Plasma sIL-2R Research Articles

Effects of symptomatic severity on elevation of plasma soluble interleukin-2 receptor in bipolar mania

Background: Circulating soluble interleukin-2 receptors (sIL-2Rs) and soluble interleukin-6 receptors (sIL-6Rs) are stable immune measures. Elevated plasma sIL-2R levels are present in patients with schizophrenia, major depression, and bipolar mania, but not with minor psychiatric disorders. The increased plasma sIL-2R levels are state-dependent in bipolar mania. However, altered production of plasma sIL-6R and the effects of clinical characteristics on plasma sIL-6R and sIL-2R levels in bipolar disorder remains uncertain. Methods: Plasma sIL-2R and sIL-6R levels were measured in 31 Taiwanese bipolar manic (DSM-IV) patients with Young Mania Rating Scale (YMRS) scores of ≥26 as well as during the subsequent remission (YMRS≤12), and equal numbers of age- and gender-matched healthy controls. The relationships of clinical variables such as age, age of onset, smoking, medication status, coexisting psychotic features, number of prior episodes, duration of illness, presence of depression before or following the manic episode, and manic severity to plasma sIL-2R and sIL-6R levels in acute mania along with remission were examined. Results: Plasma sIL-2R but not sIL-6R levels were significantly higher in acute mania than in subsequent remission ( P<0.05) and controls ( P<0.0005). In acute mania, the plasma sIL-2R levels were significantly correlated to YMRS scores ( r=0.34, P<0.05). The remaining clinical variables had no effect on plasma sIL-2R and sIL-6R levels in acute mania or remission. There was a significantly positive relationship between the reduction of plasma sIL-2R levels from the acute to follow-up measurements (ΔsIL-2R) and symptomatic improvement of acute mania (ΔYMRS) ( r=0.61, P<0.001). Limitations: Our sample included medicated and unmedicated patients in acute mania. The psychotropic medication may have divergent effects on the plasma sIL-2R levels in acute mania and subsequent remission. Conclusions: Elevation of plasma sIL-2R but not sIL-6R levels in bipolar mania supports the idea that the immunomodulatory mechanism may vary in different psychotic disorders. In contrast to being a trait marker in schizophrenia and depressive disorder, plasma sIL-2R levels may be considered a biological indicator of manic severity in a group of bipolar affective patients.

Plasma Concentrations of Interleukin-1β, Interleukin-6, Soluble Interleukin-2 Receptor and Tumor Necrosis Factor α of Depressed Patients in Japan

There are a number of investigations which indicate the important relationship between depression and cytokines. In this study, we investigated plasma interleukin (IL)-1β, IL-6, soluble IL-2 receptor (sIL-2R) and tumor necrosis factor (TNF)-α of depressed patients whose clinical evaluation was performed by the Hamilton Rating Scale for Depression (HAM-D) and the Profile of Mood States (POMS). They were compared with those of the control subjects, and before and after treatment with antidepressants. Before the treatment, plasma IL-1β, IL-6, sIL-2R and TNF-α of the patients were not significantly different from those of the control subjects. sIL-2R was positively correlated with the POMS-tension-anxiety subscale and tended to have a positive correlation with HAM-D. After pharmacotherapy, TNF-α levels of the depressed patients increased, without any relationship between the change in the HAM-D or the POMS and the change in TNF-α. These results suggest that the plasma sIL-2R concentration is associated with mood state, and that the plasma TNF-α concentration is increased after pharmacotherapy in Japanese depressed patients.

Characteristic Cytokine Products of Th1 and Th2 Cells in Hemodialysis Patients

Dysfunction of the host defense against infection in hemodialysis (HD) patients has major clinical and socioeconomic implications. T helper type 1 (Th1) and type 2 (Th2) cytokines are implicated in regulating the immune responses and, therefore, may be involved in impaired status. The present study was designed to examine Th1 and Th2 cytokine profiles in 22 stable HD patients (aged 63 ± 11 years) and 22 healthy controls (aged 60 ± 6 years). The T cell activity was significantly retarded in HD patients as compared with normal persons. The proportions of T cytotoxic/suppressor cells and natural killer cells were significantly higher in HD patients than in controls. In contrast, the proportions of T helper/inducer and B cells were significantly lower in HD patients than in controls. The production of interleukin (IL) 2, which is involved in cell-mediated immune responses, and the production of IL-4 and IL-10, which affect humoral immunity, were significantly lower in patients than in controls. The production of IL-12 by macrophages and of interferon gamma by Th1 cells was significantly higher in HD patients than in controls. The concentration of plasma sIL-2R was significantly higher in patients than in controls. These results suggest that both cellular immunity induced by Th1 and humoral immunity induced by Th2 decrease in HD patients, but that improved IL-12 secretion by macrophages activated natural killer cells to produce interferon gamma, which in turn induced macrophage activity.

Activation of indices of cell-mediated immunity in bipolar mania

Background: Evidence supports that marcophages as well as lymphocytes and their products may be involved in the pathophysiology of psychiatric disorders. Whether patients with bipolar disorder have activation or reduction of immunity during a manic episode remains unclear.Methods: The purpose of this case–control study was to investigate the lymphocyte proliferation to phytohemagglutinin (PHA), concanavalin A, and pokeweed mitogen, and plasma levels of soluble interleukin-2 receptor (sIL-2R) and sIL-6R in patients with bipolar mania (DSM-III-R). The subjects were 23 physically healthy patients with Young Mania Rating Scale (YMRS) scores ≥26 as well as aged ≤45 years and 23 age- and gender-matched normal control subjects. The above immune variables were measured in acute mania and consequent remission (YMRS scores ≤12) among bipolar patients.Results: The lymphocyte proliferation to PHA and the plasma sIL-2R levels, but not sIL-6R, of bipolar patients were significantly higher in acute mania than in consequent remission. These elevations were not due to differences in medication status. Only in acute mania were the plasma sIL-2R levels of patients significantly higher than control subjects. A positive correlation between the changes of manic severity and plasma sIL-2R levels was observed. Remitted bipolar patients and normal control subjects did not differ in any of these measures.Conclusions: Cell-mediated immunity activation in bipolar mania was demonstrated and may be through a specifically state-dependent immune response.

Effect of didanosine, stavudine, and hydroxyurea therapy on apoptosis in CD45RA+ and CD45RO+ T lymphocyte subpopulations.

The effect of aggressive antiretroviral therapy on spontaneous apoptosis (AP) in CD4+ and CD8+ lymphocytes expressing CD45RO (memory cells) and CD45RA (naive cells) and their relationship to cellular activation and viral load were examined. Ten patients receiving simultaneous treatment with d4T, ddI, and HU were evaluated. Flow cytometric analysis showed significant levels of AP (measured by TUNEL assay) among memory and naive T cells and an enhanced expression of CD38 and HLA-DR activation markers. The percentage of apoptotic CD4+CD45RO+ and CD4+CD45RA+ cells decreased, respectively, from 34 +/- 3.3 and 29 +/- 3.6 prior to treatment to 20.5 +/- 4 and 22 +/- 3.8 at week 8 into therapy. The percentage of apoptotic CD8+CD45RO+ and CD8+CD45RA+ cells similarly decreased, respectively, from 20 +/- 2.5 and 24 +/- 3 prior to treatment to 14.5 +/- 2.7 and 16 +/- 3 at week 8 into treatment. The percentage of CD4+ cells expressing the activation markers CD38 and HLA-DR decreased from 27 +/- 6 to 13 +/- 2 and from 26 +/- 4 to 13.5 +/- 3, respectively. The percentage of CD8+ cells expressing either CD38 or HLA-DR fell from 22 +/- 3 to 10 +/- 2 for the former and from 39 +/- 5 to 22 +/- 4 for the latter. This was associated with a significant decrease in viral load (mean, 1.4 log10), and a decline in circulating plasma TNF-alpha and sIL-2R levels from 50.5 +/- 10 to 21 +/- 6 and 92.5 +/- 11 to 68 +/- 9, respectively. These data indicate that short-term therapy with ddI, d4T, and HU in combination diminished AP, immune activation, and partially restored naive and memory T cell subpopulations.

PLASMA LEUKAEMIA INHIBITORY FACTOR, INTERLUEKIN 6 AND SOLUBLE INTERLEUKIN 6 RECEPTOR LEVELS DURING CARDIOPULMONARY BYPASS WITH EXTRACORPOREAL CIRCULATION

In this study the authors assessed plasma leukaemia inhibitory factor (LIF), interleukin 6 (IL-6) and soluble IL-6 receptor (sIL-6R) concentrations in 28 patients undergoing coronary artery bypass graft (CABG) with extracorporeal circulation (ECC). Plasma IL-6 levels increased during ECC, reaching a 33-fold increase 6 h after surgery as compared to pre-operative values. In contrast, plasma sIL-6R and LIF concentrations did not vary significantly during cardiac surgery. Thus, LIF is not implicated in the haematological changes and in the inflammatory syndrome observed after CABG. Despite the fact that LIF and IL-6 exhibit several common biological activities, the production of these two cytokines is differently regulated during cardiac surgery with ECC. Plasma IL-6 levels increased during cardiac surgery while sIL-6R levels did not change. These data contrast with the decreased sIL-6R concentrations with concomitantly high IL-6 levels in patients with sepsis syndrome suggesting that inflammatory reactions in sepsis and after cardiopulmonary bypass are triggered by different mechanisms.

Plasma soluble interleukin-2 receptor levels in patients with idiopathic thrombocytopenic purpura.

Soluble interleukin-2 receptor (slL-2R) was measured in the plasma of 31 patients with idiopathic thrombocytopenic purpura (ITP) and 22 normal controls. When thrombocytopenia persisted longer than 6 months, the diagnosis of chronic ITP was made. Twenty patients had acute ITP, 11 patients had chronic ITP, and all patients received high-dose methylprednisolone (HDMP) (30 mg/kg/d for 3 days, 20 mg/kg/d for 4 days). The sIL-2R levels of the patients were determined before being giving HDMP and 14 days after the end of HDMP therapy. Platelet counts were determined before administration of HDMP, one day after the end of HDMP therapy, and once every 28 days for 7 months thereafter. There was not a significant difference between the mean pre-treatment plasma sIL-2R levels of both acute and chronic ITP groups (P > 0.05), and these were higher than that of the control group (P < 0.001). The mean post-treatment sIL-2R level of the chronic ITP group was significantly higher than those of both the control and post-treatment acute ITP groups (P < 0.001). There were negative correlations between the plasma sIL-2R levels and platelet counts of both group patients in the pre-treatment period and between post-treatment sIL-2R levels and platelet counts in chronic ITP group (P < 0.05). We think that there was a good correlation between prognosis of ITP and sIL-2R levels after HDMP therapy, and platelet counts in patients with ITP are linked to sIL-2R levels.

Plasma Soluble Interleukin-2 Receptors in Patients with Myelodysplastic Syndromes

We examined the plasma soluble interleukin-2 receptor (sIL-2R) level in 80 subjects with myelodysplastic syndromes (MDS) and analyzed its correlation with hematologic/immunologic parameters and the subsequent clinical course. Compared with low-risk MDS (refractory anemia (RA) and RA with ringed sideroblasts) and normal individuals, the plasma sIL-2R level was significantly elevated in high-risk MDS (three other MDS subtypes and acute leukemia following MDS) patients. There was a significant negative correlation between the plasma sIL-2R level and the absolute counts of T and natural killer cells. Furthermore, the plasma sIL-2R level showed a significant positive correlation with the total cell mass and blast mass in particular, in the marrow, but not with the absolute count of IL-2Rα-chain-positive lymphocytes in the circulation.Fourteen of our 40 low-risk MDS subjects developed at least one of the following events during the follow-up period: erythrocyte transfusion dependence, infections requiring hospitalization, disease progression or MDS-related death. The plasma sIL-2R level was significantly higher in these patients than in event-free low-risk cases. By logistic regression analysis of various parameters in the 40 low-risk subjects, the plasma sIL-2R level was identified as a valuable independent parameter for predicting the development of events. Based on these findings, we hypothesize that the sIL-2R plays a role in the development of morbidity and mortality in MDS by inducing immunologic dysfunction.

Lower plasma CC16, a natural anti-inflammatory protein, and increased plasma interleukin-1 receptor antagonist in schizophrenia: effects of antipsychotic drugs

Recently, it was suggested that in vivo activation of the monocytic and T-lymphocytic arms of cell-mediated immunity (CMI) may occur in schizophrenia and that antipsychotic drugs may modify CMI. The aim of the present study was to examine plasma soluble interleukin-2 receptor (sIL-2R), soluble suppressor/cytotoxic antigen (sCD8), interleukin-1 receptor antagonist (IL-1RA), and Clara cell protein (CC16) concentrations in normal controls, nonmedicated schizophrenic patients, and schizophrenic patients treated with risperidone or loxapine. Plasma concentrations of IL-1RA were significantly higher in nonmedicated schizophrenic patients than in normal controls. Plasma CC16 was significantly lower in nonmedicated and loxapine-treated schizophrenic patients than in normal controls, whereas risperidone-treated patients had plasma CC16 levels which were not significantly different from normal controls. Plasma CC16 levels were significantly and positively related to age at onset of schizophrenia. Plasma sIL-2R was significantly higher in schizophrenic patients who were treated with risperidone than in normal controls and nonmedicated schizophrenic patients. The results show that (i) schizophrenia is accompanied by an activation of the monocytic arm of CMI (i.e., increased plasma IL-1RA) and lower plasma levels of a natural anti-inflammatory and immunosuppressive agent, i.e. CC16, and that the latter may constitute a trait marker of schizophrenia; and that (ii) chronic treatment with atypical antipsychotic agents, i.e., risperidone, may normalize lower plasma CC16 and increase plasma sIL-2R.

Plasma soluble interleukin-2 receptor level in patients with primary myelodysplastic syndromes: a relationship with disease subtype and clinical outcome.

To assess the hypothesis that the plasma soluble interleukin-2 receptor (sIL-2R) level may have predictive value for morbidity/mortality in patients with myelodysplastic syndromes (MDS), we determined in plasma sIL-2R level of 80 MDS patients and examined their subsequent clinical course. Compared with low-risk MDS (refractory anaemia (RA) and RA with ringed sideroblasts) patients and normal subjects, the plasma sIL-2R level was significantly elevated in high-risk MDS (three other MDS subtypes and acute leukaemia following MDS) patients (high-risk MDS versus low-risk MDS, P < 0.01; high-risk MDS versus normal subjects, P < 0.01). 14/40 low-risk MDS patients developed at least one of the following during the follow-up period: erythrocyte transfusion dependence, infections requiring hospitalization, disease progression or MDS-related death. The plasma sIL-2R level was higher in these eventful subjects than in event-free low-risk subjects (P < 0.0001), and all of 10 low-risk subjects with a plasma sIL-2R level > 540 U/ml experience at least one event. By logistic regression analysis of various parameters in these 40 low-risk subjects, the plasma sIL-2R level was identified as the strongest independent parameter for predicting eventful subjects (P < 0.0047). The plasma sIL-2R level did not show a predictive value in high-risk MDS. This study revealed that the plasma sIL-2R level is significantly elevated in high-risk MDS and suggested that the plasma sIL-2R level is a valuable predictive factors for the clinical outcome in low-risk MDS.

Interleukin-1α and soluble interleukin-2 receptor during small cell lung cancer chemotherapy: comparison of high chemotherapy dose with rhGM-CSF and standard chemotherapy dose without rhGM-CSF

This study was designed to analyze the possible immunomodulation induced in vivo by haematopoietic growth factors following anti-cancer chemotherapy. Haematologic and cytokine kinetics (IL-1, IL-6, TNFα and soluble interleukin-2 receptor (sIL-2R)) were studied in patients with SCLC receiving high dose regimens of chemotherapy and recombinant human GM-CSF (group A), or standard doses of chemotherapy without rhGM-CSF (group B). Six patients were prospectively enrolled and randomized in each group. The kinetics of haematopoiesis following chemotherapy did not significantly differ between the two groups. In group A, the plasma sIL-2R level increased regularly during rhGM-CSF treatment reaching a 2.5-fold elevation at day 12 whereas it remained stable in group B. Conversely, IL-1α decreased to an undetectable level in group A whereas it increased slightly from day 14 to day 18 in group B. As sIL-2R could compete with lymphocyte surface receptors and as IL-I is an important cytokine involved in acute phase response, our results might be regarded as reflecting a transient decrease in the cell-mediated immune response in small cell lung cancer patients receiving high dose chemotherapy combined with rhGM-CSF.

Increased plasma concentrations of interleukin-6, soluble interleukin-6, soluble interleukin-2 and transferrin receptor in major depression

Recently, it was found that major depression may be accompanied by significant changes in cell-mediated and humoral immunity. The purpose of this study was to investigate the plasma concentrations of interleukin (IL)-6, soluble IL-6 receptor (sIL-6R), sIL-2R and transferrin receptor (TfR) in patients with major depression in an acute phase of illness, in remission and during antidepressive treatment. Plasma concentrations of IL-6, sIL-6R, sIL-2R and TfR were significantly higher in major depressed subjects than in healthy controls. In major depressed subjects, but not in normal controls, there were significant positive correlations between the plasma concentrations of IL-6 and sIL-6R, IL-6 and sIL-2R, IL-6 and TfR, and between sIL-2R and TfR. Subchronic treatment with antidepressive drugs, such as fluoxetine or tricyclic antidepressants, did not significantly affect plasma IL-6, sIL-6R, sIL-2R or TfR. The latter did not significantly differ between major depressed patients in an acute phase of illness or in complete clinical remission. It is suggested that: 1. (1) a coordinated and upregulated production of IL-6, sIL-6R, sIL-2R and TfR may constitute a trait marker of major depression; and that 2. (2) an upregulated production of IL-6 may represent a contributing factor to the various immune disorders encountered in major depression and maybe to the pathophysiology or pathogenesis of that illness.

Components of biological variation in plasma haptoglobin: relationships to plasma fibrinogen and immune variables, including interleukin-6 and its receptor

We investigated the components of biological variation, including seasonality, in plasma haptoglobin (Hp) levels and the relationships between plasma Hp and interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6), sIL-2R, fibrinogen (Fb) and absolute number of peripheral blood mononuclear cells, such as leukocytes, neutrophils, monocytes, lymphocytes, CD4 +, CD8 +, CD25 + T cells and CD20 + B cells. Monthly blood samples were taken from 26 normal volunteers during one calendar year. The estimated inter- and intra-individual C.V. values for plasma Hp were 27.9% and 20.0%, respectively; the index of individuality was 0.72. No significant seasonal rhythms could be detected in plasma Hp levels. The yearly mean values in plasma Hp were significantly and positively related to those in plasma Fb, absolute number of leukocytes, neutrophils, CD4 + T cells and the CD4 +/CD8 + T cell ratio. 49.0% of the variance in the yearly mean values of plasma Hp could be explained by variances in serum IL-6 and number of CD4 + (positively related) and CD8 + (negatively related) T cells. There were significant and positive time relationships between plasma Hp, on the one hand, and plasma Fb, sIL-6R, sIL-2R and number of leukocytes, neutrophils and monocytes, on the other. A smaller part of the within-subject variability in plasma Hp (i.e. 6.0%) could be explained by serum sIL-6R and sIL-2R. It is concluded that there are (1) important between-subject differences in the homeostatic setpoints of plasma Hp, which are related to those in plasma Fb and in immune status and (2) significant within-subject, time relationships between plasma Hp and indicators of immune activation and plasma Fb.

Interleukin-2 and interleukin-6 in schizophrenia and mania: Effects of neuroleptics and mood stabilizers

There is some evidence that schizophrenia may be accompanied by alterations in cell-mediated immunity (CMI) and that antipsychotic agents may modulate CMI. The purpose of this study was to investigate the plasma levels of interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R), sIL-2R, and transferrin-receptor (TfR) in schizophrenia and mania, and the effects of treatment with neuroleptics or mood stabilizers on these variables. The subjects were 14 schizophrenic patients, 10 manic patients and 21 healthy volunteers. The above immune variables were measured in baseline conditions and after treatment with neuroleptics in schizophrenic patients and valproate in manic patients. Plasma concentrations of IL-6, sIL-6R, sIL-2R and TfR were significantly higher in the combined group of psychotic patients than in healthy volunteers. Plasma IL-6 was significantly higher in schizophrenic patients, while plasma sIL-6R and sIL-2R were significantly higher in mania than in normal controls. In schizophrenic patients, plasma levels of IL-6, sIL-6R and TfR were significantly lower after treatment with neuroleptics than before treatment. No significant effects of valproate on the immune-inflammatory markers could be found in the manic patients. It is suggested that activation of CMI may occur in both schizophrenia and mania and that neuroleptics may have immunosuppressive effects through suppression of IL-6 or IL-6R-related mechanisms.

Plasma-soluble interleukin-2 and transferrin receptor in schizophrenia and major depression.

This study was carried out to examine some components of in vivo immune function in major depression and schizophrenia. Toward this end, plasma concentrations of interleukin-1 beta (IL-1 beta) and IL-6, soluble IL-2 receptor (sIL-2R), and transferrin receptor (TfR) were measured in 28 normal controls, 11 schizophrenics and 13 major-depressed patients. Schizophrenic and major-depressed patients showed significantly higher plasma sIL-2R and TfR than normal controls. There was a trend toward higher plasma IL-6 in the psychiatric patients, and particularly in schizophrenic patients, than in normal volunteers. In normal controls and in the total study group, there were highly significant and positive correlations between plasma TfR and sIL-2R concentrations. It is suggested that schizophrenia and major depression are characterized by immune disorders that may indicate activation of cell-mediated immunity such as T-cell activation.

Effect of cyclosporin A on interleukin-6 and soluble interleukin-2 receptor in patients with rheumatoid arthritis.

To investigate the effect of cyclosporin A (CyA) therapy on circulating concentrations of interleukin-6 (IL-6) and soluble interleukin-2 receptor (sIL-2R) in patients with rheumatoid arthritis (RA). Twenty four RA patients with active disease were studied. Plasma was collected before and after 16 weeks of CyA treatment. IL-6 was measured by B9 bioassay and sIL-2R by enzyme linked immunosorbent assay (ELISA). The initial median IL-6 concentration of 165 IU/ml decreased significantly to 71 IU/ml after 16 weeks (p < 0.05). Similarly, the initial median plasma sIL-2R value of 665 U/ml decreased significantly to 570 U/ml (p < 0.05). This decrease was accompanied by an improvement in clinical parameters of disease activity. Some association between sIL-2R, IL-6, haemoglobin, and platelets was also observed. This study has demonstrated that, in vivo, CyA therapy in RA can significantly reduce circulating concentrations of IL-6 and sIL-2R. Modulation of both T and non-T cell derived cytokines may be one mechanism by which CyA improves rheumatoid disease. Whether this is a direct effect of CyA on the cells within the rheumatoid joint producing these cytokines or an indirect effect mediated by other cytokines which can influence IL-6 and Il-2R values remains to be determined.

Plasma soluble interleukin-2-receptor in depression: relationships to plasma neopterin and serum IL-2 concentrations and HPA-axis activity

The present study examined the plasma concentration of the soluble interleukin-2-receptor (sIL-2R) in depressed subjects in relation to hypothalamic pituitary adrenal (HPA) axis function and plasma neopterin and serum IL-2 concentrations. Plasma sIL-2R concentration was significantly higher in depressed patients (n = 47) than in controls (n = 19). There were no significant correlations between plasma sIL-2R and severity of illness. In the depressed subjects, there was a highly significant relationship between plasma sIL-2R and neopterin concentrations. Depressed patients with pathologically increased plasma neopterin levels had significantly higher plasma sIL-2R values than those with normal serum neopterin. There were no significant relationships between plasma sIL-2R and indices of HPA-axis function in depression. There was no significant effect of dexamethasone administration on sIL-2R levels. Significantly more depressed subjects had measurable serum IL-2 levels than normal controls. Our data support the notion that a moderate activation of cell-mediated immunity may play a role in the pathophysiology of depression.

Elevated plasma soluble interleukin 2 receptor level correlates with defective natural killer and CD8+ T-cells in myelodysplastic syndromes

The plasma soluble interleukin 2 receptor (sIL-2R) level and its relationships with haematologic and immunologic data were examined in 40 patients with myelodysplastic syndromes (MDS). The plasma sIL-2R level was significantly higher in the high-risk MDS group (refractory anaemia with excess blasts (RAEB), RAEB in transformation and chronic myelomonocytic leukaemia) than in the low-risk MDS group (refractory anaemia (RA) and RA with ringed sideroblasts) or in normal subjects, although there was considerable variation in the plasma sIL-2R level within each MDS group. The plasma sIL-2R level correlated positively with the bone marrow cellularity and bone marrow blast mass, but not with the absolute number of CD25+ lymphocytes. This may support the idea that plasma sIL-2R is derived from malignant MDS cells in the bone marrow. The plasma sIL-2R level correlated negatively with the absolute numbers of the CD8+, CD3–CD16+, and CD3–CD56+ cell populations in freshly isolated lymphocytes, the percentage of CD3–CD56+ cells in lymphokine (interleukin 2)-activated killer (LAK) cells, and the cytotoxicity of LAK cells. We conclude that MDS patients having a high plasma sIL-2R level often have a defect in natural killer and CD8+ T-cells.

Usefulness of Soluble Interleukin 2 Receptor in Differentiating Tuberculous and Carcinomatous Pleural Effusions

To evaluate the usefulness of soluble interleukin 2 receptor (sIL-2R) in differentiating tuberculous and carcinomatous pleural effusions. Levels of sIL-2R were measured simultaneously in plasma and pleural fluid in 111 patients with pleural effusions of unknown causes. The causes of pleural effusions were tuberculosis in 42 cases, carcinoma in 41 cases, pneumonia in 18 cases, and heart failure in 10 cases. In all groups of patients, sIL-2R levels were significantly higher in pleural fluid than in plasma. Plasma and effusion levels of sIL-2R were highest in the patients with tuberculosis, followed by those with carcinoma, pneumonia, and heart failure. Levels were significantly higher in the tuberculous group than in the carcinomatous group. To differentiate tuberculous from carcinomatous effusions, the highest plasma and effusion sIL-2R values obtained from the carcinomatous group were chosen as cutoff points (test specificity, 100%). The sensitivities of plasma and effusion sIL-2R levels in differentiating tuberculous and carcinomatous pleural effusions were 50% (21 of 42 samples) and 81% (34 of 42 samples), respectively. Although increased plasma and pleural fluid levels of sIL-2R should not be viewed as a diagnostic test specific for tuberculous pleural effusion, sIL-2R level appears to be clinically useful as a biochemical marker to differentiate tuberculous and carcinomatous pleural effusions.

Immune‐inflammatory markers in schizophrenia: comparison to normal controls and effects of clozapine

The purpose of this study was to investigate immune-inflammatory markers in schizophrenia and the effects of chronic treatment with clozapine, an atypical antipsychotic agent, on these variables. Toward this end, we measured interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R) and sIL-2R in the blood of 26 normal controls and 14 schizophrenic patients before and after treatment with clozapine. The sIL-2R and IL-6 levels were significantly higher in younger (< 35 years) schizophrenic subjects than in normal controls and older (> or = 35 years) schizophrenic subjects. The sIL-6R levels were significantly lower in schizophrenic subjects than in normal controls. Chronic treatment with clozapine significantly increased the blood concentration of sIL-2R; the increases in the latter were significantly related to the dose of clozapine but not to changes in severity of positive or negative symptoms. We conclude that: (a) schizophrenia in younger people is accompanied by increased IL-6 and sIL-2R secretion; and (b) subchronic treatment with clozapine increases sIL-2R levels. Increased plasma sIL-2R may be one mechanism by which neuroleptics exhibit their immunosuppressive effects.