Lewis and AB0 blood group-phenotypes in periodontitis, cardiovascular disease, obesity and stroke

The AB0 blood group has been linked to ischaemic heart disease, stroke, and periodontal disease, while the Lewis blood group has been linked to ischaemic heart disease and obesity, all of which have been associated with periodontitis. AB0 or Lewis blood group phenotype may therefore constitute common hereditary components predisposing to these disorders. In this study, we investigated if blood group phenotype associated with periodontitis in a subpopulation consisting of 702 participants from a Danish cross-sectional cohort and, secondarily, attempted to confirm their association with hypertension, ischaemic heart disease, stroke, and obesity. No significant association between blood group phenotype and periodontitis was detected, nor were previously reported associations between blood group phenotype and hypertension, ischaemic heart disease, stroke, and obesity confirmed. This may, at least partly, be attributed to differences in study type, outcome definitions, cohort sizes, and population attributable factors. However, our results suggested a strong association between self-reported stroke and the Lewis (a−b−) phenotype (P = 0.0002, OR: 22.28; CI 95: 4.72–131.63).

An Unusual Case of Multiple Malignancy in an Adult

An adult female is described who, during a clinical course of 25 years, presented malignant tumors of the rectum, breast, uterus and colon. Cytostatics were never administered. Lymphocyte subsets, a variety of lymphocyte and mononuclear cell stimulation assays with mitogens and antigens, DNA repair tests and activity of natural killer cells were normal. Serum leukocytic interleukin-1 activity was slightly elevated. Sister chromatid exchange frequency in peripheral lymphocytes was below the normal range. An explanation for the development of 4 primary malignant neoplasms was not found.

Measuring and evaluating interferon b-induced antibodies in patients with multiple sclerosis

Author for correspondence: Klaus Bendtzen, Institute for Inflammation Research IIR 7521, Rigshospitalet University Hospital, 9 Blegdamsvej, DK-2100 Copenhagen, Denmark. E-mail: address: kben@mail.dk Administration of interferons (IFNs) may induce antibodies that interfere with therapeutic efficacy. We have optimized and validated methods for large-scale economic screening. Sera from patients with relapsing-remitting multiple sclerosis (MS) were investigated for binding antibody (BAb) by protein-G affinity-chromatography radioimmunoassay and a commercially available enzyme immunoassay (EIA). Neutralizing antibody (NAb) was investigated by cytopathic effect assays (CEA) using both fixed amount and serially diluted sera. BAb correlated with log10-transformed titres obtained by EIA (r=0.70, p<0.0001); the latter, however, failed to demonstrate low-level BAb. Comparison of clinical significance of NAb-positivity measured by biological assays with different sensitivities demonstrated an optimal odds ratio for relapse rate using 10 laboratory units (LU)/mL. Purification of IgG prior to CEA removed toxicity from toxic sera. The neutralizing capacity data correlated linearly with log10-transformed titres obtained by a Kawade 10-to-1 LU/mL CEA (r=0.77, p<0.0001). In conclusion, neutralizing capacity CEA utilizing a fixed amount of serum predicts differences in relapse rates in IFNβ-treated MS patients and correlates with NAb titres of the 10-to- 1 LU/mL CEA. Neutralizing capacity CEA is less laborious and more economical than titre-based NAb assays and suitable for large-scale screenings of MS patients.

Genetic polymorphisms of dsRNA ligating pattern recognition receptors TLR3, MDA5, and RIG-I. Association with systemic lupus erythematosus and clinical phenotypes

This study aimed to demonstrate possible associations between genetic polymorphisms in Toll-like receptor 3, interferon induced with helicase C domain 1 (IFIH1) and DEAD (Asp-Glu-Ala-Asp) box polypeptide 58 and systemic lupus erythematosus (SLE), including the phenotypes lupus nephritis and malar rash, as well as the presence of autoantibodies against nucleic acid-containing complexes. Genotyping was carried out in two Danish cohorts [Copenhagen (CPH) and Odense (ODE)] totaling 344 patients and was compared with 641 previously genotyped healthy controls. In the ODE cohort, the patients were only genotyped for the rs1990760 polymorphism of IFIH1. Single nucleotide polymorphisms (SNPs) were determined by a multiplex bead-based assay (CPH cohort) or real-time PCR (ODE cohort). Associations were investigated using the Cochran-Armitage trend test. The odds ratio (OR) for minor allele homozygotes versus major allele homozygotes suggested a protective effect of the IFIH1 rs1990760 SNP for SLE in the ODE cohort [OR 0.52, 95 % confidence intervals (95 % CI) 0.31-0.88, Pcorr. = 0.05] but not in the CPH cohort, although the OR suggested a trend in the same direction, and when combining the two patient cohorts, ORs were 0.57, 95 % CI 0.37-0.88. None of the other investigated polymorphisms showed any association with SLE. Regarding phenotypes, we found a statistically significant association between rs1990760 and malar rash in the CPH cohort, with ORs suggesting a protective effect (OR 0.28, 95 % CI 0.13-0.62 for heterozygotes and OR 0.11, 95 % CI 0.03-0.41 for homozygotes, Pcorr. = 0.0001). There were no significant associations between rs1990760 and presence of anti-dsDNA, anti-U1RNP, or anti-Smith antibodies. Our study supports previous findings of an association between the rs1990760 polymorphism of IFIH1 and SLE and indicates that this SNP may also be associated with malar rash in SLE patients although this finding needs confirmation.

Single nucleotide polymorphisms in genes encoding toll-like receptors 7, 8 and 9 in Danish patients with systemic lupus erythematosus

Several studies indicate a role for toll-like receptors (TLRs) in the pathogenesis of systemic lupus erythematosus (SLE). We aimed to investigate the risk of SLE and typical clinical and serological manifestations of SLE potentially conferred by selected single nucleotide polymorphisms (SNPs) of genes encoding TLR7, TLR8, and TLR9. Using a multiplexed bead-based assay, we analyzed eight SNPs in a cohort of 142 Danish SLE patients and a gender-matched control cohort comprising 443 individuals. Our results showed an association between the rs3853839 polymorphism of TLR7 and SLE (G vs. C, P = 0.008, OR 1.60, 95 % CI 1.12-2.27 in females; P = 0.02, OR 4.50, 95 % CI 1.18-16.7 in males) confirming recent findings in other populations. Additionally, an association between the rs3764879 polymorphism of TLR8 and SLE (G vs. C, P < 0.05, OR 1.36, 95 % CI 0.99-1.86 in females; P = 0.06, OR 4.00, 95 % CI 0.90-17.3 in males) was found. None of the other investigated SNPs were associated with SLE but several SNPs were associated with clinical and serological manifestations. In summary, a previously shown association between the rs3853839 SNP of TLR7 and SLE in Asian patients was also found in Danish patients. Together with the association of several other SNPs of TLR8 and TLR9 with various clinical and serological manifestations of SLE these findings corroborate the pathogenic significance of TLRs in SLE.

Lower limb ischaemia and reperfusion injury in healthy volunteers measured by oxidative and inflammatory biomarkers

Objective:

Ischaemia-reperfusion (IR) injury is partly caused by the release of reactive oxygen species and cytokines and may result in remote organ injury. Surgical patients are exposed to surgical stress and anaesthesia, both of which can influence the IR response. An IR model without these interfering factors of surgery is, therefore, useful to test the potential of antioxidant and cytokine-modulatory treatments. The aim of this study was to characterize a human ischaemia-reperfusion model with respect to oxidative and inflammatory biomarkers.

Materials and methods:

Ten male volunteers were exposed to 20 minutes of lower limb ischaemia. Muscle biopsies and blood samples were taken at baseline and 5, 15, 30, 60 and 90 minutes after tourniquet release and analysed for malondialdehyde (MDA), ascorbic acid, dehydroascorbic acid, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-1 receptor antagonist (IL-1Ra), IL-6, IL-10, TNF-receptor (TNF-R)I, TNF-RII and YKL-40.

Results:

We found no significant increase in MDA in the muscle biopsies after reperfusion. Plasma levels of oxidative and pro- and anti-inflammatory parameters showed no significant differences between baseline and after reperfusion at any sampling time.

Conclusion:

Twenty minutes of lower limb ischaemia does not result in an ischaemia-reperfusion injury in healthy volunteers, measurable by oxidative and pro- and anti-inflammatory biomarkers in muscle biopsies and in the systemic circulation.

Pre-existing IgG antibodies cross-reacting with the Fab region of infliximab predict efficacy and safety of infliximab therapy in inflammatory bowel disease

BACKGROUND

Infliximab (IFX) is a chimeric murine/human anti-TNF antibody (Ab) used for the treatment of Crohn's disease (CD) and ulcerative colitis (UC). Loss of response is common and associated with development of anti-IFX Abs during ongoing therapy. However, human anti-murine immunoglobulin Abs are common and may cross-react with the murine part of IFX.

AIM

To investigate if Abs binding to IFX's Fab region (IFX-Fab) are present in IBD patients before exposure to IFX, and whether they predict efficacy and safety of IFX therapy.

METHODS

Observational, retrospective cohort study of patients with CD (n = 29) and UC (n = 22).

RESULTS

Pre-treatment levels of IFX-Fab reactive IgG Abs were significantly lower in CD patients in remission after 1 year of maintenance IFX (median 91 mU/L, n = 8) than in the rest of the patients (639 mU/L, n = 21; P < 0.01), and lower than in patients with secondary loss of response in particular (692 mU/L, n = 7; P < 0.01). A cut-off concentration of <439 mU IFX-Fab reactive IgG Ab per litre comprised all patients who later obtained long-term sustained remission on IFX (sensitivity 100%, specificity 67%). Similar trends were observed in UC. The pre-treatment levels of IFX-Fab reactive IgG Abs were markedly higher in patients developing infusion reactions to IFX (1037 mU/L, n = 7) than in the remaining patients (349 mU/L, n = 44; P = 0.036).

CONCLUSIONS

IFX-Fab reactive IgG antibodies present in serum from IBD patients before infliximab therapy associate with lack of long-term efficacy and safety. Assessments of such antibodies may help clinicians to choose between treatment with infliximab and more humanised agents.

Genetic polymorphisms of tumour necrosis factor receptor superfamily 1b and fas ligand are associated with clinical efficacy and/or acute severe infusion reactions to infliximab in Crohn's disease

BACKGROUND

Single nucleotide polymorphisms (SNPs) in TNF receptor superfamily (TNFRSF) 1A and 1B, and Fas ligand (FASLG) genes, have been associated with responsiveness to infliximab (IFX) in Crohn's disease.

AIM

To investigate if SNPs in TNFRSF1A and 1B, and FAS (TNFRSF6) and FASLG (TNFSF6), associated with short- or long-term clinical and biological efficacy and with acute severe infusion reactions.

METHODS

Observational, retrospective and explorative cohort study of IFX-treated Caucasian patients with Crohn's disease classified as primary nonresponders (n = 21), response failures on maintenance therapy (n = 37), maintained remission (n = 47) and occurrence of acute severe infusion reactions (n = 20).

RESULTS

During IFX maintenance therapy, minor allele carriage of TNFRSF1B, rs976881 is associated with loss of response [OR 3.3 (1.2-9.1), P = 0.014]. Minor allele homozygosity increased the risk substantially (OR estimated 19, P = 0.006), and furthermore associated with a mean CRP increase of 17 mg/L as compared to a mean decrease of 17 mg/L in all others (P = 0.036). In contrast, minor allele carriage of TNFRSF1B, rs1061622 is associated with beneficial response to IFX induction [OR 4.2 (1.2-18.2), P = 0.014], and with persistence of remission during maintenance therapy [OR 5.5 (1.5-25.5), P = 0.007]. Carriage of the minor allele of FASLG, rs76110 increased risk of severe infusion reactions [OR 4.0 (1.1-22.4), P = 0.041]; minor allele carriage of TNFRSF1B, rs652625 decreased the risk (OR estimated 0.2, P = 0.043 ).

CONCLUSIONS

The TNFRSF1B polymorphisms may contribute to predict efficacy of infliximab. Moreover, FASLG and TNFRSF1B polymorphisms may confer genetic susceptibility to severe infusion reactions. These findings could potentially aid clinical decisions if confirmed in larger studies.

Severe infusion reactions to infliximab: aetiology, immunogenicity and risk factors in patients with inflammatory bowel disease

BACKGROUND

Infliximab (IFX) elicits acute severe infusion reactions in about 5% of patients with inflammatory bowel disease (IBD).

AIM

To investigate the role of anti-IFX antibodies (Ab) and other risk factors.

METHODS

The study included all IBD patients treated with IFX at a Danish university hospital until 2010 either continuously (IFX every 4-12 weeks) or episodically (reinitiation after >12 weeks). Anti-IFX Ab were measured using radioimmunoassay.

RESULTS

Twenty-five (8%) of 315 patients experienced acute severe infusion reactions. Univariate analysis showed that patients who reacted were younger at the time of diagnosis (19 vs. 26 years, P=0.013) and at first IFX infusion (28 vs. 35 years, P=0.012). Furthermore, they more often received episodic therapy (72% vs. 31%, P<0.001) and logistic regression revealed this as the only significant predictor of reactions (OR 5 [2-13]; P<0.001). IFX reinitiation after 6 months intermission further increased the risk (OR 8 [3-20], P<0.001). Most reactions (n=14, 88%) occurred at 2nd infusion in the 2nd treatment series (P=0.006). Anti-IFX IgG Ab were highly positive in 19 of 20 patients (95%) shortly after the reactions (median 84 U/mL). Anti-IFX IgG Ab measured prior to the retreatment series were negative in 7 of 11 patients tested (64%). Anti-IFX IgE Ab were negative in all patients with reactions.

CONCLUSIONS

Acute severe infusion reactions were strongly associated with development of anti-IFX IgG Ab, but not with anti-IFX IgE Ab. The risk was particularly high at the 2nd infusion in retreatment series. Negative anti-IFX Ab before reinitiation did not rule out reactions.

In vitro cytokine responses to periodontal pathogens: generalized aggressive periodontitis is associated with increased IL-6 response to Porphyromonas gingivalis

Generalized aggressive periodontitis (GAgP) is an inflammatory condition resulting in destruction of tooth-supporting tissues. We examined the production of IL-1beta, IL-6, tumour necrosis factor (TNF)-alpha, IL-12 and IL-10 in cultures of peripheral mononuclear cells (MNC) from 10 patients with GAgP and 10 controls stimulated with periodontal pathogens or a control antigen, tetanus toxoid (TT) in the presence of autologous serum. The pathogens used were Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum, either as type strains or bacteria isolated from the participants' inherent oral flora. The P. gingivalis -induced production of IL-6 was approximately 2.5-fold higher in patients with GAgP than in healthy controls (P < 0.05), while the corresponding TNF-alpha production was non-significantly elevated. IL-1beta production induced by P. gingivalis, as all cytokine responses induced by Pr. intermedia, F. nucleatum and TT was similar in the two groups. A reduced IL-12p70 response to Pr. intermedia and F. nucleatum was observed in smokers compared to non-smoking patients (P < 0.02). To assess the role of serum factors in the elevated IL-6 response to P. gingivalis, MNC from two donors free of disease were stimulated with this bacterium in the presence of the various patient and control sera. An elevated IL-6 and TNF-alpha response was observed in the presence of patient sera (P < 0.01 and P < 0.04, respectively). The data suggest that an exaggerated production of IL-6 occurs in GAgP, and that pro-inflammatory serum factors play an essential role in the response.

Cytokine Expression in Labial Salivary Glands from Patients with Primary Sjöugren's Syndrome

The presence and distribution of 7 cytokines was examined immunohistologically in labial salivary gland (LSG) specimens from patients with primary Sjögren's syndrome (SS) and control subjects. The cytokines interleukin (IL)-1 beta IL-6, tumor necrosis factor (TNF) alpha and interferon (IFN) gamma were identified in defined parts of LSG from patients but not in the corresponding parts of control glands: (a) LSG acinar epithelium expressed IL-1 beta, (b) blood vessels located in both normal LSG stroma and within lymphocytic infiltrates expressed IL-1 beta, IL-6 and IFN gamma, and (c) lymphocytic infiltrates expressed IL-1 beta, IL-6 and TNF alpha. All four cytokines were expressed by salivary ducts within both patient and control specimens, but with generally greater intensity in patients. IL-1 alpha, IL-4 and TNF beta (lymphotoxin) could not be detected in any of the specimens from patients or controls. The locations of cytokines in LSG suggests possible mechanisms of immunologically mediated parenchymal damage in primary SS.

Leucocyte migration inhibitory activity of concanavalin-A-stimulated human lymphocytes. Modification by dipyridamole, lysine-acetylsalicylate and heparin

The in vitro effects of heparin, dipyridamole (DIPY) and lysine-acetylsalicylate (LASA) on human peripheral blood leucocyte migration and upon production/release and effect of leucocyte migration inhibitory activity (LMIA) from lymphocytes stimulated with concanavalin-A (con-A) have been studied. The final concentration of each drug was of the same order of magnitude as during clinical treatment. The leucocyte migration under agarose was significantly increased by DIPY at a concentration of 100 mug/ml. The release/production of LMIA was inhibited by DIPY at 1 mug/ml and by LASA at 0.3 mug/ml. Heparin had no influence on LMIA release, even at 10 IU/ml. The LMIA of supernatants from con-A-stimulated lymphocyte cultures was inhibited by DIPY at a concentration of 10 mug/ml, by LASA at 3 mug/ml and by heparin at 10 IU/ml. The findings suggest that DIPY and LASA could have a dual role as modifiers of inflammation: 1) the well known role as antiaggregants tending to limit and impede thrombosis, and 2) as antagonists to the lymphocyte-mediated (type IV) immune reaction through a depressive action on lymphokine production/release and activity.

The clinical effect of neutralizing antibodies against interferon-beta is independent of the type of interferon-beta used for patients with relapsing-remitting multiple sclerosis

Objective

To establish whether the clinical effect of neutralizing antibodies (NAbs) against interferon-beta (IFNβ) depends on the type of IFNβ (1a or 1b) used for treatment of patients with relapsing-remitting multiple sclerosis (MS).

Introduction

NAbs against IFNβ-1b appear faster and may be more evenly distributed on IgG subclasses, whereas NAbs against IFNβ-1a develop more slowly and may be devoid of IgG3. This might cause different clinical responses to NAbs.

Design/patients

All Danish MS-patients who had started first-time treatment with IFNβ-1a 22 μg s.c tiw (Rebif22) or IFNβ-1b 250 μg s.c. qod (Betaferon) before January 1st 2003 were included. Relapses were recorded at bi-annual visit.

Methods

We measured NAbs every 12 months using a clinically validated cytopathic effect assay. A blood sample with a neutralizing capacity of 20% or more was considered as NAb-positive. We used a mixed logistic regression analysis in which NAb-status (three levels), IFNβ-preparation, and time since treatment started were included as explanatory variables, and relapse rate as response variable.

Results

In 1,309 patients, who were observed for 21,958 months, 32.3% were classified as NAb-positive. The odds-ratio (OR) for relapses in NAb-positive months compared with NAb-negative months was 1.25; P = 0.02. The risk of relapses was higher with Betaferon than with Rebif22 (OR 1.26; P < 0.01). The effect of NAb-level on relapses was independent of whether the patients were treated with Betaferon or Rebif22 ( P = 0.89) and of time ( P = 0.80).

Conclusion

NAbs caused by IFNβ-1a s.c. do not differ from NAbs caused by IFNβ-1b in their detrimental clinical effect.

Treatment with azathioprine and cyclic methylprednisolone has little or no effect on bioactivity in anti-interferon beta antibody-positive patients with multiple sclerosis

Background

It is unknown whether immunosuppression of patients who have developed interferon-β (IFN-β) neutralizing antibodies (NAbs) hastens disappearance of NAbs in the blood.

Objective

We wanted to test whether immunosuppression with cyclic methylprednisolone (MP) in combination with azathioprine (AZA) for 6 months accelerates recovery of IFN-β bioactivity in patients with multiple sclerosis (MS) with abolished in-vivo myxovirus resistance protein A (MxA) mRNA response to IFN-β.

Methods

We included 13 patients with MS with NAbs and a low IFN-β bioavailability detected by the MxA-mRNA response in a descriptive, non-randomized trial. Another 14 NAb-positive patients with a low MxA-mRNA response served as controls. The primary outcome was the fraction of patients who regained an MxA-mRNA response to IFN-β. NAbs were measured by means of a clinically validated cytopathic effect assay and a new reporter gene assay. The in-vivo MxA-mRNA response was measured by real-time polymerase chain reaction.

Results

A total of 11 patients in the treatment group completed the trial. In all, two of these 11 patients regained an in-vivo MxA-mRNA response as compared to one of 14 patients in the control group.

Conclusion

Treatment with AZA and cyclic MP for 6 months has little or no effect on IFN-β bioactivity in NAb-positive patients with MS.

Formation of antibodies against infliximab and adalimumab strongly correlates with functional drug levels and clinical responses in rheumatoid arthritis

BACKGROUND

Tumour necrosis factor alpha (TNFalpha) neutralising antibody constructs are increasingly being used to treat rheumatoid arthritis (RA).

OBJECTIVE

To determine potential differences in clinical responses, soluble drug levels and antibody formation between patients with RA receiving infliximab and adalimumab.

METHODS

69 patients with RA fulfilling the 1987 American College of Rheumatology criteria and about to start treatment with infliximab or adalimumab, were enrolled consecutively. All patients had active disease (28-joint count Disease Activity Score >3.2). Infliximab was given intravenously at 3 mg/kg at baseline and after 2, 6 and 14 weeks. Adalimumab was administered as 40 mg biweekly subcutaneously. Concomitant drug treatment was monitored and continued at constant dosage during the study. All serum samples were tested for infliximab/adalimumab levels and anti-infliximab/anti-adalimumab antibodies.

RESULTS

35 patients received infliximab, 34 received adalimumab. At 6 months, 15 (43%), 6 (17%) and 14 (40%) of the infliximab-treated patients fulfilled the EULAR criteria for good, moderate and non-responders, respectively, whereas the corresponding figures for adalimumab-treated patients were 16 (47%), 8 (24%) and 10 (29%). Clinical responses correlated with the levels of S-infliximab/adalimumab and the formation of anti-infliximab/anti-adalimumab antibodies.

CONCLUSION

The clinical response to two anti-TNFalpha biological agents closely follows the trough drug levels and the presence of antibodies directed against the drugs. Further studies that focus on the underlying pathways leading to antibody formation are warranted to predict immunogenicity of these expensive biological agents and treatment outcomes.

Is the treatment effect of IFN-β restored after the disappearance of neutralizing antibodies?

Objective

To establish whether multiple sclerosis (MS) patients, who have lost the therapeutic effect of interferon-beta (IFN-β) owing to neutralizing antibodies (NAbs) and subsequently revert from a NAb-positive to a NAb-negative state under continued IFN-β-1b therapy, regain clinical effect after reversion.

Background

Several studies have shown that a significant proportion of patients treated with IFN-β develop NAbs that hamper or abolish the therapeutic effect of IFN-β. However, some patients, who become NAb-positive under treatment with IFN-β-1b, may revert to a NAb-negative state under continuous treatment.

Methods

We identified 40 patients from the Danish IFN protocol, who fulfilled the criteria: NAb-positive status for at least 12 months followed by reversion to NAb-negative state for at least 12 months. For comparison, we included 64 matching cases that had remained NAb-negative during an observation time of at least 36 months. The two groups were clinically and demographically alike. We measured NAb-neutralizing capacity using a clinically validated cytopathic effect assay. A blood sample with a neutralizing capacity of 20% or more was considered as NAb-positive. A patient was defined as NAb-positive after two consecutive blood tests separated by at least 6 months. Reversion to a NAb-negative state required at least two consecutive negative tests. To allow for the confounding effect of time we employed a mixed Poisson model.

Results

Patients who had been NAb-positive and reverted to a NAb-negative state regained treatment effect with the relapse rate as before the NAb-positive period adjusting for the effect of time, and the relapse rate was the same as in the permanently NAb-negative patients in corresponding time periods. The relapse rate ratio comparing the NAb-positive with the NAb-negative periods was 1.98 (95% confidence interval: 1.32–2.97).

Conclusion

Under NAb-positive periods, the clinical effect of IFN-β was abolished. When NAbs disappeared spontaneously under continued treatment, patients regained the full effect of INF-β-1b therapy with no negative carry-over effect from the previous NAb-positive period.

Monitoring Patients Treated with Type1 Interferons: Potential Reporter Genes in Patient Leucocytes

Interferon‐α/β (IFN‐α/β) is increasingly used as antiviral and immunomodulatory therapies. Unfortunately, bioavailability varies with IFN species and mode of administration, and all IFN species are potentially immunogenic. Assays for antiviral activity (IFN) and antiviral neutralization (antibodies, NAb) have been used for some time to monitor patients on IFN biologicals. These assays require laborious titrations making them unsuitable for large‐scale clinical use. Myxovirus A (MxA) is a resistance GTP‐binding protein that is specifically induced by treatment with type 1 IFNs. For example, IFN‐β‐induced MxA in blood leucocytes has been used as a biomarker in IFN‐β‐treated patients with multiple sclerosis. However, the degree of specificity of MxA in this regard is unclear, and measurements of MxA protein and/or mRNA are not yet suitable for routine clinical use. In an attempt to find new and better reporter genes (and, hopefully, genes and gene products with proven specificity for IFN‐α and ‐β), microarray screenings with U133A GeneChips (Affymetrix) were carried using human blood leucocytes and the human lung carcinoma cell line A549. We studied the simultaneous expression of 22,000 transcripts before and after exposure to human recombinant IFN‐α and IFN‐β and other antiviral and immunomodulatory cytokines. The results will be presented at the conference.

The Role of Immune Complexes Consisting of Myelin Basic Protein (MBP), Anti-MBP Antibodies and Complement in Promoting CD4+ T-cell Responses to MBP in Health and Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune condition characterized by degeneration of nerve fibre myelin sheets. A candidate autoantigen, myelin basic protein (MBP), has especially attracted attention. The presence of anti‐MBP antibodies is a predictor of definite MS, but their role in the pathogenesis remains obscure. T cells have long been known to play a pivotal role in the pathogenesis of MS. Recently, an important role for B cells as autoantigen‐presenting cells has been demonstrated in other autoimmune diseases, including rheumatoid arthritis and diabetes. The uptake of MBP by B cells and the presentation of MBP‐derive peptides to T helper (Th) cells by B cells may be promoted by the formation of complement (C) activating immune complexes (ICs) between MBP and natural autoantibodies in healthy individuals and disease‐associated anti‐MBP antibodies in MS patients, respectively. We have investigated the formation of MBP‐containing IC, the binding of MBP to B cells, the MBP‐elicited induction of Th‐cell and B‐cell proliferation and the cytokine production in peripheral blood mononuclear cells (PBMCs) from healthy donors grown in the presence of intact or C‐inactivated serum from healthy donors or patients with MS. While MBP did not induce measurable proliferation of B cells nor CD4⁺ T cells, we observed the production of TNF‐α, IFN‐γ and IL‐10 by PBMC in response to incubation with MBP in the presence of sera from healthy controls as well as sera from MS patients. By contrast, no production of IL‐2, IL‐4 and IL‐5 was detected. We are currently investigating the capability of MS sera to promote the formation of MBP‐containing IC and thereby enhance the cytokine responses, by virtue of elevated anti‐MBP contents.

Monitoring Patients Treated with Type 1 Interferons: Antiviral versus MxA Induction Assays

Interferon‐α/β (IFN‐α/β) is increasingly used as antiviral and immunomodulatory therapies. Unfortunately, bioavailability varies with IFN species and mode of administration, and all IFN species are potentially immunogenic. Assays for antiviral activity (IFN) and antiviral neutralization (antibodies, NAb) have been used for some time to monitor patients on IFN biologicals. These assays require laborious titrations making them unsuitable for large‐scale clinical use. Our laboratories have therefore modified the antiviral assays for IFN bioactivity and Nab, so that they are suitable for large‐scale screening in specialized laboratories. The read‐out is survival of a subcloned A549 cell line in the presence of an otherwise lethal amount of virus. Thus, survival increases in the presence of type 1 IFN and decreases in the presence of NAb against the IFN added to the cells. MxA is induced by type 1 IFN and can be used for measuring the Nab activity. In another assay, the MxA level in the A549 cell line is measured. In an attempt to find a new and better reporter gene for type 1 IFN than MxA and genes specific for either IFN‐α or ‐β, a micro array screen was carried using the U133A chip from Affymetrix. The expression of 22,000 genes can be studied simultaneous with this technology. The results will be presented at the conference.

Infections and treatment of patients with rheumatic diseases

Glucocorticoids (GCs) have many complex quantitative and qualitative immunosuppressive effects which induce cellular immunodeficiency and increase host susceptibility to various viral, bacterial, fungal and parasitic infections. As cortisol secretion is inadequate in chronic immune/inflammatory conditions, and current therapies have the aim of providing adequate (low) compensatory doses, the timing of GC administration, such as during the nocturnal turning-on phase of tumour necrosis factor (TNF) secretion, can be extremely important. The use of the lowest possible GC dose, at night, and for the shortest possible time should therefore greatly reduce the risk of infections. Infection is a major co-morbidity in rheumatoid arthritis (RA), and conventional disease-modifying anti-rheumatic drugs (DMARDs) can increase the risk of their occurrence, including tuberculosis. TNF-alpha plays a key role in the pathogenesis of RA, and the data concerning infections in RA patients treated with anti-TNF agents are controversial. Patients and physicians should vigilantly monitor for signs of infection when using anti-TNF agents. Recombinant gene technologies now make it possible to produce protein drugs that are almost identical to naturally occurring human polypeptides, including antibody (Ab) constructs; unfortunately, all human biological agents are potentially immunogenic. An increasing number of recent studies have demonstrated the safety of influenza and pneumococcal vaccines administered to patients with systemic lupus erythematosus (SLE) or RA. These vaccinations are generally immunogenic (i.e., capable of inducing a protective level of specific antibodies) but may not induce an adequate response in a substantial proportion of patients.

Monitoring patients treated with anti-TNF-alpha biopharmaceuticals: assessing serum infliximab and anti-infliximab antibodies

OBJECTIVES

Infliximab is an anti-tumour necrosis factor-alpha (TNF-alpha) mouse-human IgG1/kappa antibody used to treat patients with rheumatoid arthritis (RA) and other inflammatory diseases. Unfortunately, response failure and side-effects due to immunogenicity of the drug are not rare. In this study, we have compared different methods of assessing drug levels and anti-infliximab antibodies (Abs) and analysed the character of these Abs in sera of RA patients treated with infliximab for 1.5-18 months.

METHODS

Functional serum infliximab levels and anti-infliximab Abs were measured by fluid-phase RIAs using 125I-labelled ligands in combination with molecular size and affinity chromatography, and immune complex precipitation.

RESULTS

Anti-infliximab Abs were predominantly IgG, 36% being IgG4, and half the immune complexes were lambda-light-chain-positive. Ab titres were associated with inhibition of TNF binding to the drug, and low trough levels of infliximab were most frequent in anti-infliximab Ab-positive sera. Cross-binding to two other anti-TNF drugs was not observed. Detection of anti-infliximab Abs by solid-phase RIA using cross-binding of plastic-fixed and soluble infliximab exhibited low sensitivity and the data were inconsistent with results obtained from binding of the Abs to soluble infliximab.

CONCLUSIONS

Specific and neutralizing anti-infliximab antibodies develop in RA patients treated with infliximab, and that low trough levels of functional infliximab are associated with the presence of such antibodies. The most sensitive antibody assay involved binding to soluble and intact infliximab. Assessments of bioavailability and immunogenicity of anti-TNF biologicals may be used to optimize dose regimens and prevent prolonged use of inadequate therapy.

Cytokines, autoantibodies and viral antibodies in premorbid and postdiagnostic sera from patients with rheumatoid arthritis: case-control study nested in a cohort of Norwegian blood donors

OBJECTIVE

To assess the timing of changes in cytokines, cytokine-related markers, autoantibodies and viral antibodies in the pathogenesis of rheumatoid arthritis (RA).

METHODS

Case-control study nested in a prospective cohort of 31 330 blood donors in Oslo, Norway. Forty-nine donors developed RA up to 23 years after their most recent blood donation. Stored sera from these donors (case sera) and a sex- and age-matched sample of 245 healthy donors (control sera), and postdiagnostic sera from 33 of the 49 RA cases, were analysed for a panel of cytokines and cytokine-related markers, autoantibodies and antibodies against Epstein-Barr virus and parvovirus B19.

RESULTS

Cytokines and cytokine-related markers were generally negative in case sera from >5 years before the diagnosis of RA. In the 5-year interval immediately before the diagnosis of RA, more case than control sera were positive (odds ratios >2) for interleukin (IL)-1 alpha, IL-1 beta, IL-1 receptor antagonist, IL-4, IL-10, tumour necrosis factor-alpha and soluble tumour necrosis factor receptor I. In postdiagnostic sera, however, 11 of 16 examined cytokines and cytokine-related markers were statistically significantly elevated compared with control sera. Seropositivity for IgG antibodies against cyclic citrullinated peptides and for IgM and IgA rheumatoid factors were seen in case sera from up to 18 years before the diagnosis of RA. IgG antibodies against Epstein-Barr virus and parvovirus B19 did not differ significantly between case and control sera.

CONCLUSIONS

Cytokines and cytokine-related markers appear to be upregulated rather late in RA pathogenesis. In contrast, IgM rheumatoid factor and IgG anti-cyclic citrullinated peptide autoantibodies may precede the diagnosis of RA by up to two decades.

Production of interleukin (IL)-5 and IL-10 accompanies T helper cell type 1 (Th1) cytokine responses to a major thyroid self-antigen, thyroglobulin, in health and autoimmune thyroid disease

Tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma exert detrimental effects in organ-specific autoimmune disease, while both destructive and protective roles have been demonstrated for interleukin (IL)-10, IL-4 and IL-5. We examined the production of these cytokines by peripheral blood mononuclear cells (PBMC) from patients with Hashimoto's thyroiditis (HT), Graves' disease (GD) and healthy controls, upon exposure to a thyroid self-antigen, human thyroglobulin (Tg), in the presence of autologous serum. Initially, TNF-alpha and IL-2 were produced in all three groups, accompanied by IL-10. Release of IFN-gamma, IL-4 and, notably, IL-5 ensued. Both patient groups exhibited increased TNF-alpha, IL-2, IFN-gamma and IL-10 responses, and PBMC from HT patients secreted lower amounts of IL-5 than male, but not female, controls. Enhanced TNF-alpha production by HT cells also occurred in the presence of pooled normal sera, indicating a dependency on intrinsic cellular factors. Conversely, higher production of TNF-alpha and IL-5 occurred in the presence of autologous sera than in the presence of pooled normal sera in both patient groups, indicating a dependency on serum constituents. Complement appeared to promote the production of IL-2 and particularly IL-5, the levels of which were reduced by neutralization of complement by heat- or zymosan treatment. The production of IFN-gamma and IL-2 of the three groups together correlated directly with the serum anti-Tg activity. Moreover, TNF-alpha, IFN-gamma, IL-5 and IL-10 responses were markedly inhibited by partial denaturation of Tg by boiling. We hypothesize that autoantibodies and complement may promote mixed Th1/Th2 cell cytokine responses by enhancing the uptake of autoantigens by antigen-presenting cells.

Are ex vivo neutralising antibodies against IFN-beta always detrimental to therapeutic efficacy in multiple sclerosis?

Neutralising antibodies (NAbs) against interferon (IFN)-beta reduce the treatment effect in multiple sclerosis (MS). However, data from pivotal trials of IFN-beta in MS suggest that NAb-positive patients may have a reduced relapse rate during the first six to 12 months of therapy. We collected clinical data and plasma samples for NAb measurements prospectively, every six months, in 468 patients treated with the same IFN-beta preparation for at least 24 months. NAbs were measured blindly with a cytopathic effect (CPE) assay. During treatment months 0-6, patients who became NAb-positive had significantly fewer relapses compared to patients who maintained the NAb-negative status, whereas the opposite was observed after month 6. This is in accordance with observations in randomised studies of the three different IFN-beta preparations, showing that patients who become NAb-positive have lower relapse rates during the first six or 12 months of therapy. We hypothesise that low affinity NAbs, present early after the start of IFN-beta therapy, though neutralising in vitro in sensitive assays increase the half-life of IFN-beta in vivo and, thereby, enhance the therapeutic effect. With affinity maturation, NAbs effectively prevent IFN-beta binding to its receptors also in vivo and, hence, abolish the treatment effect.

Methotrexate induces poly(ADP-ribose) polymerase-dependent, caspase 3-independent apoptosis in subsets of proliferating CD4+ T cells

The mechanism of action of methotrexate (MTX) in autoimmune diseases (AID) is unclear. A pro-apoptotic effect has been demonstrated in mitogen-stimulated peripheral blood mononuclear cells (PBMC), but studies employing conventional antigens have disputed a pro-apoptotic effect. CD4+ T helper (Th) cells play a significant role in most AID. We therefore examined directly, by flow cytometry, the uptake of MTX by the T helper (Th) cells stimulated for 6 days with Candida albicans (CA) or tetanus toxoid (TT), and its consequences with respect to induction of apoptosis. While none of the resting Th cells took up MTX, nearly all the dividing Th cells did, and this abrogated further cell division. Among dividing Th cells, MTX induced an approximately sixfold increase over baseline levels in the proportion of apoptotic cells. This proportion could be reverted to baseline by the addition of folic acid. Exposure of CA-stimulated PBMC to MTX significantly increased their level of cleaved poly(ADP-ribose) polymerase (PARP), and a similar tendency was observed in TT-stimulated cells. Unlike CA and TT, the mitogen phytohaemagglutinin (PHA) induced proliferation of both CD4- and CD4+ T cells, and induced apoptosis in both undivided and divided Th cells. PHA-induced apoptosis involved activation of caspase-3 and the anti-apoptotic protein Bcl-2 in addition to PARP cleavage, suggesting that PHA induces apoptosis via different pathways than CA and TT. We suggest that the latter are more representative of stimulation with self-antigens in AID, and that a pro-apoptotic effect of MTX on self-antigen-stimulated Th cells contributes to the effect of MTX in the treatment of AID.

Neutralizing antibodies hamper IFN bioactivity and treatment effect on MRI in patients with MS

We measured neutralizing antibodies (NABs) and the in vivo biologic response to interferon-beta on neopterin and beta(2)-microglobulin blood levels. All NAB-negative patients had an in vivo biologic response (full or partial), whereas all high-level positive patients had no response. High-level NAB patients had more MRI activity than NAB-negative patients (p = 0.031). Patients with a full response had less MRI activity than patients without biologic response (p = 0.032).

Differential effect of conditioning regimens on cytokine responses during allogeneic stem cell transplantation

The purpose of this study was to characterize cytokine responses during conditioning in patients undergoing allogeneic stem cell transplantation (SCT) with the aim to identify which markers that may reliably reflect inflammatory activity during conditioning. We investigated inflammatory and anti-inflammatory mediators in plasma samples drawn daily during the conditioning of 20 patients. Soluble tumour necrosis factor alpha receptor I (sTNFRI) increased during the conditioning reflecting the type of conditioning given. Antithymocyte globulin (ATG) was the most potent inducer of sTNFRI (288% increase (median) P=0.002), followed by VP-16 (184%, P=0.03), cyclophosphamide (129%, P=0.03) and total body irradiation (148%, P=0.0005). Administration of i.v. busulfan (Busilvex; BU) was not associated with significant changes in sTNFRI levels. At day 0 (the day of stem cell infusion) the sTNFRI levels were not only elevated compared with baseline (188% increase), P<0.0001), they also correlated with the baseline values (r=0.72, P=0.0003). The levels of tumour necrosis factor, interleukin (IL)-1beta, IL-6, IL-8, IL-10 and IL-12 stayed at low levels during the conditioning, except from a transient increase in the levels of IL-6, IL-8, IL-10 and IL- receptor antagonist (IL-Ra) seen after ATG infusion. These findings suggest that further investigation of circulating sTNFRI levels may be of interest in studies of prognostic factors in SCT.

Spironolactone induces apoptosis in human mononuclear cells. Association between apoptosis and cytokine suppression

Spironolactone (SPIR) has been described to suppress accumulation of pro-inflammatory cytokines. Here, the suppression of TNF-alpha in lipopolysaccharide (LPS)-stimulated mononuclear cell cultures was confirmed. However, SPIR was also found to induce apoptosis, prompting the investigations of a possible association between the two effects: The apoptosis-inducing and the cytokine-suppressive effects of SPIR correlated with regard to the effective concentration range. Also, pre-incubation experiments demonstrated a temporal separation of the two effects of < or = 4 h, with TNF-alpha suppression preceding apoptosis. An association between the two effects was also seen when testing several SPIR analogues. Contrary to TNF-alpha, the levels of IL-1beta increased in SPIR-treated cultures. However, the amount of IL-1beta in the supernatants depended upon the order of SPIR and LPS addition, as IL-1beta was non-detectable in cultures treated with SPIR prior to LPS, whereas elevated IL-1beta levels were seen when SPIR was added after LPS-stimulation. It is possible that the extracellular accumulation of IL-1beta is due to an increased release of already produced IL-1beta as a result of cell death. In conclusion, suppression of cytokine production by SPIR may be associated with its apoptotic potential, either directly (apoptosis is a consequence of suppressed cytokine production, or vice-versa) or indirectly (suppressed cytokine production and apoptosis are parallel but otherwise unrelated phenomena).

CD26 + CD4 + T cell counts and attack risk in interferon-treated multiple sclerosis

Biomarkers that allow the identification of patients with multiple sclerosis (MS) with an insufficient response to immunomodulatory treatment would be desirable, as currently available treatments are only incompletely efficacious. Previous studies have shown that the expression of CD25, CD26 and CCR5 on T cells is altered in patients with active MS. We studied the expression of these molecules by flow cytometry in patients followed for six months during immunomodulatory treatment. In interferon (IFN)-beta-treated patients, we found that the hazard ratio for developing an attack was 28 in patients with CD26 + CD4 + T cell counts above median, and this risk was independent of the risk conferred by neutralizing anti-IFN-beta antibodies. CD26 + CD4 + T cell counts may identify patients with MS at increased risk of attack during treatment with IFN-beta.

Lack of effect of intermittently administered sodium fusidate in patients with newly diagnosed type 1 diabetes mellitus: the FUSIDM trial

AIMS/HYPOTHESIS

We evaluated in a double-blind study the effect of early treatment with the immunomodulatory drug fusidin in patients with newly diagnosed type 1 diabetes mellitus.

METHODS

Twenty-eight adults with newly diagnosed type 1 diabetes were included in the study. The patients were randomly assigned (computer-generated random number sequence) to two experimental groups. Patients allocated to the fusidin (FUS) group (n=15) received sodium fusidate (fusidin; 500 mg orally three times daily for 4 weeks). Subsequently the drug was given at the same dose and scheduled for two consecutive weeks a month followed by 2 weeks a month without the drug for 20 weeks. Subjects allocated to the placebo (PCB) group (n=13) received placebo according to the same schedule and conditions described for sodium fusidate in the FUS group. All patients received a diet adjusted to their age and BMI, and intensive insulin therapy.

RESULTS

There were no statistically significant differences between the FUS and PCB groups in beta cell function, evaluated by basal and glucagon-stimulated C-peptide values during the follow-up (24 and 48 weeks). There was also no difference between the two groups in insulin requirement after 48 weeks (0.4+/-0.2 and 0.4+/-0.2 U/kg body weight for the FUS and PCB groups, respectively). Antibody titres, including insulin autoantibodies, were similar in the two groups during the follow-up.

CONCLUSIONS/INTERPRETATION

Early treatment of newly diagnosed type 1 diabetes patients with intermittently administered fusidin failed to influence the natural course of the disease.

The effect of spironolactone on experimental periodontitis in rats

BACKGROUND

Elevated levels of tumour necrosis factor (TNF) have been found in patients with adult periodontitis. Animal studies have shown that TNF plays an important role in the pathogenesis of periodontitis. New findings suggest that the aldosterone-inhibitor spironolactone possesses an anti-TNF effect. The purpose of the study was to determine the anti-TNF effect of spironolactone in an endotoxic shock rat model and to disclose the effect of oral administration of spironolactone on the development of experimental periodontitis in rats.

METHODS

The study was divided in two parts. Part 1: oral administration of spironolactone (100 mg/kg) followed by intravenous lipopolysaccharide (1 mg/kg) infusion 45 min later. Blood samples were taken before and 90 min after lipopolysaccharide infusion to determine the TNF levels in spironolactone treated and non-treated rats. Part 2: oral administration of spironolactone [100 mg/(kg day)] starting 2 days prior to induction of experimental periodontitis established by peridental ligatures. Morphometrical and radiographical registrations of alveolar bone destruction were carried out to determine the effect of spironolactone on the progression of experimental periodontitis.

RESULTS

In part 1 the endotoxic shock model showed a significant reduction in TNF levels in the spironolactone-treated group compared to the non-treated group, suggesting that spironolactone acts as a TNF inhibitor. In part 2 spironolactone-treated rats did not demonstrate significantly less alveolar bone destruction compared to non-treated rats.

CONCLUSIONS

The insignificant effect of spironolactone treatment could be explained by the fast metabolism of spironolactone and that spironolactone does not completely inhibit TNF production in rats. Moreover, many other cytokines and mediators involved in alveolar bone destruction may account for the lacking response to spironolactone.

Appearance and disappearance of neutralizing antibodies during interferon-beta therapy

BACKGROUND

Neutralizing antibodies (NABs) occur frequently in patients receiving interferon (IFN)-beta for multiple sclerosis (MS), but it is unclear whether occurrence of NABs is predictive for the persistence of NABs during continued IFN-beta therapy.

METHODS

The authors used an antiviral neutralization bioassay to measure NABs blindly from 6 months up to 78 months in patients with MS who were followed for at least 24 months during treatment with IFN-beta. Patients were classified into three groups: 1) persistently NAB-negative patients, defined as patients without any positive samples at any time; 2) definitely NAB-positive patients, defined as patients who had at least two consecutive positive samples; and 3) patients with fluctuating NAB-positive and NAB-negative samples.

RESULTS

A total of 455 patients were included in the study. Overall, 52.3% of the patients were persistently NAB-negative, 40.9% became definitely NAB-positive, and the remaining 6.8% were fluctuating. More patients treated with IFN-beta-1a (Avonex) remained NAB-negative (p < 0.0001), whereas there was no difference between IFN-beta-1b (Betaferon) and IFN-beta-1a (Rebif). Patients who have remained NAB-negative during the first 24 months of therapy rarely developed NABs. On the contrary, the majority of patients, who had been NAB-positive from 12 through 30 months after start of therapy, remained NAB-positive.

CONCLUSIONS

NABs should be measured in all patients treated with IFN-beta. If patients have been persistently NAB-negative for 24 months, measurements can be discontinued. Patients who have been NAB-positive for a period of 18 months or more usually remain NAB-positive for a long time.

Elucidation of IL-1/TGF-beta interactions in mouse chondrocyte cell line by genome-wide gene expression

OBJECTIVE

To elucidate the antagonism between interleukin-1 (IL-1) and transforming growth factor-beta (TGF-beta) at the gene expression level, as IL-1 and TGF-beta are postulated to be critical mediators of cartilage degeneration/protection in rheumatic diseases.

METHODS

The H4 chondrocyte cell line was validated by comparing metalloproteinase expression profile with intact murine cartilage by reverse transcription polymerase chain reaction. Genome-wide gene expression in the H4 cells in response to IL-1 and TGF-beta, alone and in combination, was analyzed by using oligonucleotide arrays negotiating approximately 12,000 genes.

RESULTS

The response of cartilage and the H4 cell line to IL-1 and TGF-beta was comparable. Oligonucleotide array analysis demonstrated a mutual but asymmetrical antagonism as the dominant mode of interaction between IL-1 and TGF-beta. Cluster analysis revealed a remarkable selectivity in the mode of action exerted by TGF-beta on IL-1 regulated genes: antagonistic on pro-inflammatory genes whereas additive on growth regulators such as vascular endothelial growth factor (VEGF) and connective tissue growth factor (CTGF). While the former cluster underlined the protective effect of TGF-beta, the latter underscored the adverse effect of TGF-beta. We further identified potentially novel classes of target genes under control of TGF-beta such as ras family, histones, proteasome components, and ubiquitin family, highlighting the importance of such genes in TGF signaling besides the well-characterized SMAD pathway.

CONCLUSIONS

We identified a cluster of genes as potential targets mediating the adverse effect of TGF-beta such as fibrosis. Transcriptional regulation of ras GTPase and ubiquitin/proteasome pathways is likely to be a novel mechanism mediating the effect of TGF-beta and its interaction with IL-1. These down-stream genes and pathways can be targets in future therapy.

Plasma TNF binding capacity profiles during treatment with etanercept in rheumatoid arthritis

BACKGROUND

Etanercept (Enbrel) induces a rapid and sustained decline in disease activity in the majority of patients with refractory rheumatoid arthritis (RA). In these patients neutralization of TNFalpha and lymphotoxin (LT), previously termed TNFbeta is mediated by etanercept itself, as well as by naturally occurring soluble TNF receptors. However, the clinical response to treatment with etanercept may vary. Previously, pharmacokinetic studies have focused on the molar concentrations of etanercept, but very little is known about the kinetics of bioactive etanercept in patients treated with etanercept. The purpose of this study was to evaluate kinetics, including inter- and intraindividual variations of the total TNF binding capacity, in RA patients who were on a standard treatment schedule with etanercept.

METHODS

Plasma samples were collected daily from 16 RA patients who were in the steady-state phase during treatment with etanercept 25 mg subcutaneous once (n = 2) or twice (n = 14) weekly. The inflammatory activity, including Health Assessment Questionnaire (HAQ) score, numbers of painful and swollen joints, and ESR, was assessed at inclusion; CRP was measured on a daily basis. The samples were incubated with human recombinant LT to a concentration of 1000 pg/mL and the levels of detectable LT were measured by ELISA specific for free LT. The LT binding capacity (LTBC) was expressed in arbitrary units (AU) as the percentage value of bound LT to added LT.

RESULTS

The median LTBC values measured during the treatment schedule from Day 1 (before the injection) to Day 4 (before the next injection) were 47 AU. The LTBC values in each individual patient generally remained fairly stable through the treatment schedule, and there were no significant differences in LTBC levels in samples obtained on a daily basis during the treatment schedule. However, a pronounced variation between the patients was noticed with LTBC values ranging from 10-82 AU (coefficient of variation=38%). No significant association was found between LTBC levels and clinical measures of disease activity, including HAQ and numbers of swollen or painful joints. However, among patients with high LTBC levels (> or =65 AU), elevated levels of ESR and CRP were less frequent (0%) compared with patients who had lower LTBC levels, in which the frequencies of elevated ESR and CRP were 53% and 37%, respectively. Soluble TNF receptor 1 (sTNFR1) remained stable between the injections and correlated with the number of swollen joints, but did not correlate with LTBC values.

CONCLUSION

LTBC levels appeared stable in each individual RA patient who was on the standard treatment schedule with weekly injections of etanercept, but the inter-individual variations were considerable.

Beta-galactosylceramide increases and sulfatide decreases cytokine and chemokine production in whole blood cells

The glycosphingolipid sulfatide and its immediate precursor beta-galactosylceramide (GalCer) are present in the pancreatic beta-cell in equimolar concentrations and may play a role in islet pathology. Previous studies of mononuclear cells have shown that sulfatide tends to decrease and GalCer tends to increase the production of proinflammatory cytokines. In this study we investigated the influence of various isoforms of sulfatide on the production of cyto- and chemokines and tested whether the opposing effects of GalCer and sulfatide could counter one another in competition assays. PHA-, LPS-, or unstimulated whole blood cultures were incubated with 30 microg/ml of native sulfatide (isolated from pig brains), C:16:0 and C:24:0 analogues of sulfatide, or native GalCer preparations. After 24 h, the supernatant levels of proinflammatory cytokines and chemokines were quantitated by ELISA. The general trend was for the sulfatides to lower the production of the cytokines, and for GalCer to increase it. In competition assays, native sulfatide dampened the stimulatory effects of GalCer but did not abolish cytokine release; GalCer, on the other hand, nullified the effect of native sulfatide at a ratio of four sulfatide molecules to one GalCer molecule. C:16:0 sulfatide appeared to have a stronger effect than C:24:0 sulfatide. The C:16:0 analogue decreased IL-1beta, IL-6, TNF-alpha, MIP-1alpha and IL-8 to 3-56% of control values (P < 0.05-0.01), while GalCer increased their production 2- to 10-fold (P < 0.01). In conclusion, sulfatide decreases the in vitro production of proinflammatory cytokines, whereas GalCer has the opposite effect.

Prognostic laboratory markers of joint damage in rheumatoid arthritis

OBJECTIVE

To investigate whether determination of a set of laboratory markers at baseline provides prognostic information on joint damage in hands and feet in rheumatoid arthritis.

METHODS

183 patients with early rheumatoid arthritis included in a prospective study were examined. Radiographic changes in hands and feet at 5 and 10 years after inclusion were evaluated (Larsen). The markers analysed were: erythrocyte sedimentation rate (ESR); HLA-DRB alleles typed by restriction fragment length polymorphism; and C reactive protein, cartilage oligomeric matrix protein (COMP), rheumatoid factor (RF) (IgG, IgA, and IgM subtypes), antibodies against cyclic citrullinated peptide (anti-CCP), and antibodies against interleukin 1alpha (anti-IL1alpha), analysed by immunoassays. Multiple linear regression with backward elimination was used to determine the prognostic value of the variables.

RESULTS

117/176 patients were positive for IgG RF, 138/176 for IgA RF, 139/176 for IgM RF, 140/176 for anti-CCP, and 40/182 for anti-IL1alpha. After five years, ESR, the presence of IgA RF, serum COMP, and the presence of anti-CCP were significantly associated with more severe joint damage, and the presence of anti-IL1alpha with less severe joint damage. Baseline C reactive protein and anti-CCP predicted radiographic outcome after 10 years. A stronger prediction was obtained by combining the prognostic factors.

CONCLUSIONS

Early determination of anti-CCP, IgA RF, anti-IL-1alpha, ESR, C reactive protein, and COMP predicted the development of joint damage in hands and feet in this cohort. A combination of these measures reflecting different aspects of the disease process should be useful for evaluating prognosis in individual patients with early rheumatoid arthritis.

Infusion of hypertonic saline (7.5% NaCl) causes minor immunological changes in normovolaemic women

BACKGROUND

Haemorrhagic shock is treated effectively by infusion of hypertonic saline/colloid solutions. Furthermore, previous studies found hypertonicity to affect immune responses in animals and in human blood cell cultures. It is unknown, however, whether hypertonic saline infusion affects immune responses in humans.

METHODS

In a randomized double-blind study, we infused 4 ml kg-1 of 7.5% NaCl or 0.9% NaCl over 10 min in 20 fasting women before hysterectomy. We collected peripheral blood at baseline, 30, and 120 min after start of the infusion and before surgery for the determination of leucocyte and differential count; lymphocyte subtypes; neutrophil chemotaxis; elastase concentration; and the cytokine's tumour necrosis factor-alpha (TNFalpha), interleukin (IL)-1beta, IL-6, IL-8, IL-1 receptor antagonist (IL-1ra), and IL-10. Phytohaemagglutinin (PHA)-induced lymphocyte proliferation and natural killer cell cytotoxicity were measured before and 120 min after infusion.

RESULTS

Compared with normal saline, infusion of hypertonic saline temporarily increased the number of B cells in peripheral blood (P < 0.01); increased the concentration of plasma elastase, a marker of neutrophil degranulation (P < 0.05); and decreased the number of circulating neutrophils (P < 0.001). No other effects were detected in the measured immunological parameters.

CONCLUSION

The immunological consequences of hypertonic saline infusion seem to be modest and are unlikely to cause any clinical effects, at least in normovolaemic women.

TNF and LT binding capacities in the plasma of arthritis patients: effect of etanercept treatment in juvenile idiopathic arthritis

BACKGROUND

Etanercept (Enbrel) induces a rapid and sustained decline in disease activity in the majority of patients with refractory juvenile idiopathic arthritis (JIA). For unknown reasons, however, a number of JIA patients fail to respond to this therapy. During this treatment neutralisation of tumour necrosis factor (TNF, previously termed TNF alpha) and lymphotoxin (LT, previously termed TNF beta) may be mediated by etanercept itself as well as by naturally occurring soluble TNF receptors. In light of this, it was of interest to study the total TNF neutralizing capacity in plasma before and during treatment with etanercept.

RESULTS

In initial experiments plasma samples from healthy individuals were incubated with etanercept, and spiked with TNF or LT to a final concentration of 1000 pg/mL. Detection of TNF and LT by ELISA was found to be reduced by approximately 50% and 80% respectively, at a concentration of etanercept of 5-500 ng/mL, which is close to the pharmacological plasma concentrations. Plasma samples (n = 80) were then collected from 12 JIA patients (5 with pauciarticular, 5 with polyarticular and 2 with the systemic onset type) during treatment with etanercept (0.4 mg/kg twice weekly) for a period of 20.8 (15.6-23.9) months (median, range). The plasma samples were spiked with LT, and the inhibition of LT detection in ELISA was measured. In samples obtained 3 months after the start of etanercept, the inhibition of LT detection was augmented [72% (60-85)] compared with pre-treatment samples [16% (0.32)] (p = 0.0039). These findings were confirmed in binding assays using radiolabelled TNF. Among patients who responded insufficiently to therapy, reduced LT binding capacity, coinciding with flares of disease activity, was observed.

CONCLUSION

We have developed an assay by which LT binding capacity, reflecting the level of free, pharmacologically active etanercept, may be monitored in the blood of patients treated with etanercept. This assay may prove to be useful in guiding dose adjustments in patients with an incomplete response to etanercept.

Spironolactone inhibits production of proinflammatory cytokines, including tumour necrosis factor-alpha and interferon-gamma, and has potential in the treatment of arthritis

Evidence suggests that spironolactone, an aldosterone antagonist, has effects on many cell types independent of its binding to cytosolic mineralocorticoid receptors. We tested the effects of spironolactone on ex vivo-activated human blood leucocytes using gene expression analyses (GeneChip, 12,000 genes) and enzyme immunoassay for quantitating secreted pro- and anti-inflammatory cytokines. Furthermore, to evaluate the safety and efficacy of spironolactone as an anti-inflammatory drug 21 patients with rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA) or other arthritides were treated for up to 22 months with 1-3 mg/kg/day. Spironolactone, at in vivo attainable doses, markedly suppressed transcription of several proinflammatory cytokines and, accordingly, inhibited release of tumour necrosis factor, lymphotoxin, interferon-gamma, granulocyte-macrophage colony-stimulating factor and interleukin 6 (70-90% inhibition). Release of these cytokines was also suppressed when testing whole blood from RA patients receiving 50 mg spironolactone twice daily, indicating that pharmaceutical use of the drug may suppress the release of inflammatory cytokines. Spironolactone therapy was generally well tolerated, although treatment had to be stopped in two adults on concomitant methotrexate therapy. Sixteen patients (76%) responded favourably. American College of Rheumatology criteria (ACR)20 or better was achieved in six of nine RA patients; four reached ACR70. Eight of nine JIA patients improved. In conclusion, spironolactone inhibits production of several proinflammatory cytokines considered to be of pathogenic importance in many immunoinflammatory diseases and shows positive effect in patients with chronic arthritis. Its effect as an anti-inflammatory drug should be explored, because prolonged spironolactone therapy is reasonably safe and economically attractive compared with many modern anti-inflammatory therapies.

Long-term follow-up of kidney transplant patients with posttransplant lymphoproliferative disorder: duration of posttransplant lymphoproliferative disorder-induced operational graft tolerance, interleukin-18 course, and results of retransplantation

BACKGROUND

Posttransplant lymphoproliferative disorder (PTLD) can be resolved in many transplant patients by the reduction or cessation of immunosuppression, after which many grafts continue to function as the result of a form of operational tolerance. When graft function deteriorates, retransplantation may be an option. Cytokines such as interleukin (IL)-10 and IL-18 may play a role in PTLD tolerance induction and tumor regression. We report long-term follow-up on the duration of graft tolerance and the course of retransplantation in a series of patients who underwent kidney transplantation and demonstrated PTLD, and in whom we were able to perform IL-18 analyses.

RESULTS

Patients were followed for up to 7 years after PTLD diagnosis. Treatment consisted of immunosuppression cessation with radiation therapy in cases with overt monomorphic lymphomas. All patients' PTLDs were resolved, and all patients but one (whose graft was removed) demonstrated a period of operational graft tolerance of up to 5 years. Five patients underwent retransplantation without sign of recurrence of the PTLD up to 3 years after transplantation. In the eight patients analyzed, IL-18 increased significantly during PTLD regression and follow-up in those with long-term operational tolerance.

CONCLUSION

We report on a series of patients with resolved PTLDs demonstrating long-term recurrence-free survival, of whom most experienced a long period of operational graft tolerance. IL-18 seems to play a role in the resolution of the PTLDs. Five patients underwent retransplantation with standard immunosuppression without recurrence. A previous diagnosis of PTLD should not be regarded as a contraindication for later retransplantation.