Proinflammatory cytokines (IL-17, IL-6, IL-18 and IL-12) and Th cytokines (IFN-gamma, IL-4, IL-10 and IL-13) in patients with allergic asthma

Allergen-reactive T helper type-2 (Th2) cells and proinflammatory cytokines have been suggested to play an important role in the induction and maintenance of the inflammatory cascade in allergic asthma. We compared the plasma concentrations of novel proinflammatory cytokines IL-17 and IL-18, other proinflammatory cytokines IL-6 and IL-12, Th2 cytokines IL-10 and IL-13, and intracellular interferon-gamma (IFN-gamma) and IL-4 in Th cells of 41 allergic asthmatics and 30 sex- and age-matched health control subjects. Plasma cytokines were measured by enzyme-linked immunosorbent assay. Intracellular cytokines were quantified by flow cytometry. Plasma IL-18, IL-12, IL-10, IL-13 concentrations were significantly higher in allergic asthmatic patients than normal control subjects (IL-18: median 228.35 versus 138.72 pg/ml, P < 0.001; IL-12: 0.00 versus 0.00 pg/ml, P = 0.001; IL-10: 2.51 versus 0.05 pg/ml, P < 0.034; IL-13: 119.38 versus 17.89 pg/ml, P < 0.001). Allergic asthmatic patients showed higher plasma IL-17 and IL-6 concentrations than normal controls (22.40 versus 11.86 pg/ml and 3.42 versus 0.61 pg/ml, respectively), although the differences were not statistically significant (P = 0.077 and 0.053, respectively). The percentage of IFN-gamma-producing Th cells was significantly higher in normal control subjects than asthmatic patients (23.46 versus 5.72%, P < 0.001) but the percentage of IL-4 producing Th cells did not differ (0.72 versus 0.79%, P > 0.05). Consequently, the Th1/Th2 cell ratio was significantly higher in normal subjects than asthmatic patients (29.6 versus 8.38%, P < 0.001). We propose that allergic asthma is characterized by an elevation of both proinflammatory and Th2 cytokines. The significantly lower ratio of Th1/Th2 cells confirms a predominance of Th2 cells response in allergic asthma.     

Blood Serum Levels of IL-2, IL-6, IL-8, TNF-α and IL-1β in Patients on Maintenance Hemodialysis

Cytokines are essential mediators of immune response and inflammatory reactions. Patients with chronic renal failure (CRF) commonly present with abnormalities of immune function related with impaired kidney function and the accumulation of uremic toxins in addition to bioincompatibility of dialyzer membranes. During a hemodialysis (HD) session, cytokines are released mainly by monocytes activated by endotoxin-type compounds in dialyzer fluid, complement factors and direct contact with dialyzer membrane. The study included 15 CRF patients, aged 36.4±2.9 years, on regular HD maintenance therapy for mean 68±10 months and 15 healthy controls. It was designed to assess serum levels of a panel of inflammatory cytokines: IL-1β, IL-2, IL-6, IL-8 and TNF-αin CRF patients on regular maintenance HD before, 20, 60 and 240 minutes of a single HD session in parallel with C-reactive protein (CRP) as an additional parameter. CRP concentration was increased in HD patients when compared with healthy controls. The concentrations of IL-1, IL-6, IL-8 and TNF-αwere increased, whereas the serum level of IL-2 was not altered during a single HD session.     

IL-1beta, IL-6 and TNF-alpha in synovial fluid of patients with non-gonococcal septic arthritis

Interleukin-1 beta (IL-1beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) are the main proinflammatory cytokines responsible for the inflammatory process and cartilage destruction of inflammatory arthropathies. The present study sequentially measured the concentrations of these cytokines and their proportions of detectable levels in the synovial fluid (SF) of 23 patients with non-gonococcal (GC) septic arthritis before and after treatment. Persistently high concentrations and proportions of IL-6 and TNF-alpha were found up to day 7 of treatment, while SF IL-1beta concentration declined significantly after day 7 (p = 0.036). SF IL-1beta and TNF-alpha correlated with each other significantly and with SF WBC counts (p < 0.01). Positive correlations between SF IL-1beta concentration and joint effusion (p < 0.01) and between SF TNF-alpha concentration and joint tenderness (p < 0.001) were observed. SF IL-1beta and TNF-alpha were significantly higher in patients with local complications of septic arthritis. In conclusion, high levels of IL-1beta, IL-6 and TNF-alpha were detected in SF of patients with non-GC septic arthritis. Only IL-1beta decreased significantly after day 7 of treatment, but IL-6 and TNF-alpha concentrations were persistently high. SF IL-1beta and TNF-alpha may be useful in predicting the outcome and complications of patients with this disease.     

Levels of IL-12 in the sera of patients with systemic lupus erythematosus (SLE)--relation to Th1- and Th2-derived cytokines

IL-12 is a cytokine that induces Th1-derived cytokines (interferon-gamma (IFN-gamma) and IL-2). The significance of IL-12 in human autoimmunity is no clear, and the serum levels of IL-12 in SLE are not clearly established. Therefore, we examined the levels of IL-12 in 39 patients with active SLE, with sandwich ELISA. The levels of IL-12 in patients were significantly higher than in normal subjects. Patients with high levels of IL-12 also had high levels of IFN-gamma, while their levels of IL-13 were significantly lower than in patients with normal levels of IL-12. Patients with pulmonary involvement had high levels of IL-12, and steroid therapy decreased the IL-12 level in three patients. In a retrospective study of seven patients, various changes of IL-12 and IL-13 were recognized before disease flare. Thus, in SLE patients, the level of IL-12 was increased and this increase was related to the change of Th1- or Th2-derived cytokines with some organ involvement.     

Upregulation of Th1 cytokine profile (IL-12, IL-18) in bronchoalveolar lavage fluid in patients with pulmonary sarcoidosis.

Sarcoidosis, a systemic granulomatous disease of unknown etiology, is characterized by a predominantly Th1 cytokine milieu, which is involved in its immunopathogenesis. The role of novel immunologic markers reflecting T cell activity of the sarcoid immunologic response needs to be determined. The present study aims to evaluate the role of the Th1 cytokine pattern by estimating the local and systemic levels of interleukin-12 (IL-12) and IL-18 in bronchoalveolar lavage fluid (BALF), induced sputum, and serum of patients with pulmonary sarcoidosis. We studied prospectively 20 patients (12 women, 8 men) of median age 46 years (range 25-65) with sarcoidosis and 10 normal subjects (5 women, 5 men) of median age 39 years (range 26-60). IL-12 and IL-18 levels were measured using ELISA kits. The IL-12 BALF levels were significantly higher in sarcoidosis patients than in healthy subjects (5.64 +/- 0.21 pg/mL vs. 5.16 +/- 0.15 pg/mL, p < 0.001). In addition, IL-18 levels were significantly increased in BALF samples (47.69 +/- 6.29 pg/mL vs. 16.73 +/- 3.00 pg/mL, p < 0.001). A statistically significant decrease in IL-12 serum levels was detected in the sarcoid population compared with controls (5.77 +/- 0.50 pg/mL vs. 7.87 +/- 2.00 pg/mL, p < 0.001). No significant differences were detected in IL-12 and IL-18 levels between patients and controls in induced sputum samples. Our data suggest a potential role of IL-12 and IL-18 in the local immunologic response in pulmonary sarcoidosis. Further large-scale studies are needed to define the precise role of IL-12 and IL-18 in the immunopathogenesis of this disorder.     

Circulating proinflammatory cytokines (IL-1 beta, TNF-alpha, and IL-6) and IL-1 receptor antagonist (IL-1Ra) in fulminant hepatic failure and acute hepatitis.

Fulminant hepatic failure (FHF) is characterized by massive necroinflammation of the liver tissue and is associated with high mortality. Serum concentrations of IL-1 beta, tumour necrosis factor-alpha (TNF-alpha), IL-6 and IL-1 receptor antagonist (IL-1Ra) were measured in 30 patients with FHF and in 23 patients with acute hepatitis (AH) before start of treatment and in 23 healthy controls. Levels of all four molecules were increased significantly in FHF compared with AH, in which values were higher than in the healthy controls. High serum levels of IL-1 beta and a significantly reduced ratio of IL-1Ra to IL-1 beta (IL-1Ra/IL-1 beta) were observed in FHF patients who subsequently died compared with subjects who survived. TNF-alpha and IL-6 concentrations were correlated with levels of human hepatocyte growth factor (hHGF), an index of hepatocyte regeneration. Although serum cytokine levels varied considerably between patients within each group studied, it is suggested that the striking elevation in proinflammatory cytokine levels in FHF may reflect both the insufficiency of hepatitis virus elimination and a failure to control a vicious cytokine cascade leading to overwhelming hepatocyte destruction rather than regeneration. The high cytokine levels observed in these patients and the significantly elevated IL-1Ra/IL-1 beta ratio in FHF patients who survived compared with those who did not suggest the possible therapeutic use of cytokine antagonists for the control of this life-threatening disease.     

自身免疫甲状腺病患者血清中IL-12和IL-18水平的分析

目的:提供自身免疫甲状腺病(AITD)患者体内Th1/Th2平衡紊乱的依据。方法:应用酶联免疫吸附法(ELISA)测定27例Graves病(GD)、24例甲状腺功能正常的桥本甲状腺炎(HT)、25例甲状腺功能低下的HT患者及20例正常对照者血清中IL12和IL18的浓度,并检测GD患者的甲状腺刺激性抗体。结果:GD患者与甲状腺功能正常的HT患者血中IL12、IL18水平无明显差异,但均高于正常对照者的相应水平。甲状腺功能低下的HT患者血中IL12和IL18的水平与正常对照者无差异。在GD和甲功正常的HT,IL18与IL12呈明显正相关。在GD,IL12和IL18均与其甲状腺刺激性抗体(TSAb)活性呈正相关。在甲状腺功能正常的HT还存在IL12和IL18二者与甲状腺球蛋白抗体(TgAb)的显著性正相关。结论:提示Th1型细胞在GD和HT两种AITD的发病中均起重要作用。通过抑制Th2型免疫反应,促进向Th1型的转变来治疗GD时,有可能导致病情恶化。     

GM-CSF, IL-1 alpha, IL-1 beta, IL-6, IL-8, IL-10, ICAM-1 and VCAM-1 gene expression and cytokine production in human duodenal fibroblasts stimulated with lipopolysaccharide, IL-1 alpha and TNF-alpha.

The role of mucosal fibroblasts in intestinal inflammatory reactions is not known. In this study, we demonstrate that fibroblasts grown from histologically normal human duodenal biopsy tissues expressed mRNA genes for granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-1 alpha, IL-1 beta, IL-6, IL-8, IL-10, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) when stimulated with lipopolysaccharide (LPS) or IL-1 alpha. The increased mRNA expression of GM-CSF, IL-1 alpha, IL-1 beta, IL-6 and IL-8 in response to IL-1 alpha and LPS stimulation was time- and dose-dependent. In contrast, IL-10 was weakly expressed when fibroblasts were stimulated with LPS, IL-1 alpha or tumour necrosis factor-alpha (TNF-alpha), but the expression was enhanced in the presence of cycloheximide combined with optimal concentrations of LPS, IL-1 alpha or TNF-alpha, IL-1 alpha was a more potent stimulator than LPS for GM-CSF, IL-6, IL-8 and IL-10 expression, but not for IL-1 alpha and IL-1 beta. Increased GM-CSF, IL-6 and IL-8 gene expression was associated with the production of cytokine proteins in culture supernatant, but IL-1 alpha and IL-1 beta remained undetectable. Dexamethasone suppressed both gene expression and protein production of GM-CSF, IL-6 and IL-8 when fibroblasts were exposed to IL-1 alpha. TNF-alpha stimulated the release of GM-CSF, IL-6 and IL-8 and, combined with IL-1 alpha, cytokine production was enhanced synergistically. Finally, both LPS and IL-1 alpha up-regulated ICAM-1 and VCAM-1 gene expression. These findings implicate duodenal fibroblasts in the initiation and/or regulation of intestinal inflammation.     

Association of IL-6 gene alleles with systemic lupus erythematosus (SLE) and with elevated IL-6 expression

To evaluate the association of alleles of regions having regulatory potential in the IL-6 gene, with SLE, the AT-rich minisatellite in the 3' flanking region and the 5' promoter-enhancer of the IL-6 gene were genotyped by PCR- and RFLP-based methods. The AT-rich minisatellite allele distribution pattern was significantly different in SLE (n = 146) as compared to 139 controls (chi 2(7) = 48.97, P = 0.001, Caucasians; and chi 2(7) = 19.93, P = 0.006, African-Americans). In either race, short allele sizes (< or = 792 bp) were seen exclusively in SLE patients (P = 0.001), whereas the 828-bp allele was over-represented in controls (P = 0.015 and 0.002). In contrast, there was no preferential association of SLE with G/C alleles in the 5' region of the IL-6 gene. Furthermore, our results suggest that the 3' minisatellite alleles have biological significance: (1) B lymphoblastoid cells of patients having one or two SLE-associated alleles secreted IL-6 in 3- to 4-fold higher levels than non-allelic cells (P < 0.05); (2) higher percentages (approximately 4-fold) of IL-6 positive monocytes were observed in individuals having SLE-associated IL-6 alleles; (3) in lupus patients having SLE-associated minisatellite alleles, IL-6 mRNA stability was significantly enhanced.     

Perioperative serum levels of tumour-necrosis-factor alpha (TNF-alpha), IL-1 beta, IL-6, IL-10 and soluble IL-2 receptor in patients undergoing cardiac surgery with cardiopulmonary bypass without and with correction for haemodilution.

Cardiac surgery with cardiopulmonary bypass (CPB) leads to a systemic inflammatory response with secretion of cytokines. Alterations in the serum concentrations of cytokines have important prognostic significance. Reports on cytokine release during cardiac surgery with CPB have yielded conflicting results. Haemodilution occurs with the onset of CPB resulting in large fluid shifts during the perioperative course of cardiac procedures. In the present study we compare the perioperative course of serum concentrations of TNF-alpha, IL-1beta, IL-6, IL-10 and sIL-2R with and without correction for haemodilution in patients undergoing coronary artery bypass grafting (CABG) surgery. Twenty male patients undergoing elective CABG surgery with CPB and general anaesthesia using a balanced technique with sufentanil, isoflurane and midazolam were enrolled into the study. Serum levels of TNF-alpha, IL-1beta, IL-6, IL-10 and sIL-2R were measured using commercially available ELISA kits. Simultaneous haematocrit values were obtained at all sample times. Statistical analysis was performed by non-parametric analysis of variance and t-tests for data corrected for haemodilution and data that were not corrected for haemodilution. Adjusted significance level was P < 0.01. Intra-operatively, up to the second post-operative day PCV values were significantly decreased compared with preoperative values. Cytokine measurements not corrected for haemodilution were significantly lower than the corrected values. The perioperative haemodilution and decrease in PCV may lead to an underestimation of the cytokine secretion in post-operative patients. We conclude that cytokine measurements were significantly influenced by the perioperative haemodilution and the subsequent decrease in PCV and may in part account for the varying results reported in the literature regarding cytokine release in patients undergoing CABG surgery.     

Proinflammatory cytokines (IL-6, IL-8), cytokine inhibitors (IL-6sR, sTNFRII) and anti-inflammatory cytokines (IL-10, IL-13) in the pathogenesis of sepsis in newborns and infants.

The levels of the proinflammatory cytokines interleukin 6 (IL-6) and IL-8, and the anti-inflammatory cytokines IL-10 and IL-13 were studied in child patients with sepsis. The changes of the cytokine inhibitors soluble IL-6 receptor and soluble p75 TNF-alpha receptor were also investigated in the patients' sera. An increase of pro- and anti-inflammatory cytokine levels was demonstrated at the time of diagnosis. Pharmacotherapy was accompanied by a decrease of the elevated concentrations of both cytokines and their inhibitors. The time pattern of changes in cytokine and cytokine inhibitor serum concentrations along with the time course of acute phase indices, including procalcitonin and C-reactive protein, allows for an evaluation of the system inflammatory response and may support diagnostic and prognosis methods.     

Developmental regulation of the cytokine repertoire in human macrophages: IL-1, IL-6, TNF-alpha, and M-CSF

We were interested in the dependence of constitutive and stimulated cytokine secretion on the stage of macrophage (MAC) differentiation in vitro. Elutriation-purified blood MO were cultured up to 28 days and their secretory repertoire was analyzed under adherence conditions at various culture stages. For each of the cytokines tested, interleukin (IL)-1 beta, IL-6, tumor necrosis factor (TNF)-alpha, and macrophage colony-stimulating factor (M-CSF), a different pattern of regulation was observed. During the initial phase of maturation (up to day 7 in culture) within which the characteristics of normal MO to MAC transformation are achieved, M-CSF was the only cytokine to be secreted constitutively. From the LPS-dependent cytokines, IL-1 beta and IL-6 were downregulated whereas TNF-alpha levels increased severalfold. For the release of IL-1 beta, IL-6, and TNF-alpha a synergistic effect of interferon-gamma (IFN-g) and lipopolysaccharide (LPS) was observed. M-CSF release increased until day 7 in culture with LPS being stimulatory for this particular cytokine only during the first days of differentiation. Upon further cultivation of MAC up to 28 days, LPS-induced IL-1 beta levels remained very low, but IL-6 levels increased again reaching that of blood MO, and TNF-alpha continued to rise reaching levels up to 30-fold higher than in blood MO. M-CSF secretion stayed high with LPS even suppressing constitutive secretion. Long-term cultured MAC started to release IL-6 and TNF-alpha also in the absence of a stimulus and, furthermore, became responsive to IFN-g alone. Our data show that the release of each cytokine investigated is differently regulated during maturation. These results document the functional plasticity of human MAC and emphasize the impact that MO to MAC differentiation may have in vivo.     

Lack of association between pro-inflammatory cytokine (IL-6, IL-8 and TNF-alpha) gene polymorphisms and Graves' disease

Graves' disease (GD) is a common, autoimmune disease involving the thyroid gland, and it has been previously suggested that pro-inflammatory cytokines are involved in the disease's pathogenesis. The aim of this study was to test whether the interleukin (IL)-6 gene promoter region, or tumour necrosis factor (TNF)-alpha or IL-8 gene 3'-untranslated region (3'-UTR) polymorphisms could provide useful genetic markers for an individual's susceptibility to GD. A normal control group of 60 healthy people and 95 patients featuring GD were examined. Polymerase chain reaction (PCR)-based restriction analysis was performed for the three gene polymorphisms using endonucleases BsrBI, NcoI and ApaLI, respectively. We found no significant difference between the frequencies of genotype and allelic variants for the IL-6 gene promoter (-572 G/C), the TNF-alpha gene promoter (-308 A/G) and the IL-8 gene 3'-UTR (2767 A/G) for GD patients and for normal controls. Cytokines are a large group of proteins that may elicit multiple effects upon immunological reactions. It still appears to be very worthwhile to continue to aggressively search for cytokine gene polymorphisms in order to predict the development of such disease.     

Interaction of IL-1 beta, IL-6 and tumour necrosis factor-alpha (TNF-alpha) in human T cells activated by murine antigens.

We used a mixed leucocyte culture between human T cells and irradiated murine splenocytes which allowed us to distinguish between cytokine production from the responder and stimulator cells by the use of species-specific assays for mRNA up-regulation. Using this model of T cell activation by antigen, we studied the effects of human antigen-presenting cell-derived cytokines IL-1 beta, IL-6 and TNF-alpha on the activation of human T cell subsets. We show in this system that exogenously added IL-1 beta, IL-6 and TNF-alpha induces IL-2 receptor (R) up-regulation and IL-2 production, and proliferation by both CD4+ and CD8+ cells. The addition of IL-1 beta induces IL-6 mRNA, and anti-IL-1 antibodies or an IL-1R antagonist protein completely suppresses IL-6 and TNF-alpha supported proliferation. Similarly, addition of IL-6 or TNF-alpha induces up-regulation of IL-1 beta mRNA. However, anti-IL-6 and anti-IL-6R antibodies only partially block proliferation supported by IL-1 beta. These findings suggest that IL-6 and TNF-alpha will induce IL-2R up-regulation/IL-2 secretion via the induction of IL-1 beta production.     

LPS-induced release of IL-1beta, IL-1Ra, IL-6, and TNF-alpha in whole blood from patients with familial hypercholesterolemia: no effect of cholesterol-lowering treatment.

Proinflammatory cytokines, such as interleukin-1beta (IL-1beta), IL-6, and tumor necrosis factor-alpha (TNF-alpha), are suggested to have an important role in the process of atherosclerosis. Patients with heterozygous familial hypercholesterolemia (FH) have a marked elevation in the plasma level of low-density lipoproteins (LDL), and they show early development of atherosclerosis. The aim of the present study was to test with a whole blood culture system if hyperlipoproteinemia is associated with increased cytokine production capacity in these patients and if treatment with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors influences this production capacity of blood cells, at both the protein and mRNA levels. The capacity of blood cells in a whole blood culture to produce IL-1beta, IL-6, TNF-alpha, IL-12, IL-18, and IL-1 receptor antagonist (IL-1Ra) in response to lipopolysaccharide (LPS) appeared to be similar for heterozygous FH patients and healthy volunteers. Furthermore, the capacity to produce IL-1beta, IL-6, and TNF-alpha in response to LPS was not modified by cholesterol synthesis inhibitors at the level of mRNA expression or at the level of release. On the other hand, the release of IL-1Ra was significantly increased after treatment with HMG-CoA reductase inhibitors, although only at the protein level. This suggests a possible beneficial anti-inflammatory role for this therapy.     

Proinflammatory cytokine (TNFalpha/IL-1alpha) induction of human osteoclast formation

TNFalpha and IL-1alpha are potent stimulators of bone resorption in vivo and in vitro. Recently, it has been demonstrated that these two cytokines directly induce osteoclastogenesis in mouse marrow cultures. This study determined whether TNFalpha (+/- IL-1alpha) is also capable of inducing human osteoclastogenesis. The CD14(+) monocyte fraction of human peripheral mononuclear cells was cultured with TNFalpha +/- IL-1alpha in the presence of M-CSF. TNFalpha induced the formation of multinucleated cells (MNCs) which were positive for TRAP, VNR and cathepsin K and showed evidence of resorption pit formation. IL-1alpha stimulated TNFalpha-induced lacunar resorption two- to four-fold. Osteoprotegerin, the decoy receptor for RANKL, did not inhibit this process. Anti-human IL-1alpha neutralizing antibodies significantly inhibited resorption without inhibiting the formation of TRAP(+)/VNR(+) MNCs. These results suggest that, in the presence of M-CSF, TNFalpha is sufficient for inducing human osteoclast differentiation from circulating precursors by a process which is distinct from the RANK/RANKL signalling pathway.     

Th1 (IL-2, interferon-gamma (IFN-γ)) and Th2 (IL-10, IL-4) cytokine production by peripheral blood mononuclear cells (PBMC) from patients with systemic lupus erythematosus (SLE)

We investigated the production of IL-2, IFN-γ, IL-10 and IL-4 by PBMC from 24 patients with SLE and 10 healthy individuals. Basal and mitogen-stimulated (lipopolysaccharide and phytohaemagglutinin (LPS + PHA)) cytokine production was determined in a whole blood assay (WBA). Supernatants were collected and assayed with specific ELISAs. Although the IL-2 and IFN-γ contents did not differ significantly between patients and controls under both conditions, statistically significant correlations were found between each cytokine and disease activity (SLAM index) after stimulation (respectively, r= 0.501, P = 0.01 and r = 0.631, P = 0.001). PBMC IL-10 production was significantly higher for patients than controls (P = 0.05), but no correlation between IL-10 levels and the SLAM index was obtained. IL-4 production was not statistically different between SLE patients and controls. For stimulated WBAs, the IL-10/IL-2 and IL-10/IFN-γ ratios were significantly correlated with disease severity (P = 0.02; P = 0.001, respectively). Overall, our data suggest that SLE is characterized by an elevated production of IL-10, reflecting the basal state of activation of the immune system. During exacerbation of SLE, IL-2 and IFN-γ are synthesized in larger amounts and may cause the tissue damage observed.     

Pregnancy, but not the allergic status, influences spontaneous and induced interleukin-1beta (IL-1beta), IL-6, IL-10 and IL-12 responses

In this study, we investigated how pregnancy influences cytokine production in response to stimulation of the innate and the adaptive immune system, respectively. Peripheral blood mononuclear cells (PBMCs) from allergic (n = 44) and non-allergic (n = 36) women were collected at three time-points: during the third trimester, at delivery and at a non-pregnant state 2 years after delivery. The production of interleukin-1beta (IL-1beta), IL-6, IL-10 and IL-12 was measured by enzyme-linked immunosorbent assay (ELISA) or enzyme-linked immunospot assay (ELISPOT). The spontaneous cytokine production, and the response following stimulation with agents that primarily activate the adaptive part of the immune system [phytohaemagglutinin (PHA), allergen extracts from cat and birch], or lipopolysaccharide (LPS) that activate innate immunity was measured in vitro. There was a significantly higher spontaneous in vitro production of IL-1beta, IL-6 and IL-10 by PBMCs during pregnancy than 2 years after pregnancy, and this was not affected by the allergic status of the women. Conversely, in PHA-stimulated cell cultures there was a lower production of IL-10 and IL-12 during pregnancy than 2 years after pregnancy. LPS-induced IL-6 levels were significantly lower in PBMCs obtained during pregnancy than at 2 years after pregnancy. In addition, we made the interesting observation that in allergic women total immunoglobulin E (IgE) levels were significantly lower 2 years after pregnancy compared to the levels during pregnancy. Taken together, our results indicate that while atopic allergy in women does not have a substantial effect on cytokine production, pregnancy has an obvious effect on the immune system in terms of cytokine production as well as on the total IgE levels.