF-alpha-Rp55 and sIL-6R) using an enzyme-linked immunosorbent assay (ELISA) in 55 patients with systemic lupus erythematodes (SLE) and 16 healthy controls. We also examined a possible association between the serum levels of these peptides and SLE activity, as well as TNF-alpha and IL-6 concentrations and the levels of their soluble receptors. The median concentrations of TNF-alpha, sTNF-alpha-Rp55 and IL-6 were significantly higher in SLE patients than in normal individuals. In contrast, there was no difference between the serum level of sIL-6R in both groups. We found positive correlations between the serum concentrations of TNF-alpha and IL-6 as well as their soluble receptors and disease activity. There were also correlations between TNF-alpha and sTNF-alpha-Rp55 as well as IL-6 and sIL-6R serum levels in SLE patients but there were no such correlations in the normal control group. In conclusion, an increase in the serum levels of TNF-alpha, sTNF-alpha-Rp55 and IL-6 may become useful markers for SLE activity. Patients with SLE have sIL-6R serum concentration similar to that as in normal individuals. However, it correlates with disease activity and the level of IL-6.     

The significance of an increase in soluble interleukin-2 receptor level in colorectal cancer and its biological regulating role in the physiological switching of the immune response cytokine network from TH1 to TH2 and back

 Current research has still not clarified the biological role of soluble interleukin(IL)-2 receptor (sIL-2R) and the significance of its increase in the serum of colon cancer patients compared to healthy subjects. To address these questions at the immunological level in a group of patients and healthy subjects, we determined the sIL-2R level in the serum and its release from peripheral blood mononuclear cells (PBMC) as a function of tumour necrosis factor (TNF) α, IL-1α, IL-1β, IL-2, interferon (IFN) γ, IL-4, IL-6 and IL-10 levels in the serum and PBMC production; and PBMC proliferative responses to IL-2, IL-4 and anti-CD3 monoclonal antibody (CD3), variously combined. The level of sIL-2R in patients’ serum was higher than in healthy subjects and correlated with the stage of advancement. Moreover, while in healthy subjects the serum level of sIL-2R was not significantly correlated with other parameters, in patients it was positively related to IL-4, IL-6 and IL-10 serum levels, PBMC IL-4 production and to the PBMC proliferative response to CD3 and CD3+IL-2; it was negatively correlated to IL-2 serum level and IL-1β PBMC release. A negative connection between IFNγ serum level and the PBMC production of sIL-2R was also found. This suggests that the increase of sIL-2R in the serum of patients, compared to healthy subjects, is involved in the inappropriate expansion of the T helper (TH2) suppressive immune response, which we previously reported. The multivariate statistical method supported the above suggestions and we also found that, in healthy subjects, the up- and down-regulation of sIL-2R in the serum within the physiological ranges seems to have a regulating role in the relationships between TNFα, IFNγ and IL-4, IL-6, contributing to the operation of the cytokine network between TH1 and TH2 cells. However, in patients compared to healthy subjects the increased sIL-2R serum level seems to direct the immune response towards a suppressive type, which may be due to an alteration in the above-mentioned physiological regulating role. Received: 12 April 1997 / Accepted: 4 September 1997     

Serum level of soluble interleukin-2 receptor α correlates with the clinical course and activity of Wilms’ tumour and soft tissue sarcomas in children

Wilms’ tumour (WT) and soft tissue sarcomas (SA) in children lack reliable biochemical markers. This study was carried out to determine the clinical significance of serum soluble interleukin-2 receptor α (sIL-2Rα) in the diagnostics and treatment monitoring of children with WT and SA. The study included 48 children: ten with WT, eight with SA and 30 healthy controls. The sIL-2Rα levels (ELISA) and rates of elevated sIL-2Rα values were estimated prospectively at diagnosis and in complete remission during treatment and after therapy. As the dependence on age was determined, the levels of sIL-2Rα were expressed as multiplications of the upper value of the normal range for a particular age (xN). Median pretreatment levels of sIL-2Rα in patients exceeded those of healthy controls (1.79 xN for WT and 1.53 for SA vs. 0.61 for controls; p<0.001) as did the rates of elevated sIL-2Rα values (80% of WT and 87.5% of SA patients vs. 0% of controls). Good response to therapy was paralleled by a significant decline of pretreatment sIL-2Rα levels and its elevated rates. Thus, sIL-2Rα determination may be of some value in the diagnostics and treatment monitoring of childhood WT and SA.     

Pigment epithelium-derived factor in ulcerative colitis: possible relationship with disease activity

OBJECTIVES: Pigment epithelium-derived factor (PEDF) is an endogenous most potential angiogenic inhibitor and increased expression of PEDF in intestinal mucosa specimens was shown in the course of ulcerative colitis (UC). The aim of the present study was to evaluate serum concentration of pigment epithelium-derived growth factor, a potent anti-angiogenic factor and its possible association with vascular endothelial growth factor (VEGF) levels and disease activity. METHODS: Concentrations of PEDF and VEGF were measured in sera of 33 patients (13 females and 20 males) with active UC. RESULTS: There was significant increase of serum PEDF (32.3+/-2.9 vs. 20.6+/-4.7 ng/mL, P<0.05) as well as VEGF (326.4+/-58.1 vs. 110.9+/-15.7 pg/mL, P<0.05) in UC patients compared to healthy controls. Serum PEDF showed strong, positive correlation with endoscopic score (r=0.622, P<0.001), while such association was absent in respect to VEGF (r=0.05, P=0.77). In contrast serum VEGF decreased in severe UC comparing to patients with a mild course of disease, however the difference was not significant (274.9+/-64.9 vs. 360.4+/-103.4 pg/mL, P=0.53). CONCLUSIONS: Increase in serum PEDF during UC, especially in severe forms of disease suggests its involvement in UC pathogenesis.