Effects of 1-year tofacitinib therapy on angiogenic biomarkers in rheumatoid arthritis

OBJECTIVES

Cardiovascular (CV) morbidity and mortality, and perpetuated synovial angiogenesis have been associated with RA. In our study we evaluated angiogenic factors in relation to vascular inflammation and function, and clinical markers in RA patients undergoing 1-year tofacitinib therapy.

METHODS

Thirty RA patients treated with either 5 mg or 10 mg twice daily tofacitinib were included in a 12-month follow-up study. Eventually, 26 patients completed the study and were included in data analysis. Levels of various angiogenic cytokines (TNF-α, IL-6), growth factors [VEGF, basic fibroblast (bFGF), epidermal (EGF), placental (PlGF)], cathepsin K (CathK), CXC chemokine ligand 8 (CXCL8), galectin-3 (Gal-3) and N-terminal prohormone brain natriuretic peptide (NT-proBNP) were determined at baseline, and at 6 and 12 months after initiating tofacitinib treatment. In order to assess flow-mediated vasodilation, common carotid intima-media thickness (ccIMT) and carotid-femoral pulse-wave velocity, ultrasonography was performed. Synovial and aortic inflammation was also assessed by 18F-fluorodeoxyglucose-PET/CT.

RESULTS

One-year tofacitinib therapy significantly decreased IL-6, VEGF, bFGF, EGF, PlGF and CathK, while it increased Gal-3 production (P < 0.05). bFGF, PlGF and NT-proBNP levels were higher, while platelet-endothelial cell adhesion molecule 1 (PECAM-1) levels were lower in RF-seropositive patients (P < 0.05). TNF-α, bFGF and PlGF correlated with post-treatment synovial inflammation, while aortic inflammation was rather dependent on IL-6 and PECAM-1 as determined by PET/CT (P < 0.05). In the correlation analyses, NT-proBNP, CXCL8 and Cath variables correlated with ccIMT (P < 0.05).

CONCLUSIONS

Decreasing production of bFGF, PlGF or IL-6 by 1-year tofacitinib therapy potentially inhibits synovial and aortic inflammation. Although NT-proBNP, CXCL8 and CathK were associated with ccIMT, their role in RA-associated atherosclerosis needs to be further evaluated.

Effect of tofacitinib therapy on angiotensin converting enzyme activity in rheumatoid arthritis

Introduction

The Renin-Angiotensin-Aldosterone system (RAAS) has been implicated in the regulation of the cardiovascular system and linked to rheumatoid arthritis (RA). Little information has become available on the effects of Janus kinase (JAK) inhibition on RAAS. Here we studied the effects of 12-month tofacitinib treatment on angiotensin converting enzyme (ACE), ACE2 production and ACE/ACE2 ratios in RA along with numerous other biomarkers.

Patients and methods

Thirty RA patients were treated with tofacitinib in this prospective study. Serum ACE concentrations were assessed by ELISA. ACE2 activity was determined by a specific quenched fluorescent substrate. ACE/ACE2 ratios were calculated. We also determined common carotid intima-media thickness (ccIMT), brachial artery flow-mediated vasodilation (FMD) and carotid-femoral pulse-wave velocity (cfPWV) by ultrasound. C-reactive protein (CRP), rheumatoid factor (RF) and anti-citrullinated protein autoantibodies (ACPA) were also determined. All measurements were performed at baseline, as well as after 6 and 12 months of tofacitinib treatment.

Results

After the dropout of 4 patients, 26 completed the study. Tofacitinib treatment increased ACE levels after 6 and 12 months, while ACE2 activity only transiently increased at 6 months. The ACE/ACE2 ratio increased after 1 year of therapy (p < 0.05). Logistic regression analyses identified correlations between ACE, ACE2 or ACE/ACE2 ratios and RF at various time points. Baseline disease duration also correlated with erythrocyte sedimentation rate (ESR) (p < 0.05). One-year changes of ACE or ACE2 were determined by tofacitinib treatment plus ACPA or RF, respectively (p < 0.05).

Conclusion

JAK inhibition increases serum ACE and ACE/ACE2 ratio in RA. Baseline inflammation (ESR), disease duration and ACPA, as well as RF levels at various time points can be coupled to the regulation of ACE/ACE2 ratio. The effect of tofacitinib on RAAS provides a plausible explanation for the cardiovascular effects of JAK inhibition in RA.

Effects of tofacitinib therapy on arginine and methionine metabolites in association with vascular pathophysiology in rheumatoid arthritis: A metabolomic approach

Introduction

Rheumatoid arthritis (RA) has been associated with changes in lipid, arginine and NO metabolism with increased cardiovascular (CV) risk. The aim of this study is to evaluate the effect of tofacitinib, a Janus kinase (JAK) inhibitor, on arginine and methionine metabolism in correlation with inflammation, functional and pathological vascular changes during one-year treatment of patients with RA.

Materials and 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. We assessed brachial artery flow-mediated vasodilation (FMD), carotid intima-media thickness (IMT) and pulse-wave velocity (PWV) by ultrasound at baseline and after 6 and 12 months. 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 at these time points.

Results

Twenty-six patients (13 on each arm) completed the study. CRP, ESR and DAS28 decreased significantly during one-year treatment with tofacitinib. Arginine and ADMA showed a negative univariate correlation with CRP but not with FMD, PWV or IMT. Tofacitinib at 10 mg bid significantly increased L-arginine, L-ornithine, iNOS and methionine levels after 12 months. ADMA and SDMA levels did not change in our study. Methionine showed negative correlation with FMD at baseline and positive correlation with PWV after 12 months. No change was observed in FMD and PWV but a significant increase was measured in IMT at 6 and 12 months. 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 anti-CCP after one-year treatment. With respect to vascular pathophysiology, only PWV and methionine correlated with each other.

Conclusion

One-year tofacitinib treatment suppressed systemic inflammation and improved functional status in RA. FMD, PWV have not been affected by one-year tofacitinib treatment., while IMT increased further despite treatment. Increased arginine and methionine might contribute to the anti-inflammatory effects of tofacitinib. Increased arginine availability with no changing ADMA may protect FMD and PWV from deterioration. The increase of IMT in the anti-inflammatory environment cannot be explained by arginine or methionine metabolism in this study.

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

Angiotensin Converting Enzyme Activity in Anti-TNF-Treated Rheumatoid Arthritis and Ankylosing Spondylitis Patients

Introduction

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 tumor necrosis factor α (TNF-α) inhibition on ACE or ACE2 homeostasis. 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.

Patients and 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).

Conclusions

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.

Peripheral quantitative computed tomography in the assessment of bone mineral density in anti-TNF-treated rheumatoid arthritis and ankylosing spondylitis patients

Abstract

Introduction

Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) are associated with osteoporosis. There have not been many peripheral quantitative computed tomography (QCT) studies in patients receiving biologics. We assessed volumetric and areal bone mineral density (BMD) by forearm QCT and dual-energy X-ray absorptiometry (DXA), respectively in addition to laboratory biomarkers in these arthritides.

Methods

Forty RA and AS patients treated with either etanercept (ETN) or certolizumab pegol (CZP) were undergoing follow-ups for one year. Volumetric and areal BMD, as well as parathyroid hormone (PTH), osteocalcin, RANKL, 25-hydroxyvitamin D (VITD), P1NP, CTX, sclerostin (SOST), Dickkopf 1 (DKK-1) and cathepsin K (CATHK) were determined.

Results

We did not observe any further bone loss during the 12-month treatment period. Volumetric and areal BMD showed significant correlations with each other (p<0.017 after Bonferroni’s correction). Trabecular QCT BMD at baseline (p=0.015) and cortical QCT BMD after 12 months (p=0.005) were inversely determined by disease activity at baseline in the full cohort. Trabecular QCT BMD at baseline also correlated with CTX (p=0.011). In RA, CRP negatively (p=0.014), while SOST positively (p=0.013) correlated with different QCT parameters. In AS, RANKL at baseline (p=0.014) and after 12 months (p=0.007) correlated with cortical QCT BMD. In the full cohort, 12-month change in QTRABBMD was related to TNF inhibition together with elevated VITD-0 levels (p=0.031). Treatment and lower CATHK correlated with QCORTBMD changes (p=0.006). In RA, TNF inhibition together with VITD-0 (p<0.01) or CATHK-0 (p=0.002), while in AS, treatment and RANKL-0 (p<0.05) determined one-year changes in QCT BMD.

Conclusions

BMD as determined by QCT did not change over one year of anti-TNF treatment. Disease activity, CATHK, RANKL and VITD may be associated with the effects of anti-TNF treatment on QCT BMD changes. RA and AS may differ in this respect.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04708-5.

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

Soluble Vascular Biomarkers in Rheumatoid Arthritis and Ankylosing Spondylitis: Effects of 1-year Antitumor Necrosis Factor-α Therapy

OBJECTIVE

Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) have been associated with cardiovascular disease. The treatment of arthritis by tumor necrosis factor-α (TNF-α) inhibitors may decrease the serum concentrations of vascular biomarkers. We determined circulating levels of oxidized low-density lipoprotein (oxLDL)/β₂ glycoprotein I (β₂-GPI) complexes, antibodies to 60 kDa heat shock protein (anti-Hsp60), soluble urokinase plasminogen activator receptor (suPAR), and B-type natriuretic peptide (BNP) fragment in sera of RA and AS patients undergoing anti-TNF treatment.

METHODS

Fifty-three patients with RA/AS were treated with etanercept or certolizumab pegol for 1 year. Circulating oxLDL/β₂-GPI complex (AtherOx), anti-Hsp60 IgG, and BNP8-29 fragment levels were assessed by ELISA. suPAR levels were determined by suPARnostic Quick Triage test. Flow-mediated vasodilation (FMD), carotid intima-media thickness (CIMT), and arterial pulse wave velocity (PWV) were determined by ultrasound.

RESULTS

One-year anti-TNF treatment significantly decreased oxLDL/β₂-GPI levels, as well as suPAR levels in patients with critically high suPAR levels at baseline. In RA, BNP levels were higher in seropositive vs seronegative patients. Serum levels of these vascular biomarkers variably correlated with lipids, anticitrullinated protein antibodies, rheumatoid factor, and C-reactive protein. CIMT positively correlated with BNP, and PWV with suPAR and anti-Hsp60, whereas FMD inversely associated with anti-Hsp60. In repeated measures ANOVA analysis, disease activity supported the effects of anti-TNF treatment on 12-month changes in oxLDL/β₂-GPI. CIMT supported the effects of therapy on changes in anti-Hsp60 and suPAR.

CONCLUSION

These biomarkers may be involved in the pathogenesis of atherosclerosis underlying RA/AS. TNF inhibition variably affects the serum levels of oxLDL/β₂-GPI, suPAR, and BNP.

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

Effects of 1-year anti-TNF-α therapy on vascular function in rheumatoid arthritis and ankylosing spondylitis

Accelerated atherosclerosis, increased cardiovascular morbidity and mortality have been associated with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Vascular function, clinical and laboratory markers and the effects of anti-TNF therapy were assessed in arthritides. Fifty-three 53 patients including 36 RA patients treated with either etanercept (ETN) or certolizumab pegol and 17 AS patients treated with ETN were included in a 12-month follow-up study. Ultrasonography was performed to determine flow-mediated vasodilation (FMD), common carotid intima-media thickness (ccIMT) and arterial pulse-wave velocity (PWV) in all patients. All assessments were performed at baseline and 6 and 12 months after treatment initiation. A significant improvement of brachial artery FMD was observed after 6 months (p = 0.004). A tendency of FMD improvement was also observed after 12 months (p = 0.065). ccIMT did not change throughout the year. PWV significantly improved after 12 months (p = 0.034). Higher baseline ccIMT (p = 0.009) and PWV (p = 0.038) were associated with clinical non-response (cNR) versus response (cR) to biologics. Multiple analysis confirmed the association of baseline ccIMT with age (p = 0.003) and cNR (p = 0.009), as well as that of baseline PWV with age at diagnosis (p = 0.022) and current chest pain (p = 0.004). Treatment itself determined the 12-month changes in FMD (p = 0.020) and PWV (p = 0.007). In a mixed cohort of RA and AS patients, TNF inhibition improved or stabilized vascular pathophysiology. Inflammation may be associated with FMD, while, among others, cNR may influence vascular function.

Complex assessment of bone mineral density, fracture risk, vitamin D status, and bone metabolism in Hungarian systemic sclerosis patients

Objective

We wished to determine bone alterations in systemic sclerosis (SSc) patients by conventional densitometry (DXA), peripheral quantitative computed tomography (pQCT), and bone biomarkers.

Methods

We included 44 SSc patients and 33 age-matched healthy controls. Lumbar spine and femoral neck bone mineral density (BMD) was assessed by DXA. Volumetric BMD was measured by pQCT at the radius. FRAX, 25-hydroxyvitamin-D₃ (25-OH-D₃), parathyroid hormone, osteocalcin, C-terminal collagen telopeptide, and procollagen type I amino-terminal propeptide were also assessed.

Results

SSc patients had lower L2–4 BMD (0.880 ± 0.108 vs. 0.996 ± 0.181 g/cm²; p = 0.019) and femoral neck (FN) BMD (0.786 ± 0.134 vs. 0.910 ± 0.090 g/cm²; p = 0.007) by DXA. In SSc vs. controls, pQCT indicated lower mean cortical (328.03 ± 103.32 vs. 487.06 ± 42.45 mg/cm³; p < 0.001) and trabecular density (150.93 ± 61.91 vs. 184.76 ± 33.03 mg/cm³; p = 0.037). Vitamin D₃ deficiency was more common in SSc vs. controls (60.0% vs. 39.3%; p = 0.003). L2–4 (p = 0.002) and FN BMD (p = 0.015) positively correlated with BMI. pQCT assessments confirmed an inverse correlation between pulmonary manifestation and total (p = 0.024), trabecular (p = 0.035), and cortical density (p = 0.015). Anti-Scl70 positivity inversely correlated with pQCT total density (p = 0.015) and the presence of digital ulcers with cortical density (p = 0.001). We also found that vertebral and FN BMD as determined by DXA significantly correlated with pQCT total, trabecular, and cortical density (p < 0.05).

Conclusion

The results of our study suggest that bone loss in SSc patients may be associated with lower BMI, anti-Scl70 positivity, and the presence of pulmonary manifestations and digital ulcers. Both DXA and pQCT are appropriate tools to evaluate the bone alterations in SSc patients.

Effects of 1-year anti-TNF-α therapies on bone mineral density and bone biomarkers in rheumatoid arthritis and ankylosing spondylitis

Objectives

Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) have been associated with generalized and localized bone loss. We conducted a comprehensive study using imaging (dual-energy X-ray absorptiometry, DXA) and laboratory biomarkers in order to determine bone health and to study the effects of anti-tumor necrosis factor (TNF) biologics in RA and AS.

Patients and methods

Thirty-six RA and 17 AS patients undergoing 1-year etanercept (ETN) or certolizumab-pegol (CZP) therapy were studied. Bone density was assessed by DXA at baseline and after 12 months. Serum C-reactive protein (CRP), calcium, phosphate, parathyroid hormone (PTH), vitamin D3, osteocalcin, procollagen type I N-propeptide (P1NP), C-terminal telopeptide (βCTX), osteoprotegerin, sclerostin (SOST), Dickkopf-1 (DKK-1), soluble receptor activator nuclear kappa B ligand (sRANKL), and cathepsin K (cathK) levels were determined at baseline and after 6 and 12 months.

Results

TNF-α inhibition was clinically effective. Anti-TNF-α halted further bone loss over 1 year. In general, anti-TNF therapy significantly increased P1NP, SOST levels, and the P1NP/βCTX ratios, while decreased DKK-1 and CathK production at different time points in most patient subsets. In the full cohort and in RA, baseline and/or 12-month bone mineral density (BMD) at multiple sites exerted inverse relationships with CRP and βCTX, and positive correlation with SOST. In AS, L2-4 BMD after 1-year biologic therapy inversely correlated with baseline βCTX, while femoral neck BMD rather showed inverse correlations with CRP.

Conclusions

Anti-TNF therapy slowed down generalized bone loss, in association with clinical improvements, in both diseases. TNF blockade may enhance bone formation and suppress joint destruction. Anti-TNF therapy may act inversely on DKK-1 and SOST. Independent predictors of BMD were SOST and βCTX in RA, whilst CRP in AS.Key Points• One-year anti-TNF therapy halted generalized bone loss in association with clinical improvement in arthritides.• Anti-TNF therapy may inversely act on DKK-1 and SOST.• Independent predictors of BMD were SOST and βCTX in RA, while CRP in AS.

Gene expression analysis of vascular pathophysiology related to anti-TNF treatment in rheumatoid arthritis

OBJECTIVES

Impaired vascular pathophysiology and increased cardiovascular (CV) mortality are associated with rheumatoid arthritis (RA). To date, no genomic analysis of RA- and RA treatment-related vascular pathophysiology has been published. In this pilot study, we performed gene expression profiling in association with vascular pathophysiology in RA patients.

METHODS

Sixteen and 19 biologic-naïve RA patients were included in study 1 and study 2, respectively. In study 1, genetic signatures determined by microarray were related to flow-mediated vasodilation (FMD), pulse-wave velocity (PWV), and common carotid intima-media thickness (IMT) of patients. In study 2, clinical response (cR) vs non-response (cNR) to 1-year etanercept (ETN) or certolizumab pegol (CZP) treatment, as well as "vascular" response (vR) vs non-response (vNR) to biologics, were also associated with genomic profiles. Multiple testing could not be performed due to the relatively small number of patients; therefore, our pilot study may lack power.

RESULTS

In study 1, multiple genes were up- or downregulated in patients with abnormal vs normal FMD, IMT, and PWV. In study 2, there were 13 cR and 6 cNR anti-tumor necrosis factor (TNF)-treated patients. In addition, 10, 9, and 8 patients were FMD-20%, IMT-20%, and PWV-20% responders. Again, vascular responder status was associated with changes of the expression of various genes. The highest number of genes showing significant enrichment were involved in positive regulation of immune effector process, regulation of glucose transport, and Golgi vesicle budding.

CONCLUSION

Differential expression of multiple genetic profiles may be associated with vascular pathophysiology associated with RA. Moreover, distinct genetic signatures may also be associated with clinical and vascular responses to 1-year anti-TNF treatment.

[Experience with a rheumatoid arthritis biobank: analysis of biological samples and clinical data of 204 patients]

INTRODUCTION

A biobank is a registry, which is suitable for the storage of biological samples (e.g. tissues, DNA, protein), genetical abnormalities and clinical data. Several biobanks have been created worldwide, which contribute to research and the better understanding of disease pathogenesis, genetical polymorphisms. Biobanking also helps to improve the efficacy of therapies.

AIM

Our purpose was to create an internet-based biobank, in which laboratory test results, genetic alterations and related disorders of rheumatoid arthritis (RA) patients can be registered. This biobank would be able to make the research easier and it can help to improve our knowledge about diseases and it can inhibit loss of data.

PATIENTS AND METHOD

We have biological samples from 204 RA patients and we have entered their data in the biobank which can be found on the website http://rheuma.biobank.eu . Statistical analysis was performed by SPSS20 statistical programme.

RESULTS

By the creation of biobank that contains clinical data and biological samples of 204 RA patients, we have a database which can help to improve our knowledge about the disease and help to develop new treatment strategies.

CONCLUSION

Biobanking is suitable to analyze blood samples and clinical data together. Orv. Hetil., 2017, 158(7), 270-277.

Evaluation of the immunogenicity of the 13-valent conjugated pneumococcal vaccine in rheumatoid arthritis patients treated with etanercept

OBJECTIVES

To prospectively evaluate the immunogenicity of a 13-valent conjugated pneumococcal vaccine (PCV13) in rheumatoid arthritis (RA) patients undergoing etanercept therapy.

METHODS

Twenty-two RA patients treated with etanercept (ETA) in combination with methotrexate (MTX) (n=15) or monotherapy (n=7) for at least one year were included. Altogether 24 osteoarthritis patients not receiving biological or MTX therapy, treating only NSAIDs or analgesics served as controls. All subjects were vaccinated with a single dose (0.5ml) of the PCV13. Pneumococcal antibody levels at baseline, 4 and 8weeks were assessed by a VaccZyme™ Anti-PCP IgG Enzyme Immunoassay Kit. Based on recommendations of the American Academy of Allergy, Asthma & Immunology, an at least two-fold increase in antibody level, as the protective antibody response (pAR) was an indicator of responsiveness (i.e., ratio of postvaccination and prevaccination antibody levels). The antibody levels and their ratios were analysed in a variety of different ways, vaccine safety parameters (fever, infections, changes in regular antirheumatic treatments) were assessed at baseline, 4 and 8weeks after vaccination.

RESULTS

Four weeks after vaccination, the anti-pneumococcal antibody levels significantly increased in both groups. At week 8, antibody levels somewhat decreased in both groups, however, still remained significantly higher compared to baseline. Compared with postvaccination levels at 4 and 8weeks between two groups, the mean protective antibody levels were higher in control group (1st month P=0.016; 2nd month: P=0.039). Possible predictors of pAR were analysed by logistic regression model. In RA, increases of antibody levels at week 8 compared to baseline exerted a negative correlation with age, (Spearman's R=-0,431; P=0.045). There were no clinically significant side effects or reaction after administration of vaccine observed in any of these patients after the 2-month follow-up period, all patients medical condition were stable.

CONCLUSIONS

In RA patients treated with ETA, vaccination with PCV13 is effective and safe, resulting in pAR one and two months after vaccination. Higher age at vaccination was identified as predictors of impaired pAR. The efficacy of vaccination may be more pronounced in younger RA patients. The vaccine is safe in RA patients on ETA.

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.