Cytokine measurements and interpretation of cytokine assays in human disease

Sensitive and Multiplexed SERS Nanotags for the Detection of Cytokines Secreted by Lymphoma

The sensitive and simultaneous detection of cytokines will provide new insights into the physiological process and disease pathways due to the complex nature of cytokine networks. However, the key challenge is the lack of probes that can simultaneously detect multiple cytokines in a single sample. In this contribution, we proposed an alternative approach for sensitive cytokine detection in a multiplex manner by the use of a new set of surface-enhanced Raman spectroscopy (SERS) nanotags. Typically, the newly designed SERS nanotags are composed of gold nanoparticles as the core, tuneable Raman molecules as the reporters, and a thin silver layer as the shell. As demonstrated through rigorous numerical simulations, enhanced Raman signal is achieved due to a strong localization of light in the 0.2 nm thin, optically deep-subwavelength region between the Au core and the Ag shell. Sensitive detection of cytokines is realized by forming a sandwich immunoassay. The detection limit is down to 4.5 pg mL^-1 (S/N = 3). The specificity of the assay is proved as negligible signals were detected for the false targets. Furthermore, multiple cytokines are simultaneously detected in a single assay from the secretion of B-lymphocyte cell line (Raji) after concanavalin A (Con A) stimulation. The results indicate that our method holds a significant potential for sensitive and multiplexed detection of cytokines and offers the opportunity for future applications in clinical settings.

Analysis of effectiveness of Iranian snake antivenom on Viper venom induced effects including analysis of immunologic biomarkers in the Echis carinatus sochureki envenomed victims

Snakebite is an important toxicologic emergency with the potential of triggering local and systemic inflammation. Antivenom has remained the mainstay of treatment for snakebite envenomation. In this study we sought to investigate the effectiveness of Iranian antivenom in a series of 44 viper envenomed patients through analysis of changes in clinical severity and the levels of inflammatory markers. Clinical envenomation severity assessed by snakebite severity score (SSS) and laboratory exams of the patients were recorded before (baseline visit) and after antivenom therapy. During 12-h antivenom therapy, the median (range) score of SSS significantly decreased from 3.5 (2-10) on admission to 1 (0-5) in the last visit (P < 0.001). Moreover, a significant decrease in prothrombin time and international normalized ratio was found (P = 0.006 and 0.008; respectively). Plasma concentrations of interleukin (IL) 1-β, IL-6, IL-8, tumor necrosis factor α (TNF-α), complement hemolytic activity (CH50) were also measured in 10 severely Echis carinatus sochureki envenomed victims and 10 age and gender-matched healthy controls. Except IL-8, the baseline levels of IL-1β, IL-6 and TNF-α in victims were significantly higher than healthy controls (P = 0.005, <0.001 and < 0.001, respectively). Moreover, the baseline level of CH50 was significantly lower in the patients compared to healthy controls (P < 0.001). After 12-h antivenom therapy, the plasma levels of IL-1β, IL-6 and TNF-α significantly decreased (P = 0.032, 0.006 and 0.003, respectively), the levels of IL-8 remained relatively unchanged and the CH50 significantly increased (P = 0.011). Iranian snake antivenom was effective in treating viper bite envenomation as it reversed clinical venom effects and restored near normal underlying inflammatory status. This study is the first to ascertain and report the effectiveness of this antivenom in human subjects.

Respiratory and GIT tract immune responses of broiler chickens following experimental infection with Newcastle disease's virus

Newcastle disease causes a lymphoproliferative response in the tracheal and intestinal mucosa of the infected birds. In this study, the Hitchner B1 and I-2 vaccine and challenging of ND field strains were used to evaluate the populations of T lymphocyte subsets infiltrated intestinal and tracheal, also to shed some light on cell-mediated immune response using enzyme-linked immunosorbent assay (ELISA) detecting chicken's serum interferon-γ. Three hundred-day-old broilers were randomly divided into four groups. Groups 1 and 2 received I-2 and B1 vaccines, respectively, while groups 3 and 4 were challenged-unvaccinated and unchallenged-unvaccinated groups. Blood samples were taken from five random chicks and were then tested with ELISA test. Three chicks of each group were euthanized after vaccine administration and also challenging with acute virus. Interferon-γ changes were significant in time (p < 0.001). Totally, there was no significant difference between I-2 and B1 groups. The number of CD3+, CD4+, and CD8+ cells of I-2 and B1 vaccinated group's intestine and the trachea samples was significantly increased compared with the negative control group (p < 0.001). The results indicated the significant increase in CD4+ and CD8+ in intestinal and tracheal tissues, while the level of interferon-γ of the vaccinated group was more than the unvaccinated one. Finding no significant differences between the vaccinated groups indicated the potential of both vaccines in producing CD4+ and CD8+ in the tracheal and intestinal tissues and the equality of interferon-γ production in the sera.

Biomarkers for wound healing and their evaluation

A biological marker (biomarker) is a substance used as an indicator of biological state. Advances in genomics, proteomics and molecular pathology have generated many candidate biomarkers with potential clinical value. Research has identified several cellular events and mediators associated with wound healing that can serve as biomarkers. Macrophages, neutrophils, fibroblasts and platelets release cytokines molecules including TNF-α, interleukins (ILs) and growth factors, of which platelet-derived growth factor (PDGF) holds the greatest importance. As a result, various white cells and connective tissue cells release both matrix metalloproteinases (MMPs) and the tissue inhibitors of metalloproteinases (TIMPs). Studies have demonstrated that IL-1, IL-6, and MMPs, levels above normal, and an abnormally high MMP/TIMP ratio are often present in non-healing wounds. Clinical examination of wounds for these mediators could predict which wounds will heal and which will not, suggesting use of these chemicals as biomarkers of wound healing. There is also evidence that the application of growth factors like PDGF will alleviate the recuperating process of chronic, non-healing wounds. Finding a specific biomarker for wound healing status would be a breakthrough in this field and helping treat impaired wound healing.

Inflammation and Nutritional Science for Programs/Policies and Interpretation of Research Evidence (INSPIRE)

An increasing recognition has emerged of the complexities of the global health agenda—specifically, the collision of infections and noncommunicable diseases and the dual burden of over- and undernutrition. Of particular practical concern are both 1) the need for a better understanding of the bidirectional relations between nutritional status and the development and function of the immune and inflammatory response and 2) the specific impact of the inflammatory response on the selection, use, and interpretation of nutrient biomarkers. The goal of the Inflammation and Nutritional Science for Programs/Policies and Interpretation of Research Evidence (INSPIRE) is to provide guidance for those users represented by the global food and nutrition enterprise. These include researchers (bench and clinical), clinicians providing care/treatment, those developing and evaluating programs/interventions at scale, and those responsible for generating evidence-based policy. The INSPIRE process included convening 5 thematic working groups (WGs) charged with developing summary reports around the following issues: 1) basic overview of the interactions between nutrition, immune function, and the inflammatory response; 2) examination of the evidence regarding the impact of nutrition on immune function and inflammation; 3) evaluation of the impact of inflammation and clinical conditions (acute and chronic) on nutrition; 4) examination of existing and potential new approaches to account for the impact of inflammation on biomarker interpretation and use; and 5) the presentation of new approaches to the study of these relations. Each WG was tasked with synthesizing a summary of the evidence for each of these topics and delineating the remaining gaps in our knowledge. This review consists of a summary of the INSPIRE workshop and the WG deliberations.

Femtogram detection of cytokines in a direct dot-blot assay using SERS microspectroscopy and hydrophilically stabilized Au–Ag nanoshells

Rapid duplex detection of cytokines at femtogram levels in a direct dot-blot assay is demonstrated by using hydrophilically stabilized Au–Ag nanoshells and SERS.

Evaluation of the reactivity of commercially available monoclonal antibodies with equine cytokines

Research on equine cytokines is often performed by analyses of mRNA. For many equine cytokines an analysis on the actual protein level is limited by the availability of antibodies against the targeted cytokines. Generation of new antibodies is ongoing but time consuming. Thus, testing the reactivity of commercially available antibodies for cross-reactivity with equine cytokines is of particular interest. Fifteen monoclonal antibodies against IL-1β, IL-6, IL-8, IL-12, IL-18 and Granulocyte Macrophage Colony stimulating factor (GM-CSF) of different species were evaluated for reactivity with their corresponding equine cytokines. Dot Blot (DB) and Western Blot (WB) analyses were performed using recombinant equine cytokines as positive controls. Immunohistochemistry (IHC) was carried out on equine tissue and flow cytometry on equine PBMC as positive controls. As expected, three equine IL-1β antibodies detected equine IL-1β in DB, WB and IHC. For these, reactivity in IHC has not been described before. One of them was also found to be suitable for intracellular staining of equine PBMC and flow cytometric analysis. Two antibodies raised against ovine GM-CSF cross-reacted with equine GM-CSF in DB, WB and IHC. For these anti-GM-CSF mAbs this is the first experimental description of cross-reactivity with equine GM-CSF (one mAb was predicted to be cross-reactive in WB in the respective data sheet). The other clone additionally proved to be appropriate in flow cytometric analysis. Two mAbs targeting porcine IL-18 cross-reacted in IHC, but did not show specificity in the other applications. No reactivity was shown for the remaining five antibodies in DB, although cross-reactivity of two of the antibodies was described previously. The results obtained in this study can provide beneficial information for choosing of antibodies for immunological tests on equine cytokines.

Diagnostic accuracy of interleukin-6 levels in peritoneal fluid for detection of endometriosis

PURPOSE

To determine, with extended receiver operating characteristic (ROC) curve analysis, the diagnostic value of cytokines showing significantly different peritoneal concentrations between women with and without endometriosis.

METHODS

Multiplex cytokine concentration measurement of IL-2, IL-4, IL-6, IL-10, TNF-α and IFN-γ levels in peritoneal fluid of women with minimal to mild (n = 10) and moderate to severe (n = 26) endometriosis, and 42 controls.

RESULTS

Only IL-6 and IL-10 concentrations were significantly higher in endometriosis patients than in controls. Specifically, significantly higher IL-6 and IL-10 levels were found in moderate to severe but not in minimal to mild endometriosis as compared to controls. For evaluation of diagnostic significance, ROC analysis determined discriminating parameters for IL-6, while those calculated for IL-10 were useless. Importantly, ROC analysis for IL-6 levels limited to women with moderate to severe endometriosis showed the highest area under the curve with the sample size sufficient to achieve 90 % power of the test. Finally, extended ROC including cost of analysis for this group of patients determined the optimal cut-off leading to high specificity and positive likelihood ratio resulting in 79 % effectiveness of the test.

CONCLUSIONS

While our outcomes show moderate usefulness of peritoneal IL-6 levels in discrimination of moderate to severe endometriosis, further studies might be needed to determine the usefulness of peritoneal IL-6 levels in detection of early stages of endometriosis, as such a finding would be more relevant in clinical decision making.

Prediagnosis biomarkers of insulin-like growth factor-1, insulin, and interleukin-6 dysregulation and multiple myeloma risk in the Multiple Myeloma Cohort Consortium

Insulin-like growth factor-1 (IGF-1), insulin, and IL-6 are dysregulated in multiple myeloma pathogenesis and may also contribute to multiple myeloma etiology. To examine their etiologic role, we prospectively analyzed concentrations of serologic markers in 493 multiple myeloma cases and 978 controls from 8 cohorts in the Multiple Myeloma Cohort Consortium. We computed odds ratios (ORs) and 95% confidence intervals (CIs) for multiple myeloma per 1-SD increase in biomarker concentration using conditional logistic regression. We examined heterogeneity by time since blood collection (≤ 3, 4- ≤ 6, and > 6 years) in stratified models. Fasting IGF binding protein-1 concentration was associated with multiple myeloma risk within 3 years (OR, 95% CI per 1-SD increase: 2.3, 1.4-3.8, P = .001) and soluble IL-6 receptor level was associated within 6 years after blood draw (OR (≤ 3 years), 95% CI, 1.4, 1.1-1.9, P = .01; OR(4- ≤ 6 years), 95% CI, 1.4, 1.1-1.7, P = .002). No biomarker was associated with longer-term multiple myeloma risk (ie, > 6 years). Interactions with time were statistically significant (IGF binding protein-1, P-heterogeneity = .0016; sIL6R, P-heterogeneity = .016). The time-restricted associations probably reflect the bioactivity of tumor and microenvironment cells in transformation from monoclonal gammopathy of undetermined significance or smoldering multiple myeloma to clinically manifest multiple myeloma.

Psychological stress alters the ultrastructure and increases IL-1β and TNF-α in mandibular condylar cartilage

Psychological factors can be correlated with temporomandibular disorders (TMDs), but the mechanisms are unknown. In the present study, we examined the microstructural changes and expression of proinflammatory cytokines in mandibular condylar cartilage of the temporomandibular joint (TMJ) in a psychological stress animal model. Male Sprague-Dawley rats (8 weeks old, 210 ± 10 g) were randomly divided into 3 groups: psychological stress (PS, N = 48), foot shock (FS, N = 24), and control (N = 48). After inducing psychological stress using a communication box with the FS rats for 1, 3, or 5 weeks, PS rats were sacrificed and compared to their matched control littermates, which received no stress and were killed at the same times as the PS rats. Body and adrenal gland weight were measured and corticosterone and adrenocorticotropic hormone levels were determined by radioimmunoassay. After hematoxylin-eosin staining for histological observation, the ultrastructure of the TMJ was examined by scanning electron microscopy. Transcription and protein levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were evaluated by ELISA and semi-quantitative RT-PCR. The PS group showed a significantly higher adrenal gland weight after 3 weeks of stress and higher hormone levels at weeks 1, 3, and 5. Histopathological changes and thinning cartilage were apparent at weeks 3 and 5. In the PS group, TNF-α increased at 1, 3, and 5 weeks and IL-1β increased significantly after 1 and 3 weeks of stress, and then decreased to normal levels by 5 weeks. Psychological stress increased plasma hormone levels and RT-PCR indicated increased IL-1β and TNF-α expression in the TMJ in a time-dependent manner. These results suggest that cytokine up-regulation was accompanied by stress-induced cartilage degeneration in the mandibular condyle. The proinflammatory cytokines play a potential role in initiating the cartilage destruction that eventually leads to the TMDs.

Impact of HIV on liver fibrosis in men with hepatitis C infection and haemophilia

Hepatitis C virus (HCV) is the major cause of liver disease in haemophilia. Few data exist on the proportion with liver fibrosis in this group after long-term HCV and HIV co-infection. We conducted a cross-sectional multi-centre study to determine the impact of HIV on the prevalence and risk factors for fibrosis in haemophilic men with chronic hepatitis C. Biopsies were independently scored by Ishak, Metavir and Knodell systems. Variables were tested for associations with fibrosis using logistic regression and receiver operating curves (ROC). Of 220 biopsied HCV(+) men, 23.6% had Metavir ≥ F3 fibrosis, with higher mean Metavir fibrosis scores among HIV/HCV co-infected than HCV mono-infected, 1.6 vs. 1.3 (P = 0.044). Variables significantly associated with fibrosis included AST, ALT, APRI score (AST/ULN × 100/platelet × 10(9) /L), alpha-fetoprotein (all P < 0.0001), platelets (P = 0.0003) and ferritin (P = 0.0008). In multiple logistic regression of serum markers, alpha-fetoprotein, APRI and ALT were significantly associated with ≥ F3 fibrosis [AUROC = 0.77 (95% CI 0.69, 0.86)]. Alpha-fetoprotein, APRI and ferritin were significant in HIV(-) [AUROC = 0.82 (95% CI 0.72, 0.92)], and alpha-fetoprotein and platelets in HIV(+) [AUROC = 0.77 (95% CI 0.65, 0.88]. In a multivariable model of demographic and clinical variables, transformed (natural logarithm) of alpha-fetoprotein (P = 0.0003), age (P = 0.006) and HCV treatment (P = 0.027) were significantly associated with fibrosis. Nearly one-fourth of haemophilic men have Metavir ≥ 3 fibrosis. The odds for developing fibrosis are increased in those with elevated alpha-fetoprotein, increasing age and past HCV treatment.

Assessment of the cell-mediated immune response in chickens by detection of chicken interferon-γ in response to mitogen and recall Newcastle disease viral antigen stimulation

The potential of a capture enzyme-linked immunosorbent assay (ELISA) specific for chicken interferon-gamma (ChIFN-gamma) has been evaluated as a tool to assess cell-mediated immunity (CMI) in the chicken. In a first step, ChIFN-gamma production and cell proliferation of mitogen-activated chicken splenocytes have been compared. In general, for each of the stimulation conditions where significant proliferation was observed, production of ChIFN-gamma could be measured by ELISA. In our hands, the combination of ionomycin and phorbol-12-myristate 13-acetate or the use of recombinant chicken interleukin-2 gave the most satisfactory results. Then, the CMI response induced by live or killed Newcastle disease virus (NDV) vaccines has been evaluated sequentially by ex vivo antigen-specific ChIFN-gamma production and cell proliferation of splenocytes from immune chickens. The ex vivo data showed that both types of NDV vaccines are capable of stimulating CMI responses to NDV in chickens as measured by the ChIFN-gamma ELISA. However, most of the chickens vaccinated with the live vaccine produced ChIFN-gamma after antigen recall stimulation, from 2 to 4 weeks after vaccination, when only some chickens vaccinated with the inactivated vaccine showed a specific response 4 weeks after vaccination. No significant proliferative responses to either NDV vaccine were detectable during the 4 weeks of the study. From our results, it appears that antigen-specific ChIFN-gamma production can be used as a good indicator of actively acquired immunity to NDV and that the sensitivity range of the capture ELISA test is well adequate to measure ex vivo release of ChIFN-gamma.

Recurrent miscarriage: current concepts in diagnosis and treatment

Although recurrent miscarriage (RM) affects only 1-3% of couples, it has a major influence on the wellbeing and psychosocial status of patients. Therefore, research into improved diagnosis and development of new treatment strategies is essential. In this review, we summarize current concepts on diagnosis and treatment in RM, drawing upon research reports and international guidelines to provide insights into the pathophysiology of pregnancy disrupted by repeated miscarriage. Anatomical malformations, infectious diseases, endocrine disorders, autoimmune defects as well as acquired and inherited thrombophilia are established risk factors in RM. In addition, our recent findings indicate an impact on miscarriage incidence of glycoproteins such as glycodelin, and nuclear hormone receptors such as the peroxisome proliferator-activated receptors (PPARs). Significantly reduced glycodelin expression is associated with miscarriage, whereas up-regulation of PPARs appears to compensate for either the activated immune response or the disturbed cytotrophoblast differentiation in RM patients. There is also evidence that circulating placental microparticles are increased in a subgroup of RM patients, indicating an acquired procoagulant state even outside pregnancy. Treatment strategies like aspirin and low molecular weight heparin (LMWH) are standard medications in RM, although only a few placebo-controlled trials have proven their benefit in respect to live birth rate. There is emerging evidence that new treatment options, including drugs like TNFalpha inhibitors and granulocyte colony-stimulating factor (G-CSF) might be beneficial in some cases of RM. However, larger clinical trials must be completed to further prove or disprove benefits of these drugs in the treatment of RM patients.

Interleukin-5 and interleukin-10 are produced in central nervous system tumor cysts

Interleukin-5 and interleukin-10, as important mediators of vascular permeability, contribute to the development of various pathologic effusions. However, little is known regarding the involvement of these two cytokines in the formation of cysts associated with central nervous system (CNS) tumors. Twenty-eight patients with various cystic CNS tumors were investigated for expression of interleukin-5 and interleukin-10 in cyst fluid and their matched cytokine receptors in tumor tissue. Interleukin-5 and interleukin-10 were detected in cyst fluid, and interleukin-5 concentration was significantly correlated with interleukin-10 concentration (r=0.508, p=0.006). Moreover, both receptors were also detectable in the tumor tissue specimens and high levels of expression were also found in perivascular cells. Therefore, the local production of interleukin-5 and interleukin-10 might be implicated in some types of cyst formation.

Population differences in immune marker profiles associated with human T-lymphotropic virus type I infection in Japan and Jamaica

The natural history of human T-lymphotropic virus type I (HTLV-I) has been shown to differ markedly by geographic area. The differences include contrasting patterns of risk of adult T-cell lymphoma (ATL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), which may be due in part to differences in host immune response to infection. To characterize variations in host immunity across populations, we compared serologic immune marker patterns in HTLV-I-endemic populations in Japan and Jamaica. We matched 204 participants with archived blood from the Miyazaki Cohort Study (Japan) and the Food Handlers Study (Jamaica)-i.e., 51 HTLV-I-positive ("carriers") and 51 HTLV-I-negative individuals ("noncarriers") from each population-by age, sex and blood collection year. We compared plasma concentrations of markers of T-cell-mediated (antigen-specific) and nonspecific immunity using regression models and correlation coefficients. Compared to Jamaican HTLV-I noncarriers, Japanese noncarriers had higher covariate-adjusted mean levels of T-cell activation markers, including antibody to Epstein-Barr virus nuclear antigen-1 (reciprocal titer 27 vs. 71, respectively, p=0.005), soluble interleukin-2 receptor-alpha (477 vs. 623 pg/mL, p=0.0008) and soluble CD30 (34 vs. 46 U/mL, p=0.0001) and lower levels of C-reactive protein (1.1 vs. 0.43 microg/mL, p=0.0004). HTLV-I infection was associated with activated T-cell immunity in Jamaicans but with diminished T-cell immunity in Japanese persons. The observed population differences in background and HTLV-I-related host immunity correspond closely to the divergent natural histories of infection observed among HTLV-I carriers in Japan and Jamaica and corroborate a role for host immune status in the contrasting patterns of ATL and HAM/TSP risk.

Oral and Maxillofacial Pathology: Interleukin-1 β, interleukin-6, and tissue inhibitor of metalloproteinase-1 in the synovial fluid of the temporomandibular joint with respect to cartilage destruction

OBJECTIVE

The distribution and biological roles of interleukin (IL)-1 beta, IL-6, and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the synovial fluid of patients with non-inflammatory chronic temporomandibular joint (TMJ) disorders were evaluated in relation to pain upon joint movements and X-ray and magnetic resonance imaging (MRI) findings.

MATERIALS AND METHODS

TMJ aspirates were obtained from 48 patients (48 joints) with chronic TMJ disorders and from 18 controls (18 joints). The IL-1 beta and IL-6 levels in the aspirates were determined by using an enzyme-linked immunosorbent assay and the TIMP-1 level was measured by an enzyme immunoassay. Following examinations for pain upon joint movements and X-ray and MRI observations, the IL-1 beta, IL-6, and TIMP-1 levels and frequencies of their detection were compared.

RESULTS

The IL-1 beta level and frequency of detection showed no correlation with pain upon joint movements or with the X-ray and MRI findings. In the frequency of detection of IL-6, there were significant differences between control (no detection) and all chronic TMJ disorder groups that were classified by imaging diagnosis (P < 0.001). A correlation was also noted between the presence of IL-6 and pain upon joint movements. The IL-6 level was correlated with the TIMP-1 level and with pain upon joint movements. TIMP-1 level was correlated with pain upon joint movements. The TIMP-1 was present in higher level from patients with chronic TMJ disorders who exhibited osseous changes on the X-ray images.

CONCLUSION

The results indicated that the IL-6 and TIMP-1 levels in the TMJ aspirates of patients with chronic TMJ disorders have been raised. The former was not detected in the TMJ aspirates of the control. These findings suggest that IL-6 and TIMP-1 might play a role in the etiology of chronic TMJ disorders, but further studies are needed to validate this.

Rosiglitazone decreases serum bone-specific alkaline phosphatase activity in postmenopausal diabetic women

OBJECTIVES

Our objectives were to evaluate the effect of rosiglitazone on bone metabolism and to assess the association between changes in bone turnover parameters and plasma cytokine levels in postmenopausal diabetic women.

DESIGN

This was a 12-wk open-label randomized-controlled trial.

PATIENTS OR OTHER PARTICIPANTS

A total of 56 obese postmenopausal women with newly diagnosed diabetes and 26 nondiabetic healthy controls matched for age and body mass index were included in the study.

INTERVENTIONS

The subjects were instructed to follow a weight-maintenance diet. Half were randomly assigned to receive rosiglitazone 4 mg/d, and the other half remained on diet alone.

MAIN OUTCOME MEASURES

Before and after the interventions, metabolic bone markers and serum cytokine levels were assessed.

RESULTS

Serum total alkaline phosphatase (ALP) and bone-specific ALP levels were statistically significantly lower 12 wk after initiation of rosiglitazone treatment. There were no statistically significant changes in osteocalcin levels among the three groups or in deoxypyridinoline levels in the rosiglitazone group. At the end of 12 wk, all patients had statistically significantly decreased IL-1beta and TNF-alpha levels compared with baseline. Changes in bone-specific ALP levels showed a moderate negative correlation with the changes in the TNF-alpha levels after rosiglitazone treatment and after diet in the diabetic control group.

CONCLUSIONS

Rosiglitazone use is associated with reduced bone formation at earlier stages in postmenopausal diabetic women. The cytokine-lowering effects of rosiglitazone and lifestyle changes could reverse the early inhibitory effect of rosiglitazone therapy on bone formation. Further studies will clarify the long-term effects of rosiglitazone therapy on bone loss and fracture.

Induction of inflammatory cytokines by cartilage extracts

Shark cartilage extracts were examined for induction of cytokines and chemokines in human peripheral blood leukocytes. Primary leukocyte cultures were exposed to a variety of aqueous and organic extracts prepared from several commercial brands of shark cartilage. From all commercial sources of shark cartilage tested the acid extracts induced higher levels of TNFalpha than other extracts. Different commercial brands of shark cartilage varied significantly in cytokine-inducing activity. TNFalpha induction was seen as early as 4 h and IFNgamma at detectable levels for up to four days. Shark cartilage extracts did not induce physiologically significant levels of IL-4. Results suggest that shark cartilage, preferentially, induces Th1 type inflammatory cytokines. When compared to bovine cartilage extract, collagen, and chondroitin sulfate, shark cartilage induced significantly higher levels of TNFalpha. Treatment with digestive proteases (trypsin and chymotrypsin) reduced the cytokine induction response by 80%, suggesting that the active component(s) in cartilage extracts is proteinaceous. The induction of Th1 type cytokine response in leukocytes is a significant finding since shark cartilage, taken as a dietary supplement for a variety of chronic degenerative diseases, would be contraindicated in cases where the underlying pathology of the chronic condition is caused by inflammation.

Depressive symptoms and production of proinflammatory cytokines by peripheral blood mononuclear cells stimulated in vitro

One potential pathway by which depression may impact health is through modulation of immune function. Depressed individuals have been shown to display reductions in measures of cellular immune competence as well as elevated markers of systemic inflammation. The current study assessed the in vitro production of proinflammatory cytokines IL-6, IL-1beta, and TNF-alpha by peripheral blood mononuclear cells (PBMCs) in response to mitogen stimulation within a community-based sample of 79 midlife women. Results indicate that midlife women with higher levels of depressive symptoms (as assessed with the Center for Epidemiologic Studies Depression scale) and greater body mass index (BMI) displayed diminished production of IL-6, IL-1beta, and TNF-alpha by stimulated PBMCs, as compared with their less-depressed counterparts. These relationships remained after controlling for such health-related variables as age, recent sleep disruption, physical activity level, and self-reported medical history. In contrast, depressive symptoms were not significantly associated with circulating levels of the same proinflammatory cytokines (IL-6, IL-1beta, and TNF-alpha) obtained from serum samples available for a subset of 62 of the study participants. Moreover, circulating proinflammatory cytokine levels were not significantly associated with the in vitro proinflammatory cytokine production outcomes. Further research is needed to clarify the clinical significance of the current study findings, and the extent to which in vitro tests of stimulated proinflammatory cytokine production are associated with other measures of cellular immune function and/or circulating markers of systemic inflammation obtained across various study populations.

Effect of multiple micronutrient supplementation during pregnancy on inflammatory markers in Nepalese women

BACKGROUND

Multiple micronutrient supplementation of Nepalese women during pregnancy is associated with a significant increase in birth weight.

OBJECTIVE

We tested the hypothesis that improved birth weight in infants of mothers supplemented with micronutrients is associated with a decrease in inflammatory responses and an increase in the production of T helper 1 cells and T helper 2 cells.

DESIGN

The study was embedded in a randomized controlled trial of 15 micronutrients, compared with iron-folate supplementation (control), given during pregnancy with the aim of increasing birth weight. Blood samples were collected at 32 wk of gestation, 12-20 wk after supplementation began, for the measurement of inflammatory markers. Breast-milk samples were collected 1 mo after delivery for the measurement of the ratio of milk sodium to potassium (milk Na:K). In an opportunistically selected subgroup of 70 women, mitogen-stimulated cytokine production was measured ex vivo in whole blood.

RESULTS

Blood eosinophils; plasma concentrations of the acute phase reactants C-reactive protein, alpha(1)-acid glycoprotein (AGP), neopterin, and ferritin; milk Na:K; and the production of interleukin (IL) 10, IL-4, interferon gamma, and tumor necrosis factor alpha in whole blood did not differ significantly between the supplemented and control groups. Plasma C-reactive protein and AGP were higher in women who had a preterm delivery, and AGP was higher in women who delivered a low-birth-weight term infant than in women who delivered a normal-birth-weight term infant.

CONCLUSIONS

The results indicate an association between systemic inflammation in late pregnancy and compromised delivery outcome in Nepalese women but do not support the hypothesis that multiple micronutrient supplementation changes cytokine production or inflammatory markers.

Patterns of serum type 1 and type 2 immune markers in healthy carriers of HTLV-I

Type 1 immunity appears to be diminished in healthy Japanese carriers of human T-lymphotropic virus type I (HTLV-I), but type 2 status remains undetermined. To further examine the subclinical effect of HTLV-I on host immunity, we measured serum antibodies to the Epstein-Barr virus (EBV) in 415 healthy Japanese adults to broadly characterize type 1 status. Levels of the type 2 biomarkers total immunoglobulin E (IgE), soluble CD23 (sCD23), and soluble CD30 (sCD30) were assessed in 167, 142, and 135 of these subjects, respectively. We analyzed the association of HTLV-I with levels of each serum marker using linear and logistic regression. Altered EBV antibody profiles that are consistent with deficient type 1 immunity were more prevalent in HTLV-I carriers than non-carriers (odds ratio (OR) = 2.8, 95% confidence interval (CI) = 1.5-5.3). Carriers also had 45% lower total IgE levels (P = 0.04) than non-carriers. In contrast, HTLV-I infection was not significantly associated with elevated levels of sCD23 or sCD30. These observations are contrary to our expectation of elevated type 2 biomarkers among carriers. We conclude that in this population, healthy carriers of HTLV-I may have subclinical deficiencies in both type 1 and type 2 immunity, and that type 1 and type 2 immunity are not necessarily reciprocal in persons with subclinical immune dysregulation.

Levels of gastrin-releasing peptide and substance P in synovial fluid and serum correlate with levels of cytokines in rheumatoid arthritis

It is well known that cytokines are highly involved in the disease process of rheumatoid arthritis (RA). Recently, targeting of neuropeptides has been suggested to have potential therapeutic effects in RA. The aim of this study was to investigate possible interrelations between five neuropeptides (bombesin/gastrin-releasing peptide (BN/GRP), substance P (SP), vasoactive intestinal peptide, calcitonin-gene-related peptide, and neuropeptide Y) and the three cytokines tumour necrosis factor (TNF)-α, IL-6, and monocyte chemoattractant protein-1 in synovial fluid of patients with RA. We also investigated possible interrelations between these neuropeptides and soluble TNF receptor 1 in serum from RA patients. Synovial fluid and sera were collected and assayed with ELISA or RIA. The most interesting findings were correlations between BN/GRP and SP and the cytokines. Thus, in synovial fluid, the concentrations of BN/GRP and SP grouped together with IL-6, and SP also grouped together with TNF-α and monocyte chemoattractant protein-1. BN/GRP and SP concentrations in synovial fluid also grouped together with the erythrocyte sedimentation rate. In the sera, BN/GRP concentrations and soluble TNF receptor 1 concentrations were correlated. These results are of interest because blocking of SP effects has long been discussed in relation to RA treatment and because BN/GRP is known to have trophic and growth-promoting effects and to play a role in inflammation and wound healing. Furthermore, the observations strengthen a suggestion that combination treatment with agents interfering with neuropeptides and cytokines would be efficacious in the treatment of RA. In conclusion, BN/GRP and SP are involved together with cytokines in the neuroimmunomodulation that occurs in the arthritic joint.

Synovial tissue interleukin-18 expression and the response to treatment in patients with inflammatory arthritis

OBJECTIVE

To measure synovial tissue interleukin-18 (IL-18) expression in patients with inflammatory arthritis, and to identify associations with serum levels, disease activity, and response to treatment.

METHODS

Synovial tissue biopsies and serum samples were obtained from patients with early, active, rheumatoid arthritis (RA) (n = 12), undifferentiated seronegative arthritis (SnA) (n = 9), psoriatic arthritis (PsA) (n = 5), and reactive arthritis (ReA) (n = 2) before and one year after introduction of disease modifying antirheumatic drug (DMARD) treatment. Osteoarthritis (OA) tissues were compared. Tissue IL-18 expression was determined after immunohistochemical staining using a semiquantitative scale. Serum IL-18 was measured by enzyme linked immunosorbent assay.

RESULTS

Before treatment was started, tissue IL-18 expression was increased in each diagnostic group compared with OA (p<0.05). Tissue IL-18 expression was correlated with serum C reactive protein levels (r = 0.53, p = 0.003) but not with serum IL-18. After DMARD treatment, 12 patients (five RA, four SnA, three PsA) were re-evaluated. Decreases in tissue IL-18 expression were observed in eight, although the trend did not reach significance (p = 0.068). Changes in tissue IL-18 expression were correlated with changes in serum IL-18 (r = 0.62, p = 0.041) and C reactive protein (r = 0.72, p = 0.009).

CONCLUSIONS

Synovial tissue IL-18 expression was correlated with disease activity in inflammatory arthritis. After treatment, tissue levels changed in parallel with changes in serum IL-18 and with changes in the acute phase response. These observations support a role for IL-18 in the pathophysiology of inflammatory arthritis.

Serologic Assessment of Type 1 and Type 2 Immunity in Healthy Japanese Adults

We assessed the informativeness of several serologic biomarkers of immune function using serum specimens collected in the Miyazaki Cohort Study from subjects who were seronegative for anti–human T-cell lymphotrophic virus I and anti–hepatitis C virus. To broadly characterize type 1 immune status, we measured EBV antibody titers, because titer profiles associated with cellular immune suppression are well described. We also tested for three type 2 biomarkers: total serum IgE, soluble CD23, and soluble CD30. Nonreactivity to a tuberculin purified protein derivative (PPD) skin test is indicative of diminished delayed-type hypersensitivity (type 1) responsiveness in the study population due to a history of tuberculosis exposure or Bacillus Calmette-Guérin vaccination. We therefore evaluated the serologic markers as predictors of PPD nonreactivity using logistic regression. Subjects whose EBV antibody profiles were consistent with deficient type 1 immunity were more than thrice as likely to be PPD nonreactive as persons with “normal” antibody titers. Elevated total IgE was also strongly associated with PPD nonreactivity (odds ratio 3.4, 95% confidence interval 1.2-9.9); elevated soluble CD23 had a weaker, but positive, odds ratio, whereas soluble CD30 levels were not predictive of PPD status. Therefore, PPD nonreactivity is associated, in this population, with a pattern of serum biomarkers that is indicative of diminished type 1 and elevated type 2 immunity. We conclude that, with the exception of soluble CD30, the serologic markers are informative for the characterization of type 1/type 2 immune status using archived sera from study populations of healthy adults.

Comparison of cytokine level in synovial fluid between successful and unsuccessful cases in arthrocentesis of the temporomandibular joint

PURPOSE

The aim of this study was to compare proinflammatory cytokine levels between successful cases and unsuccessful cases of arthrocentesis in patients with internal derangement of the temporomandibular joint (TMJ).

PATIENTS AND METHODS

This study involved 73 joints judged as successful and 30 judged as unsuccessful of 103 joints in 100 patients diagnosed with internal derangement of the TMJ and who underwent arthrocentesis. The diluted synovial fluid before undergoing arthrocentesis was aspirated from the superior joint space. The concentrations of interleukin (IL)-1beta, tumor necrosis factor-alpha, IL-6, and IL-8 were measured using an enzyme-linked immunosorbent assay. The differences in the detection rate and concentration of each cytokine between successful cases and unsuccessful cases were analyzed statistically.

RESULTS

There was a statistically significant difference between successful cases (72.2%) and unsuccessful cases (95.5%) in the detection ratio of IL-6 (P <.05). There was a statistically significant difference between successful cases (0.017 pg/100 microg protein) and unsuccessful cases (0.046 pg/100 microg protein) in the concentration of IL-1beta (P <.05).

CONCLUSION

It has been shown that the presence of IL-1beta and IL-6 in synovial fluid may be indicators of possible unsuccessful treatment following arthrocentesis for internal derangement of the TMJ.

Immunosuppression and oxidative stress induced by acute and chronic exposure to cocaine in rat

The objective of the present study was to verify if immunosuppression caused by cocaine (CO) can be mediated, at least in part, by increased formation of oxidative metabolites and reactive oxygen species (ROS) in rat. Pharmacokinetics of cocaine and its metabolites, cell-mediated immune function and cytokines production, biomarkers of cell redox state maintenance and lipidic peroxidation, and variations of activity in the enzymatic systems involved in cell antioxidant defence were measured in spleen of Wistar rats acutely and chronically treated with cocaine.C(max), AUC, and t(1/2) of norcocaine (NC) significantly increased after chronic exposure to cocaine while kinetic parameters of benzoylecgonine (BE) significantly decreased. A decrease in cultured T-lymphocytes proliferation and natural killer (NK) cell activity, a high increase of immunosuppressive cytokines and a switch from Th1-type cytokines to Th2-type cytokines together with an unbalance toward anti-inflammatory cytokines recovered within 4 h after acute treatment while subsisted for 14 days after chronic treatment. A significant increase in ascorbic acid (AA), reduced glutathione and glutathione reductase (GR) with a simultaneous decrease in oxidized glutathione were observed in the first hours after acute administration. Conversely, the increase in oxidized glutathione and malondialdehyde (MDA) production and the simultaneous depletion of reduced glutathione and ascorbic acid persisted at least 24 h after chronic cocaine treatment as well as the increase in the activities of glutathione reductase, glutathione peroxidase (GPx) and superoxide dismutase (SOD). The results suggest that chronic cocaine administration affects cellular enzyme and non-enzyme-mediated antioxidant defence systems and promotes immunotoxicity in rat. Cocaine N-oxidative metabolism may be an indirect contributor, via oxidative stress.

Proinflammatory cytokines and arthroscopic findings of patients with internal derangement and osteoarthritis of the temporomandibular joint

This study investigated the correlations between the concentrations of proinflammatory cytokines in synovial fluid and the degree of synovitis on the one hand, and the degree of degeneration of articular cartilage on the other hand, in patients with internal derangement and osteoarthritis of the temporomandibular joint. We measured the concentrations of interleukin-1beta (IL-1beta), tumour necrosis factor-alpha (TNF-alpha), IL-6 and IL-8 in synovial fluid and the degree of arthroscopic synovitis and degeneration of articular cartilage in 37 joints with internal derangement and osteoarthritis. The correlations between the concentration of each cytokine and the score of each arthroscopic feature were analysed statistically. The detection rates of IL-1beta,TNF-alpha, IL-6 and IL-8 were 57%, 78%, 89% and 70%, respectively. There was a positive correlation between the IL-6 concentration and the synovitis score (P = 0.02). Measurement of IL-6 in synovial fluid might be useful as an indicator of the extent of synovitis.

Multiplexed fluorescent bead-based immunoassays for quantitation of human cytokines in serum and culture supernatants

BACKGROUND

An increasing volume of data suggests a relationship between cytokine levels in human body fluids and disease pathogenesis. Traditionally, many individual assays would be performed to measure the large number of known cytokines and determine their associations with disease. A new technique for the simultaneous measurement of multiple cytokines in cell culture supernatants by fluorescent microsphere-based flow cytometry was adapted to human sera.

METHODS

Multiplexed sandwich immunoassays for eight cytokines were developed by coupling cytokine-specific capture antibodies to beads with different emission spectra. The binding of biotinylated detection antibodies bound with a streptavidin-conjugated fluorochrome was analyzed. Recovery of "spiked" cytokines, sensitivity, and variability of the assays were evaluated. In addition, the results of the bead assays were compared with the results of commercial enzyme-linked immunosorbent assays (ELISAs) that used the same antibody pairs.

RESULTS

Correlations of the bead assays and the ELISAs were 0.974 (n = 18) for supernatant samples and 0.859 (n = 28) for serum samples. High, false-positive values observed with some sera, assumed to be produced by heterophilic antibodies, were reduced by preincubation with a cocktail of animal sera.

CONCLUSIONS

Fluorescent bead-based immunoassays can be used to quantitate multiple cytokines in human sera and contribute to an understanding of the role of cytokines in disease processes. This methodology is applicable to many combinations of purified analytes and high-affinity antibodies. Published 2001 Wiley-Liss, Inc.

The functions of cytokines and their uses in toxicology

Cytokines are critical controllers of cell, and hence tissue, growth, migration, development and differentiation. The family includes the inflammatory cytokines such as the interleukins and interferons, growth factors such as epidermal and hepatocyte growth factor and chemokines such as the macrophage inflammatory proteins, MIP-1alpha and MIP-1beta. They do not include the peptide and steroid hormones of the endocrine system. Cytokines have important roles in chemically induced tissue damage repair, in cancer development and progression, in the control of cell replication and apoptosis, and in the modulation of immune reactions such as sensitization. They have the potential for being sensitive markers of chemically induced perturbations in function but from a toxicological point of view, the detection of cytokine changes in the whole animal is limited by the fact that they are locally released, with plasma measures being generally unreliable or irrelevant, and they have short half lives which require precise timing to detect. Even where methodology is adequate the interpretation of the downstream effects of high, local concentrations of a particular cytokine is problematic because of their interdependence and the pleiotropism of their action. A range of techniques exist for their measurement including those dependent upon antibodies specific for the respective cytokines, but with the introduction of genomic and proteomic technology, a more complete study of cytokine changes occurring under the influence of chemical toxicity should be possible. Their further study, as markers of chemical toxicity, will undoubtedly lead to a greater understanding of how synthetic molecules perturb normal cell biology and if, and how, this can be avoided by more intuitive molecular design in the future.

Cellular and cytokine responses in the circulation and tissue reactions in the lung of rhesus monkeys (Macaca mulatta) pretreated with cyclosporin A and challenged with staphylococcal enterotoxin B

Cyclosporin A (CsA), an inhibitor of T cell cytokine production, protects mice against staphylococcal enterotoxin B (SEB) intoxication. To determine whether CsA treatment would work in a species closer to humans. 4 rhesus monkeys were given 50 mg/kg CsA followed by an intratracheal challenge with approximately 6 LD50 of SEB. The CsA was not protective: one of the monkeys died and the other three had to be euthanised when they became moribund. All monkeys made IL-2, TNF, and IFN-gamma in response to SEB. In addition, there was about a 10-fold increase in ACTH levels 2 hr after SEB challenge. CsA significantly suppressed in vitro proliferation of lymphocytes from treated monkeys. Both CsA-treated monkeys and monkeys that had been challenged in a previous experiment with a lethal dose of SEB but had received no cyclosporin had pathologic changes in several organs. The most prominent changes were marked edema and leukocytic infiltration of the bronchial and bronchiolar mucosa. The CsA treatment appeared to reduce the intensity of lung inflammation, but this effect was not sufficient to protect the monkeys. The results suggest that CsA alone may not be an effective therapeutic agent for humans suffering from SEB intoxication or gram-positive septic shock.

Quantification of immunoglobulins and cytokines in human cervical mucus during each trimester of pregnancy

OBJECTIVES

Our aims were to determine immunoglobulin and cytokine levels in cervical mucus obtained from women during each trimester of pregnancy and to compare these levels with those reported in normally menstruating women and in women taking oral contraceptives.

STUDY DESIGN

Cervical mucus samples were collected at specified intervals from 36 pregnant women. An enzyme-linked immunosorbent assay was used to quantitate the presence of immunoglobulins A and G and interleukins 1 beta, 6, and 10 in cervical mucus.

RESULTS

Immunoglobulin A in cervical mucus remained stable during each trimester of pregnancy (26 mg/dL). Cervical mucus immunoglobulin G decreased from a first-trimester high of 44.4 mg/dL to lower levels in the second and third trimesters. Levels of interleukin 1 beta increased significantly from the first trimester (4261 pg/mL) to 12,899 pg/mL in the second trimester (P <.01).

CONCLUSION

These data suggest a possible correlation of reproductive hormones and immunologic factors in the female reproductive tract during pregnancy.

The increase of IFN-gamma production through aging correlates with the expanded CD8(+high)CD28(-)CD57(+) subpopulation

The use of flow cytometry to detect intracellular cytokines at the single cell level has the potential to quantify cytokine production together with the possibility of phenotypic identification of the cell population concerned. The unbalanced presence of intracellular cytokines produced by T cells has been recognized in some pathological conditions. To better address this issue, we studied the production of IFN-gamma and IL-4 in CD4(+) and CD8(+high) T cells in healthy donors of a broad range of age (17-62 years). Given that an increase of IFN-gamma and IL-4 with aging had been reported by some authors in healthy controls, we have performed a multivariate analysis to assess the intrinsic role of aging or of other external factors, such as chronic antigenic exposures (i.e., viruses), over the cytokine production of phenotypically characterized T cells. In this respect we show that, mainly in CD8(+high) T cells, the production of IFN-gamma is directly correlated with age. Besides, the cytokine production correlates with the CD8(+high)CD28(-)CD57(+) T-cell population, which we have recently reported elevated in aged individuals. Perhaps this T-cell subpopulation plays a regulatory role as a Tc1 response in aging individuals.

Pharmacokinetics and cytokine production in heroin and morphine-treated mice

The parallelism between serum levels of heroin and morphine (M) metabolites and the production of interleukin-1beta (IL-1beta), interleukin-2 (IL-2), interleukin-10 (IL-10), tumor necrosis factor alpha (TNF-alpha), transforming growth factor-beta1 (TGF-beta1), and interferon-gamma (IFN-gamma) from murine splenocyte cultures following s.c. injection with 20 mg/kg heroin or M in C57/BL mice is described. The pharmacokinetic profiles of M and inactive morphine-3-glucuronide (M3G) in morphine-treated mice nearly overlapped those in heroin-treated mice, with the only difference being the presence of 6-monoacetylmorphine (AM) in profiles of the latter group. Heroin and M significantly increased production of IL-1beta, IL-2, TNF-alpha and IFN-gamma at 3, 20 and 40 min from treatment, peaking at 20 min, though the effect was very brief. At 24 h production was greatly inhibited, and this depressive effect lasted longer than the stimulatory effect. At 48 h only a partial recovery was observed. Heroin and M also had a highly stimulatory effect on the release of anti-inflammatory cytokines such as TGF-beta1 and IL-10, though this effect was observed after 120 min, peaking at 24 h and then somewhat decreasing at 48 h. This study demonstrates that the more rapid and pronounced immune response to heroin treatment was due to the presence of AM. Both heroin and M produced a biphasic effect on cytokine production: the central opioid or non-opioid receptors are involved in exogenous opiod-induced stimulatory effects, whereas peripheral opioid or non-opioid receptors are involved in depressive effects. Deficient or excess expression of these key mediators may predispose the host to aberrant defence mechanisms.

Tumor necrosis factor-alpha in synovial fluid and plasma from patients with chronic connective tissue disease and its relation to temporomandibular joint pain

PURPOSE

The purpose of this study was to determine the level of tumor necrosis factor-alpha (TNF-alpha) in the temporomandibular joint (TMJ) synovial fluid (SF-TNF-alpha) and blood plasma (P-TNF-alpha) of patients with chronic inflammatory connective tissue disease and investigate its relation to TMJ pain, hyperalgesia, and allodynia.

PATIENTS AND METHODS

Twenty-four patients with a diagnosis of chronic inflammatory connective tissue disease and TMJ pain were included in the study. Visual analog scale, tenderness of the TMJ, and pain at mandibular movements were registered, and the pressure pain threshold and pressure pain tolerance levels were measured. TMJ synovial fluid samples and blood plasma were analyzed for TNF-alpha and the levels related to TMJ pain, hyperalgesia, and allodynia.

RESULTS

TNF-alpha was present in the TMJ synovial fluid of 8 of 24 patients at levels significantly exceeding those in plasma at the same visit. The presence of SF-TNF-alpha showed a significant positive correlation to TMJ pain at maximum voluntary mouth opening and tenderness to posterior palpation of the TMJ.

CONCLUSION

Local production of TNF-alpha occurs in the TMJ synovium of patients with chronic inflammatory connective tissue disease. Pain on mandibular movement and tenderness on posterior palpation (allodynia) of the TMJ is related to the level of SF-TNF-alpha.

The clinical usefulness of the measurement of cytokines

The utilization of accurate and sensitive methods for the measurement of cytokines in body fluids is prerequisite for the proper use of these mediators in clinical practice. Many factors contribute to the complexity of cytokine quantitation. Bioassays historically preceded immunoassays, which are now very popular, but there is a need for standardization. Nevertheless, due to the local effects of cytokines, the study of their blood levels is of limited value for an understanding of the pathophysiology of these mediators. This explains the development of alternative approaches to assess the ability of cells to produce cytokines. These include the Enzyme-Linked Immuno Spot Assay (ELISPOT), the measurement of cell-associated cytokines by flow cytometry, and the study of cytokine secretion by isolated peripheral blood mononuclear cells or by whole blood test. All these techniques, associated with a local detection of cytokines by immunohistochemistry or in situ hybridization and reverse transcriptase polymerase chain reaction, appear to be complementary tools for a better understanding of the biology of cytokines. Selected examples of possible clinical applications related to infectious diseases, cancer, autoimmune diseases, allergy, transplantation and preclinical evaluation of drugs and biotechnology products are given.

A method for correcting for the variability of inhibitory effects of soluble human interleukin 1 receptor II measured by different ELISAS

Seven ELISAs were developed by using several combinations of anti-human IL-1beta antibodies for detecting interleukin 1beta (IL-1beta) in cell culture supernatants. These ELISAs have different sensitivities in detecting standard preparations of recombinant human IL-1beta (WHO reference standard) compared with conventional preparations of IL-1beta produced by stimulated human peripheral blood mononuclear cells. The observed differences were attributed to differences in epitope specificity of the various monoclonal antibodies used and the heterogeneity of IL-1beta secreted into culture supernatants. The presence of soluble IL-1 receptor type I did not alter the levels of IL-1beta detected by these ELISAs. However, soluble IL-1 receptor type II interfered with the detection of IL-1beta to different degrees in these ELISAs. A method involving standarization by means of separate measurement of the amount of receptor and its inhibitory effect in the IL-1beta ELISA, yields consistent estimates of the correct IL-1beta levels.

Cytokine flow cytometry differentiates the clinical status of multiple sclerosis (MS) patients

In this study we have examined intracellular cytokines in peripheral blood mononuclear cells (PBMC) of MS patients by flow cytometry (cytokine flow cytometry). MS progressive patients showed an increased number of cells producing interferon-gamma (IFN-gamma) after activation with phorbol 12-myristate 13-acetate and ionomycin, compared with patients with clinically inactive forms (P < 0001) and with healthy controls (P = 0001). These cells belonged to the CD4+ and CD8+ subsets in similar proportions. Clinically inactive patients showed a lower level of cells producing IL-2 than controls (P = 0.03) and active MS patients (P = 0.03). Most IL-2-producing cells were CD4+ lymphocytes, although a small part of the IL-2 was also produced by CD8+ cells. The percentage of cells producing simultaneously IL-2 and IFN-gamma was increased in active MS and they were mainly CD4+ lymphocytes. No differences in the production of IL-4 were observed between groups. However, we found an increased IL-10 production in clinically active MS patients (P = 0.03). Treatment with IFN-beta of active MS patients showed lower levels of cytokines when compared with untreated MS patients. This methodological approach could help in the follow up and therapeutic monitoring of MS patients.

Immunoendocrinology of preterm labor: the link between corticotropin-releasing hormone and inflammation

Preterm labor is the final common pathway after several potential insults to the uterus or fetus. The preterm labor syndrome may be precipitated by several different pathophysiologic events, including intrauterine infection, uterine ischemia, uterine overdistention, hormonal disturbances, and other problems. Intrauterine infections (both clinically evident and subclinical) are associated with increased amniotic fluid concentrations of proinflammatory cytokines, and gestational tissues and the fetus are potential sources of these cytokines. In addition to culture-proven intrauterine infection, there may be an "intrauterine inflammatory response syndrome" that could account for cases of preterm labor in which no infectious organism can be identified. Because the immunologic and endocrinologic systems regulate each other extensively, there is potential for corticotropin-releasing hormone to regulate inflammatory responses and vice versa. The cytokine interleukin 1 stimulates production of corticotropin-releasing hormone, and corticotropin-releasing hormone in turn regulates cytokine production by immune effector cells. Because maternal stress is associated with preterm birth, abnormalities in the regulation of corticotropin-releasing hormone and the production of inflammatory cytokines may be a mechanism that could form the pathophysiologic basis for this association.

Imbalances in serum proinflammatory cytokines and their soluble receptors: a putative role in the progression of idiopathic IgA nephropathy (IgAN) and Henoch-Schönlein purpura nephritis, and a potential target of immunoglobulin therapy?

Following recent experimental data suggesting an aggravating effect of circulating proinflammatory cytokines on the histological lesions of IgAN, we studied changes in serum proinflammatory cytokines and their soluble receptors and antagonists in patients treated with polyvalent immunoglobulins (15 with severe nephropathy who had indicators of poor prognosis: heavy proteinuria, hypertension, altered renal function and Lee's histological grade III or IV; and 14 with moderate forms of IgAN who had permanent albuminuria > 300 mg/day and < 2000 mg/day, Lee's histological grade II and a glomerular filtration rate > 70 ml/min) in comparison with healthy controls (n = 20) and patients with non-IgA nephritides (n = 50). These were measured by means of specific immunometric assays before and after 9 months of immunoglobulin therapy. Total tumour necrosis factor (TNF) serum and IL-6 levels were elevated in IgAN patients before therapy, relative to controls, and normalized after immunoglobulin therapy. Levels of soluble TNF receptor of type I (sR55) and type II (sR75) increased on immunoglobulin therapy. TNF index alpha-55,75 used to assess biologically available TNF-alpha (ratio of total TNF-alpha divided by levels of soluble TNF receptors sR55 and sR75) was elevated before therapy and was below healthy control values after 9 months of immunoglobulin administration. Levels of serum IL-1 receptor antagonist were low prior to immunoglobulin administration in patients with severe forms of IgAN, and normalized on therapy. Serum interferon-gamma was unmodified. The histological activity index correlated with serum total TNF-alpha, TNF index alpha-55,75 and serum IL-6 levels, whereas proteinuria correlated with serum total TNF-alpha and TNF index alpha-55,75 but not with serum IL-6. These data suggest that the overproduction of proinflammatory cytokine is unbalanced by their natural antagonists in IgAN and Henoch-Schönlein syndrome. This process may play a role in the progression of the disease and be one of the targets of immunoglobulin therapy.