Hyperglycemia enhances coagulation and reduces neutrophil degranulation, whereas hyperinsulinemia inhibits fibrinolysis during human endotoxemia

Type 2 diabetes is associated with altered immune and hemostatic responses. We investigated the selective effects of hyperglycemia and hyperinsulinemia on innate immune, coagulation, and fibrinolytic responses during systemic inflammation. Twenty-four healthy humans were studied for 8 hours during clamp experiments in which either plasma glucose, insulin, both, or none was increased, depending on randomization. Target plasma concentrations were 5 versus 12 mM for glucose, and 100 versus 400 pmol/L for insulin. After 3 hours, 4 ng/kg Escherichia coli endotoxin was injected intravenously to induce a systemic inflammatory and procoagulant response. Endotoxin administration induced cytokine release, activation of neutrophils, endothelium and coagulation, and inhibition of fibrinolysis. Hyperglycemia reduced neutrophil degranulation (plasma elastase levels, P < .001) and exaggerated coagulation (plasma concentrations of thrombin-antithrombin complexes and soluble tissue factor, both P < .001). Hyperinsulinemia attenuated fibrinolytic activity due to elevated plasminogen activator-inhibitor-1 levels (P < .001). Endothelial cell activation markers and cytokine concentrations did not differ between clamps. We conclude that in humans with systemic inflammation induced by intravenous endotoxin administration hyperglycemia impairs neutrophil degranulation and potentiates coagulation, whereas hyperinsulinemia inhibits fibrinolysis. These data suggest that type 2 diabetes patients may be especially vulnerable to prothrombotic events during inflammatory states.     

Acute nateglinide administration in subjects with type 2 diabetes: effects on postprandial metabolism, coagulation, and fibrinolysis

BACKGROUND AND AIM: Postprandial glycaemia and lipaemia are known risk factors for atherosclerosis in type 2 diabetes. Coagulation activation in the postprandial state also contributes to acceleration of atherosclerosis. Nateglinide is effective in reducing postprandial glycaemia. Its effect on glycaemia may also be beneficial in postprandial lipaemia and coagulation. The aim of this study was to examine the potential effect of a single dose of nateglinide on postprandial triglyceridaemia, coagulation, and fibrinolysis in patients with type 2 diabetes. METHODS AND RESULTS: Ten subjects with type 2 diabetes, treated with diet alone were recruited in a crossover randomized study. In the morning, after a 12- to 14-h fast, each subject received a standard mixed meal (total energy 783 kcal), preceded by one tablet of 120 mg nateglinide or placebo. Venous blood samples were drawn prior to meal consumption and 6h afterwards for the measurement of plasma glucose, insulin, and C-peptide, lipids, coagulation, and fibrinolysis factors. As expected, there was a significant reduction in postprandial glycaemia after nateglinide administration compared to placebo (P<0.001). Plasma insulin levels were significantly higher after nateglinide than after placebo (P=0.002). Nateglinide administration resulted in a lower overall postprandial reduction of tissue-plasminogen activator than placebo (-2.9+/-1.3 vs. -8.3+/-3.7 ng/ml h, P=0.003). In addition, a significant reduction of postprandial plasminogen activator inhibitor-1 was observed in comparison with the baseline values after nateglinide (P=0.001), although the overall response was not significantly different after nateglinide and placebo (P=0.31). Plasma concentrations of C-peptide, lipids and the remaining coagulation parameters studied were not different between nateglinide and placebo. CONCLUSIONS: Acute nateglinide administration improves postprandial glycaemia and fibrinolytic activity in patients with type 2 diabetes. This combined effect, if confirmed by a long-treatment study, might reduce cardiovascular risk in type 2 diabetes.     

Effect of central administration of interleukin-1 receptor antagonist on protein synthesis in skeletal muscle, kidney, and liver during sepsis

Inflammatory cytokines may mediate the host response to infection via central nervous system (CNS), endocrine, and/or paracrine pathways. The purpose of the present study was to determine whether intracerebroventricular (ICV) infusion of interleukin-1 receptor antagonist (IL-1ra) influences the effects of sepsis on protein metabolism in peripheral organs (skeletal muscle, kidney, and liver). A constant ICV infusion of IL-1ra (100 microg/h) or saline was begun immediately before the induction of sepsis or sterile inflammation and continued for 5 days. ICV infusion of IL-1ra did not alter protein metabolism in animals with a sterile abscess. Sepsis reduced muscle weight, protein content, and rates of protein synthesis in gastrocnemius. ICV infusion of IL-1ra attenuated the sepsis-induced loss of muscle mass and protein and the inhibition of protein synthesis in gastrocnemius by augmenting the translational efficiency. Similar results were observed in kidney, with respect to kidney weight, total protein, rates of protein synthesis, and translational efficiency. However, central infusion of IL-1ra did result in a small (12%) increase in the renal RNA content in either sterile or septic abscess rats. In liver, ICV infusion of IL-1ra prevented the sepsis-induced inhibition of protein synthesis and reduction in translational efficiency. These results suggest that central administration IL-1ra can modulate protein metabolism in peripheral organs during sepsis by preventing the sepsis-induced defects in the translational efficiency.     

Single administration of stem cell factor, FLT-3 ligand, megakaryocyte growth and development factor, and interleukin-3 in combination soon after irradiation prevents nonhuman primates from myelosuppression: long-term follow-up of hematopoiesis

Preservation of hematopoietic stem and progenitor cell survival is required for recovery from radiation-induced myelosuppression. We recently showed that short-term injection of antiapoptotic cytokine combinations into mice soon after lethal gamma irradiation promoted survival. The present study investigated the hematopoietic response of cynomolgus monkeys to a single dose of stem cell factor, FLT-3 ligand, megakaryocyte growth and development factor, and interleukin-3 in combination (4F, each factor given intravenously at 50 microg/kg) administered 2 hours after 5-Gy gamma irradiation. Treated monkeys (n = 4) experienced no thrombocytopenia. Only 1 in 4 displayed a transient period of neutropenia (neutrophil [ANC] count < 0.5 x 10(9)/L), whereas all irradiated controls (n = 4) experienced neutropenia (5-12 days) and thrombocytopenia (platelet [PLT] count < 20 x 10(9)/L, 5-31 days). Treated animals exhibited an impressive 2-wave PLT response that peaked at days 8 and 22 after total body irradiation (TBI). Areas under the curve (AUC) of PLTs, ANCs, white blood cells (WBCs), and red blood cells (RBCs) between days 0 and 90 were significantly higher in treated animals than in controls. Humeral bone marrow-derived clonogenic activity was significantly spared at 24 hours and 4 days after TBI in treated monkeys. No apparent impairment of the hematopoietic status and stem cell pool, in terms of long-term culture-initiating cells (LTC-ICs) and side population (SP) cells, was observed after 15 months. These results strongly suggest that the 4F cytokine combination, as a single dose regimen, could act as an emergency treatment for nuclear accident or terrorism victims.     

Inhibition of coagulation,fibrinolysis, and endothelial cell activation by a p38 mitogen-activated protein kinase inhibitor during human endotoxemia

P38 mitogen-activated protein kinase (MAPK) is an important component of intracellular signaling cascades that initiate various inflammatory cellular responses. To determine the role of p38 MAPK in the procoagulant response to lipopolysaccharide (LPS), 24 healthy subjects were exposed to an intravenous dose of LPS (4 ng/kg), preceded 3 hours earlier by orally administered 600 or 50 mg BIRB 796 BS (a specific p38 MAPK inhibitor), or placebo. The 600-mg dose of BIRB 796 BS strongly inhibited LPS-induced coagulation activation, as measured by plasma concentrations of the prothrombin fragment F1 + 2. BIRB 796 BS also dose dependently attenuated the activation and subsequent inhibition of the fibrinolytic system (plasma tissue-type plasminogen activator, plasmin-alpha2-antiplasmin complexes, and plasminogen activator inhibitor type 1) and endothelial cell activation (plasma soluble E-selectin and von Willebrand factor). Activation of p38 MAPK plays an important role in the procoagulant and endothelial cell response after in vivo exposure to LPS.     

Comparative studies of microscopically determined aggregation, degranulation, and light transmission after chemotactic activation of adult and newborn neutrophils

Changes in the light transmission of suspensions of activated neutrophils are widely used to measure the dynamics of neutrophil aggregation. Such studies have suggested, for example, that aggregation is irreversible for human newborn neutrophils but fully reversible for adult cells. We have evaluated aggregation directly by microscopic particle counting and compared it with changes in light transmission (delta T) and with release from three granule subsets for neutrophils activated with N-formyl-methionyl-leucyl-phenylalanine (FMLP). Maximal increases in %T in response to 0.5 micromol/L FMLP were approximately 25% larger for newborn than for adult neutrophils, and were only partially reversible by 8 minutes, while %T increases for adult neutrophils were fully reversible. However, measurements of neutrophil aggregation using light microscopy showed that both newborn and adult neutrophils fully deaggregated. A further independence of delta T from aggregation was found by pretreating adult neutrophils with cytochalasin B (5 micrograms/mL) in the presence of 0.5% gelatin, a pretreatment that blocked FMLP-induced neutrophil aggregation while allowing large increases in %T and degranulation. In response to FMLP, newborn neutrophils released more enzyme from each granule subset than did adult neutrophils. Our results suggest that cellular events associated with neutrophil activation (other than aggregation) are implicated in light transmission responses and that these differ for adults and newborns. These results also suggest that reports of neutrophil aggregation should be based on direct particle counting methods rather than on %T responses.     

Effects of interleukin-6, interleukin-2, and tumor necrosis factor alpha on transferrin release from Sertoli cells in culture

Recent studies demonstrate that several cytokines are potent modulators of steroid release from the testis. In an attempt to determine whether these agents may influence other types of secreted substances, we used plaque assays to measure the effect of interleukin-6 (IL-6), interleukin-2 (IL-2), and tumor necrosis factor alpha on transferrin (TF) release from Sertoli cells in culture. Because Sertoli cells from different parts of the tubule respond differently to modulatory factors, we used cultures obtained by microdissection from stages III-V, VII, IX-XI, and XIII of the cycle of the seminiferous epithelium. Our results revealed that each agent increased the rate of TF plaque formation from cultures of IX-XI, and XIII staged segments but not from those staged III-V and VII. Moreover, IL-6, but not the other cytokines, modified the response of Sertoli cells to another regulator, FSH. This was evidenced by our findings that pretreatment with IL-6 for 1 h resulted in FSH-induced increases in the rate of plaque formation for cells from IX-XI segments, in addition to those segments which are normally responsive without pretreatment (III-V and VII segments). Further experiments revealed that IL-6 also had a chronic influence on the proportion of TF secretors present in certain staged cultures. Treatment for 24 h with IL-6 markedly reduced the percentage of TF secretors in cultures from stage XIII segments and resulted in a slight increase in TF cells for stage VII cultures. However, no chronic influences in TF secretors were detected with either IL-2 or tumor necrosis factor alpha treatment. Our results demonstrate very clearly that certain cytokines acting in a stage specific manner have acute and/or chronic influences on the release of TF from Sertoli cells. These findings, when viewed in light of reports of the presence of these factors in the testis, suggest strongly that cytokines or cytokine-like substances, by modulating the release of Sertoli cell substances, may play an important role in testis function.     

Diagnostic value of interleukin-1alpha, interleukin-6, and tumor necrosis factor in pleural effusions

STUDY OBJECTIVES: Interleukin (IL)-1alpha, IL-6, and tumor necrosis factor (TNF)-alpha were measured in pleural fluid from 57 patients with pleural effusion in order to evaluate the diagnostic utility of these cytokines. We studied 20 patients with malignant pleural effusion, 11 patients with parapneumonic pleural effusion, 9 patients with tuberculous pleural effusion, and 17 patients with transudative pleural effusion. Cytokines were measured by radioimmunoassay. SETTING: University tertiary hospital. RESULTS: The mean values of the three cytokines measured in pleural fluid or in serum were significantly higher in patients with exudates than with transudates (p < 0.05). The ratio of IL-6 in pleural fluid to serum was significantly higher in exudates than in transudates (p < 0.05). The level of IL-6 in pleural fluid was significantly higher in tuberculous than malignant (p < 0.007) or parapneumonic pleural effusions (p < 0.04). No significant difference between the three types of exudates was found in pleural fluid levels of IL-1alpha or TNF-alpha. CONCLUSIONS: Serum levels of IL-1alpha, TNF-alpha, and in particular IL-6 can distinguish exudates from transudates, while pleural fluid IL-6 levels could be useful as an additional marker in the differential diagnosis of tuberculous, malignant, and parapneumonic exudates. Finally, our results suggest that there is local cytokine production in exudative pleural effusions.     

Effects of IC14, an anti-CD14 antibody,on coagulation and fibrinolysis during low-grade endotoxemia in humans

To determine the role of CD14 in lipopolysaccharide (LPS)-induced effects on coagulation and fibrinolysis in humans, 16 healthy subjects received an intravenous injection of LPS preceded by intravenous IC14, a recombinant chimeric monoclonal antibody against human CD14, or placebo. LPS-induced coagulation activation (tissue-factor mRNA in whole blood cells and plasma concentrations of F1+2) was not influenced by IC14, whereas the antibody reduced the increase in thrombin-antithrombin complexes and soluble fibrin. LPS injection also was associated with an early activation of fibrinolysis (plasma concentrations of tissue-type plasminogen activator and plasmin-alpha(2)-antiplasmin complexes), followed by an inhibitory response (plasminogen activator inhibitor type 1), which were attenuated by IC14. Furthermore, LPS reduced thrombin-activatable fibrinolysis-inhibitor antigen levels and increased soluble thrombomodulin levels, which were not influenced by IC14. These results suggest that different hemostatic responses during endotoxemia may proceed via CD14-dependent and -independent pathways.     

Inhibition of factor XII in septic baboons attenuates the activation of complement and fibrinolytic systems and reduces the release of interleukin-6 and neutrophil elastase

In previous studies, we have shown that administration of monoclonal antibody (MoAb) C6B7 against human factor XII to baboons challenged with a lethal dose of Escherichia coli abrogates activation of the contact system and modulates secondary hypotension. To evaluate the contribution of activated contact proteases to the appearance of other inflammatory mediators in this experimental model of sepsis, we studied the effect of administration of MoAb C6B7 on activation of complement and fibrinolytic cascades, stimulation of neutrophil degranulation, and release of the proinflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). Activation of the complement system, as reflected by circulating C3b/c and C4b/c levels, was significantly reduced in five animals that had received MoAb C6B7 before a lethal dose of E coli as compared with five control animals that had been given a lethal challenge only. Inhibition of contact activation also modulated the fibrinolytic response, since the release of tissue-type plasminogen activator (t-PA) and the appearance of plasmin-alpha2-antiplasmin (PAP) complexes into the circulation was significantly attenuated upon pretreatment with anti-factor XII MoAb. In contrast, plasma levels of plasminogen activator inhibitor (PAI) were modestly enhanced in the treatment group. Degranulation of neutrophils, as assessed by circulating elastase-alpha1-protease inhibitor complexes, and release of IL-6 but not of TNF-alpha was decreased in anti-factor XII-treated animals. Observed differences in the inflammatory response between treatment and control groups were not likely due to different challenges, since the number of E coli that had been infused, as well as circulating levels of endotoxin after the challenge, were similar for both groups. These data suggest that activation of the contact system modulates directly or indirectly various mediator systems involved in the inflammatory response during severe sepsis in nonhuman primates.     

The cleavage and inactivation of plasminogen activator inhibitor type 1 by neutrophil elastase: the evaluation of its physiologic relevance in fibrinolysis

The effect of the proteolytic cleavage of plasminogen activator inhibitor type 1 (PAI-1) by human neutrophil elastase (HNE) on fibrinolysis was investigated. HNE cleaved active PAI-1 and produced low molecular weight forms of inactive PAI-1, as previously reported. Latent PAI-1 was resistant to HNE treatment. Vitronectin (VN) partially protected the cleavage. NH2-terminal sequence analysis indicated that the cleavage site was Val355-Ser356 (P4-P3). The effects of PAI-1 cleavage by HNE on clot lysis was studied in a purified system. Clot lysis time without PAI-1 was 20.0 +/- 5.0 minutes and was prolonged to 86.7 +/- 2.9 minutes by 68 nmol/L of PAI-1. It was shortened when HNE (from 0.6 nmol/L to 80 nmol/L) was added and returned to the value obtained without PAI-1 by 80 nmol/L of HNE (20.0 +/- 5.8 minutes). However, in the absence of PAI-1, elastase did not enhance clot lysis at all. Euglobulin clot lysis time was also shortened after HNE treatment. The cleavage and inactivation of PAI-1 by HNE was shown to be a novel pathway to enhance fibrinolysis.     

Release of cytokines, soluble cytokine receptors, and interleukin-1 receptor antagonist after intravenous immunoglobulin administration in vivo

We investigated the in vivo effects of one bolus injection (400 mg/kg) of intravenous immunoglobulin (IVIG) on a number of cytokines, soluble cytokine receptors, and interleukin-1 receptor antagonist (IL-1Ra) in plasma in 12 patients with primary hypogammaglobulinemia. A significant and rapid increase in plasma levels of IL-6, IL-8, and tumor necrosis factor alpha (TNF alpha) was seen within 1 hour after IVIG infusion. This increase was accompanied by a more prolonged elevation in levels of both types of soluble TNF receptors (sTNFRs), which remained elevated throughout the study period (44 hours) although they reached peak levels within 1 hour. After an initial increase in the ratio between TNF alpha and sTNFRs, this ratio decreased to values significantly lower than baseline values 20 and 44 hours postinfusion with approximately 600-fold molar excess of sTNFRs to TNF alpha (trimer). Although only a modest but statistically significant increase in plasma levels of IL-1 beta was seen, IVIG infusion was followed by a marked increase in plasma levels of IL-1Ra with 1,000-fold molar excess of IL-1Ra to IL-1 beta in some patients. The demonstrated effects of IVIG infusion on the cytokine network, particularly the induction of IL- 1Ra and sTNFRs release, might be important for the therapeutic effects of IVIG in several immune-mediated disorders.     

Genetic association studies of interleukin-13 receptor alpha1 subunit gene polymorphisms in asthma and atopy.

Interleukin (IL)-13 plays a central role in asthma pathogenesis by binding to the IL-13 receptor, which is a heterodimer composed of the IL-13 receptor alpha1 subunit (IL-13Ralpha1) and IL-4Ralpha. The genetic diversity at the IL-13Ralpha1 gene (IL13RA1) locus on chromosome Xq24 was characterised and the association of identified polymorphisms with asthma and atopy phenotypes examined. The promoter and coding region of IL13RA1 were screened for common genetic variants, and polymorphisms found were genotyped in a large cohort of 341 asthmatic Caucasian families (each containing at least two asthmatic siblings) and 182 nonasthmatic control subjects. Genetic association was determined using case-control and transmission disequilibrium test analyses. Two common polymorphisms were identified, a newly found thymidine (T) to guanine (G) transition of nucleotide -281 (-281T>G) single nucleotide polymorphism in the IL13RA1 promoter and the previously described 1365A>G variant in the IL13RA1 proximal 3' untranslated region. No significant association of either -281T>G or 1365A>G with risk of asthma or atopy phenotypes was found, apart from a suggestive association between the IL13RA1 -281T/1365A haplotype and raised total serum immunoglobulin E levels in adult female asthmatics. These findings indicate that the interleukin-13 receptor alpha1 subunit gene -281T>G and 1365A>G polymorphisms do not contribute to asthma susceptibility or severity, although the interleukin-13 receptor alpha1 subunit gene locus might be involved in the control of immunoglobulin E production.     

Binding of recombinant interleukin-1 beta to the third complement component and alpha 2-macroglobulin after activation of serum by immune complexes.

Activation of human normal serum with tetanus/antitetanus immune complexes (TAT-IC) resulted in increased binding of 125I-labeled interleukin-1 beta (IL-1 beta) to serum factors, as opposed to untreated serum. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by autoradiography showed labeling of two large molecular mass factors of an apparent molecular weight (Mr) of 200,000 and 400,000, respectively. These complexes could be dissociated by reduction. No complexes were formed when reducing compounds were added to serum-TAT-IC-125I-IL-1 beta mixtures. Complex formation was largely prevented by alkylating compounds. Molecular sieve chromatography of TAT-IC-activated serum confirmed that 125I-IL-1 beta became bound to high Mr serum proteins. Fractions containing high molecular 125I-IL-1 serum protein complexes partially retained IL-1-like activity since they induced proliferation of an IL-1-dependent murine T helper (D10G4) cell lineage. The 125I-IL-1 beta binding factors could be immunoprecipitated from TAT-IC-activated serum 125I-IL-1 beta solutions by antisera to alpha 2-macroglobulin (alpha 2M) or to the third complement component (C3). SDS-PAGE of the immunoprecipitates showed radioactive bands corresponding to the expected Mr resulting from complex formation between 125I-IL-1 beta and these two proteins. Treatment of purified plasma alpha 2M and C3 with trypsin or activation with methylamine, which causes cleavage of the internal thiol ester and the appearance of free thiol groups in these proteins, mediated binding of 125I-IL-1 beta to alpha 2M and C3b. The results suggest that cleavage of the internal thiol ester in C3 and alpha 2M makes these plasma proteins susceptible to binding of 125I-IL-1 beta and that free thiol groups do play a role in the formation of 125I-IL-1 beta plasma protein complexes. Activated C3 and alpha 2M may function as IL-1 beta carrier proteins in biologic fluids, in addition to their other physiologic roles.     

实验性肺血栓栓塞症后凝血纤溶系统及肺血管内皮功能变化的临床意义

目的　探讨实验性兔肺血栓栓塞症 (PTE)后凝血纤溶系统、肺血管内皮功能的变化及其临床意义 ,了解尿激酶对凝血纤溶系统及肺血管内皮功能的影响。方法　 2 4只雄性新西兰大耳白兔随机分为正常对照组、单纯栓塞组及尿激酶组 ,每组 8只。单纯栓塞组及尿激酶组经兔股静脉注入自体血凝块制备兔PTE模型。尿激酶组用尿激酶治疗动态观察尿激酶治疗前后兔凝血纤溶系统活性和血浆中内皮素 1(ET 1)、一氧化氮 (NO)、血管性血友病因子 (vWF)的变化。结果　解剖肺脏栓塞部位肉眼观 ,见肺表面点片状出血灶 ;镜下肺动脉血管内可见注入的血凝块与继发的血栓形成 ,肺泡周围有大量炎性细胞浸润 ,肺泡和间质内有局灶出血。肺栓塞后血D 二聚体 (D dimer)、ET 1、vWF水平明显增高 ,而组织型纤溶酶原激活剂 (t PA)、NO、抗凝血酶Ⅲ (AT Ⅲ )水平明显下降 (P <0 0 5 )。PTE兔经尿激酶治疗后肺脏病理改变减轻 ,D dimer水平在栓塞后 1及 2h高于栓塞前 (P <0 0 5 ) ,4h后降至栓塞前水平 ;t PA、NO及AT Ⅲ在肺栓塞后低于栓塞前 (P <0 0 5 ) ;ET 1在栓塞后 2h高于栓塞前(P <0 0 5 ) ,4h降至栓塞前水平。结论　PTE对体内凝血纤溶系统及肺血管内皮功能均有重要影响。PTE兔经尿激酶溶栓治疗可维持机体凝血纤溶系统的平衡及保护肺血     

Renal, volume, and hormonal changes during therapeutic administration of recombinant interleukin-2 in man

Changes in blood pressure, renal function, and fluid balance were studied in 12 patients receiving intravenous recombinant interleukin-2 (IL-2) (100,000 units/kg every eight hours) over five days for treatment of metastatic melanoma and renal and colorectal cancers. The IL-2 regimen produced progressive hypotension, azotemia, and sodium avidity (fractional excretion of sodium = 0.20 +/- 0.07 percent) despite massive fluid administration (mean: 18.4 liter per five days) and weight gain (mean: 4.0 kg). Plasma renin activity rose. Hypoalbuminemia developed rapidly (3.6 +/- 0.1 g/dl to 2.2 +/- 0.1 g/dl, p less than 0.01) with widespread edema formation despite normal central venous pressures. Hematocrit did not change during the IL-2 period, consistent with a "capillary-leak." Hemodynamic and renal functional changes reversed after the IL-2 regimen was discontinued, but hypoalbuminemia and elevated urinary n-acetyl-glucosaminidase levels persisted after six days. These studies demonstrate widespread hemodynamic and vascular effects of IL-2 administration that limit its safe use and suggest a possible role for the lymphokine in mediating cardiovascular instability under other circumstances, such as endotoxic shock.     

In vivo production of interleukin-5, granulocyte-macrophage colony-stimulating factor, macrophages colony-stimulating factor, and interleukin-6 during intravenous administration of high-dose interleukin-2 in cancer patients

Recombinant human interleukin-2 (IL-2), administered to cancer patients by continuous intravenous (IV) infusion (3 x 10(6) U/m2/d), was found to induce the in vivo production of colony-stimulating factors (CSF). Plasma obtained from patients during IL-2 treatment stimulated in vitro colony formation of normal human bone marrow cells, depleted of mononuclear phagocytes and T lymphocytes. This colony-stimulating activity (CSA) was identified as IL-5, granulocyte-macrophage CSF (GM-CSF), and macrophage CSF (M-CSF), by the ability of specific antibodies against these factors to neutralize their effects. The presence of IL-2-induced GM-CSF and M-CSF was also demonstrated by specific radioimmunoassays. During IL-2 treatment, plasma also contained detectable levels of IL-6, which was measured in a bioassay. Using a cDNA-polymerase chain reaction (PCR) with specific primer sets for the various CSF, we showed that IL-2 treatment induced the expression of mRNA for M-CSF, GM-CSF, IL-3, and IL-5, but not for granulocyte CSF (G-CSF) in peripheral blood mononuclear cells, suggesting differential expression of CSF in vivo in response to IL-2. Furthermore, no negative regulators of hematopoiesis, such as interferon gamma (IFN-gamma) or tumor necrosis factor-alpha (TNF-alpha), were found in plasma. These data illustrate that in vivo administration of high-dose IL-2 may result in a stimulatory effect on hematopoiesis. The induction of detectable levels of IL-5 and GM-CSF in the circulation may explain the eosinophilia and neutrophilia observed in these patients.