AB0062 ANGIOTENSIN CONVERTING ENZYME ACTIVITY IN ANTI-TNF-TREATED RHEUMATOID ARTHRITIS AND ANKYLOSING SPONDYLITIS PATIENTS

Background

Angiotensin-converting enzyme (ACE) and ACE2 have been implicated in the regulation of vascular physiology. Elevated synovial and decreased or normal ACE or ACE2 levels have been found in rheumatoid arthritis (RA). Very little is known about the effects of tumour necrosis factor α (TNF-α) inhibition on ACE or ACE2 homeostasis.

Objectives

In this study, we assessed the effects of one-year anti-TNF therapy on ACE and ACE2 production in RA and ankylosing spondylitis (AS) in association with other biomarkers.

Methods

Forty patients including 24 RA patients treated with either etanercept (ETN) or certolizumab pegol (CZP) and 16 AS patients treated with ETN were included in a 12-month follow-up study. Serum ACE levels were determined by commercial ELISA, while serum ACE2 activity was assessed using a specific quenched fluorescent substrate. Ultrasonography was performed to determine flow-mediated vasodilation (FMD), common carotid intima-media thickness (ccIMT) and arterial pulse-wave velocity (PWV) in all patients. In addition, CRP, rheumatoid factor (RF) and ACPA were also measured. All assessments were performed at baseline and 6 and 12 months after treatment initiation.

Results

Anti-TNF therapy increased ACE levels in the full cohort, as well as in the RA and AS subsets. ACE2 activity increased in the full cohort, while the ACE/ACE2 ratio increased in the full cohort and in the RA subset (p<0.05). Uni- and multivariable regression analyses determined associations between ACE or ACE/ACE2 ratios at different time points and disease duration, CRP, RF, FMD and IMT (p<0.05). ACE2 activity correlated with CRP. The changes of ACE or ACE2 over 12 months were determined by treatment together with either RF or FMD (p<0.05).

Conclusion

Anti-TNF treatment may increase ACE and ACE2 in the sera of RA and AS patients. ACE and ACE2 may be associated with disease duration, markers of inflammation and vascular pathophysiology. The effects of TNF inhibition on ACE and ACE2 may reflect, in part, the effects of these biologics on the cardiovascular system.

Disclosure of Interests

Boglárka Soós: None declared, Miklós Fagyas: None declared, Ágnes Horváth: None declared, Edit Végh: None declared, Anita Pusztai: None declared, Monika Czókolyová: None declared, Alexandra Csongrádi: None declared, Attila Hamar: None declared, Zsófia Pethö: None declared, Nóra Bodnár: None declared, György Kerekes: None declared, Katalin Hodosi: None declared, ​Éva Szekanecz​: None declared, Szilvia Szamosi Speakers bureau: Roche, Sager, Amgen, Sándor Szántó Speakers bureau: AbbVie, Novartis, Lilly, MSD, UCB, Consultant of: AbbVie, Novartis, UCB, Gabriella Szücs Speakers bureau: Roche, Lilly, Actelion, Zoltán Papp: None declared, Zoltán Szekanecz Speakers bureau: AbbVie, Pfizer, Roche, MSD, Novartis, Lilly, Richter, Consultant of: Pfizer, Novartis, Richter, Grant/research support from: Pfizer, UCB

Effects of one-year tofacitinib therapy on bone metabolism in rheumatoid arthritis

Janus kinase (JAK) inhibitors are used to treat rheumatoid arthritis (RA). We assessed the effects of tofacitinib on bone density and bone markers in association with clinical and laboratory parameters in RA. Tofacitinib stabilized bone density and resulted in a positive balance of bone turnover.

INTRODUCTION

Janus kinase (JAK) inhibitors emerged as new therapeutic options in rheumatoid arthritis (RA). We have little information on how it affects areal and volumetric bone mineral density (BMD) and bone turnover markers. The aim of this study was to assess the effects of 1-year tofacitinib therapy on bone metabolism in RA.

METHODS

Thirty RA patients with active disease were treated with either 5 mg bid or 10 mg bid tofacitinib for 12 months. We determined DAS28, CRP, IgM rheumatoid factor (RF), and anti-cyclic citrullinated peptide (CCP) levels, as well as serum levels of sclerostin, osteocalcin (OC), P1NP, DKK-1, OPG, RANKL, and 25-hydroxy-vitamin D3. Areal and volumetric BMD were assessed by DXA and peripheral quantitative CT (QCT), respectively.

RESULTS

Twenty-six patients (13 on each arm) completed the study. Tofacitinib was clinically effective by suppressing DAS28, CRP, and HAQ. This was accompanied by the attenuation of further bone loss. Tofacitinib therapy significantly increased OC, OPG, and vitamin D3, while decreased CTX levels (p < 0.05). Age and multiple bone markers (OC, CTX, P1NP, RANKL) inversely correlated with L2-4 and femoral neck BMD by DXA. CRP, DAS28, and RANKL inversely determined volumetric BMD by QCT. Age, CRP, anti-CCP, and DKK-1 influenced the effects of tofacitinib therapy on BMD changes.

CONCLUSIONS

One-year tofacitinib treatment stabilized BMD in RA patients and resulted in a positive balance of bone turnover as indicated by bone biomarkers. Further studies are needed to evaluate the potential beneficial effects of JAK inhibitors on inflammatory bone loss.

POS0390 SIMULTANEOUS ASSESSMENT OF JOINT AND VASCULAR INFLAMMATION BY PET-CT IN TOFACITINIB-TREATED PATIENTS WITH RHEUMATOID ARTHRITIS: A PROSPECTIVE STUDY

Background:

Rheumatoid arthritis (RA) has bene associated with atherosclerosis and cardiovascular (CV) disease. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18FDG-PET/CT) is suitable to detect synovial and vascular inflammation. Tofacitinib has been used to effectively treat RA.

Objectives:

We wished to assess the effects of tofacitinib treatment on synovitis and vascular inflammation simultaneously by 18FDG-PET/CT.

Methods:

Thirty RA patients with active disease were treated with either 5 mg bid or 10 mg bid tofacitinib and evaluated at baseline and after 6 and 12 months. We determined DAS28, CRP, IgM rheumatoid factor (RF) and anti-cyclic citrullinated peptide (aCCP) levels. All patients underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in order to determine vascular and synovial inflammation in five aortic segments and five articular regions, respectively. In the joints, mean (SUVmean) and maximum standard uptake values (SUVmax), while in the aorta, mean (TBRmean) and maximum target-to-background ratios (TBRmax) were determined. Carotid intima-media thickness (IMT), arterial stiffness (PWV) and endothelial dysfunction (FMD) were determined by ultrasound.

Results:

One-year tofacitinib treatment significantly attenuated vascular and synovial inflammation as visualized by PET/CT. Articular SUVmean (p=0.010), SUVmax (p=0.001), as well as aorta TBRmax (p<0.001) significantly decreased over time. Synovial inflammation as determined by PET/CT variably and positively associated with aCCP, RF, CRP, ApoB, lipoprotein A (LpA), IMT and PWV. Vascular inflammation (TBRmax) inversely correlated with HAQ and positively with ESR, ApoA, and PWV. Uni- and multivariable analyses suggested that articular SUV values were independently associated with CRP, ApoB, LpA, IMT and PWV, while aortic TBRmax was determined by HAQ and PWV.

Conclusion:

18F-PET/CT is suitable to simultaneously assess synovial and vascular inflammation in RA. One-year tofacitinib treatment dampened inflammation. PET/CT changes were associated with markers of systemic inflammation, atherogenic lipids, carotid atherosclerosis and arterial stiffness.

References:

[1]Gotthardt M, Bleeker-Rovers CP, Boerman OC, Oyen WJ. Imaging of inflammation by PET, conventional scintigraphy, and other imaging techniques. J Nucl Med. 2010;51(12):1937-49.

[2]Bucerius J, Hyafil F, Verberne HJ, Slart RH, Lindner O, Sciagra R, et al. Position paper of the Cardiovascular Committee of the European Association of Nuclear Medicine (EANM) on PET imaging of atherosclerosis. Eur J Nucl Med Mol Imaging. 2016;43(4):780-92.

Acknowledgements:

This research was supported by the European Union and the State of Hungary and co-financed by the European Social Fund in the framework of TAMOP-4.2.4.A/2-11/1-2012-0001 ‘National Excellence Program’ (Z.S.); by the European Union grant GINOP-2.3.2-15-2016-00015 (G.P., G.T. and Z.S.) and by the Pfizer Investigator Initiated Research Grant no. WI188341 (Z.S.).

Disclosure of Interests:

Attila Hamar: None declared, Zsolt Hascsi: None declared, Anita Pusztai: None declared, Monika Czókolyová: None declared, Edit Végh: None declared, Zsófia Pethö: None declared, Katalin Gulyás: None declared, Boglárka Soós: None declared, György Kerekes: None declared, Éva Szekanecz: None declared, Katalin Hodosi: None declared, Sándor Szántó Speakers bureau: Abbvie, MSD, Novartis, Consultant of: Abbvie, MSD, Novartis, Gabriella Szücs Speakers bureau: Boehringer, Actelion, Roche, Consultant of: Boehringer, Actelion, Roche, Tamas Seres: None declared, Zoltán Szekanecz Speakers bureau: Abbvie, Pfizer, Roche, Novartis, Lilly, Sager, Janssen, Consultant of: Pfizer, Abbvie, Roche, Novartis, Grant/research support from: Pfizer, Szilvia Szamosi Speakers bureau: Roche

POS0043 PERIPHERAL QUANTITATIVE COMPUTED TOMOGRAPHY IN THE ASSESSMENT OF BONE MINERAL DENSITY IN ANTI-TNF-TREATED RHEUMATOID ARTHRITIS AND ANKYLOSING SPONDYLITIS PATIENTS

Background:

Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) have been associated with osteoporosis. There have been very few data on the use of peripheral quantitative computed tomography (QCT) in anti-TNF-treated patients.

Objectives:

We wished to assess volumetric bone mineral density (BMD) by forearm QCT in conjunction with dual-energy X-ray absorptiometry (DXA) and bone biomarkers in RA and AS.

Methods:

Forty RA and AS patients treated with etanercept (ETN) or certolizumab pegol (CZP) were included in a 12-month follow-up study. Peripheral QCT and DXA BMD were determined. Bone biomarkers, such as PTH, osteocalcin, RANKL, 25-hydroxyvitamin D (VITD), P1NP, CTX, sclerostin, DKK-1 and cathepsin K (CATHK) were assessed by ELISA.

Results:

There was no further bone loss during anti-TNF treatment. Volumetric and areal BMD showed significant correlations with each other (p<0.05). Total QCT BMD after 12 months was inversely determined by disease activity at baseline in the full cohort (p=0.030). Cortical BMD was negatively determined by baseline disease activity (p=0.005) and CATHK (p=0.025). In RA, VITD-0 determined QTRABBMD-12 (p=0.005). In the full cohort, the one-year change in QTRABBMD was related to TNF inhibition together with higher VITD-0 (p=0.031). Therapy and lower CATHK determined QCORTBMD changes (p=0.006). In RA, treatment together with VITD-0 (p<0.01) or CATHK-0 (p=0.002), while in AS, treatment together with RANKL-0 (p<0.05) determined QCT BMD changes.

Conclusion:

QCT confirmed that biologics may attenuate bone loss. Disease activity, CATHK, RANKL and VITD may predict the effects of anti-TNF treatment on volumetric BMD changes. There may be differences between RA and AS in this respect.

Acknowledgements:

This research was supported by Hungarian National Scientific Research Fund (OTKA) grant No. K 105073 (H.P.B. and Z.S.); by the European Union and the State of Hungary and co-financed by the European Social Fund in the framework of TAMOP-4.2.4.A/2-11/1-2012-0001 ‘National Excellence Program ’(Z.S.); by the European Union grant GINOP-2.3.2-15-2016-00050 (Z.S.); and by the Pfizer Investigator Initiated Research Grants no. WS1695414 and WS1695450 (Z.S.).

Disclosure of Interests:

Balázs Juhász: None declared, Katalin Gulyás: None declared, Ágnes Horváth: None declared, Edit Végh: None declared, Anita Pusztai: None declared, Agnes Szentpetery: None declared, Zsófia Pethö: None declared, Nóra Bodnár: None declared, Attila Hamar: None declared, Levente Bodoki: None declared, Harjit Pal Bhattoa: None declared, Éva Szekanecz: None declared, Katalin Hodosi: None declared, Andrea Domjan: None declared, Szilvia Szamosi Speakers bureau: Roche, Csaba Horváth: None declared, Sándor Szántó Speakers bureau: Abbvie, MSD, Novartis, Consultant of: Abbvie, Novartis, Gabriella Szücs Speakers bureau: Roche, Boehringer, Actelion, Sager, Consultant of: Actelion, Boehringer, Hennie Raterman: None declared, WIllem Lems Speakers bureau: Pfizer, Amgen, Lilly, UCB, Galapagos, Consultant of: Pfizer, Amgen, Lilly, UCB, Galapagos, Oliver FitzGerald Speakers bureau: AbbVie, Janssen, Pfizer, Consultant of: BMS, Celgene, Eli Lilly, Janssen, Pfizer, Grant/research support from: AbbVie, BMS, Eli Lilly, Novartis, Pfizer, Zoltán Szekanecz Speakers bureau: Pfizer, Roche, Abbvie, Novartis, Lilly, Sanofi, Consultant of: Pfizer, Abbvie, Novartis, Grant/research support from: Pfizer, UCB.

POS0383 EFFECTS OF TOFACITINIB THERAPY ON ARGININE AND METHIONINE METABOLITES IN ASSOCIATION WITH VASCULAR PATHOPHYSIOLOGY IN RHEUMATOID ARTHRITIS: A METABOLOMIC APPROACH

Background:

Rheumatoid arthritis (RA) has been associated with increased cardiovascular (CV) risk and metabolic changes.

Objectives:

We wished to determine how the Janus kinase (JAK) inhibitor tofacitinib influences vascular pathophysiology and metabolites of the arginine and methionine-homocysteine pathways.

Methods:

Thirty RA patients with active disease were treated with either 5 mg bid or 10 mg bid tofacitinib and evaluated at baseline and after 6 and 12 months. We determined DAS28, CRP, IgM rheumatoid factor (RF) and anti-cyclic citrullinated peptide (aCCP) levels. We assessed brachial artery flow-mediated vasodilation (FMD), carotid intima-media thickness (IMT) and pulse-wave velocity (PWV) by ultrasound. We also determined plasma L-arginine, L-citrulline, L-ornithine, inducible nitric oxide synthase (iNOS), asymmetric (ADMA) and symmetric dimethylarginine (SDMA), L-N-monomethyl-arginine (L-NMMA), cysteine, homocysteine, and methionine levels.

Results:

Twenty-six patients completed the study. Tofacitinib treatment maintained FMD and PWV. Ten mg bid tofacitinib significantly increased L-arginine, L-ornithine, iNOS and methionine levels after 12 months. Tofacitinib transiently increased L-citrulline and L-NMMA and decreased homocysteine levels after 12 months. Based on L-citrulline, L-ornithine, ADMA and SDMA levels, L-arginine remained highly available for endothelial NO production. Multivariate analysis indicated variable correlations of L-arginine, L-citrulline, ADMA, L-NMMA, homocysteine and methionine with DAS28, CRP, ESR and RF but not with aCCP. Regarding vascular pathophysiology, only PWV and methionine correlated with each other after 12 months.

Conclusion:

Tofacitinib suppressed systemic inflammation in RA yielding stabilization of vascular function. It may exert CV protective effects in RA, at least in part, by shifting L-arginine metabolism to high arginine availability and decreasing homocysteine levels.

Acknowledgements:

This research was supported by the European Union and the State of Hungary and co-financed by the European Social Fund in the framework of TAMOP-4.2.4.A/2-11/1-2012-0001 ‘National Excellence Program ’(Z.S.); by the European Union grant GINOP-2.3.2-15-2016-00015 (Z.S.) and by the WI188341 investigator-initiated research (IIR) grant obtained from Pfizer US (Z.S.).

Disclosure of Interests:

Boglárka Soós: None declared, Attila Hamar: None declared, Anita Pusztai: None declared, Monika Czókolyová: None declared, Edit Végh: None declared, Szilvia Szamosi Speakers bureau: Roche, Zsófia Pethö: None declared, Katalin Gulyás: None declared, György Kerekes: None declared, Éva Szekanecz: None declared, Sándor Szántó Speakers bureau: Abbvie, MSD, Novartis, Consultant of: Abbvie, Novartis, Gabriella Szücs Speakers bureau: Actelion, Roche, Sager, Boehringer, Consultant of: Boehringer, Actelion, Sager, Uwe Christians: None declared, Jelena Klawitter: None declared, Tamas Seres: None declared, Zoltán Szekanecz Speakers bureau: Pfizer, Abbvie, Roche, Lilly, Novartis, Boehringer, Consultant of: Pfizer, Abbvie, Novartis, Grant/research support from: Pfizer

FRI0373 ASSOCIATIONS OF VASCULAR PATHOPHYSIOLOGY AND BONE METABOLISM IN ANTI-TNF- TREATED RHEUMATOID ARTHRITIS AND ANKYLOSING SPONDYLITIS PATIENTS

Background:

Cardiovascular (CV) disease and osteoporosis (OP) have become increasing challenges in the ageing population, even more in patients with inflammatory rheumatic diseases, such as rheumatoid arthritis (RA) and spondyloarthropathies. Both RA and ankylosing spondylitis (AS) have been associated with generalized and localized bone loss, accelerated atherosclerosis, increased CV morbidity and mortality.

Objectives:

Bone and vascular biomarkers and parameters along with the effect of one-year anti-TNF therapy on these markers were assessed in order to determine correlations between vascular pathophysiology and bone metabolism in RA and AS.

Methods:

Fifty-three patients including 36 RA patients treated with etanercept (ETN) or certolizumab pegol (CZP) and 17 AS patients treated with ETN were included in a 12-month follow-up study. Bone and vascular markers were assessed by ELISA. Bone density was assessed by DXA and quantitative CT (QCT). Flow-mediated vasodilation (FMD), common carotid intima-media thickness (ccIMT) and pulse-wave velocity (PWV) were assessed by ultrasound. The effects of vascular markers on bone and bone effects on vasculature undergone statistical analysis.

Results:

Serum levels of vascular endothelial growth factor (VEGF), PDGF-BB, angiopoietin 2 (Ang2) and cathepsin K (CathK) decreased, procollagen type 1 N-propeptide (P1NP) and sclerostin (SOST) levels increased, soluble receptor activator nuclear kappa B ligand (sRANKL) and osteoprotegerin (OPG) levels showed no differences. When bone and vascular markers were correlated with each other, at baseline, OPG correlated with Ang2 and adiponectin. SOST correlated positively with ccIMT. DXA L2-4 BMD, DXA L1 BMD and DXA femoral neck (FN) BMD correlated with FMD and CRP. QCT trabecular BMD correlated with ccIMT and PON1. According to the univariate analysis, FMD correlated with OPG, ccIMT correlated with SOST and QCT trabecular BMD. Ang1, Ang2 and PDGF-BB showed correlation with Dickkopf-1 (DKK1). Ang2 also correlated with OPG. As suggested by the multivariate analysis, OPG determined FMD; DKK1 was an independent predictor of Ang1, Ang2 and PDGF-BB. OPG was a predictor of Ang2.

Conclusion:

In our study of anti-TNF treated RA and AS patients, vascular and bone parameters showed numerous correlations. The therapy was clinically effective, it halted further bone loss over 1 year and reduced the production of angiogenic markers.

Acknowledgments:

This research was supported by an investigator-initiated research grant from Pfizer.

Disclosure of Interests:

Monika Czókolyová: None declared, Katalin Gulyás: None declared, Ágnes Horváth: None declared, Edit Végh: None declared, Zsófia Pethö: None declared, Szilvia Szamosi: None declared, Attila Hamar: None declared, Anita Pusztai: None declared, Emese Balogh: None declared, Nóra Bodnár: None declared, Levente Bodoki: None declared, Agnes Szentpetery: None declared, Harjit Pal Bhattoa: None declared, György Kerekes: None declared, Katalin Hodosi: None declared, Andrea Domjan: None declared, Sándor Szántó: None declared, Gabriella Szücs: None declared, Hennie Raterman Grant/research support from: UCB, Consultant of: Abbvie, Amgen, Bristol-Myers Sqibb, Cellgene and Sanofi Genzyme, WIllem Lems Grant/research support from: Pfizer, Consultant of: Lilly, Pfizer, Zoltán Szekanecz Grant/research support from: Pfizer, UCB, Consultant of: Sanofi, MSD, Abbvie, Pfizer, Roche, Novertis, Lilly, Gedeon Richter, Amgen

THU0181 SOLUBLE VASCULAR BIOMARKERS IN RHEUMATOID ARTHRITIS AND ANKYLOSING SPONDYLITIS: EFFECTS OF ONE-YEAR ANTI-TNF-Α THERAPY

Background:

Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) have been associated with inflammatory atherosclerosis, increased cardiovascular (CV) morbidity and mortality. Numerous proteins may serve as biomarkers of inflammatory atherosclerosis. The treatment of arthritis by tumour necrosis factor α (TNF-α) inhibitors may decrease the serum concentrations of these biomarkers.

Objectives:

In this study we wished to determine circulating levels of oxidized LDL (oxLDL) - β2 glycoprotein I (β2GPI) complexes (AtherOx), anti-hsp60 antibodies, soluble urokinase plasminogen activator receptor (sUPAR) and N-terminal B-type natriuretic peptide (NT-proBNP) in sera of RA and AS patients. We also wished to assess the effects of anti-TNF treatment on these biomarkers.

Methods:

Altogether 53 arthritis patients including 36 RA patients treated with either etanercept (ETN) or certolizumab pegol (CZP) and 17 AS patients treated with ETN were included in a 12-month follow-up study.Circulating oxLDL/β2gpI complexes, anti-human Hsp60 immunoglobulin G (IgG) levels and BNP8-29fragment levels were assessed by ELISA. suPAR levels were assessed by suPARnostic®Quick Triage test. All laboratory assessments were performed at baseline, as well as 6 and 12 months after treatment initiation. Results were associated with DAS28, BASDAI, CRP.

Results:

In the mixed cohort of 53 arthritis patients, the circulating levels of oxLDL/β2gpI significantly decreased after 12 months of anti-TNF therapy (0.20±0.11 U/ml) compared to baseline (0.24±0.10 U/ml; p=0.014). There was a tendency of non-significant decrease after 6 months (0.23±0.14 U/ml) versus baseline. Anti-Hsp60 antibody levels did not change after 6 months (158.6±138.6 AU/ml) and 12 months (167.3±143.3 AU/ml) compared to baseline (170.3±140.4 AU/ml). Among the patients, 21.2% had low, 36.4% “observe”, 9.1% high and 33.3% critical suPAR levels. suPAR levels showed a tendency of non-significant decrease after 6 months (11.3±17.7 ng/ml) and 12 months (10.3±15.3 ng/ml) versus baseline (11.5±16.4 ng/ml). However, when the four serum level categories described above were considered, suPAR concentrations exerted significant decrease in RA patients with critical suPAR levels (>9ng/ml) (p=0.04). Similarly, BNP fragment levels showed only a tendency of decrease after 6 months (518.2±422.4 pmol/l) and 12 months (484.1±418.2 pmol/l) versus baseline (530.8±441.8 pmol/l). However, serum BNP levels at baseline and after 12 months were significantly increased in CCP positive compared to CCP negative RA patients (baseline: 670.6±323.0 versus 138.0±436.4 pmol/l; p=0.030 and 12 months: 652.9±283.2 versus 456.5±423.1 pmol/l; p=0.021), as well as in RF positive compared to RF negative RA patients (baseline: 680.6±381.6 versus 292.9±198.3 pmol/l; p=0.007 and 12 months: 668.9±346.5 versus 312.2±207.0 pmol/l; p=0.001).

Conclusion:

One-year anti-TNF therapy significantly decreased circulating oxLDL/β2gpI complex levels. This therapy also decreased suPAR levels in patients with critically high suPAR. BNP fragment levels were associated with seropositivity in RA. These vascular biomarkers may reflect the effects of TNF inhibition on endothelial activation.

Acknowledgments:

This study was sponsored by an investigator-initiated grant from Pfizer.

Disclosure of Interests:

Anita Pusztai: None declared, Attila Hamar: None declared, Ágnes Horváth: None declared, Edit Végh: None declared, Nóra Bodnár: None declared, György Kerekes: None declared, Monika Czókolyová: None declared, Szilvia Szamosi: None declared, Levente Bodoki: None declared, Katalin Hodosi: None declared, Andrea Domjan: None declared, Gábor Nagy: None declared, Ibolya Szöllösi: None declared, Luis Lopez Employee of: Retired employee of Corgenix Inc., Eiji Matsuura: None declared, Zoltán Prohászka: None declared, Sándor Szántó: None declared, Zoltán Nagy: None declared, Yehuda Shoenfeld: None declared, Zoltán Szekanecz Grant/research support from: Pfizer, UCB, Consultant of: Sanofi, MSD, Abbvie, Pfizer, Roche, Novertis, Lilly, Gedeon Richter, Amgen, Gabriella Szücs: None declared

SAT0471 EFFECTS OF ONE YEAR TOFACITINIB THERAPY ON BONE DENSITY AND BIOMARKERS OF BONE TURNOVER IN RHEUMATOID ARTHRITIS

Background:

Oral JAK inhibitor, tofacitinib appeared as a new therapeutic option, beside biological therapies, which has already proven its safety and effectivity in RA, but we lack of knowledge how it affects density of bone structures and bone turnover markers.

Objectives:

The aim of this study was to assess the effects of one-year tofacitinib therapy on bone metabolism in patients with RA.

Methods:

Altogether 30 RA patients with active disease were recruited and treated with tofacitinib in this 12-months follow-up study. Mean age of patients were 52.8±10.0 years, duration of rheumatoid arthritis were 7.7±5.0 years. Half of the patients haven’t received biological treatment prior tofacitinib therapy, other half of the patients switched to tofacitinib therapy after completing washout. 15 patients received 2x5mg and 15 patients received 2x10mg tofacitinib daily for 12 months. On both arms 2-2 patients have discontinued treatment and excluded from the study. Assessments were performed at baseline, month 6 and 12. Levels of CRP and IgM rheumatoid factor (RF) antibodies were measured by quantitaive nephelometry and levels of anti-CCP, sclerostin, osteocalcin (OC), P1NP were assesed by ELISA. Bone density was assesed by DXA (dual-energy X-ray absorptiometry, Lunar) and pQCT imaging techniques. Levels of DKK-1, OPG, RANKL were measured by multiplex microbead immunoassay (BioLegend LEGENDplex). In addition, disease activity (DAS28), age and disease duration were also measured. Correlations were determined by Spearman’s analysis. Univariate and multiple regression analysis using the stepwise method was applied to investigate independent associations between DXA measurements (dependent variables) and laboratory parameters (independent variables).

Results:

Tofacitinib significantly reduced DAS28 (p<0.001) and HAQ values (p=0.001), also level of CRP (p<0.001) and We (p=0.014). With respect to bone biomarkers we have experienced significant increase in levels of OC (p=0.013), OPG (p=0.006), sclerostin (p=0.026) and vitamin-D (p=0.017) at month 6, also in levels of OPG and vitamin-D (p=0.004, p=0.003) at month 12. We have found decrease in levels of CTX at month 6 (p=0.009) and 12 (p=0.003). When we examined the groups separately, we’ve found significant increase in levels of P1NP (p=0.027, p=0.005), OPG (p=0.005, p=0.002) and vitamin-D (p=0.001, p=0.004) at month 6 and 12, also in OC at month 6 (p=0.027) in Group A (2x5mg). In Group B (2x10mg) we’ve experienced a significant decrease in levels of phosphate and CTX at month 6 and 12 (p=0.012, p=0.021, and p=0.005, p=0.007).

Conclusion:

One year tofacitinib treatment effectively stabilized bone density in patients with rheumatoid arthritis, and led to the increase of bone turnover markers, which is beneficial for ossification in long term.

Acknowledgments:

This research was supported by an investigator-initiated research grant from Pfizer.

Disclosure of Interests:

Attila Hamar: None declared, Anita Pusztai: None declared, Edit Végh: None declared, Ágnes Horváth: None declared, Szilvia Szamosi: None declared, Zsófia Pethö: None declared, Sándor Szántó: None declared, Gabriella Szücs: None declared, Harjit Pal Bhattoa: None declared, Gábor Tajti: None declared, György Panyi: None declared, Katalin Hodosi: None declared, Zoltán Szekanecz Grant/research support from: Pfizer, UCB, Consultant of: Sanofi, MSD, Abbvie, Pfizer, Roche, Novertis, Lilly, Gedeon Richter, Amgen

Vitamin D status in men with psoriatic arthritis: a case-control study

We determined hypovitaminosis D prevalence in men with psoriatic arthritis. This is a cross-sectional, analyst blinded, age- and sex-matched, case-control study. Men with psoriatic arthritis have significantly lower 25-hydroxyvitamin D levels. Men with psoriatic arthritis are at increased odds of suffering from hypovitaminosis D.

INTRODUCTION

Skeletal manifestations as a result of abrupted bone metabolism may be predominant in psoriatic arthritis (PsA). Vitamin D plays a vital role in maintenance of skeletal health and is known to modulate the immune system in various autoimmune diseases including PsA. The aim of the present study was to determine the prevalence of hypovitaminosis D in a treatment naïve, de novo psoriatic arthritis male cohort in a cross-sectional, analyst blinded, age- and sex-matched, case-control study.

METHODS

25 hydroxyvitamin D (25OHD), parathyroid (PTH), osteocalcin (OC) and C-terminal telopeptides of type-I collagen (CTx) levels, and lumbar spine and femoral neck bone mineral density were compared between 53 PsA and controls.

RESULTS

The prevalence of hypovitaminosis D (25 hydroxyvitamin D (25OHD) levels <75 nmol/L) was 81 and 57 % in the PsA and control groups, respectively. Compared to the healthy controls, 25OHD (67.2 (12-137) nmol/L vs. 51.9 (15-95) nmol/L; p = 0.001) was significantly lower, and osteocalcin (13.6 (5-33) μg/L vs. 18.2 (6-35) μg/L; p = 0.003) and C-terminal telopeptides of type-I collagen (0.20 (0.01-0.71) μg/L vs. 0.28 (0.06-0.69) μg/L; p = 0.008) were significantly higher in the PsA group. A significant association was found between hypovitaminosis D and PsA; the odds for patients with PsA of having hypovitaminosis D was 3.297 (95 % confidence interval 1.372 to 7.922).

CONCLUSION

The results of this study suggest that men with PsA have significantly lower 25-hydroxyvitamin D levels, and furthermore, men with PsA are at statistically significant increased odds of suffering from hypovitaminosis D.

Kidney transplantation in hereditary coproporphyria using tacrolimus and mycophenolate mofetil: a case report

BACKGROUND

The porphyrias are a group of disorders of the heme biosynthesis pathway that may present with acute life-threatening attacks, commonly exacerbated by a wide variety of medications. Many newer immunosuppressive medications, which are in use following kidney transplantation, have not been fully explored in acute porphyrias.

CASE REPORT

A 53-year-old woman received a kidney from a deceased donor, after being on hemodialysis for 4 years. Hereditary coproporphyria was diagnosed at age 19 years. We administered tacrolimus, mycophenolate mofetil and steroid immunosuppression. In the immediate post-transplant periods she displayed abdominal pain and transient uroporphyrin elevation in parallel with slightly elevated (15 ng/mL) tacrolimus concentrations. As the target tacrolimus level was achieved, these findings disappeared.

CONCLUSIONS

Tacrolimus, mycophenolate- mofetil, and steroid therapy for hereditery coproporphyri was safe, in the long term.

Effect of phytohemagglutinin on the growth of krebs-ii tumor-cells, body metabolism and internal organs of mice

Neoplastic proliferation requires the availability of polyamines. Phytohaemagglutinin (PHA) is a potent growth factor which induces polyamine-dependent growth of the gut. In the hope of directing polyamines and other nutrients away from the tumour to the growing gut, mice fed PHA-containing or lactalbumin diets were injected intraperitoneally with Krebs II ascites cells and the number of tumour cells and the weights of internal organs were followed. PHA-treatment significantly slowed down the proliferation of tumour cells. Changes in the weight and polyamine content of tissues indicated that inter-organ competition between the tumour and vital organs can be used to manipulate the metabolism of tumour-bearing mice.

Origin and mediation of secretion induced by oral phytohaemagglutinin (PHA) in rats

After oral administration several gut-binding lectins induce accumulation of liquor and amylase in the proximal small intestine. Orally administered Phaseolus vulgaris phytohaemagglutinin (PHA) was used to study the mediation of these effects in rats. The regulation of amylase secretion clearly differed from that of the liquor. The amylase activity was of pancreatic origin, in agreement with the known cholecystokinin-releasing effect of PHA. It appears that CCK exerts its effect both directly and by facilitating neural stimulatory pathways. Intestinal secretion was identified as the source of the liquor, without a contribution by other secretions. It was mediated by a local cholinergic reflex with the involvement of both muscarinic and nicotinic acetylcholine receptors. It is speculated that the observed enteric reflex may enable the gut to transport secreted antibacterial peptides or secretory antibodies from the crypts to adherent bacteria on adjacent villi.

Suppression of growth of tumour cell lines in vitro and tumours in vivo by mistletoe lectins

A variety of studies have shown that incubation of different tumour cell lines with mistletoe lectins (MLs) in vitro has a marked cytotoxic effect. In the concentration range of low cytotoxicity cell death induced by ML-I is quantitatively due to apoptotic processes. The first events observed being membrane perforation and protusions. Simultaneous treatment of certain tumour cells with MLs rendered them more sensitive to induction of apoptosis by TNFalpha. The immunomodulatory activity of ML-I was investigated by measuring cytokine release and the results confirmed that cytokine induction by the lectin is regulated at the transcriptional level. ML-I has been shown to potentiate the effect of chemotherapeutic drugs. In addition to an in vitro effect a number of workers have demonstrated that MLs suppress tumour growth in vivo. Mistletoe lectins have been administered to animals locally to the tumour, systemic, subcutaneously or by the oral route via the diet. In many cases apoptosis was observed in the tumour and instances where complete tumour ablation has occurred have been reported. It has been hypothesized that the anticancer efficacy of tumour necrosis factor-alpha (TNFalpha) is potentiated by MLs isolated from both European and Korean mistletoe. There is accumulating evidence that both types of MLs are able to induce an anti-angiogenic response in the host suggesting that the anti-metastatic effect observed on a series of tumour cell lines in mice is in part due to an inhibition of tumour-induced angiogenesis and in part due to an induction of apoptosis.

Effect of orally administered plant lectins on intestinal liquor accumulation and amylase activity in rats

Short-term effects of orally administered plant lectins, with special reference to the Phaseolus vulgaris agglutinin (phytohaemagglutinin, PHA), were studied in growing rats. The orally administered PHA elicited a dose-dependent accumulation of liquor with elevated pH in the proximal small intestine. Although the concentration of alpha-amylase activity did not change, total alpha-amylase activity slightly, but significantly increased in the gut. When a panel of plant lectins with different carbohydrate binding specificities was tested at the dose of 100 mg/kg body weight, most of them stimulated the secretion of liquor, but the total alpha-amylase activity was increased only by PHA, ConA or WGA.

Effect of orally and intraperitoneally administered plant lectins on food consumption of rats

A panel of orally administered lectins (100 mg/kg b.w.) of different binding specificities was tested for suppression of voluntary food consumption in prefasted rats. PHA isolectins (Phaseolus vulgaris) and RPA-I (Robinia pseudoacacia) were found to exert a marked and significant effect, but two other gut-binding lectins, i.e. SBA (Glycine max) and WGA (Triticum vulgar) and several non-binding lectins were ineffective. In cannulated rats PHA infused into the duodenum induced food suppression, i.e. binding of the lectin to the mouth or stomach was unnecessary. Suppression of food consumption lasted through the whole nocturnal feeding period, control (BSA) and experimental (PHA) curves of cumulative food consumption showed a V-like divergence. Suppression by PHA or RPA-I showed very similar time courses, but a long-lasting inhibition of gastric emptying was only observed in the RPA-treated animals. Intraperitoneally administered lectins suppressed food consumption much more effectively than the oral ones, whereas Galanthus nivalis agglutinin (ONA) had little or no effect. It is concluded that lectins can be used as effective tools for the modulation of food consumption and gastric emptying in experimental animals.

Assessment of lectin inactivation by heat and digestion

Proteins/glycoproteins from plants, particularly lectins, are more resistant to heat denaturation than animal proteins (1, 2). With legume seeds, whose lectin content is appreciable, this presents potentially serious problems in nutritional practice. Therefore, before they can be used safely, legume-based food/ feeds usually require thorough and expensive heat processing to inactivate antinutritive components. Indeed, dry or moist heating of seeds at 70°C for several h has little or no effect on their lectin activity (Fig. 1) and treatment at much higher temperatures is needed to inactivate the biological and antinutritional effects of legume lectins (1, 2). The safety aspect is even more serious with some monocot lectins, such as wheatgerm agglutinin or a number of oilseed lectins, such as peanut agglutinin and many others because they are extremely heat stable and normal cooking or other conventional heat treatments may fail to inactivate them (3) Thus, the best way to avoid potential harmful effects of these heat-resistant lectins is to limit their dietary intake to a minimum. Fig. 1. Loss of lectin activity during aqueous heat treatment of soybean at various temperatures.

Mistletoe lectins enhance immune responses to intranasally co-administered herpes simplex virus glycoprotein D2

The mucosal adjuvant properties of the three type 2 ribosome-inactivating proteins (RIPs) from the European mistletoe, Viscum album L., were investigated. Mistletoe lectins were compared with cholera toxin (CT) as adjuvants when delivered nasotracheally together with herpes simplex virus glycoprotein D2 (gD2). All three mistletoe lectins (MLI, MLII, MLIII) were potent mucosal adjuvants. Co-administration of MLI, MLII or MLIII with gD2 led to significantly higher levels of gD2-specific mucosal immunoglobulin A (IgA) and systemic immunoglobulin G (IgG) antibody than when the antigen was delivered alone. The levels of antibodies induced were similar to those generated in mice immunized with gD2 and the potent mucosal adjuvant CT. Administration of ML1 with gD2 enhanced the antigen-specific splenic T-cell proliferative response. Interleukin-5 (IL-5), but not interferon-gamma (IFN-gamma), was detected in supernatants from splenocytes stimulated in vitro with gD2. This indicates that MLI enhanced type 2 T-helper cell (Th2) responses to the bystander antigen, gD2. Analysis of the gD2- and lectin-specific IgG subclass titres in mice immunized with gD2 and MLI, MLII or MLIII revealed a high ratio of IgG1 : IgG2a, which is compatible with the selective induction of Th2-type immune responses.

Dietary mistletoe lectin supplementation and reduced growth of a murine non-Hodgkin lymphoma

The growth of a murine non-Hodgkin lymphoma (NHL) tumour has been shown to be reduced by incorporating mistletoe lectin (ML-1) into the diet. The morphological characteristics of NHL tumours in mice fed ML-1-supplemented diets were different from those in LA (control)-fed mice. The degree of mitotic activity was lower and nuclear area reduced. The degree of lymphocyte infiltration was increased in tumours from ML-1 fed mice and this was accompanied by a high incidence of apoptotic bodies. Visual observation of NHL tumours from individuals fed ML-1 diet showed a poorly developed blood supply in contrast to control-fed mice. A major reduction in number of blood capillaries in NHL tumours was confirmed by microscopic evaluation of tumour sections. The results suggested an anti-angiogenic response in ML-1-fed mice. The feeding of ML-1 compared to control diet thus provided several identifiable changes in the morphology of NHL tumours which were consistent with the observed reduction in tumour weight. There was no longer histological evidence of viable tumour in 25% mice fed the ML-1 diet for 11 days. Morphological studies of the small bowel indicated (a) that the lectin induces hyperplasia, and (b) that the lectin binds avidly to lymphoid tissue of Peyer's patches. There was evidence of limited endocytosis of the lectin. An experiment where ML-3 was added to the diet of mice three days after inoculation of tumour cells showed that the lectin was able to slow down further growth of an established tumour. The results show that ML lectins induce powerful anti-cancer effects when provided by the oral route.

Effect of large dietary doses of beta-carotene on plasma retinoid and beta-carotene levels and on progesterone production in the granulosa cells of Japanese quail

An experiment was conducted to study the effect of large-dose beta-carotene supplementation on blood retinoid and beta-carotene levels as well as on the progesterone secretion of the granulosa cells in Japanese quail. Laying quails were assigned to three dietary groups. The control group (Group C) received the basal diet (laying feed containing 9000 IU vitamin A/kg). In the treated groups (Groups BC1 and BC2) the basal diet was supplemented with 10(2) and 10(3) mg/kg beta-carotene (BC), respectively. At the end of the two-week feeding period, 10 birds from each group were euthanised. Blood samples were analysed for retinol, retinyl palmitate and beta-carotene concentrations. Granulosa cells were isolated from ovarian follicles (F1 and F2), and PMSG-induced in vitro progesterone (P4) secretion was measured. Similar retinol concentrations were found in both beta-carotene supplemented groups, indicating saturation of the retinol-transporting system. beta-carotene supplementation was accompanied by hypercarotenaemia, but did not increase the retinyl palmitate levels in the blood. PMSG-induced P4 production of the granulosa cells decreased significantly in Groups BC1 and BC2 in a dose-dependent manner.

Evaluation of polyphenol bioavailability in rat small intestine

BACKGROUND

Dietary polyphenols, which are contained in several foods of plant origin, have been reported to be effective protective agents against cardiovascular diseases and cancer. However, data on their absorption from the gastrointestinal tract are still scarce and, often, contradictory.

AIM OF THE STUDY

In this report, evaluation of polyphenol bioavailability was carried out by using segments of the small intestine from rat. The extent of absorption throughout the small intestine of rat was evaluated with two model compounds, tannic acid and catechin, as representatives of high and low molecular weight polyphenols, respectively. The consequence of the binding of tannic acid to BSA on both tannic acid absorption and in vivo protein digestibility was also examined.

METHODS

Polyphenol solutions of different concentrations were injected into the lumen of ligated segments (6 cm) of the small intestine and the segments incubated in buffer for 5 min. The residual amount of polyphenol in the lumen of each segment was assayed by maximum absorption in the UV/VIS optical spectrum as was the amount of compound that had crossed the gut wall into the incubation buffer. Digestibility of BSA and of a BSA- tannic acid complex was assayed with rats.

RESULTS

The results indicated a significant, concentration-dependent, disappearance of both polyphenols from the small intestine of the rat, with higher uptake levels being evident for tannic acid (50%) than catechin (30%). However, complete transfer through the gut wall was not observed with tannic acid whilst low but significant amounts (10%) were detected in incubation buffers with catechin. Partial binding of polyphenols by endogenous proteins in the intestinal lumen was also demonstrated. Complexing tannic acid with BSA (1:10 mol/mol) was not found to affect either the extent of interaction of tannic acid with the small intestine or the in vivo digestibility of the protein.

CONCLUSIONS

Our experiments show that tannic acid and catechin both interact with the gut but only catechin appears able to traverse the gut. In addition, they provide evidence for binding of tannic acid and catechin by endogenous proteins in the intestinal lumen. This may limit their absorption from the small intestine. BSA complexed with tannic acid was as readily digested as BSA alone. This may suggest that tannic acid exerts anti-nutritional effects by binding to proteins of the gut wall and interfering with gut function rather than by inhibition of dietary protein digestion.

Phytohaemagglutinin inhibits gastric acid but not pepsin secretion in conscious rats

Phytohaemagglutinin (PHA), a kidney bean lectin, is known for its binding capability to the small intestinal surface. There has been no data available, however, on the biological activity of PHA in the stomach. Recent observations indicate that PHA is able to attach to gastric mucosal and parietal cells. Therefore, we examined whether PHA affects gastric acid and pepsin secretion in rats. Rats were surgically prepared with chronic stainless steel gastric cannula and with indwelling polyethylene jugular vein catheter. During experiments, animals were slightly restrained. Gastric acid secretion was collected in 30 min periods. Acid secretion was determined by titration of the collected gastric juice with 0.02 N NaOH to pH 7.0. Pepsin activity was estimated by measuring enzymatic activity. Saline, pentagastrin and histamine were infused intravenously. PHA or bovine serum albumin (BSA) were dissolved in saline and given intragastrically through the gastric cannula. PHA significantly inhibited basal acid secretion. Inhibition of acid output reached 72% during the first collection period following PHA administration when compared, then gradually disappeared. Pentagastrin-stimulated acid secretion was repressed dose-dependently by PHA as well. Maximal inhibition was observed during the first 30 min following application of PHA. Histamine-stimulated acid secretion was inhibited by PHA in a similar manner. Pepsin secretion was not affected by PHA under either basal or stimulated conditions. These results provide evidence that PHA is a potent inhibitor of gastric acid secretion in conscious rats, but it does not affect pepsin output from the stomach.

The identification of plant lectins with mucosal adjuvant activity

To date, the most potent mucosal vaccine adjuvants to be identified have been bacterial toxins. The present data demonstrate that the type 2 ribosome-inactivating protein (type 2 RIP), mistletoe lectin I (ML-I) is a strong mucosal adjuvant of plant origin. A number of plant lectins were investigated as intranasal (i.n.) coadjuvants for a bystander protein, ovalbumin (OVA). As a positive control, a potent mucosal adjuvant, cholera toxin (CT), was used. Co-administration of ML-I or CT with OVA stimulated high titres of OVA-specific serum immunoglobulin G (IgG) in addition to OVA-specific IgA in mucosal secretions. CT and ML-I were also strongly immunogenic, inducing high titres of specific serum IgG and specific IgA at mucosal sites. None of the other plant lectins investigated significantly boosted the response to co-administered OVA. Immunization with phytohaemagglutinin (PHA) plus OVA elicited a lectin-specific response but did not stimulate an enhanced response to OVA compared with the antigen alone. Intranasal delivery of tomato lectin (LEA) elicited a strong lectin-specific systemic and mucosal antibody response but only weakly potentiated the response to co-delivered OVA. In contrast, administration of wheatgerm agglutinin (WGA) or Ulex europaeus lectin 1 (UEA-I) with OVA stimulated a serum IgG response to OVA while the lectin-specific responses (particularly for WGA) were relatively low. Thus, there was not a direct correlation between immunogenicity and adjuvanticity although the strongest adjuvants (CT, ML-I) were also highly immunogenic.

Investigation of the mechanisms affecting Cu and Fe bioavailability from legumes: role of seed protein and antinutritional (nonprotein) factors

Chemical composition and content in polyphenols, phytic acid, and dietary fiber of whole cooked common bean (Phaseolus vulgaris L.) and faba bean (Vicia faba L.) and of soluble and insoluble fractions separated from them were determined. Simultaneous determination of Cu, Fe, and protein bioavailability in the small intestine of rat was carried out in single-dose, short-term (1 h) experiments. After cooking, about 80% of seed components (on a weight basis) of either legume was recovered in the precipitate (insoluble fraction) after extraction with water. Protein, lipid, starch, dietary fiber, and polyphenols underwent the most severe insolubilization, together with more than 70% of total Cu and Fe. Cu, Fe, and protein bioavailability showed a similar trend (i.e., the lower the protein, the lower the Cu and Fe availability). Availability of proteins, Cu, and Fe in the insoluble fractions were the lowest, but Cu bioavailability was higher than that of Fe in all fractions. The results provide evidence that the heat-induced insolubilization process adversely affects not only protein but also Cu and Fe bioavailability from legumes and that polyphenols are likely to be a major inhibitor on absorption.

Adhesion of Salmonella enterica var Enteritidis strains lacking fimbriae and flagella to rat ileal explants cultured at the air interface or submerged in tissue culture medium

Rat ileal air interface and submerged explant models were developed and used to compare the adhesion of Salmonella enterica var Enteritidis wild-type strains with that of their isogenic single and multiple deletion mutants. The modified strains studied were defective for fimbriae, flagella, motility or chemotaxis and binding was assessed on tissues with and without an intact mucus layer. A multiple afimbriate/aflagellate (fim-/fla-) strain, a fimbriate but aflagellate (fla-) strain and a fimbriate/flagellate but non-motile (mot-) strain bound significantly less extensively to the explants than the corresponding wild-type strains. With the submerged explant model this difference was evident in tissues with or without a mucus layer, whereas in the air interface model it was observed only in tissues with an intact mucus layer. A smooth swimming chemotaxis-defective (che-) strain and single or multiple afimbriate strains bound to explants as well as their corresponding wild-type strain. This suggests that under the present experimental conditions fimbriae were not essential for attachment of S. enterica var Enteritidis to rat ileal explants. However, the possession of active flagella did appear to be an important factor in enabling salmonellae to penetrate the gastrointestinal mucus layer and attach specifically to epithelial cells.

Identification of acute intermittent porphyria carriers by molecular biologic methods

Acute intermittent porphyria (AIP) is an autosomal dominant disease caused by mutations of the gene coding for hydroxymethylbilane synthase. Acute attack of AIP is a potentially life-threatening condition precipitated by certain drugs, alcohol, fasting and stress. Biochemical diagnosis before the manifestation of the symptoms is problematic, and genetic screening is required to identify asymptotic carriers. The aim of this study was to establish a fast, reproducible and reliable genetic method to detect mutations causing AIP. Exon 10 of one healthy individual and 12 AIP patients was studied using a recently developed method, temporal temperature gradient electrophoresis (TTGE). Mutation of exon 10 was detected using TTGE in one patient, DNA sequence analysis confirmed the presence of a heterozygous point mutation causing substitution of the arginine in position 173 of the gene with glutamine. These results were also confirmed using restriction enzyme analysis, and this method and TTGE identified a child of this patient as an asymptotic carrier of AIP.

Decreased levels of heat shock proteins in gut epithelial cells after exposure to plant lectins

BACKGROUND

The enterocytes of the intestinal epithelium are regularly exposed to potentially harmful substances of dietary origin, such as lectins. Expression of heat shock proteins (HSPs) by this epithelium may be part of a protective mechanism developed by intestinal epithelial cells to deal with noxious components in the intestinal lumen.

AIM

To investigate if the lectins PHA, a lectin from kidney beans (Phaseolus vulgaris) and WGA, a lectin from wheat germ (Triticum aestivum) could modify the heat shock response in gut epithelial cells and to establish the extent of this effect.

METHODS

Jejunal tissue sections from PHA and WGA fed rats were screened for expression of HSP70, HSP72, and HSP90 using monoclonal antibodies. Differentiated Caco-2 cells, the in vitro counterpart of villus enterocytes, were exposed to 100 microg/ml of PHA-E(4) or WGA for 48 hours and investigated for changes in DNA and protein synthesis by double labelling with [2-(14)C]thymidine and L-[methyl-(3)H]methionine. The relative concentrations of HSP60, HSP70, HSP72, and HSP90 and binding protein (BiP) in these cells exposed to lectins were analysed by polyacrylamide gel electrophoresis and immunoblotting. To establish if lectin exposed differentiated Caco-2 cells were still capable of producing a heat shock response, these cells received a heat shock (40 degrees C, 41 degrees C, and 42 degrees C) for one hour and were allowed to recover for six hours at 37 degrees C. During heat shock and recovery periods, lectin exposure was continued.

RESULTS

Constitutive levels of HSPs were measured in the intestinal cells of lactalbumin fed (control) rats, as may be expected from the function of this tissue. However, in PHA and WGA fed rats a marked decline in the binding of antibodies against several HSPs to the intestinal epithelium was found. These results were confirmed by in vitro experiments using differentiated Caco-2 cells exposed to PHA-E(4) and WGA. However, after exposure to lectins, these cells were still capable of heat induced heat shock protein synthesis, and total protein synthesis was not impaired indicating specific inhibition of HSP synthesis in non-stressed cells.

CONCLUSIONS

We conclude that PHA and WGA decrease levels of stress proteins in rat gut and enterocyte-like Caco-2 cells, leaving these cells less well protected against the potentially harmful content of the gut lumen.

Modulation of Salmonella infection by the lectins of Canavalia ensiformis (Con A) and Galanthus nivalis (GNA) in a rat model in vivo

The plant lectins, Concanavalin A (Con A) and Galanthus nivalis agglutinin (GNA) have been prefed to rats for 3 d pre- and 6 d postinfection with Salmonella typhimurium S986 or Salm. enteritidis 857. Con A significantly increased numbers of Salm. typhimurium S986 in the large intestine and in faeces, and severely impaired growth of the rats, more severely than is the case of infection with Salmonella typhimurium alone. Con A had much less effect on rats infected with Salm. enteritidis 857 only showing a significant increase in numbers in the colon, accompanied by intermittent increases of Salmonella in the faeces during the study. GNA significantly reduced pathogen numbers in the lower part of the small bowel and the large intestine of rats infected with Salm. typhimurium S986 and significantly improved rat growth. GNA had little effect on infection by Salm. enteritidis 857 with slight decreases in Salmonella numbers in the small intestine and large intestine and transient increases in the faeces.

Perspectives into factors limiting in vivo digestion of legume proteins: antinutritional compounds or storage proteins?

The in vivo protein digestibility of raw and cooked common bean (Phaseolus vulgaris L.) and faba bean (Vicia faba L.) and of protein fractions extracted from them was determined with growing rats. Overnight-fasted rats were intubated with a protein suspension or fed the same amount of protein added to a basal diet. The rats were killed 1 h later, the contents of stomach and small intestine were washed out, and their protein contents were measured. The in vivo digestibility of proteins of raw common bean flour was 72.4% and not significantly improved after cooking. In contrast, the digestibility of faba bean proteins was decreased from 86.5 to 60.6% by the thermal treatment. Globulins from either species had similar digestibilities (approximately 70%). Proteins in the soluble fraction of cooked beans were more digestible than those in the insoluble fraction, which contained the bulk of the proteins. Hemagglutination assay and trypsin inhibitor determination indicated that after the thermal treatment only very low, nonharmful, levels of both lectin and inhibitor remained. Faba bean contained more polyphenols than common bean samples, with most of the polyphenols being bound to globulins. However, protein-bound polyphenols were markedly decreased after cooking. SDS-PAGE characterization of the gastrointestinal digesta of globulins and amino acid analysis of undigested proteins of whole cooked common bean and faba bean suggested that it is mainly the structural properties of the storage proteins and not their binding of polyphenols, which determines the extent of protein aggregation on autoclaving and may therefore be responsible for their low digestibility.

Mucosal immunogenicity of plant lectins in mice

The mucosal immunogenicity of a number of plant lectins with different sugar specificities was investigated in mice. Following intranasal (i.n.) or oral administration, the systemic and mucosal antibody responses elicited were compared with those induced by a potent mucosal immunogen (cholera toxin; CT) and a poorly immunogenic protein (ovalbumin; OVA). After three oral or i.n. doses of CT, high levels of specific serum antibodies were measured and specific IgA was detected in the serum, saliva, vaginal wash, nasal wash and gut wash of mice. Immunization with OVA elicited low titres of serum IgG but specific IgA was not detected in mucosal secretions. Both oral and i.n. delivery of all five plant lectins investigated ¿Viscum album (mistletoe lectin 1; ML-1), Lycospersicum esculentum (tomato lectin; LEA), Phaseolus vulgaris (PHA), Triticum vulgaris (wheat germ agglutinin (WGA), Ulex europaeus I (UEA-1) stimulated the production of specific serum IgG and IgA antibody after three i. n. or oral doses. Immunization with ML-1 induced high titres of serum IgG and IgA in addition to specific IgA in mucosal secretions. The response to orally delivered ML-1 was comparable to that induced by CT, although a 10-fold higher dose was administered. Immunization with LEA also induced high titres of serum IgG, particularly after i. n. delivery. Low specific IgA titres were also detected to LEA in mucosal secretions. Responses to PHA, WGA and UEA-1 were measured at a relatively low level in the serum, and little or no specific mucosal IgA was detected.

Diverse effects of phytohaemagglutinin on gastrointestinal secretions in rats

Kidney bean lectin phytohaemagglutinin (PHA) is known for its binding capacity to the small intestinal surface inducing marked hyperplasia and hypertrophy and an increased pancreatic function. Recent observations indicate that PHA is able to attach to gastric mucosal and parietal cells. Therefore, we compared the effects of PHA on gastric acid secretion, and pancreatic amylase secretion in rats. To study gastric secretion in conscious animals, rats were surgically prepared with chronic stainless steel gastric cannula and with indwelling polyethylene jugular vein catheter. Acid secretion was determined by titration of the collected gastric juice to pH 7.0. Similar studies were performed to investigate the effect of PHA on pancreatic enzyme secretion in conscious rats supplied with pancreatic cannula. Pancreatic enzyme secretion was also studied in rats anesthetized with either halothane or urethane. In conscious rats PHA significantly inhibited basal acid secretion when compared to vehicle-treated controls. The effect was dose-dependent and reversible. On the other hand, given in the same doses as in the acid-secretory studies, PHA stimulated pancreatic amylase secretion in rats prepared with chronic pancreatic cannula. This effect was blocked by devazepide, a CCK-A receptor antagonist. In halothane-anesthetized rats PHA administration increased pancreatic amylase secretion, too. During urethane anesthesia, however, the stimulatory effect of PHA was not observed. These results provide evidence that intragastric PHA treatment induces opposite effects on gastric acid secretion and pancreatic enzyme secretion: it is a potent inhibitor of acid output, and a stimulator of pancreatic enzyme discharge. Our data also show that the stimulatory effect of PHA on pancreatic enzyme secretion can be blocked by urethane, an anaesthetic that is known to turn off the negative pancreatic feedback control of pancreatic function in rats.

Secretion of pancreatic digestive enzymes induced in rats by first-time oral exposure to kidney bean E2L2 lectin is mediated only in part by cholecystokinin (CCK)

The acute effects of kidney bean (Phaseolus vulgaris) E2L2 lectins (PHA) given orally to conscious rats or continually infused into the duodenum of anesthetized rats on blood cholecystokinin (CCK), secretin, and gastrin and on secretion of pancreatic digestive enzymes have been evaluated. PHA increased circulating levels of CCK and secretin but did not alter gastrin. In addition, PHA induced dose-dependent secretion of trypsinogen, chymotrypsinogen, and alpha-amylase by the pancreas in vivo. This pancreas output appeared to be modulated only in part through CCK. Thus pretreatment of rats with a CCK-A receptor antagonist (L-364718) attenuated the immediate (< or = 90 min) pancreas secretory response to PHA but could not prevent a PHA-associated increase in digestive enzyme output in the longer term (after 90 min). In contrast, treatment of rats with L-364718 abolished the stimulatory effects of soyabean trypsin inhibitors on digestive enzyme secretion in both the short and long term. Additional mechanisms or hormones, such as secretin, may play a role in modulating later exocrine pancreas responses to PHA.

The growth of an established murine non-Hodgkin lymphoma tumour is limited by switching to a phytohaemagglutinin-containing diet

The growth of a non-Hodgkin lymphoma, developing subcutaneously as a solid tumour in NMRI mice, is markedly diminished by including phytohaemagglutinin (PHA), a lectin present in raw kidney bean (Phaseolus vulgaris), in the diet. In the experiment described in this communication the effect of first allowing tumours to develop for 5 days before switching the mice to a diet containing PHA at different concentrations was tested to establish whether or not feeding the lectin at late times also resulted in reducing tumour growth. This switch of diet indeed proved to be effective in slowing down growth of the lymphoma tumour. The reduced rate of growth occurs in a dose-dependent manner. We have suggested that a competition between the gut epithelium undergoing PHA-stimulated hyperplasia and the developing tumour may occur for polyamines and other nutrients from a common body pool and this could be an important contributory factor with regard to the observed low level of tumour growth following the feeding of PHA-containing diet. Recent data which showed that the level of hyperplasia of the small bowel in response to feeding the PHA diets was higher in non-injected mice compared to those which had been injected with tumour cells substantiated the concept of competition between gut and tumour for nutrients and other requirements for growth.

Effect of diets containing genetically modified potatoes expressing Galanthus nivalis lectin on rat small intestine

Diets containing genetically modified (GM) potatoes expressing the lectin Galanthus nivalis agglutinin (GNA) had variable effects on different parts of the rat gastrointestinal tract. Some effects, such as the proliferation of the gastric mucosa, were mainly due to the expression of the GNA transgene. However, other parts of the construct or the genetic transformation (or both) could also have contributed to the overall biological effects of the GNA-GM potatoes, particularly on the small intestine and caecum.

Expression of the insecticidal bean alpha-amylase inhibitor transgene has minimal detrimental effect on the nutritional value of peas fed to rats at 30% of the diet

The effect of expression of bean alpha-amylase inhibitor (alpha-AI) transgene on the nutritional value of peas has been evaluated by pair-feeding rats diets containing transgenic or parent peas at 300 and 650 g/kg, respectively, and at 150 g protein/kg diet, supplemented with essential amino acids to target requirements. The results were also compared with the effects of diets containing lactalbumin with or without 0.9 or 2.0 mg bean alpha-AI, levels equivalent to those in transgenic pea diets. When 300 and 650 g peas/kg diet were fed, the daily intake of alpha-AI was 11.5 or 26.3 mg alpha-AI, respectively. At the 300 g/kg level, the nutritional value of the transgenic and parent line peas was not significantly different. The weight gain and tissue weights of rats fed either of the two pea diets were not significantly different from each other or from those of rats given the lactalbumin diet even when this was supplemented with 0.9 g alpha-AI/kg. The digestibilities of protein and dry matter of the pea diets were slightly but significantly lower than those of the lactalbumin diet, probably due to the presence of naturally occurring antinutrients in peas. The nutritional value of diets containing peas at the higher (650 g) inclusion level was less than that of the lactalbumin diet. However, the differences between transgenic and parent pea lines were small, possibly because neither the purified recombinant alpha-AI nor that in transgenic peas inhibited starch digestion in the rat small intestine in vivo to the same extent as did bean alpha-AI. This was the case even though both forms of alpha-AI equally inhibited alpha-amylase in vitro. Thus, this short-term study indicated that transgenic peas expressing bean alpha-AI gene could be used in rat diets at 300 g/kg level without major harmful effects on their growth, metabolism and health, raising the possibility that transgenic peas may also be used at this level in the diet of farm animals.

A combination of dietary protein depletion and PHA-induced gut growth reduce the mass of a murine non-Hodgkin lymphoma

The results presented in this study show that a switch from a non-protein diet (NPD) to one of a normal protein content (LA) on the day of subcutaneous injection of non-Hodgkin lymphoma tumour cells greatly favoured the development and growth of the tumour. Interestingly, however, inclusion of the plant lectin phytohaemagglutinin (PHA) in the LA diet appeared to compete with the effect of switch to the protein-rich diet, resulting in decreased tumour size and an increased incidence of necrosis. PHA was shown to induce hyperplasia of the gut even in the presence of the growing tumour. This observation together with the fact that gut hyperplasia also occurred in animals which were fed NPD supplemented with PHA, indicated the strength of PHA as a growth signal. It would seem likely that this 'normal' growth is able to compete with the tumour for important growth factors and nutrients, including polyamines, effectively starving the tumour for these molecules and resulting in its decreased rate of proliferation.

Gastrointestinal responses to a panel of lectins in rats maintained on total parenteral nutrition

Total parenteral nutrition (TPN) causes atrophy of gastrointestinal epithelia, so we asked whether lectins that stimulate epithelial proliferation can reverse this effect of TPN. Two lectins stimulate pancreatic proliferation by releasing CCK, so we asked whether lectins that stimulate gastrointestinal proliferation also release hormones that might mediate their effects. Six rats per group received continuous infusion of TPN and a once daily bolus dose of purified lectin (25 mg. rat-1. day-1) or vehicle alone (control group) for 4 days via an intragastric cannula. Proliferation rates were estimated by metaphase arrest, and hormones were measured by RIAs. Phytohemagglutinin (PHA) increased proliferation by 90% in the gastric fundus (P < 0.05), doubled proliferation in the small intestine (P < 0.001), and had a small effect in the midcolon (P < 0.05). Peanut agglutinin (PNA) had a minor trophic effect in the proximal small intestine (P < 0.05) and increased proliferation by 166% in the proximal colon (P < 0.001) and by 40% in the midcolon (P < 0.001). PNA elevated circulating gastrin and CCK by 97 (P < 0.05) and 81% (P < 0.01), respectively, and PHA elevated plasma enteroglucagon by 69% and CCK by 60% (both P < 0.05). Only wheat germ agglutinin increased the release of glucagon-like peptide-1 by 100% (P < 0.05). PHA and PNA consistently reverse the fall in gastrointestinal and pancreatic growth associated with TPN in rats. Both lectins stimulated the release of specific hormones that may have been responsible for the trophic effects. It is suggested that lectins could be used to prevent gastrointestinal atrophy during TPN. Their hormone-releasing effects might be involved.

In vivo degradation and stimulating effect of phaseolin on nitrogen secretion in rats

In short-term feeding experiments, about 78% of the phaseolin administered to rats was degraded regardless of the amounts of phaseolin intubated. In contrast, the total N found in the feces increased rapidly and exceeded the original administered amounts. The bulk of N output was not immunologically related to the glycoprotein. The effects of phaseolin on the stimulation of endogenous N secretion in the small intestine were confirmed from the results of acute experiments. Phaseolin fragments, derived from the breakdown of the native protein, when reapplied intragastrically to rats, were broken down further and to a similar extent as the original glycoprotein and were even more potent related to stimulation of N secretion. It is suggested that this secretagogue biological activity of phaseolin and not its resistance to gut proteolysis, is the main reason for the poor nutritional value of this glycoprotein.

Nutritional utilization by rats of chickpea (Cicer arietinum) meal and its isolated globulin proteins is poorer than that of defatted soybean or lactalbumin

The effects on performance, digestibility, N utilization and plasma amino acid concentrations of dietary chickpea (Cicer arietinum, var. Kabuli) seed meal, globulin proteins or buffer-insoluble residue [starch + non-starch polysaccharides (NSP) + lignin] were studied in growing rats. Chickpea meal, defatted soybean meal, chickpea globulins and lactalbumin were each incorporated into diets as the sole source of dietary protein (100 g/kg). In addition, chickpea insoluble residue was included in a control diet in the same proportion found in the chickpea meal. Rats were killed while under halothane anesthesia after 10 d of consuming the diets, and ileal contents were washed out and freeze-dried for digestibility measurements. Weight gains and gain:feed ratios of rats fed chickpea diets for 10 d did not differ from those of rats fed defatted soybean but were significantly lower than those of rats given the control (lactalbumin) diet. However, ileal and fecal N digestibilities and N retention by rats fed the chickpea diet were significantly lower than those obtained with the lactalbumin or soybean diet. The inclusion of both chickpea meal or its globulin proteins in the diet significantly increased the amount of N excreted, primarily as urea, through the urine. However, although ileal N digestibility values for chickpea meal were significantly lower, those for its constituent globulins did not differ from control values. Urea levels in plasma in rats fed diets containing chickpea meal, globulins or soybean meal were significantly higher than in those fed lactalbumin. Furthermore, the concentrations of glycine, phenylalanine, histidine, arginine and ornithine in the plasma of rats fed chickpea meal, its globulins or defatted soybean were significantly higher, whereas those of threonine, leucine, lysine and tryptophan were significantly lower than lactalbumin-fed controls. The chickpea insoluble residue had no adverse effects on performance or N utilization by rats. We conclude that the low nutritional value of chickpea meal is likely to be due mainly to adverse effects of its globulin proteins on growth and N metabolism rather than to the action of any known antinutritional factor present in the diet.