Soluble CD163 is a biomarker for accelerated atherosclerosis in systemic lupus erythematosus patients at apparent low risk for cardiovascular disease.

Objective: This study aimed to determine whether sCD163, a soluble macrophage marker up-regulated in numerous inflammatory disorders, is predictive of accelerated atherosclerosis associated with systemic lupus erythematosus (SLE).Methods: Carotid ultrasound was prospectively performed, at baseline and during follow-up, in 63 consecutive SLE patients asymptomatic for cardiovascular disease (CVD) and 18 volunteer health workers. Serum sCD163 level was determined at baseline using enzyme-linked immunosorbent assay. The primary outcome was the presence of a carotid plaque. Factors associated with carotid plaques were identified through multivariate analysis.Results: Despite a low risk for cardiovascular events according to Framingham score in both groups (2.1 ± 3.8% in SLE vs 2.1 ± 2.9% in controls; p = 0.416), ultrasound at baseline showed a carotid plaque in 23 SLE patients (36.5%) and two controls (11.1%) (p = 0.039). Multivariate analysis showed that SLE status increased the risk for carotid plaque by a factor of 9 (p = 0.017). In SLE patients, sCD163 level was high (483.7 ± 260.8 ng/mL vs 282.1 ± 97.5 ng/mL in controls; p < 0.001) and independently associated with carotid plaques, as assessed by stratification based on sCD163 quartile values (p = 0.009), receiver operating characteristics (p = 0.001), and multivariate analysis (p = 0.015). sCD163 at baseline was associated with the onset of carotid plaque during follow-up (3 ± 1.4 years) in SLE patients who had no carotid plaque at the first evaluation (p = 0.041).Conclusion: sCD163 is associated with progressing carotid plaque in SLE and may be a useful biomarker for accelerated atherosclerosis in SLE patients at apparent low risk for CVD.

Role of IGF-I and the TNFα/NF-κB pathway in the induction of muscle atrogenes by acute inflammation.

Several catabolic states (sepsis, cancer, etc.) associated with acute inflammation are characterized by a loss of skeletal muscle due to accelerated proteolysis. The main proteolytic systems involved are the autophagy and the ubiquitin-proteasome (UPS) pathways. Among the signaling pathways that could mediate proteolysis induced by acute inflammation, the transcription factor NF-κB, induced by TNFα, and the transcription factor forkhead box O (FOXO), induced by glucocorticoids (GC) and inhibited by IGF-I, are likely to play a key role. The aim of this study was to identify the nature of the molecular mediators responsible for the induction of these muscle proteolytic systems in response to acute inflammation caused by LPS injection. LPS injection robustly stimulated the expression of several components of the autophagy and the UPS pathways in the skeletal muscle. This induction was associated with a rapid increase of circulating levels of TNFα together with a muscular activation of NF-κB followed by a decrease in circulating and muscle levels of IGF-I. Neither restoration of circulating IGF-I nor restoration of muscle IGF-I levels prevented the activation of autophagy and UPS genes by LPS. The inhibition of TNFα production and muscle NF-κB activation, respectively by using pentoxifilline and a repressor of NF-κB, did not prevent the activation of autophagy and UPS genes by LPS. Finally, inhibition of GC action with RU-486 blunted completely the activation of these atrogenes by LPS. In conclusion, we show that increased GC production plays a more crucial role than decreased IGF-I and increased TNFα/NF-κB pathway for the induction of the proteolytic systems caused by acute inflammation.

Alveolar fibroblasts in acute lung injury: biological behaviour and clinical relevance.

Although fibroblasts are key cells in the lung repair/fibrosis process, their characteristics are poorly studied in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). The aims of our study were to: 1) determine the biological behaviour of alveolar fibroblasts during ALI; and 2) to evaluate the clinical relevance of positive alveolar fibroblast culture from patients with ALI/ARDS. Cells were cultured from bronchoalveolar lavage (BAL) obtained from 68 critically ill, ventilated patients: ALI n = 17; ARDS n = 31; and ventilated controls n = 20. Patients were followed for 28 days and clinical data was recorded. We studied proliferation, migration and collagen-1 synthesis capacities of fibroblasts. Cells expressing fibroblast markers were cultured from BAL obtained in six (35%) ALI patients and six (19%) ARDS patients, but never from ventilated controls. Alveolar fibroblasts exhibited a persistent activated phenotype with enhanced migratory and collagen-1 production capacities, with hyporesponsiveness to prostaglandin E(2) compared to normal lung fibroblasts (p< or =0.04). Positive fibroblast culture was associated with both an increased collagen-1 concentration and monocyte/macrophage percentage in BAL fluid (p< or =0.01), and with a reduced duration of mechanical ventilation (p<0.001). We conclude that activated alveolar fibroblasts can be cultured either in ALI or ARDS and that their presence might reflect the initiation of the organising phase of ALI.

Immunohistochemical study of HLA-G expression in lung transplant recipients.

Human leukocyte antigen-G (HLA-G), a nonclassical HLA class I protein, promotes immune tolerance of solid-organ allografts, yet its role in lung transplantation (LTx) is unknown. We examined the expression of HLA-G in lung allografts through immunohistochemistry by a cross-sectional study of 64 LTx recipients, classified into four groups (stable patients, acute rejection [AR], bronchiolitis obliterans syndrome [BOS] and symptomatic viral shedders). A marked expression of HLA-G in bronchial epithelial cells (BEC) was frequently observed in stable recipients (n = 18/35 [51%]), but not in patients with AR (n = 14) or with BOS (n = 8). HLA-G was also expressed by 4 of 7 symptomatic viral shedders. In addition, HLA-G-positive patients from the stable group (n = 35) experienced lower incidence of resistant AR and/or BOS during long-term follow-up, as compared with their HLA-G-negative counterparts. Finally, in vitro data showed that interferon-gamma, a cytokine present in lung allograft microenvironment, upregulated HLA-G mRNA and protein expression in primary cultured human BEC. We conclude that HLA-G expression in the bronchial epithelium of lung allograft is elevated in some LTx recipients in association with their functional stability, suggesting a potential role of HLA-G as a tolerance marker.

Selenoprotein P, rather than glutathione peroxidase, as a potential marker of septic shock and related syndromes.

BACKGROUND/AIMS: Oxidative stress is involved in sepsis-related endothelium dysfunction. Selenoprotein-P (Sel-P), the main plasma selenoprotein, may have high antioxidant potential, and binds to endothelium. We hypothesize that, in septic shock, and similar syndromes such as systemic inflammatory response syndrome (SIRS), Sel-P binds massively to endothelium, causing a drop in Sel-P plasma concentration. METHODS: Plasma Se, Sel-P and albumin concentrations, and glutathione peroxidase (GPx) activity were measured in patients with septic shock and SIRS with organ failure (S group, n = 7 and n = 3, respectively) admitted to the intensive care unit (ICU) and compared to non-SIRS patients (NS group, n = 11) and healthy volunteers (HV group, n = 7). RESULTS: On ICU admission, plasma Sel-P concentrations were 70% lower in the S group than in the other groups [15 (10-26) vs. 44 (29-71) and 50 (45-53) nmol/l] and were lower in nonsurviving septic-shock patients. GPx activity did not differ between groups. Sel-P was significantly lower before ICU death in the 3 deceased patients of the S group (septic shock) than in the 3 patients of the non-SIRS group. CONCLUSIONS: Early decrease in Sel-P plasma concentrations was specifically observed in septic shock and was similar in SIRS patients whereas GPx activity remained unchanged. Further studies are needed to determine whether Sel-P can be an early marker of septic shock linked to microvascular injury.

Modulation of bleomycin-induced lung fibrosis by serotonin receptor antagonists in mice.

Serotonin (5-hydroxytryptamine; 5-HT) is known to increase proliferation and collagen synthesis by fibroblasts. Two receptor subtypes, 5-HT2A and 5-HT2B, have been shown to play the most important roles in the lung. In the present study, the role of serotonin in lung fibrosis was investigated using the bleomycin mouse model. Serotonin concentrations in lung homogenates increased significantly over the time course of bleomycin-induced fibrosis, with a maximum at day seven. The expression of serotonin receptors 5-HT2A and 5-HT2B increased in the lung after bleomycin treatment, as assessed by PCR, specific binding and immunohistochemistry. Blockage of 5-HT2A receptors by ketanserin and 5-HT2B receptors by SB215505 reduced bleomycin-induced lung fibrosis, as demonstrated by reduced lung collagen content and reduced procollagen 1 and procollagen 3 mRNA expression. Serotonin antagonists promoted an antifibrotic environment by decreasing the lung mRNA levels of transforming growth factor-beta1, connective growth factor and plasminogen activator inhibitor-1 mRNA, but had minimal effects on lung inflammation as assessed by bronchoalveolar lavage cytology analysis. Interestingly, the 5-HT2B receptor was strongly expressed by fibroblasts in the fibroblastic foci in human idiopathic pulmonary fibrosis samples. In conclusion, the present study showed involvement of serotonin in the pathophysiology of bleomycin-induced lung fibrosis in mice and identified it as a potential therapeutic target in lung fibrotic disorders.

Alveolar type II epithelial cells produce interleukin-6 in vitro and in vivo. Regulation by alveolar macrophage secretory products.

The aims of this study were (a) to determine if rat alveolar type II (ATII) cells and human pulmonary epithelial-derived cells (A549 cell line) could generate IL-6 in vitro, (b) to characterize the cytokine regulation of IL-6 gene and protein expression in these cells, and (c) to detect the in vivo expression of immunoreactive IL-6 by human ATII cells. Rat ATII cells in primary culture secreted bioactive IL-6 and immunostained with an anti-IL-6 antiserum. Spontaneous IL-6 secretion by rat ATII cells amounted to 5,690 +/- 770 pg/ml/10(6) cells (n = 12) and was fivefold higher than spontaneous rat alveolar macrophages IL-6 secretion (1,052 +/- 286 pg/ml/10(6) cells, n = 8, P = 0.001). Rat alveolar macrophage conditioned media (CM) increased IL-6 secretion by rat ATII cells through the effect of IL-1 and TNF. IL-6 gene expression and IL-6 secretion by A549 cells was induced by IL-1 beta, TNF alpha, and by human alveolar macrophages and THP1 cells CM. Induction was abolished when CM were preincubated with anti-IL-1 beta and anti-TNF alpha antibody. The combination of IFN gamma and LPS induced the expression of IL-6 mRNA by A549 cells whereas LPS alone had no effect. Immunohistochemical staining evidenced the expression of immunoreactive IL-6 by hyperplastic ATII cells in fibrotic human lung, a condition in which alveolar macrophages are known to be activated. ATII cells in normal human lung did not express immunoreactive IL-6. Our findings demonstrate that ATII cells may be an important source of IL-6 in the alveolar space thereby participating to the regulation of the intra-alveolar immune response.

[The use of cardiac troponins (T or I) measurement in cardiology and various clinical settings]. / Dosage des isoformes cardiaques des troponines T ou I: intérêt en cardiologie et en anesthésie-réanimation.

Measurement of cardiac troponin I or T in serum (highly specific for the myocardium) have replaced classical markers, such as creatine kinase MB. Cardiac troponins are preferred markers because of their high specificity and sensitivity. This had led to modifications of the original World Health Organization criteria for acute myocardial infarction. Furthermore, the place of the troponins as superior markers of subsequent cardiac risk in acute coronary syndrome has now become firmly established, for both diagnostic and risk stratification purposes. The use of C-reactive protein and/or other inflammatory biomarkers may add independent information in this context. After non cardiac surgery, the total cardiospecificity of cardiac troponins explains why other biomarkers of necrosis should no longer be used. Recent studies suggest that any elevation of troponin in the postoperative period is indicative of increased risk of long-term cardiac complications. This prognostic value has been previously demonstrated in other clinical settings such as invasive coronary intervention (surgical myocardial revascularization and percutaneous coronary intervention) and after heart valve surgery. Increases of troponin indicate cardiac damage, whatever the mechanism (ischemic or not). Other causes of cardiac injury include: pulmonary embolism, myocarditis, pericarditis, congestive heart failure, septic shock, myocardial contusion. In most cases, elevation of troponins has been shown to be associated with a bad outcome.

Alteration of mannose transport in fibroblasts from type I carbohydrate deficient glycoprotein syndrome patients.

The aim of the present study was to explore how mannose enters fibroblasts derived from a panel of children suffering from different subtypes of type I carbohydrate deficient glycoprotein syndrome: seven carbohydrate deficient glycoprotein syndrome subtype Ia (phosphomannomutase deficiency), two carbohydrate deficient glycoprotein syndrome subtype Ib (phosphomannose isomerase deficiency) and two carbohydrate deficient glycoprotein syndrome subtype Ix (not identified deficiency). We showed that a specific mannose transport system exists in all the cells tested but has different characteristics with respect to carbohydrate deficient glycoprotein syndrome subtypes. Subtype Ia fibroblasts presented a mannose uptake equivalent or higher (maximum 1.6-fold) than control cells with a D-[2-3H]-mannose incorporation in nascent N-glycoproteins decreased up to 7-fold. Compared to control cells, the mannose uptake was greatly stimulated in subtype Ib (4.0-fold), due to lower Kuptake and higher Vmax values. Subtype Ib cells showed an increased incorporation of D-[2-3H]-mannose into nascent N-glycoproteins. Subtype Ix fibroblasts presented an intermediary status with mannose uptake equivalent to the control but with an increased incorporation of D-[2-3H]-mannose in nascent N-glycoproteins. All together, our results demonstrate quantitative and/or qualitative modifications in mannose transport of all carbohydrate deficient glycoprotein syndrome fibroblasts in comparison to control cells, with a relative homogeneity within a considered subtype of carbohydrate deficient glycoprotein syndrome. These results are consistent with the possible use of mannose as a therapeutic agent in carbohydrate deficient glycoprotein syndrome Ib and Ix.

Secretion of alpha 1-antitrypsin by alveolar epithelial cells.

We have investigated the ability of alveolar epithelial cells (human A549 cell line and rat type-II pneumocytes) to produce alpha 1-antitrypsin (AAT). Northern blot analysis demonstrated the presence of an AAT-specific mRNA transcript in A549 cells. Unstimulated A549 cells secreted immunoreactive AAT at a rate of 0.51 +/- 0.04 ng/10(6) cells/h, with a modified glycosylation compared to serum AAT. AAT formed a complex with neutrophil elastase. Rat type-II pneumocytes secreted immunoreactive AAT. Our results suggest that alveolar epithelial cells could participate in antiprotease defense within the lung through local AAT production.

Patterns of myoglobin and MM creatine kinase isoforms release early after intravenous thrombolysis or direct percutaneous transluminal coronary angioplasty for acute myocardial infarction, and implications for the early noninvasive diagnosis of reperfusion.

Early noninvasive detection of reperfusion after thrombolysis for acute myocardial infarction may enable detection of unsuccessful thrombolysis in time for rescue percutaneous transluminal coronary angioplasty (PTCA). It has been suggested that repeated measurement of myoglobin or of MM creatine kinase (CK) isoforms enables early detection of reperfusion. Twenty consecutive patients with acute myocardial infarction treated by intravenous thrombolysis underwent serial determination of myoglobin, MM3 and MM1 CK isoforms every 30 minutes after the beginning of thrombolysis. At 90 minutes, coronary angiography was performed, enabling classification of patients as with (group A) and without (group B) reperfusion. A third group of 7 patients (group C) underwent direct PTCA without antecedent thrombolysis. In all groups, there were increases in myoglobin, percentage of MM3 isoform, and ratio of MM3/MM1. These increases appeared on the average steeper and faster in group B, but the large dispersion of values in this group resulted in a wide overlap with group A. Retrospective analysis suggests that an increase in the MM3/MM1 ratio > 0.35 after 60 minutes is very specific for reperfusion (sensitivity 60% and specificity 100%). In group C, PTCA always led to a sharp increase in all biochemical parameters measured within 30 minutes. Thus, macromolecular markers can be used for very early, noninvasive detection of reperfusion with a high specificity. This could help reduce the need for emergency angiography to select candidates for rescue PTCA. Furthermore, the patterns of biochemical markers of reperfusion differ when reperfusion is initiated by either thrombolysis or PTCA.

Circulating cytokines in patients undergoing normothermic cardiopulmonary bypass.

To determine the cytokine release during normothermic cardiopulmonary bypass, we have measured plasmatic levels of tumor necrosis factor-alpha and interleukins-1 beta, 6, and 8 in 10 patients during the first 24 hours after the start of bypass. Arterial blood samples were collected at intervals before, during, and after bypass. Interleukin-1 beta was not detectable in the plasma, and traces of tumor necrosis factor-alpha were detected in only three patients at times independent of the cardiopulmonary bypass procedure. Circulating endotoxin remained undetectable. Plasma interleukin-6 and interleukin-8 rose significantly from 2 until 24 hours after the start of bypass (p < 0.05) and peaked respectively at 4 and 2 hours after the beginning of bypass (interleukin-6, 268.1 +/- 131.43 pg/ml; interleukin-8, 370 +/- 420 pg/ml; mean peak +/- standard deviation). Peak values of interleukin-6 and interleukin-8 were correlated neither with the duration of aortic crossclamping or the bypass procedure nor with the hemodynamic parameters recorded at the same times. This study shows that normothermic cardiopulmonary bypass does not induce systemic release of tumor necrosis factor-alpha and interleukin-1 beta. A local production of these cytokines cannot be excluded, because interleukin-6 and interleukin-8 are produced by stimulated macrophages and monocytes in response to tumor necrosis factor-alpha and interleukin-1 beta. Our results, at normothermia, show a similar pattern of interleukin-6 and interleukin-8 release when compared with release during hypothermic cardiopulmonary bypass. Interleukin-8, an important chemotactic neutrophil factor, might play a role in reperfusion injuries observed in lungs and heart after cardiopulmonary bypass.

Early release of proinflammatory cytokines after lung transplantation.

BACKGROUND: Systemic hypotension may complicate the early postoperative period after lung transplantation. A release of proinflammatory cytokines secondary to lung ischemia/reperfusion injury could be involved in the pathogenesis of this early hemodynamic failure (EHF). STUDY OBJECTIVE: To assess prospectively whether the occurrence of EHF is associated with a release of cytokines in the systemic circulation. DESIGN: Blood samples were taken daily during the first postoperative week in 26 patients who underwent a double or a single-lung transplantation. These patients were divided into three groups: 7 patients who experienced EHF and subsequently died (EHF group); 15 patients without EHF (control group); and 4 patients without EHF but with an identified sepsis (sepsis group). The serum levels of interleukin (IL)-1beta, tumor necrosis factor-alpha (TNF-alpha), IL-6, and IL-8 were compared among the three groups. RESULTS: In the EHF group, the levels of each cytokine peaked at day 1 postoperatively. Cytokine levels at day 1 were significantly higher in the EHF group than in the control group (p<0.0006) or in the sepsis group (p<0.003 except for TNF-alpha). CONCLUSION: We conclude that EHF is associated with a massive release of proinflammatory cytokines that could play a determinant role in the pathogenesis of this complication.

IL6 and acute phase plasma proteins in peritoneal fluid of women with endometriosis.

Several authors have documented signs of chronic inflammation in the pelvis of women with endometriosis. We investigated the possible involvement of interleukin 6 (IL6), an important regulator of inflammation and immunity, in minimal and mild endometriosis by measuring levels of IL6 and proteins (alpha 1-acid glycoprotein, alpha 1-antitrypsin, alpha 2-HS glycoprotein and albumin) the synthesis of which is regulated by IL6, in peritoneal fluid (PF) from infertile women with histologically confirmed endometriosis (stage I and II; n = 28) and from endometriosis-free fertile (n = 14) and infertile women (n = 13). Spontaneous and LPS-induced IL6 secretion by cultured PF macrophages from women with endometriosis (n = 12) and without endometriosis (n = 9) were also studied. No significant differences were observed in the concentrations of the four proteins studied. Immunoreactive IL6 was detected in all three groups, with no significant differences. In contrast, significantly higher levels of IL6 were released by both unstimulated (P = 0.01) and LPS-stimulated (P = 0.006) peritoneal macrophages from the women with endometriosis. We conclude that local IL6 synthesis by activated macrophages may play a role in the endometriosis process.

Comparison of enhanced chemiluminescence and colorimetric techniques for the immuno-detection of alpha 1-antitrypsin.

In order to detect, characterize and quantify blotted proteins, such as human alpha 1-antitrypsin (AAT), there is a need for a specific, extremely sensitive, non-radioactive and uniform revelation system applicable to diluted biological fluids and to culture supernatants of cells isolated from such fluids. We compared two immunochemical revelation systems, enhanced chemiluminescence (ECL) and colorimetric procedures, applied to human ATT, after determining their optimal conditions of performance. ECL was the most sensitive method (down to 50 pg blotted AAT), but could not be used to quantify AAT. In contrast, the colorimetric method enables quantification of blotted AAT, either simply dotted or transferred after SDS-polyacrylamide gel electrophoresis, but is not as sensitive as ECL. Using these two complementary procedures, we have been able to detect AAT in the culture supernatant of a monocytic cell line (THP-1), to characterize the different forms of AAT present in the culture supernatant of blood monocytes and to quantify both.

Utility of cardiac troponin measurement after cardiac surgery.

Postoperative cardiac failure due to myocardial necrosis remains a major complication in cardiac surgical procedures and its diagnosis is still difficult. In fact, cardiac enzymes, electrocardiogram and echographic signs are often misleading. The prognostic valve of troponin I after coronary artery bypass or conventional value surgery has been evaluated in 500 adult patients. Postoperative troponin I concentrations after cardiac surgery represent an independent variable associated with mortality (in-hospital death) and morbidity (low cardiac output and acute renal failure).

Is maternal serum creatine kinase actually a marker for early diagnosis of ectopic pregnancy?

OBJECTIVE: Our purpose was to investigate whether serum creatine kinase (CK) levels could be used as an early marker of ectopic pregnancy. Student's t-test was used for statistical analysis. STUDY DESIGN: In a prospective study we therefore measured serum progesterone, beta hCG and CK levels in 30 women with ectopic pregnancies, 30 women with ongoing pregnancies and 30 women with missed abortion. RESULTS: The mean serum CK concentration for patients with an ectopic pregnancy, ongoing pregnancy, and the women with missed abortion was 81.4 +/- 66.2, 81.5 +/- 40.3, 84.8 +/- 49.3, respectively. No relationship was found between CK level and the location of the pregnancy. CONCLUSION: Conversely to the first report of Lavie et al. (Am J Obstet Gynecol 1993; 169: 1149), our data suggest that serum CK level is not discriminative in the early diagnosis of tubal pregnancy.

[Keratinocyte growth factor and Hepatocyte growth factor: their roles in alveolar epithelial repair]. / Keratinocyte growth factor et Hepatocyte growth factor: rôles dans la réparation épithéliale alvéolaire.

INTRODUCTION: The alveolar epithelium is the principal target in the course of acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) and to a lesser extent in chronic reactions like pulmonary fibrosis. STATE OF ART: Keratinocyte growth factor (KGF) and Hepatocyte growth factor (HGF) are potent growth factors for type II pneumocytes and seem to play a specific role in the process of alveolar repair. PERSPECTIVES: The studies conducted by our group have demonstrated 1) that KGF and HGF are present in biologically active concentrations in human pulmonary alveoli in ALI and ARDS, 2) that in these patients as well as those with pulmonary fibrosis circulating neutrophils are an important source of HGF. HGF and KGF act within a system involving other factors such as parathyroid hormone related protein (PTHrP). PTHrP acts in an autocrine and paracrine manner to regulate the balance between proliferation and apoptosis of alveolar epithelial cells. CONCLUSIONS: Our results obtained in humans suggest a beneficial role for neutrophils in the alveolar repair after acute or chronic lung injury. The experimental data suggest that use of KGF and HGF might be considered in the future in the treatment of human acute or chronic lung injury.

Pituitary-adrenal function after prolonged glucocorticoid therapy for systemic inflammatory disorders: an observational study.

CONTEXT: Glucocorticoid therapy is being used in a wide variety of systemic disorders. Reference papers, published more than 20 years ago, showed no correlation between adrenal insufficiency risk and dose or duration of glucocorticoid therapy. OBJECTIVE: Our objective was to evaluate the extent to which long-term glucocorticoid therapy damages the pituitary-adrenal axis in patients with systemic inflammatory disorders. DESIGN: We conducted a retrospective observational study from January 2011 to August 2012. SETTING: This was a monocentric study at the Department of Internal Medicine, Bichat Hospital, Paris-Diderot University, Paris, France. PARTICIPANTS: Sixty consecutive patients who were receiving long-term prednisone therapy for systemic inflammatory disorders and in whom discontinuation of glucocorticoid treatment was planned. INTERVENTION: A short Synacthen test was performed. A bolus of 0.25 mg 1-24-ACTH was injected in the morning, 24 hours after the most recent dose of prednisone. Cortisol was measured at baseline and 60 minutes after Synacthen injection. MAIN OUTCOME MEASURES: We assessed frequency and risk estimate of pituitary-adrenal dysfunction. RESULTS: Twenty-nine patients (48.3%) had adrenal insufficiency defined by a plasmatic cortisol <100 nmol/L (n = 13) at baseline (time 0) or <550 nmol/L (n = 16) 60 minutes after Synacthen injection. Cumulative dose (area under the receiver operating characteristic curve = 0.77 [95% confidence interval = 0.62-0.91], P = .007) and exposure (area under the receiver operating characteristic curve 0.80 [95% confidence interval = 0.67-0.93], P = .002) to prednisone were predictive for adrenal insufficiency based on a T0 <100 nmol/L. Prednisone was stopped in 29 of 31 patients (93.5%) showing a normal response to short Synacthen test; none of these patients required hydrocortisone replacement with a mean follow-up of 10 (± 6) months. CONCLUSION: Adrenal insufficiency is frequent in patients treated with long-term glucocorticoids for systemic inflammatory disorders and is related to duration and cumulative dose of steroids.