101
|
Weinberg ME, Roman MC, Jacob P, Wen M, Cheung P, Walker UA, Mulligan K, Schambelan M. Enhanced uridine bioavailability following administration of a triacetyluridine-rich nutritional supplement. PLoS One 2011; 6:e14709. [PMID: 21379380 PMCID: PMC3040752 DOI: 10.1371/journal.pone.0014709] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2010] [Accepted: 09/03/2010] [Indexed: 11/19/2022] Open
Abstract
Background Uridine is a therapy for hereditary orotic aciduria and is being investigated in other disorders caused by mitochondrial dysfunction, including toxicities resulting from treatment with nucleoside reverse transcriptase inhibitors in HIV. Historically, the use of uridine as a therapeutic agent has been limited by poor bioavailability. A food supplement containing nucleosides, NucleomaxX®, has been reported to raise plasma uridine to supraphysiologic levels. Methodology/Principal Findings Single- and multi-dose PK studies following NucleomaxX® were compared to single-dose PK studies of equimolar doses of pure uridine in healthy human volunteers. Product analysis documented that more than 90% of the nucleoside component of NucleomaxX® is in the form of triacetyluridine (TAU). Single and repeated dosing with NucleomaxX® resulted in peak plasma uridine concentrations 1–2 hours later of 150.9±39.3 µM and 161.4±31.5 µM, respectively, levels known to ameliorate mitochondrial toxicity in vitro. Cmax and AUC were four-fold higher after a single dose of NucleomaxX® than after uridine. No adverse effects of either treatment were observed. Conclusions/Significance NucleomaxX®, containing predominantly TAU, has significantly greater bioavailability than pure uridine in human subjects and may be useful in the management of mitochondrial toxicity.
Collapse
|
102
|
Beyer C, Distler JHW, Allanore Y, Aringer M, Avouac J, Czirják L, Cutolo M, Damjanov N, Del Galdo F, Fligelstone K, Guiducci S, Kowal-Bielecka O, van Laar JM, Martucci-Cerinic M, Müller-Ladner U, Riemekasten G, Tarner IH, Tyndall A, Kennedy AT, Valentini G, Vettori S, Walker UA, Denton C, Distler O. EUSTAR biobanking: recommendations for the collection, storage and distribution of biospecimens in scleroderma research. Ann Rheum Dis 2011; 70:1178-82. [PMID: 21285118 DOI: 10.1136/ard.2010.142489] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The European League Against Rheumatism Scleroderma Trials and Research Group (EUSTAR) has established an online database with clinical data of currently more than 8200 patients with systemic sclerosis (SSc). In addition to clinical research, EUSTAR fosters biomolecular studies to develop novel biomarkers and therapies for SSc. High-quality biospecimens are the basis for successful biomolecular studies. The EUSTAR biobanking group has therefore developed recommendations to standardise the collection, storage and distribution of SSc biospecimens at EUSTAR centres. These recommendations consider the scientific challenges associated with biomolecular research in SSc and the organisational requirements of EUSTAR. They were approved by the EUSTAR executive committee as well as the EUSTAR board. Once they become effective, these recommendations will be the basis for international EUSTAR studies with large numbers of SSc biospecimens. These recommendations might also be followed by other SSc consortia to enable exchange of biosamples between different SSc initiatives and might serve as a template for biobanking initiatives in other rheumatic diseases.
Collapse
|
103
|
Pöllinger B, Junt T, Metzler B, Walker UA, Tyndall A, Allard C, Bay S, Keller R, Raulf F, Di Padova F, O'Reilly T, Horwood NJ, Patel DD, Littlewood-Evans A. Th17 cells, not IL-17+ γδ T cells, drive arthritic bone destruction in mice and humans. THE JOURNAL OF IMMUNOLOGY 2011; 186:2602-12. [PMID: 21217016 DOI: 10.4049/jimmunol.1003370] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The mechanism whereby IL-17 drives rheumatoid arthritis remains incompletely understood. We demonstrate that anti-IL-17 therapy in collagen-induced arthritis ameliorates bone damage by reducing the number of osteoclasts in joints. We found equal numbers of CD4(+) Th17 and IL-17 producing γδ T cells in the joints of arthritic mice, and in vitro, both populations similarly induced osteoclastogenesis. However, individual depletion and adoptive transfer studies revealed that in vivo, Th17 cells dominated with regard to bone destruction. Unlike γδ T cells, Th17 cells were found in apposition to tartrate-resistant acid phosphatase positive osteoclasts in subchondral areas of inflamed joints, a pattern reproduced in patient biopsies. This localization was caused by Ag-specific retention, because OVA-primed Th17 cells showed a γδ T cell-like diffuse distribution. Because IL-23, as produced by osteoclasts, enhanced T cell-mediated osteoclastogenesis, we propose that Ag-specific juxtaposition is key to foster the molecular cross talk of Th17 cells and osteoclasts, thus driving arthritic bone destruction.
Collapse
|
104
|
Avouac J, Fransen J, Walker UA, Riccieri V, Smith V, Muller C, Miniati I, Tarner IH, Randone SB, Cutolo M, Allanore Y, Distler O, Valentini G, Czirjak L, Müller-Ladner U, Furst DE, Tyndall A, Matucci-Cerinic M. Preliminary criteria for the very early diagnosis of systemic sclerosis: results of a Delphi Consensus Study from EULAR Scleroderma Trials and Research Group. Ann Rheum Dis 2010; 70:476-81. [PMID: 21081523 DOI: 10.1136/ard.2010.136929] [Citation(s) in RCA: 253] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE To identify a core set of preliminary items considered as important for the very early diagnosis of systemic sclerosis (SSc). METHODS A list of items provided by European League Against Rheumatism (EULAR) Scleroderma Trial and Research(EUSTAR) centres were subjected to a Delphi exercise among 110 experts in the field of SSc. In round 1, experts were asked to choose the items they considered as the most important for the very early diagnosis of SSc. In round 2, experts were asked to reconsider the items accepted after the first stage. In round 3, the clinical relevance of selected items and their importance as measures that would lead to an early referral process were rated using appropriateness scores. RESULTS Physicians from 85 EUSTAR centres participated in the study and provided an initial list of 121 items. After three Delphi rounds, the steering committee, with input from external experts, collapsed the 121 items into three domains containing seven items, developed as follows: skin domain (puffy fingers/puffy swollen digits turning into sclerodactily); vascular domain (Raynaud's phenomenon, abnormal capillaroscopy with scleroderma pattern) and laboratory domain (antinuclear, anticentromere and antitopoisomerase-I antibodies). Finally, the whole assembly of EUSTAR centres ratified with a majority vote the results in a final face-to-face meeting. CONCLUSION The three Delphi rounds allowed us to identify the items considered by experts as necessary for the very early diagnosis of SSc. The validation of these items to establish diagnostic criteria is currently ongoing in a prospective observational cohort.
Collapse
|
105
|
Hügle T, Schuetz P, Daikeler T, Tyndall A, Matucci-Cerinic M, Walker UA, van Laar JM. Late-onset systemic sclerosis--a systematic survey of the EULAR scleroderma trials and research group database. Rheumatology (Oxford) 2010; 50:161-5. [PMID: 20884657 DOI: 10.1093/rheumatology/keq321] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVE The clinical course of SSc depends on subtype, organ involvement and age. Few data are reported on patients suffering from late-onset SSc. METHODS We analysed data from 8554 patients prospectively followed in the EULAR Scleroderma Trials and Research (EUSTAR) group database. Late-onset SSc was defined as onset of non-RP disease features at or beyond 75 years of age. Disease characteristics, clinical features, disease course and mortality were evaluated. RESULTS A total of 123 patients with SSc onset at or beyond 75 years of age were identified. Compared with patients<75 years they had more frequently limited than diffuse SSc and a higher prevalence of anti-centromere autoantibodies. Fewer old patients had digital ulcers. The modified Rodnan's skin score, the prevalence of lung fibrosis and renal crisis did not differ significantly between groups. Pulmonary hypertension (PH) measured by echocardiography was more prevalent in the late-onset group, as well as arterial hypertension and diastolic dysfunction. Late-onset SSc remained a positive predictor for PH in multivariate analyses. No significant difference of the two groups in skin score or diffusion capacity was observed during follow-up. Mortality due to SSc was higher in the late-onset group, but the survival time from diagnosis was longer compared with the younger patients. CONCLUSION Late-onset SSc shows a distinct clinical presentation and outcome. Patients with late-onset SSc suffer more frequently from the limited subtype and PH, but fewer patients have digital ulcers. PH may in part be determined by underlying cardiovascular disease.
Collapse
|
106
|
Aschwanden M, Jaeger K, Benz D, Tyndall A, Walker UA. Clinical images: Calcinosis and capillaries. ACTA ACUST UNITED AC 2010; 63:179. [PMID: 20830694 DOI: 10.1002/art.27738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
107
|
Walker UA, Courvoisier DS, Dudler J, Aeberli D, von Kempis J, Scherer A, Finckh A. Do new biologics meet the unmet medical need in rheumatoid arthritis? Safety and efficacy of abatacept following B-cell depletion. Rheumatology (Oxford) 2010; 50:243-4. [PMID: 20716674 DOI: 10.1093/rheumatology/keq258] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
108
|
Dudler J, Finckh A, Kyburz D, Langenegger T, Möller B, Schmiedel U, Walker UA. Swiss consensus statement: Recommendations for optimising re-treatment with MabThera (rituximab) in rheumatoid arthritis. Swiss Med Wkly 2010; 140:w13073. [PMID: 20648402 DOI: 10.4414/smw.2010.13073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rituximab is an effective treatment of rheumatoid arthritis (RA), which has been approved for the treatment of moderate to severe disease in patients with an inadequate response to anti-TNF therapies. Rituximab differs from other available biological agents for RA by way of its unique mode of action and unrivalled long dosing interval. The efficacy of rituximab subsides progressively over time and re-therapy is generally required to maintain long term disease control. The timing of re-treatment is currently not well established and varies widely in clinical practice. The present document is a concise recommendation regarding re-treatment with rituximab, based on validated outcomes such as the DAS28 and the EULAR response criteria. The recommendation was established through consensus between practitioners familiar with rituximab therapy in RA. Optimisation of the rituximab re-treatment schedule may improve patient outcomes and balance risks and benefits for the individual patient.
Collapse
|
109
|
Rizzi M, Knoth R, Hampe CS, Lorenz P, Gougeon ML, Lemercier B, Venhoff N, Ferrera F, Salzer U, Thiesen HJ, Peter HH, Walker UA, Eibel H. Long-lived plasma cells and memory B cells produce pathogenic anti-GAD65 autoantibodies in Stiff Person Syndrome. PLoS One 2010; 5:e10838. [PMID: 20520773 PMCID: PMC2877104 DOI: 10.1371/journal.pone.0010838] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Accepted: 04/22/2010] [Indexed: 11/25/2022] Open
Abstract
Stiff person syndrome (SPS) is a rare, neurological disorder characterized by sudden cramps and spasms. High titers of enzyme-inhibiting IgG autoantibodies against the 65 kD isoform of glutamic acid decarboxylase (GAD65) are a hallmark of SPS, implicating an autoimmune component in the pathology of the syndrome. Studying the B cell compartment and the anti-GAD65 B cell response in two monozygotic twins suffering from SPS, who were treated with the B cell-depleting monoclonal anti-CD20 antibody rituximab, we found that the humoral autoimmune response in SPS is composed of a rituximab-sensitive part that is rapidly cleared after treatment, and a rituximab-resistant component, which persists and acts as a reservoir for autoantibodies inhibiting GAD65 enzyme activity. Our data show that these potentially pathogenic anti-GAD65 autoantibodies are secreted by long-lived plasma cells, which may either be persistent or develop from rituximab-resistant memory B lymphocytes. Both subsets represent only a fraction of anti-GAD65 autoantibody secreting cells. Therefore, the identification and targeting of this compartment is a key factor for successful treatment planning of SPS and of similar autoimmune diseases.
Collapse
|
110
|
Aschwanden M, Kesten F, Stern M, Thalhammer C, Walker UA, Tyndall A, Jaeger KA, Hess C, Daikeler T. Vascular involvement in patients with giant cell arteritis determined by duplex sonography of 2x11 arterial regions. Ann Rheum Dis 2010; 69:1356-9. [PMID: 20498213 DOI: 10.1136/ard.2009.122135] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To define the specificity and extent of duplex sonography (DS) findings suggestive of vessel wall inflammation in patients with giant cell arteritis (GCA). METHODS Patients admitted between December 2006 and April 2009 to the University Hospital Basel with a suspicion of GCA were eligible for the study. DS of 2x11 arterial regions was performed in all study participants, and American College of Rheumatology criteria were applied to classify patients into GCA or non-GCA groups. RESULTS GCA was diagnosed in 38 of the 72 participants (53%). A DS pattern suggestive of vessel wall inflammation was not observed in any of the patients in the non-GCA group but, in 21 of the 38 patients with GCA (55%), DS signs suggestive of vessel wall inflammation of > or =1 vessel region were detected. In 12 of the 38 patients with GCA (32%), DS signs of large vessel vasculitis (LVV) were found in > or =1 vessel region(s) of both upper and lower limb vessels. Follow-up DS was performed 6 months after the baseline examination in 9 of the 12 patients with LVV and showed the persistence of most findings despite normalised signs of systemic inflammation. CONCLUSION DS detects changes in the vessel wall that appear to be specific for GCA; they can be present in upper and lower limb arteries of patients with GCA. Surprisingly, DS-detectable LVV and signs of systemic inflammation are largely dissociated.
Collapse
|
111
|
Allanore Y, Meune C, Vonk MC, Airo P, Hachulla E, Caramaschi P, Riemekasten G, Cozzi F, Beretta L, Derk CT, Komócsi A, Farge D, Balbir A, Riccieri V, Distler O, Chialà A, Del Papa N, Simic KP, Ghio M, Stamenkovic B, Rednic S, Host N, Pellerito R, Zegers E, Kahan A, Walker UA, Matucci-Cerinic M. Prevalence and factors associated with left ventricular dysfunction in the EULAR Scleroderma Trial and Research group (EUSTAR) database of patients with systemic sclerosis. Ann Rheum Dis 2010; 69:218-21. [PMID: 19279015 DOI: 10.1136/ard.2008.103382] [Citation(s) in RCA: 173] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVES To measure the prevalence of, and factors associated with, left ventricular (LV) dysfunction in systemic sclerosis (SSc). METHODS The EUSTAR database was first searched. A case-control study of a patient subset was then performed to further identify independent factors associated with LV dysfunction by simple and multiple regression. RESULTS Of 7073 patients, 383 (5.4%) had an LV ejection fraction (EF) of <55%. By multiple regression analysis, age, sex, diffuse cutaneous disease, disease duration, digital ulcerations, renal and muscle involvement, disease activity score, pulmonary fibrosis and pulmonary arterial hypertension were associated with LV dysfunction. In the second phase, 129 patients with SSc with LVEF <55% were compared with 256 patients with SSc with normal LVEF. Male sex (OR 3.48; 95% CI 1.74 to 6.98), age (OR 1.03; 95% CI 1.01 to 1.06), digital ulcerations (OR 1.91; 95% CI 1.05 to 3.50), myositis (OR 2.88; 95% CI 1.15 to 7.19) and use of calcium channel blockers (OR 0.41; 95% CI 0.22 to 0.74) were independent factors associated with LV dysfunction. CONCLUSION The prevalence of LV dysfunction in SSc is 5.4%. Age, male gender, digital ulcerations, myositis and lung involvement are independently associated with an increased prevalence of LV dysfunction. Conversely, the use of calcium channel blockers may be protective.
Collapse
|
112
|
Venhoff N, Lebrecht D, Deveaud C, Beauvoit B, Bonnet J, Müller K, Kirschner J, Venhoff AC, Walker UA. Oral uridine supplementation antagonizes the peripheral neuropathy and encephalopathy induced by antiretroviral nucleoside analogues. AIDS 2010; 24:345-52. [PMID: 20032772 DOI: 10.1097/qad.0b013e328335cdea] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Peripheral neuropathy and central nervous system neurodegeneration may result from the mitochondrial toxicity of some antiretroviral nucleoside analogues. We investigated whether this neuropathology may be antagonized by uridine supplementation in vivo. DESIGN Because of the obvious difficulties in obtaining human neural tissues, the mitochondrial neurotoxicity of the nucleoside analogues was studied in mice. METHODS BALB/C mice (7 weeks of age) were fed for 9 weeks with zalcitabine (13 mg/kg per day) or zidovudine (100 mg/kg per day) with or without mitocnol (340 mg/kg per day), a dietary supplement with high uridine bioavailability. Hippocampal and sciatic nerve mitochondria were analyzed. RESULTS Zalcitabine and to a lesser extent zidovudine induced a significant peripheral neuropathy and encephalopathy with disrupted mitochondrial ultrastructure, depleted mitochondrial DNA, reduced levels of cytochrome c oxidase activity and diminished expression of mitochondrial DNA-encoded cytochrome c oxidase subunit I. Mitocnol had no intrinsic effects but attenuated or fully normalized all measured disorder of the peripheral and central nervous system. CONCLUSION Zidovudine and zalcitabine induce a mitochondrial disorder in the peripheral and central nervous system, both of which are antagonized by uridine supplementation.
Collapse
|
113
|
Abstract
A 38-year-old man presented to our clinic with a 6-year history of chronic low back pain. Physical examination showed limited spine mobility; radiographs of the spine demonstrated narrowed disk spaces and calcifications. Lumbar spine magnetic resonance imaging showed Modic type II signal intensity changes in the bone marrow consistent with chronic disk degeneration. The finding of a massively elevated excretion of homogentisic acid (HGA) in the patient's urine confirmed the suspicion that the complaints were due to underlying alkaptonuria. Alkaptonuria (ochronosis) is an uncommon cause of backache and results from mutations in homogentisate 1,2-dioxygenase, an enzyme involved in tyrosine catabolism. Homogentisic acid accumulates in the plasma of the affected individuals, and HGA polymers deposit in connective tissues where they cause cartilage degeneration. So far, there is no proven treatment; but preclinical and phase I data with nitisinone, an inhibitor of HGA formation, are promising. Currently, the effects of nitisinone on joint mobility are being evaluated in a randomized trial. Clinicians involved in the care of musculoskeletal problems should be aware of this rare disorder, particularly because the correct diagnosis may have therapeutic implications.
Collapse
|
114
|
Wanner DP, Tyndall A, Walker UA. Tenofovir-induced osteomalacia. Clin Exp Rheumatol 2009; 27:1001-1003. [PMID: 20149322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We present an HIV-infected woman in whom antiretroviral treatment with tenofovir disoproxil fumarate (TDF) induced severe skeletal pain, synovial effusions and multiple fractures secondary to a Fanconi syndrome with hypophosphatemia and osteomalacia. TDF interferes with the replication of mitochondrial DNA in the proximal tubules of the kidney, which can explain the delayed onset of this form of renal phosphate loss. Nephrotoxicity had been precipitated by cotreatment with lopinavir/r, an HIV protease inhibitor which increases tenofovir serum levels and inhibits the tubular multidrug resistance protein 4, which is responsible for the efflux of tenofovir from tubular cells.Awareness is needed to link the typically prolonged onset of clinical symptoms with TDF exposure and then establish the correct diagnosis.
Collapse
|
115
|
Sievers M, Walker UA, Sevastianova K, Setzer B, Wågsäter D, Eriksson P, Yki-Järvinen H, Sutinen J. Gene expression and immunohistochemistry in adipose tissue of HIV type 1-infected patients with nucleoside analogue reverse-transcriptase inhibitor-associated lipoatrophy. J Infect Dis 2009; 200:252-62. [PMID: 19519254 DOI: 10.1086/599986] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Long-term use of both zidovudine (AZT) and stavudine (d4T) is associated with lipoatrophy, but it occurs possibly through different mechanisms. METHODS Surgical biopsy specimens of subcutaneous adipose tissue were obtained from 18 human immunodeficiency virus type 1 (HIV-1)-infected lipoatrophic patients (the LA+ group) who were treated with either zidovudine (the AZT+LA+ group; n = 10) or stavudine (the d4T+LA+ group; n = 8) and from 10 nonlipoatrophic HIV-1-infected patients (the LA- group) who received antiretroviral therapy. Mitochondrial DNA (mtDNA) copy numbers, gene expression, and immunohistochemistry data were analyzed. RESULTS mtDNA copy numbers were significantly reduced in the LA+ group, compared with the LA- group, and in the d4T+LA+ group, compared with the AZT+LA+ group. The ratio of mtDNA-encoded cytochrome COX3 to nuclear DNA-encoded COX4 expression was significantly lower in the LA+ group than in the LA- group. Compared with the LA- group, the LA+ group had significantly lower expression of genes involved in adipogenesis (SREBP1c and CEBPB), lipid (fatty acid synthase), and glucose (GLUT4) metabolism. Expression of genes involved in mitochondrial biogenesis (PGC1B), apoptosis (FAS), inflammation (IL1B), oxidative stress (PCNA and SOD1), and lamin B was significantly higher in the LA+ group than in the LA- group. The d4T+LA+ group had significantly lower expression of genes involved in mitochondrial biogenesis (POLG1), energy metabolism (the COX3/COX4 ratio), adipogenesis (SREBP1c and CEBPA), perilipin, and hexokinase than did the AZT+LA+ group. There were 7-fold more macrophages in adipose tissue specimens obtained from patients in the LA+ group, compared with the LA- group. CONCLUSIONS Lipoatrophy is characterized by mtDNA depletion, inflammation, and signs of apoptosis. Changes were more profound in the d4T+LA+ group than in the AZT+LA+ group.
Collapse
|
116
|
Venhoff N, Rizzi M, Salzer U, Bossaller L, Thoden J, Eibel H, Walker UA. Monozygotic twins with stiff person syndrome and autoimmune thyroiditis: rituximab inefficacy in a double-blind, randomised, placebo controlled crossover study. Ann Rheum Dis 2009; 68:1506-8. [DOI: 10.1136/ard.2008.103721] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
117
|
Abstract
A dose-escalating phase II trial studied masitinib, an oral tyrosine kinase inhibitor, in 43 patients with rheumatoid arthritis. Masitinib induced American College of Rheumatology (ACR)20, ACR50 and ACR70 responses in 54%, 26% and 8% of patients, respectively. A placebo group was not included. Thirty-seven per cent of the patients withdrew before the 12-week end-point was reached, primarily because of adverse events. These findings are the first on the efficacy of tyrosine kinase inhibition in a sizeable population. Future work should focus on delineating the tyrosine kinase that is most important in maintaining rheumatoid activity and address potential long-term toxicities such as gonadal insufficiency, teratogenicity and cardiotoxicity.
Collapse
|
118
|
|
119
|
Spoerl D, Bär D, Cooper J, Vogt T, Tyndall A, Walker UA. Multisegmental spondylitis due to Tropheryma whipplei: case report. Orphanet J Rare Dis 2009; 4:13. [PMID: 19493331 PMCID: PMC2697142 DOI: 10.1186/1750-1172-4-13] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Accepted: 06/03/2009] [Indexed: 12/18/2022] Open
Abstract
We report a patient who presented with inflammatory back pain due to multisegmental spondylitis. Following a vertebral biopsy which failed to detect an infectious organism, the patient was treated with etanercept, a tumor necrosis factor (TNF)-α inhibitor, for suspected undifferentiated spondyloarthritis. The back pain worsened and the spondylitic lesions increased. Only in a vertebral rebiopsy with polymerase chain reaction (PCR) amplification of Tropheryma whipplei, the causative agent of Whipple's disease was identified. Tropheryma whipplei should be considered as a cause of spondylitis even with multisegmental involvement and in the absence of gastrointestinal symptoms. In this clinical setting, routine PCR for Tropheryma whipplei from vertebral biopsies is recommended.
Collapse
|
120
|
Finckh A, Ciurea A, Brulhart L, Möller B, Walker UA, Courvoisier D, Kyburz D, Dudler J, Gabay C. Which subgroup of patients with rheumatoid arthritis benefits from switching to rituximab versus alternative anti-tumour necrosis factor (TNF) agents after previous failure of an anti-TNF agent? Ann Rheum Dis 2009; 69:387-93. [PMID: 19416802 PMCID: PMC2800201 DOI: 10.1136/ard.2008.105064] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Patients with rheumatoid arthritis (RA) with an inadequate response to TNF antagonists (aTNFs) may switch to an alternative aTNF or start treatment from a different class of drugs, such as rituximab (RTX). It remains unclear in which clinical settings these therapeutic strategies offer most benefit. OBJECTIVE To analyse the effectiveness of RTX versus alternative aTNFs on RA disease activity in different subgroups of patients. METHODS A prospective cohort study of patients with RA who discontinued at least one aTNF and subsequently received either RTX or an alternative aTNF, nested within the Swiss RA registry (SCQM-RA) was carried out. The primary outcome, longitudinal improvement in 28-joint count Disease Activity Score (DAS28), was analysed using multivariate regression models for longitudinal data and adjusted for potential confounders. RESULTS Of the 318 patients with RA included; 155 received RTX and 163 received an alternative aTNF. The relative benefit of RTX varied with the type of prior aTNF failure: when the motive for switching was ineffectiveness to previous aTNFs, the longitudinal improvement in DAS28 was significantly better with RTX than with an alternative aTNF (p = 0.03; at 6 months, -1.34 (95% CI -1.54 to -1.15) vs -0.93 (95% CI -1.28 to -0.59), respectively). When the motive for switching was other causes, the longitudinal improvement in DAS28 was similar for RTX and alternative aTNFs (p = 0.40). These results were not significantly modified by the number of previous aTNF failures, the type of aTNF switches, or the presence of co-treatment with a disease-modifying antirheumatic drug. CONCLUSION This observational study suggests that in patients with RA who have stopped a previous aTNF treatment because of ineffectiveness changing to RTX is more effective than switching to an alternative aTNF.
Collapse
|
121
|
Kremer H, Sonnenberg-Schwan U, Arendt G, Brockmeyer NH, Potthoff A, Ulmer A, Graefe K, Lorenzen T, Starke W, Walker UA. HIV or HIV-therapy? Causal attributions of symptoms and their impact on treatment decisions among women and men with HIV. Eur J Med Res 2009; 14:139-46. [PMID: 19380286 PMCID: PMC3401004 DOI: 10.1186/2047-783x-14-4-139] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Accepted: 03/04/2009] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES Among people with HIV, we examined symptom attribution to HIV or HIV-therapy, awareness of potential side effects and discontinuation of treatment, as well as sex/gender differences. METHODS HIV-patients (N=168, 46% female) completed a comprehensive symptom checklist (attributing each endorsed symptom to HIV, HIV-therapy, or other causes), reported reasons for treatment discontinuations and potential ART-related laboratory abnormalities. RESULTS Main symptom areas were fatigue/sleep/energy, depression/mood, lipodystrophy, and gastrointestinal, dermatological, and neurological problems. Top HIV-attributed symptoms were lack of stamina/energy in both genders, night sweats, depression, mood swings in women; and fatigue, lethargy, difficulties concentrating in men. Women attributed symptoms less frequently to HIV than men, particularly fatigue (p<.01). Top treatment-attributed symptoms were lipodystrophy and gastrointestinal problems in both genders. Symptom attribution to HIV-therapy did not differ between genders. Over the past six months, 22% switched/interrupted ART due to side effects. In women, side effect-related treatment decisions were more complex, involving more side effects and substances. Remarkably, women took predominantly protease inhibitor-sparing regimens (p=.05). Both genders reported only 15% of potential ART-related laboratory abnormalities but more than 50% had laboratory abnormalities. Notably, women had fewer elevated renal parameters (p<.01). CONCLUSIONS Men may attribute symptoms more often to HIV and maintain a treatment-regimen despite side effects, whereas women may be more prudent in avoiding treatment side effects. Lacking awareness of laboratory abnormalities in both genders potentially indicates gaps in physician-patient communication. Gender differences in causal attributions of symptoms/side effects may influence treatment decisions.
Collapse
|
122
|
Abstract
Fibroblasts and myofibroblasts play an important role in the pathogenesis of systemic sclerosis, fibromatoses, arthrofibrosis, and Ormond's disease. These conditions are characterized by an excessive fibroblast proliferation and partly accompanied by inflammation. Scleroderma is either localized or systemic, and features additional vasculopathy. Scleroderma-like skin lesions can be found in graft-versus-host disease following allogeneic hematopoietic stem cell transplantation, complicated malignoma or can represent an adverse drug reaction. The fibromatoses are found in superficial, or as semi-malignant desmoids in deep body compartments. Ormond's disease is a chronic periaortitis of unknown origin which extends into the retroperitoneal space. The diagnostic relevance of a histopathological diagnosis of fibrosing diseases varies and ranges from a disease-supporting to a disease-defining value.
Collapse
|
123
|
Gingelmaier A, Grubert TA, Kost BP, Setzer B, Lebrecht D, Mylonas I, Mueller-Hoecker J, Jeschke U, Hiedl S, Friese K, Walker UA. Mitochondrial toxicity in HIV type-1-exposed pregnancies in the era of highly active antiretroviral therapy. Antivir Ther 2009. [DOI: 10.1177/135965350901400309] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background The aim of this study was to determine the effects of HIV type-1 (HIV-1) infection and antiretroviral therapy (ART) on placental mitochondria. Methods HIV-1-infected pregnant women and HIV-1 -uninfected controls were enrolled prospectively. Placental mitochondrial DNA (mtDNA) copy numbers were determined by quantitative PCR, subunits II and IV of cytochrome c oxidase (COX) were quantified by western blot and mitochondrial ultrastructure was evaluated by electron microscopy. Venous blood lactate was measured in newborns. Results In total, 45 HIV-1-infected pregnant women on ART and 32 controls were included. Mean ±sd mtDNA copy numbers were significantly reduced in ART and HIV-1-exposed placentas (240 ±118 copies/ cell) in comparison with controls (686 ±842 copies/cell; P<0.001). The mean COX II/IV ratio was 48% lower in the investigational group compared with controls ( P<0.001). There was no evidence of severe ultrastructural damage within mitochondria of HIV-1-infected ART-exposed placentas. Although lactate levels between newborns did not differ, they were negatively correlated with placental mtDNA levels. There was no clear association between mitochondrial parameters and a particular nucleoside reverse transcriptase inhibitor (NRTI), the number of NRTIs or time of NRTI exposure. Conclusions Placental tissue of HIV-1-infected ART-exposed pregnancies shows evidence of mtDNA depletion with secondary respiratory chain compromise. The clinical effects of this finding warrant further investigation.
Collapse
|
124
|
Gingelmaier A, Grubert TA, Kost BP, Setzer B, Lebrecht D, Mylonas I, Mueller-Hoecker J, Jeschke U, Hiedl S, Friese K, Walker UA. Mitochondrial toxicity in HIV type-1-exposed pregnancies in the era of highly active antiretroviral therapy. Antivir Ther 2009; 14:331-338. [PMID: 19474467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
BACKGROUND The aim of this study was to determine the effects of HIV type-1 (HIV-1) infection and antiretroviral therapy (ART) on placental mitochondria. METHODS HIV-1-infected pregnant women and HIV-1-uninfected controls were enrolled prospectively. Placental mitochondrial DNA (mtDNA) copy numbers were determined by quantitative PCR, subunits II and IV of cytochrome c oxidase (COX) were quantified by western blot and mitochondrial ultrastructure was evaluated by electron microscopy. Venous blood lactate was measured in newborns. RESULTS In total, 45 HIV-1-infected pregnant women on ART and 32 controls were included. Mean +/-sd mtDNA copy numbers were significantly reduced in ART and HIV-1-exposed placentas (240 +/-118 copies/cell) in comparison with controls (686 +/-842 copies/cell; P<0.001). The mean COX II/IV ratio was 48% lower in the investigational group compared with controls (P<0.001). There was no evidence of severe ultrastructural damage within mitochondria of HIV-1-infected ART-exposed placentas. Although lactate levels between newborns did not differ, they were negatively correlated with placental mtDNA levels. There was no clear association between mitochondrial parameters and a particular nucleoside reverse transcriptase inhibitor (NRTI), the number of NRTIs or time of NRTI exposure. CONCLUSIONS Placental tissue of HIV-1-infected ART-exposed pregnancies shows evidence of mtDNA depletion with secondary respiratory chain compromise. The clinical effects of this finding warrant further investigation.
Collapse
|
125
|
McComsey GA, Lo Re V, O'Riordan M, Walker UA, Lebrecht D, Baron E, Mounzer K, Frank I. Effect of reducing the dose of stavudine on body composition, bone density, and markers of mitochondrial toxicity in HIV-infected subjects: a randomized, controlled study. Clin Infect Dis 2008; 46:1290-6. [PMID: 18444869 DOI: 10.1086/529384] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Stavudine is widely used in developing countries. Lipoatrophy and mitochondrial toxicity have been linked to stavudine use, but it is unclear whether switching to a lower dose can reduce these toxicities while maintaining human immunodeficiency virus (HIV) suppression. METHODS HIV-infected subjects receiving standard-dose stavudine with undetectable HIV type 1 RNA for > or =6 months were randomized (ratio, 3:2) to receive one-half of the stavudine dose (switch arm) or to maintain the dose (continuation arm) while continuing to receive all other prescribed antiretrovirals. The following measurements were obtained at baseline and week 48: fasting lactate, pyruvate, and lipid levels; results of whole-body dual-energy x-ray absorptiometry; and mitochondrial DNA (mtDNA) measurements in fat and peripheral blood mononuclear cells. Change from baseline to week 48 was compared within and between groups. RESULTS Twenty-four patients (79% of whom were men and 79% of whom were African American; median age, 45 years) were enrolled in the study, 15 were enrolled in the switch arm, and 9 were enrolled in the continuation arm. The median duration of stavudine treatment was 55 months (range, 21-126 months). The median CD4 cell count was 558 cells/mm(3) (range, 207-1698 cells/mm(3)). At baseline, the study arms had similar demographic characteristics and laboratory indices, except for body mass index, total lean body mass, and triglyceride levels (all of which were higher in the switch arm). Three patients (2 in the switch arm) discontinued the study because of study-unrelated reasons. CD4 cell counts remained unchanged. At 48 weeks, 6 patients (4 [27%] in the switch arm and 2 [22%] in the continuation arm) had detectable HIV RNA levels (median, 972 copies/mL; range, 60-49,400 copies/mL). All patients with detectable HIV RNA levels reported significant lapses in treatment adherence; none exhibited mutations in HIV genotype. After the treatment switch, significant changes from study entry to week 48 were noted only for lactate level (median change, -0.27 mmol/L; range, -1.2 to 0.25 mmol/L; P = .02) and fat mtDNA (median change, 40 copies/cell; range, -49 to 261 copies/cell; P = .02). In the continuation arm, a significant loss of bone mineral density was seen at week 48 (median change, -1.7%; range, -6.3% to 0.8%; P = .02). The only significant between-group difference was the change in bone mineral density from baseline (P = .003). CONCLUSIONS Reducing stavudine dose by one-half increased fat mtDNA and decreased lactate levels, suggesting improvement in mitochondrial indices while preserving HIV suppression in subjects who maintained adherence. A significant loss of bone mineral density was seen in patients receiving standard-dose stavudine but not in those receiving low-dose stavudine. These results suggest that switching to low-dose stavudine may improve mitochondrial indices while maintaining virological suppression.
Collapse
|
126
|
Distler JHW, Allanore Y, Avouac J, Giacomelli R, Guiducci S, Moritz F, Akhmetshina A, Walker UA, Gabrielli A, Müller-Ladner U, Tyndall A, Matucci-Cerinic M, Distler O. EULAR Scleroderma Trials and Research group statement and recommendations on endothelial precursor cells. Ann Rheum Dis 2008; 68:163-8. [PMID: 18653485 DOI: 10.1136/ard.2008.091918] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Systemic sclerosis (SSc) is characterised by a progressive microangiopathy that contributes significantly to the morbidity of patients with SSc. Besides insufficient angiogenesis, defective vasculogenesis with altered numbers of endothelial precursor cells (EPCs) might also contribute to the vascular pathogenesis of SSc. However, different protocols for isolation, enrichment, culture and quantification of EPCs are currently used, which complicate comparison and interpretation of the results from different studies. The aim of the European League Against Rheumatism Scleroderma Trials and Research (EUSTAR) group expert panel was to provide recommendations for standardisation of future research on EPCs. Consensus statements and recommendations were developed in a face to face meeting by an expert panel of the basic science working group of EUSTAR. The findings were: cardiovascular risk factors and medications such as statins should be described in detail. A detailed description of methods considering isolation, culture, enrichment and detection of EPCs should be given. For in vitro culture of EPCs, no protocol has been shown to be superior to another, but coating with laminin and type IV collagen would resemble most closely the situation in vivo. The endothelial phenotype should be confirmed in all in vitro cultures at the end of the culture period. We recommend using CD133, vascular endothelial growth factor type 2 receptor (VEGFR2) and CD34 in combination with a viability marker for quantification of EPCs in the blood. Finally, exact standard operating procedures for fluorescence-activated cell sorting (FACS) analysis are given that should be strictly followed. In summary, the EUSTAR recommendations will help to unify EPC research and allow better comparison between the results of different studies.
Collapse
|
127
|
Walker UA, Tyndall A, Czirjak L, Denton CP, Farge-Bancel D, Kowal-Bielecka O, Muller-Ladner U, Matucci-Cerinic M. Geographical variation of disease manifestations in systemic sclerosis: a report from the EULAR Scleroderma Trials and Research (EUSTAR) group database. Ann Rheum Dis 2008; 68:856-62. [DOI: 10.1136/ard.2008.091348] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
128
|
McComsey GA, Kang M, Ross AC, Lebrecht D, Livingston E, Melvin A, Hitti J, Cohn SE, Walker UA. Increased mtDNA levels without change in mitochondrial enzymes in peripheral blood mononuclear cells of infants born to HIV-infected mothers on antiretroviral therapy. HIV CLINICAL TRIALS 2008; 9:126-36. [PMID: 18474497 DOI: 10.1310/hct0902-126] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND The effects of gestational nucleoside reverse transcriptase inhibitors (NRTIs) on mitochondrial DNA (mtDNA) are controversial. The effects of mtDNA depletion on mitochondrial function have not been assessed. METHOD In peripheral blood mononuclear cells (PBMCs) from infants born to HIV-infected women and infants born to HIV-1-uninfected women, mtDNA copy numbers were determined by quantitative PCR; nuclear (COXIV)- and mitochondrial (COXII)-encoded polypeptides of the oxidative phosphorylation enzyme cytochrome c-oxidase (COX or complex IV) were quantified by Western blot. RESULTS Overall, 86 infants born to HIV-infected women and 50 controls were studied. HIV-infected mothers had a median CD4 count of 506 cells/microL; 59% had HIV RNA 50 copies/mL. No infant had clinical evidence of mitochondrial disease. The birth weight was lower (p = .016) and the body length higher (p = .002) in the HIV-exposed newborns. Eighty-one HIV-infected women had received gestational NRTIs (median duration 162 days). Median mtDNA copies/PBMC in the HIV-exposed infants were 505 (range, 120-1365) vs. 213 (27-426) in controls (p < .001). COX II/IV ratios were similar in both groups. Although mtDNA levels correlated inversely with maternal lactate, mitochondrial indices did not correlate with maternal CD4+ count, HIV RNA, smoking, or alcohol consumption. CONCLUSION We found elevated mtDNA copy numbers in PBMC of infants born to HIV-infected women, the majority of whom received NRTI-based therapy, when compared to those born to healthy HIV-negative controls, but there was no difference in mtDNA-encoded respiratory chain protein. The clinical consequence of these findings is unknown and requires further investigations.
Collapse
|
129
|
Walker UA, Hasler P. Stellenwert von gegen TNF-α und CD20 gerichteten Biologika in der Therapie der Vaskulitis und des systemischen Lupus erythematodes. THERAPEUTISCHE UMSCHAU 2008; 65:303-10. [DOI: 10.1024/0040-5930.65.5.303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Während die Hemmung von TNF-α bei Vaskulitis sowohl in vitro und in Tiermodellen Wirkung gezeigt hat, basiert die klinische Evidenz für die Effektivität der TNF-α Blockade bei den meisten Vaskulitiden im Wesentlichen auf Fallberichten und Fallserien. Randomisierte kontrollierte Studien haben bisher keine Überlegenheit eines anti-TNF-α Präparates beim M. Wegener und der Riesenzellarteritis gezeigt. Vielmehr ist im Kontext eines M. Wegener mit häufigeren und schweren Infektionen zu rechnen. Beim M. Behçet ist in refraktären Fällen die Behandlung der Uveitis und anderer Organmanifestationen mit einem TNF-α Hemmer aussichtsreich. Rituximab hat in einzelnen Fallberichten bei Vaskulitis eine gute Wirkung erzielt, Ergebnisse aus kontrollierten Studien sind bisher nicht verfügbar. Beobachtungsstudien lassen annehmen, dass bei refraktärem systemischem Lupus erythematodes und möglicherweise auch bei manchen Kleingefäßvaskulitiden mit Rituximab gute Ergebnisse erzielt werden können. Die unter TNF-α Blockade häufiger auftretenden schweren Infektionen setzen eine strenge multidisziplinäre Indikationsstellung und Risikoabwägung sowie eine Analyse der Verlaufsparameter voraus. Eine eingehende Information der Patienten über die Zeichen einer möglichen Infektion, sowie die Notwendigkeit einer umgehenden Abklärung und gegebenenfalls Therapie des Erregers ist notwendig. Wegen der Komplexität der Fragestellung und der Gefahr der Morbidität durch die Vaskulitis oder des systemischen Lupus erythematodes einerseits und deren Therapie andererseits sollten Biologika in der Therapie dieser Erkrankungen nur in dafür umfassend ausgestatteten Institutionen angewendet werden.
Collapse
|
130
|
Walker UA, Tyndall A, Daikeler T. Rheumatic conditions in human immunodeficiency virus infection. Rheumatology (Oxford) 2008; 47:952-9. [PMID: 18413346 DOI: 10.1093/rheumatology/ken132] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Many rheumatic diseases have been observed in HIV-infected persons. We, therefore, conducted a comprehensive literature search in order to review the prevalence, presentation and pathogenesis of rheumatic manifestations in HIV-infected subjects. Articular conditions (arthralgia, arthritis and SpAs) are either caused by the HIV infection itself, triggered by adaptive changes in the immune system, or secondary to microbial infections. Muscular symptoms may result from rhabdomyolysis, myositis or from side-effects of highly active anti-retroviral therapy (HAART). Osseous complications include osteonecrosis, osteoporosis and osteomyelitis. Some conditions such as the diffuse infiltrative lymphocytosis syndrome and sarcoidosis affect multiple organ systems. SLE may be observed but may be difficult to differentiate from HIV infection. Some anti-retroviral agents can precipitate hyperuricaemia and are associated with arthralgia. When indicated, immunosuppressants and even anti-TNF-alpha agents can be used in the carefully monitored HIV patient. Thus, rheumatic diseases and asymptomatic immune phenomena remain prevalent in HIV-infected persons even after the widespread implementation of highly active anti-retroviral therapy.
Collapse
|
131
|
Lebrecht D, Deveaud C, Beauvoit B, Bonnet J, Kirschner J, Walker UA. Uridine supplementation antagonizes zidovudine-induced mitochondrial myopathy and hyperlactatemia in mice. ACTA ACUST UNITED AC 2008; 58:318-26. [PMID: 18163507 DOI: 10.1002/art.23235] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Zidovudine is an antiretroviral nucleoside analog reverse transcriptase inhibitor that induces mitochondrial myopathy by interfering with the replication of mitochondrial DNA (mtDNA). Because zidovudine inhibits thymidine kinases, the mechanism of mtDNA depletion may be related to an impairment of the de novo synthesis of pyrimidine nucleotides, which are required building blocks of mtDNA. This study was undertaken to determine whether mitochondrial myopathy is a class effect of antiretroviral nucleoside analogs, and whether the muscle disease can be prevented by treatment with uridine as a pyrimidine nucleotide precursor. METHODS BALB/c mice were treated with zidovudine or zalcitabine. Some of the mice were cotreated with mitocnol, a dietary supplement with high uridine bioavailability. Mice hind limb muscles were examined after 10 weeks. RESULTS Zidovudine induced muscle fiber thinning, myocellular fat deposition, and abnormalities of mitochondrial ultrastructure. In mice treated with zidovudine, organelles contained low mtDNA copy numbers and reduced cytochrome c oxidase activity. The expression of the mtDNA-encoded cytochrome c oxidase I subunit, but not of nucleus-encoded mitochondrial proteins, was impaired. Zidovudine also increased the levels of myocellular reactive oxygen species and blood lactate. Uridine supplementation attenuated or normalized all pathologic abnormalities and had no intrinsic effects. Zalcitabine did not elicit muscle toxicity. CONCLUSION Our findings indicate that zidovudine, but not zalcitabine, induces mitochondrial myopathy, which is substantially antagonized by uridine supplementation. These results provide proof of the importance of pyrimidine pools in the pathogenesis of zidovudine myopathy. Since uridine supplementation is tolerated well by humans, this treatment strategy should be investigated in clinical trials.
Collapse
|
132
|
Setzer B, Lebrecht D, Walker UA. Pyrimidine nucleoside depletion sensitizes to the mitochondrial hepatotoxicity of the reverse transcriptase inhibitor stavudine. THE AMERICAN JOURNAL OF PATHOLOGY 2008; 172:681-90. [PMID: 18276780 DOI: 10.2353/ajpath.2008.070613] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Stavudine is a hepatotoxic antiretroviral nucleoside analogue that also inhibits the replication of mitochondrial DNA (mtDNA). To elucidate the mechanism and consequences of mtDNA depletion, we treated HepG2 cells with stavudine and either redoxal, an inhibitor of de novo pyrimidine synthesis, or uridine, from which pyrimidine pools are salvaged. Compared with treatment with stavudine alone, co-treatment with redoxal accelerated mtDNA depletion, impaired cell division, and activated caspase 3. These adverse effects were completely abrogated by uridine. Intracellular ATP levels were unaffected. Transcriptosome profiling demonstrated that redoxal and stavudine acted synergistically to induce CDKN2A and p21, indicating cell cycle arrest in G1, as well as genes involved in intrinsic and extrinsic apoptosis. Moreover, redoxal and stavudine showed synergistic interaction in the up-regulation of transcripts encoded by mtDNA and the induction of nuclear transcripts participating in energy metabolism, mitochondrial biogenesis, oxidative stress, and DNA repair. Genes involved in nucleotide metabolism were also synergistically up-regulated by both agents; this effect was completely antagonized by uridine. Thus, pyrimidine depletion sensitizes cells to stavudine-mediated mtDNA depletion and enhances secondary cell toxicity. Our results indicate that drugs that diminish pyrimidine pools should be avoided in stavudine-treated human immunodeficiency virus patients. Uridine supplementation reverses this toxicity and, because of its good tolerability, has potential clinical value for the treatment of side effects associated with pyrimidine depletion.
Collapse
|
133
|
Weiner SM, Jurenz S, Uhl M, Lange-Nolde A, Warnatz K, Peter HH, Walker UA. Ultrasonography in the assessment of peripheral joint involvement in psoriatic arthritis : a comparison with radiography, MRI and scintigraphy. Clin Rheumatol 2008; 27:983-9. [PMID: 18259687 DOI: 10.1007/s10067-008-0835-y] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2007] [Revised: 12/23/2007] [Accepted: 01/01/2008] [Indexed: 11/26/2022]
Abstract
The objective of our study was to investigate the role of musculoskeletal ultrasound (US) in the assessment of hand and foot small joints in psoriatic arthritis (PsA). Thirteen consecutive patients with PsA of hands or feet underwent B-mode US using a 9- to 13-MHz transducer and simultaneous magnetic resonance imaging (MRI), bone scintigraphy and radiography. US findings were compared with radiography, MRI and scintigraphy in 190, 182 and 109 joints, respectively. To assess the sensitivity and specificity of US, radiography was considered as gold standard for the detection of erosions and osteoproliferations and MRI as gold standard for the detection of joint effusion and synovitis. US, MRI and scintigraphy had a higher sensitivity in the detection of overall joint pathology than radiography in painful and/or swollen joints (71%, 72%, 82% vs 32%) and clinically unaffected joints (17%, 21%, 9% vs 2%). US and radiography detected more erosions and osteoproliferations than MRI, with low agreement between the methods in the detection of erosions. Radiography was superior to US in the visualisation of osteoproliferations. Joint effusions and/or synovitis were more frequently detected by MRI than US. Agreement between both imaging methods was better in carpal joints, carpometacarpal joint I, metacarpophalangeal (MCP)/metatarsophalangeal (MTP) joint I, II and V than in MCP/MTP III, IV, PIP and DIP joints. Compared with MRI, radiography and scintigraphy, the specificity of US ranges between 0.84 and 0.94, depending on the joint pathology. In conclusion, the diagnostic sensitivity of US in the detection of PsA-related synovitis of hands and feet is lower than MRI and depends on the joint region. However, the low cost and the acceptable specificity suggest that US is a useful imaging method in addition to radiography in PsA of hands and feet.
Collapse
|
134
|
Hügle T, Gratzl S, Daikeler T, Frey D, Tyndall A, Walker UA. Sclerosing skin disorders in association with multiple sclerosis. Coincidence, underlying autoimmune pathology or interferon induced?: Table 1. Ann Rheum Dis 2008; 68:47-50. [DOI: 10.1136/ard.2007.083246] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Objectives:To describe and analyse the manifestation of sclerosing skin disorders in patients with multiple sclerosis (MS).Case reports:We describe three patients with relapsing-remitting MS who developed skin sclerosis while receiving interferon (IFN)-β treatment and review nine further cases of systemic sclerosis (SSc) in MS from the literature. Of all 12 patients reported, eight had limited cutaneous SSc, three had diffuse cutaneous SSc and one patient had an antisynthetase syndrome. Localised scleroderma such as morphoea was not described. The mean age at diagnosis was 25.2 years for MS (range 12 to 51) and 38.3 years for SSc (range 16 to 66). Eleven patients developed SSc after the onset of MS and manifested with skin sclerosis after a mean of 14.9 years (range 1 to 45). In five patients IFN-β was commenced before the development of skin sclerosis (mean 4.6 years, range 1 to 8 years). There was no relationship between the onset of skin sclerosis and MS activity. With the exception of one individual, all patients had antinuclear antibodies.Conclusions:Sclerosing skin disorders may develop in the course of MS. The relatively early age of SSc onset in patients with MS suggests a genetic predisposition and/or an IFN-associated trigger.
Collapse
|
135
|
Lebrecht D, Deveaud C, Beauvoit B, Bonnet J, Kirschner J, Mueller K, Venhoff N, Walker UA. Uridine supplementation with Mitocnol antagonizes antiretroviral nucleoside analogue-induced mitochondrial peripheral and cerebral neuropathy in vivo. J Int AIDS Soc 2008. [DOI: 10.1186/1758-2652-11-s1-p148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
136
|
Thoden J, Lebrecht D, Venhoff N, Neumann JH, Müller K, Walker UA. Quantitative and qualitative mtDNA-lesions with mitochondrial dysfunction in multiple organs after HAART-associated fatal lactacidosis. J Int AIDS Soc 2008. [DOI: 10.1186/1758-2652-11-s1-p145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
137
|
Venhoff N, Walker UA. Mitochondrial disease in the offspring as a result of antiretroviral therapy. Expert Opin Drug Saf 2007; 5:373-81. [PMID: 16610967 DOI: 10.1517/14740338.5.3.373] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Nucleoside analogue reverse transcriptase inhibitors (NRTIs) have substantially lowered the risk of the mother-to-child transmission of HIV. Evidence of mitochondrial toxicity in vitro, in animal models and in adult HIV-infected patients, has raised concern about the perinatal safety of these antiretrovirals. In zidovudine-exposed, but HIV-uninfected infants, transient anaemia and additional long-term blood abnormalities (neutropenia, thrombopenia and lymphopenia) and hyperlactatemia have been documented. The overall risk of mortality and congenital abnormalities does not appear to be increased, but rare mitochondrial events cannot be excluded for lack of statistical power. French data suggest an above background incidence of mitochondrial symptomatology. Preclinical data demonstrate zidovudine also to be a carcinogen. Long-term systematic follow-up of exposed babies in large cohorts is needed, as are randomised trials with NRTIs carrying a lower risk of mitochondrial toxicity.
Collapse
|
138
|
Venhoff N, Setzer B, Melkaoui K, Walker UA. Mitochondrial Toxicity of Tenofovir, Emtricitabine and Abacavir Alone and in Combination with Additional Nucleoside Reverse Transcriptase Inhibitors. Antivir Ther 2007. [DOI: 10.1177/135965350701200704] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Background Some nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) combinations cause additive or synergistic interactions in vitro and in vivo. Methods We evaluated the mitochondrial toxicity of tenofovir (TFV), emtricitabine (FTC) and abacavir as carbovir (CBV) alone, with each other, and in combination with additional NRTIs. HepG2 human hepatoma cells were incubated with TFV, FTC, CBV, didanosine (ddI), stavudine (d4T), lamivudine (3TC) and zidovudine (AZT) at concentrations equivalent to 1 and 10x clinical steady-state peak plasma levels (Cmax). NRTIs were also used in double and triple combinations. Cell growth, lactate production, intracellular lipids, mtDNA and the mtDNA-encoded respiratory chain subunit II of cytochrome c oxidase (COXII) were monitored for 25 days. Results TFV and 3TC had no or minimal toxicity. FTC moderately reduced hepatocyte proliferation independent of effects on mtDNA. ddI and d4T induced a time- and dose-dependent loss of mtDNA and COXII, decreased cell growth and increased levels of lactate and intracellular lipids. CBV and AZT strongly impaired hepatocyte proliferation and increased lactate and lipid production, but did not induce mtDNA depletion. The dual combination of TFV plus 3TC had only minimal toxicity; TFV plus FTC slightly reduced cell proliferation without affecting mitochondrial parameters. All other combinations exhibited more pronounced adverse effects on mitochondrial endpoints. Toxic effects on mitochondrial parameters were observed in all combinations with ddI, d4T, AZT or CBV. TFV and 3TC both attenuated ddI-related cytotoxicity, but worsened the effects of CBV and AZT. Conclusions The data demonstrate unpredicted interactions between NRTIs with respect to toxicological endpoints and provide an argument against the liberal use of NRTI cocktails without first obtaining data from clinical trials.
Collapse
|
139
|
McComsey GA, O'Riordan M, Setzer B, Lebrecht D, Baron E, Walker UA. Uridine supplementation in HIV lipoatrophy: pilot trial on safety and effect on mitochondrial indices. Eur J Clin Nutr 2007; 62:1031-7. [PMID: 17538545 PMCID: PMC4105300 DOI: 10.1038/sj.ejcn.1602793] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVES Uridine abrogates mitochondrial toxicities of nucleoside reverse transcriptase inhibitor in adipocyte cell culture. We aim to study the effect of uridine supplementation on human adipocyte mitochondrial DNA (mtDNA) levels in subjects with human immunodeficiency (HIV) lipoatrophy. METHODS Sixteen patients with lipoatrophy on stavudine-containing antiretroviral therapy were enrolled, and received NucleomaxX, a dietary supplement with a high bioavailability of uridine (36 g TID every other day for 16 weeks). Patients were then followed off-uridine for another 16 weeks. Highly active antiretroviral therapy remained unchanged during the trial. RESULTS Fourteen patients completed the study. Two subjects dropped out before week 4 for study-unrelated reasons. No adverse events were noted throughout the study. HIV-1 RNA, CD4 counts, liver enzymes and hemoglobin remained unchanged. Body mass index, lactate, lipids, insulin and homeostasis model assessment of insulin resistance were unaltered. Fat and peripheral blood and mononuclear cell mtDNA levels did not correlate with each other and exhibited no changes throughout the study. Lipoatrophy scores by patients and physician improved significantly at weeks 16 and 32 compared to study entry. CONCLUSION In this pilot study, NucleomaxX was safe, well tolerated without apparent deleterious effect on HIV indices. In contrast to in vitro data, NucleomaxX did not lead to changes in fat or blood mtDNA levels.
Collapse
|
140
|
Lebrecht D, Geist A, Ketelsen UP, Haberstroh J, Setzer B, Walker UA. Dexrazoxane prevents doxorubicin-induced long-term cardiotoxicity and protects myocardial mitochondria from genetic and functional lesions in rats. Br J Pharmacol 2007; 151:771-8. [PMID: 17519947 PMCID: PMC2014121 DOI: 10.1038/sj.bjp.0707294] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND AND PURPOSE Doxorubicin causes a chronic cardiomyopathy in which reactive oxygen species (ROS) accumulate over time and are associated with genetic and functional lesions of mitochondria. Dexrazoxane is a cardioprotective iron chelator that interferes with ROS production. We aim to analyze the effects of dexrazoxane on mitochondria in the prevention of doxorubicin-induced chronic myocardial lesions. EXPERIMENTAL APPROACH Wistar rats (11 weeks of age) were injected with intravenous doxorubicin (0.8 mg kg(-1) weekly for 7 weeks) with or without simultaneous dexrazoxane (8 mg kg(-1)). Animals were killed at 48 weeks. Cardiomyopathy was scored clinically and histologically and cardiac mitochondria were analyzed. KEY RESULTS Compared to control rats receiving saline, rats treated with doxorubicin alone developed a clinical, macroscopic, histological and ultrastructural cardiomyopathy with low cytochrome c-oxidase (COX) activity (26% of controls). The expression of the mtDNA-encoded COX II subunit was reduced (64% of controls). Myocardia exhibited a high production of ROS (malondialdehyde 338% and superoxide 787% of controls). Mitochondria were depleted of mitochondrial DNA (mtDNA copy number 46% of controls) and contained elevated levels of mtDNA deletions. Dexrazoxane co-administration prevented all these effects of doxorubicin on mitochondria, except that hearts co-exposed to doxorubicin and dexrazoxane had a slightly lower mtDNA content (81% of controls) and mtDNA deletions at low frequency. CONCLUSIONS AND IMPLICATIONS Dexrazoxane prevented doxorubicin induced late-onset cardiomyopathy and also protected the cardiac mitochondria from acquired ultrastructural, genetic and functional damage.
Collapse
|
141
|
Tyndall A, Walker UA, Cope A, Dazzi F, De Bari C, Fibbe W, Guiducci S, Jones S, Jorgensen C, Le Blanc K, Luyten F, McGonagle D, Martin I, Bocelli-Tyndall C, Pennesi G, Pistoia V, Pitzalis C, Uccelli A, Wulffraat N, Feldmann M. Immunomodulatory properties of mesenchymal stem cells: a review based on an interdisciplinary meeting held at the Kennedy Institute of Rheumatology Division, London, UK, 31 October 2005. Arthritis Res Ther 2007; 9:301. [PMID: 17284303 PMCID: PMC1860056 DOI: 10.1186/ar2103] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Multipotent mesenchymal stromal cells isolated from bone marrow and other sites are currently being studied to determine their potential role in the pathogenesis and/or management of autoimmune diseases. In vitro studies have shown that they exhibit a dose-dependent antiproliferative effect on T and B lymphocytes, dendritic cells, natural killer cells and various B cell tumour lines – an effect that is both cell contact and soluble factor dependent. Animal models of autoimmune disease treated with multipotent mesenchymal stromal cells have mostly exhibited a positive clinical response, as have a limited number of patients suffering from acute graft versus host disease. This review summarizes the findings of a 1-day meeting devoted to the subject with the aim of coordinating efforts.
Collapse
|
142
|
Lebrecht D, Walker UA. Role of mtDNA lesions in anthracycline cardiotoxicity. Cardiovasc Toxicol 2007; 7:108-13. [PMID: 17652814 DOI: 10.1007/s12012-007-0009-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 10/23/2022]
Abstract
Doxorubicin (adriamycin) is an effective drug in the treatment of many malignancies. Its prolonged use is, however, limited by an irreversible, dose-dependent and progressive cardiomyopathy, which may become evident even years after completion of therapy. Data from rats and humans show that oxidative phosphorylation is impaired rapidly after acute doxorubicin-exposure. Such respiratory chain dysfunction is known to enhance the production of reactive oxygen species and may lead to quantitative and qualitative injury of mitochondrial DNA (mtDNA) and its encoded respiratory chain subunits. MtDNA depletion, mtDNA mutations and respiratory defects then accumulate with time also in the absence of continued anthracycline exposure. Chronic cardiotoxicity then manifests, when the bioenergetic capacity of the organelles is severely impaired. The mitochondrial damage in late-onset doxorubicin cardiomyopathy is heart specific and not found in skeletal muscle. DOXO-EMCH, a 6-maleimidocaproyl hydrazone derivative of doxorubicin has evolved from the search for less cardiotoxic anthracyclines. At equieffective antitumor doses, DOXO-EMCH has a substantially lower heart toxicity than free doxorubicin.
Collapse
|
143
|
Walker UA, Tyndall A, Czirják L, Denton C, Farge-Bancel D, Kowal-Bielecka O, Müller-Ladner U, Bocelli-Tyndall C, Matucci-Cerinic M. Clinical risk assessment of organ manifestations in systemic sclerosis: a report from the EULAR Scleroderma Trials And Research group database. Ann Rheum Dis 2007; 66:754-63. [PMID: 17234652 PMCID: PMC1954657 DOI: 10.1136/ard.2006.062901] [Citation(s) in RCA: 593] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Systemic sclerosis (SSc) is a multisystem autoimmune disease, which is classified into a diffuse cutaneous (dcSSc) and a limited cutaneous (lcSSc) subset according to the skin involvement. In order to better understand the vascular, immunological and fibrotic processes of SSc and to guide its treatment, the EULAR Scleroderma Trials And Research (EUSTAR) group was formed in June 2004. AIMS AND METHODS EUSTAR collects prospectively the Minimal Essential Data Set (MEDS) on all sequential patients fulfilling the American College of Rheumatology diagnostic criteria in participating centres. We aimed to characterise demographic, clinical and laboratory characteristics of disease presentation in SSc and analysed EUSTAR baseline visits. RESULTS In April 2006, a total of 3656 patients (1349 with dcSSc and 2101 with lcSSc) were enrolled in 102 centres and 30 countries. 1330 individuals had autoantibodies against Scl70 and 1106 against anticentromere antibodies. 87% of patients were women. On multivariate analysis, scleroderma subsets (dcSSc vs lcSSc), antibody status and age at onset of Raynaud's phenomenon, but not gender, were found to be independently associated with the prevalence of organ manifestations. Autoantibody status in this analysis was more closely associated with clinical manifestations than were SSc subsets. CONCLUSION dcSSc and lcSSc subsets are associated with particular organ manifestations, but in this analysis the clinical distinction seemed to be superseded by an antibody-based classification in predicting some scleroderma complications. The EUSTAR MEDS database facilitates the analysis of clinical patterns in SSc, and contributes to the standardised assessment and monitoring of SSc internationally.
Collapse
|
144
|
Sutinen J, Walker UA, Sevastianova K, Klinker H, Häkkinen AM, Ristola M, Yki-Järvinen H. Uridine supplementation for the treatment of antiretroviral therapy-associated lipoatrophy: a randomized, double-blind, placebo-controlled trial. Antivir Ther 2007; 12:97-105. [PMID: 17503753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
BACKGROUND Highly active antiretroviral therapy (HAART) is associated with loss of subcutaneous fat (lipoatrophy) presumably due to mitochondrial toxicity of nucleoside reverse transcriptase inhibitors. In vitro, uridine abrogates thymidine analogue-induced toxicity in adipocytes. METHODS A total of 20 patients with HAART-associated lipoatrophy were randomized to receive either a dietary uridine supplement (36 g three times a day for 10 consecutive days/month) or placebo, for 3 months. Body composition was measured using dual energy X-ray absorptiometry, magnetic resonance imaging and proton spectroscopy. Data are mean +/- standard error of mean. RESULTS The mean increases in limb fat (880 +/- 140 versus 230 +/- 270 g; P < 0.05), intra-abdominal fat (210 +/- 80 versus -80 +/- 70 cm3; P < 0.05) and total body fat (1920 +/- 240 versus 240 +/- 520 g; P < 0.01) were significantly greater in the uridine than in the placebo group. Within the uridine group, the changes from baseline to 3 months were statistically significant in total limb fat (P < 0.001), intra-abdominal fat (P < 0.05) and total body fat (P < 0.001). The proportion of limb fat to total fat increased from 18% to 25% (P < 0.05) in the uridine group. Liver fat content and lean body mass remained unchanged in both groups. High-density lipoprotein-cholesterol concentrations decreased in the uridine and increased in the placebo group, whereas fasting serum insulin concentrations did not change. Uridine supplementation was well tolerated and the virological effect of HAART was not affected. CONCLUSION Uridine supplementation significantly and predominantly increased subcutaneous fat mass in lipoatrophic HIV-infected patients during unchanged HAART.
Collapse
|
145
|
Lebrecht D, Vargas-Infante YA, Setzer B, Kirschner J, Walker UA. Uridine supplementation antagonizes zalcitabine-induced microvesicular steatohepatitis in mice. Hepatology 2007; 45:72-9. [PMID: 17187420 DOI: 10.1002/hep.21490] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
UNLABELLED Zalcitabine is an antiretroviral nucleoside analogue that exhibits long-term toxicity to hepatocytes by interfering with the replication of mitochondrial DNA (mtDNA). Uridine antagonizes this effect in vitro. In the present study we investigate the mechanisms of zalcitabine-induced hepatotoxicity in mice and explore therapeutic outcomes with oral uridine supplementation. BalbC mice (7 weeks of age, 9 mice in each group) were fed 0.36 mg/kg/d of zalcitabine (corresponding to human dosing adapted for body surface), or 13 mg/kg/d of zalcitabine. Both zalcitabine groups were treated with or without Mitocnol (0.34 g/kg/d), a dietary supplement with high bioavailability of uridine. Liver histology and mitochondrial functions were assessed after 15 weeks. One mouse exposed to high dose zalcitabine died at 19 weeks of age. Zalcitabine induced a dose dependent microvesicular steatohepatitis with abundant mitochondria. The organelles were enlarged and contained disrupted cristae. Terminal transferase dUTP nick end labeling (TUNEL) assays showed frequent hepatocyte apoptosis. mtDNA was depleted in liver tissue, cytochrome c-oxidase but not succinate dehydrogenase activities were decreased, superoxide and malondialdehyde were elevated. The expression of COX I, an mtDNA-encoded respiratory chain subunit was reduced, whereas COX IV, a nucleus-encoded subunit was preserved. Uridine supplementation normalized or attenuated all toxic abnormalities in both zalcitabine groups, but had no effects when given without zalcitabine. Uridine supplementation was without apparent side effects. CONCLUSION Zalcitabine induces mtDNA-depletion in murine liver with consequent respiratory chain dysfunction, up-regulated synthesis of reactive oxygen species and microvesicular steatohepatitis. Uridine supplementation attenuates this mitochondrial hepatotoxicity without apparent intrinsic effects.
Collapse
|
146
|
Sutinen J, Walker UA, Sevastianova K, Klinker H, Häkkinen AM, Ristola M, Yki-Järvinen H. Uridine Supplementation for the treatment of Antiretroviral Therapy-Associated Lipoatrophy: A Randomized, Double-Blind, Placebo-Controlled Trial. Antivir Ther 2007. [DOI: 10.1177/135965350701200113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background Highly active antiretroviral therapy (HAART) is associated with loss of subcutaneous fat (lipoatrophy) presumably due to mitochondrial toxicity of nucleoside reverse transcriptase inhibitors. In vitro, uridine abrogates thymidine analogue-induced toxicity in adipocytes. Methods A total of 20 patients with HAART-associated lipoatrophy were randomized to receive either a dietary uridine supplement (36 g three times a day for 10 consecutive days/month) or placebo, for 3 months. Body composition was measured using dual energy X-ray absorptiometry, magnetic resonance imaging and proton spectroscopy. Data are mean ± standard error of mean. Results The mean increases in limb fat (880 ±140 versus 230 ±270 g; P<0.05), intra-abdominal fat (210 ±80 versus -80 ±70 cm3; P<0.05) and total body fat (1,920 ±240 versus 240 ±520 g; P<0.01) were significantly greater in the uridine than in the placebo group. Within the uridine group, the changes from baseline to 3 months were statistically significant in total limb fat ( P<0.001), intra-abdominal fat ( P<0.05) and total body fat ( P<0.001). The proportion of limb fat to total fat increased from 18% to 25% ( P<0.05) in the uridine group. Liver fat content and lean body mass remained unchanged in both groups. High-density lipoprotein-cholesterol concentrations decreased in the uridine and increased in the placebo group, whereas fasting serum insulin concentrations did not change. Uridine supplementation was well tolerated and the virological effect of HAART was not affected. Conclusion Uridine supplementation significantly and predominantly increased subcutaneous fat mass in lipoatrophic HIV-infected patients during unchanged HAART.
Collapse
|
147
|
Venhoff N, Setzer B, Melkaoui K, Walker UA. Mitochondrial toxicity of tenofovir, emtricitabine and abacavir alone and in combination with additional nucleoside reverse transcriptase inhibitors. Antivir Ther 2007; 12:1075-1085. [PMID: 18018766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
BACKGROUND Some nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) combinations cause additive or synergistic interactions in vitro and in vivo. METHODS We evaluated the mitochondrial toxicity of tenofovir (TFV), emtricitabine (FTC) and abacavir as carbovir (CBV) alone, with each other, and in combination with additional NRTIs. HepG2 human hepatoma cells were incubated with TFV, FTC, CBV, didanosine (ddl), stavudine (d4T), lamivudine (3TC) and zidovudine (AZT) at concentrations equivalent to 1 and 10x clinical steady-state peak plasma levels (C(max)). NRTIs were also used in double and triple combinations. Cell growth, lactate production, intracellular lipids, mtDNA and the mtDNA-encoded respiratory chain subunit II of cytochrome c oxidase (COXII) were monitored for 25 days. RESULTS TFV and 3TC had no or minimal toxicity. FTC moderately reduced hepatocyte proliferation independent of effects on mtDNA. ddl and d4T induced a time- and dose-dependent loss of mtDNA and COXII, decreased cell growth and increased levels of lactate and intracellular lipids. CBV and AZT strongly impaired hepatocyte proliferation and increased lactate and lipid production, but did not induce mtDNA depletion. The dual combination of TFV plus 3TC had only minimal toxicity; TFV plus FTC slightly reduced cell proliferation without affecting mitochondrial parameters. All other combinations exhibited more pronounced adverse effects on mitochondrial endpoints. Toxic effects on mitochondrial parameters were observed in all combinations with ddI, d4T, AZT or CBV. TFV and 3TC both attenuated ddI-related cytotoxicity, but worsened the effects of CBV and AZT. CONCLUSIONS The data demonstrate unpredicted interactions between NRTIs with respect to toxicological endpoints and provide an argument against the liberal use of NRTI cocktails without first obtaining data from clinical trials.
Collapse
|
148
|
Lebrecht D, Geist A, Ketelsen UP, Haberstroh J, Setzer B, Kratz F, Walker UA. The 6-maleimidocaproyl hydrazone derivative of doxorubicin (DOXO-EMCH) is superior to free doxorubicin with respect to cardiotoxicity and mitochondrial damage. Int J Cancer 2006; 120:927-34. [PMID: 17131338 DOI: 10.1002/ijc.22409] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Doxorubicin causes a chronic cardiomyopathy in which genetic and functional lesions of mitochondria accumulate in the long-term and explain in part the delayed onset of heart dysfunction. DOXO-EMCH a 6-maleimidocaproyl hydrazone derivative of doxorubicin, is an albumin binding prodrug which has entered clinical trials because of its superior antitumor and toxicological profile. In the present work, we examined the chronic cardiotoxicity of DOXO-EMCH in direct comparison with doxorubicin. Rats (11 weeks of age) were treated with intravenous doxorubicin (0.8 mg/kg weekly for 7 weeks), an equimolar dose of DOXO-EMCH (1.1 mg/kg), or with 3.3 mg/kg of DOXO-EMCH. Controls received saline. Animals were euthanized at 48th week. Rats exposed to doxorubicin had a severe clinical, and histopathological cardiomyopathy with depressed myocardial activity of cytochrome c-oxidase (COX, 26% of controls), reduced expression of the mtDNA-encoded COX II subunit, decreased mtDNA copy numbers (46% of controls), and high levels of malondialdehyde and superoxide (787% of controls). All parameters were highly correlated with myocardial damage. Both DOXO-EMCH groups did not differ from controls with regard to clinical symptomatology, mortality and mitochondrial enzymes, although the myocardia of the high-dose group had slightly increased histopathological abnormalities, depressed mtDNA copies (74% of controls) and elevated superoxide levels (347% of controls). Doxorubicin-exposed hearts and to a lesser extent the myocardia of both DOXO-EMCH groups contained mtDNA-deletions. In summary both DOXO-EMCH doses were superior over doxorubicin with respect to clinical and histopathological evidence of cardiomyopathy, myocardial COX-activity, COX II expression, mtDNA-content, mtDNA mutation loads and superoxide production in rats.
Collapse
|
149
|
Walker UA, Garve K, Brink I, Miehle N, Peter HH, Kelly T. 99mTechnetium pyrophosphate scintigraphy in the detection of skeletal muscle disease. Clin Rheumatol 2006; 26:1119-22. [PMID: 17119862 DOI: 10.1007/s10067-006-0463-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Revised: 10/03/2006] [Accepted: 10/04/2006] [Indexed: 11/24/2022]
Abstract
We aimed to assess the specificity and sensitivity of (99m)technetium pyrophosphate muscle scintigraphy in the diagnostic workup of patients with suspected myopathy. We reviewed the charts of 166 patients; 52% of the subjects had myalgias, 36% had muscle weakness, 45% had an elevated serum creatine kinase (CK), and 49% had an increased C reactive protein (CRP). Scintigraphy was positive in 34 patients (20%). The test was more sensitive in the presence of muscle weakness, elevated CK, or increased CRP. The presence of myalgias did not influence the odds. Sensitivity was 60% in patients with the final diagnosis of polymyositis, dermatomyositis, or inclusion body myositis, and 70% in noninflammatory myopathies. Eight percent had false positive scintigrams. In individuals with biopsy-proven myopathy (51 subjects), the diagnostic sensitivity was 43%, and its specificity was 60%. Low positive and high negative likelihood ratios (5.0 and 0.65, respectively) document an only limited diagnostic efficiency of (99m)Tc-PYP scintigraphy in the evaluation of inflammatory and noninflammatory myopathies and suggest that the test is not helpful in the routine diagnostic workup of muscle complaints, even after a priori selection of patients for CK plus CRP abnormalities.
Collapse
|
150
|
Ghanem N, Uhl M, Pache G, Bley T, Walker UA, Langer M. MRI in psoriatic arthritis with hand and foot involvement. Rheumatol Int 2006; 27:387-93. [PMID: 17028861 DOI: 10.1007/s00296-006-0220-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Accepted: 09/02/2006] [Indexed: 10/24/2022]
Abstract
Evaluation of MRI-findings in patients with involvement of psoriatic arthritis (PsA) in small joints in hands and feet. Twenty-five patients with symptomatic joint involvement were studied by MRI. All patients were found to be positive for one or more imaging criteria. Soft tissue oedema was identified in 22/25 (88%) patients. Joint effusion was observed in 23/25 (92%) patients, whereas bone erosion was seen in 20/25 (80%) patients. Bone marrow oedema was evident in 21/25 (84%) cases. In 12/25 (48%) cases, bone proliferation was noted. Tendon sheath effusion was present in 17/25 (68%) patients. Contrast enhancement of the synovia was detected in all patients (n = 25) (100%), whereas adjacent periost was enhanced in 22/25 (88%) and epiphysial bone marrow in 18/25 (72%) patients. MRI allows the assessment of PsA-alterations of soft tissue, cartilage, bone, bone marrow, and adjacent tendon sheath in patients with hand and foot involvement.
Collapse
|