UV-Vis Photodissociation Action Spectroscopy on Thermo LTQ-XL ETD and Bruker amaZon Ion Trap Mass Spectrometers: a Practical Guide.

We report automated procedures for multiple tandem mass spectra acquisition allowing UV-Vis photodissociation action spectroscopy measurements of ions and radicals. The procedures were developed for two commercial ion trap mass spectrometers and applied to collision-induced and electron-transfer dissociation tandem mass spectrometry modes of ion generation.

Hydrogen-Rich Cation Radicals of DNA Dinucleotides: Generation and Structure Elucidation by UV-Vis Action Spectroscopy.

Hydrogen-rich DNA dinucleotide cation radicals (dGG + 2H)+•, (dCG + 2H)+•, and (dGC + 2H)+• represent transient species comprising protonated and hydrogen atom adducted nucleobase rings that serve as models for proton and radical migrations in ionized DNA. These DNA cation radicals were generated in the gas phase by electron-transfer dissociation of dinucleotide dication-crown-ether complexes and characterized by UV-vis photodissociation action spectra, ab initio calculations of structures and relative energies, and time-dependent density functional theory calculations of UV-vis absorption spectra. Theoretical calculations indicate that (dGG + 2H)+• cation radicals formed by electron transfer underwent an exothermic conformational collapse that was accompanied by guanine ring stacking and facile internucleobase hydrogen atom transfer, forming 3'-guanine C-8-H radicals. In contrast, exothermic hydrogen transfer from the 5'-cytosine radical onto the guanine ring in (dCG + 2H)+• was kinetically hampered, resulting in the formation of a mixture of 5'-cytosine and 3'-guanine radicals. Conformational folding and nucleobase stacking were energetically unfavorable in (dGC + 2H)+• that retained its structure of a 3'-cytosine radical, as formed by one-electron reduction of the dication. Hydrogen-rich guanine (G + H)• and cytosine (C + H)• radicals were calculated to have vastly different basicities in water, as illustrated by the respective p Ka values of 20.0 and 4.6, which is pertinent to their different abilities to undergo proton-transfer reactions in solution.

UV-Vis Action Spectroscopy Reveals a Conformational Collapse in Hydrogen-Rich Dinucleotide Cation Radicals.

We report the generation of deoxyriboadenosine dinucleotide cation radicals by gas-phase electron transfer to dinucleotide dications and their noncovalent complexes with crown ether ligands. Stable dinucleotide cation radicals of a novel hydrogen-rich type were generated and characterized by tandem mass spectrometry and UV-vis photodissociation (UVPD) action spectroscopy. Electron structure theory analysis indicated that upon electron attachment the dinucleotide dications underwent a conformational collapse followed by intramolecular proton migrations between the nucleobases to give species whose calculated UV-vis absorption spectra matched the UVPD action spectra. Hydrogen-rich cation radicals generated from chimeric riboadenosine 5'-diesters gave UVPD action spectra that pointed to novel zwitterionic structures consisting of aromatic π-electron anion radicals intercalated between stacked positively charged adenine rings. Analogies with DNA ionization are discussed.

Cytosine Radical Cations: A Gas-Phase Study Combining IRMPD Spectroscopy, UVPD Spectroscopy, Ion-Molecule Reactions, and Theoretical Calculations.

The radical cation of cytosine (Cyt.+ ) is generated by dissociative oxidation from a ternary CuII complex in the gas phase. The radical cation is characterized by infrared multiple photon dissociation (IRMPD) spectroscopy in the fingerprint region, UV/Vis photodissociation (UVPD) spectroscopy, ion-molecule reactions, and theoretical calculations (density functional theory and ab initio). The experimental IRMPD spectrum features diagnostic bands for two enol-amino and two keto-amino tautomers of Cyt.+ that are calculated to be among the lowest energy isomers, in agreement with a previous study. Although the UVPD action spectrum can also be matched to a combination of the four lowest energy tautomers, the presence of a nonclassical distonic radical cation cannot be ruled out. Its formation is, however, unlikely due to the high energy of this isomer and the respective ternary CuII complex. Gas-phase ion-molecule reactions showed that Cyt.+ undergoes hydrogen-atom abstraction from 1-propanethiol, radical recombination reactions with nitric oxide, and electron transfer from dimethyl disulfide.

Conformation-specific spectroscopy of alkyl benzyl radicals: Effects of a radical center on the CH stretch infrared spectrum of an alkyl chain.

An important initial step in the combustion of gasoline and diesel fuels is the abstraction of hydrogen from alkylbenzenes to form resonance-stabilized alkyl benzyl radicals. This work uses, for the first time, double resonance spectroscopy methods to explore the conformation-specific vibronic and infrared spectroscopy of the α-ethylbenzyl (αEtBz) and α-propylbenzyl (αPrBz) radicals. Local mode Hamiltonian modeling enables assignment of the alkyl CH stretch IR spectra, accounting for Fermi resonance that complicates aliphatic alkyl CH stretch IR spectroscopy. The ground state conformational preferences of the ethyl and propyl chains are changed from those in the alkylbenzenes themselves, with global minima occurring for an in-plane orientation of the alkyl chain (trans) about its first dihedral angle (ϕf123, numbers are alkyl C atoms. C1 is CH radical site). This in-plane structure is the only observed conformer for the α-EtBz radical, while two conformers, tt and tg' share this orientation at the first dihedral, but differ in the second (ϕ1234) for the αPrBz radical. The in-plane orientation lowers the local site frequencies of the CH2 group stretches immediately adjacent to the benzylic radical site by about 50 cm-1 relative to those in pure alkyl chains or alkylbenzenes. This effect of the radical site is localized on the first CH2 group, with little effect on subsequent members of the alkyl chain. In the D1 excited electronic state, an out-of-plane orientation is preferred for the alkyl chains, leading to torsional mode Franck-Condon activity in the D0-D1 spectra that is both conformer-specific and diagnostic of the conformational change.

Infrared and Electronic Spectroscopy of the Jet-Cooled 5-Methyl-2-furanylmethyl Radical Derived from the Biofuel 2,5-Dimethylfuran.

The electronic and infrared spectra of the 5-methyl-2-furanylmethyl (MFM) radical have been characterized under jet-cooled conditions in the gas phase. This resonance-stabilized radical is formed by H atom loss from one of the methyl groups of 2,5-dimethylfuran (DMF), a promising second-generation biofuel. As a resonance-stabilized radical, it plays an important role in the flame chemistry of DMF. The D0-D1 transition was studied using two-color resonant two-photon ionization (2C-R2PI) spectroscopy. The electronic origin is in the middle of the visible spectrum (21934 cm(-1) = 455.9 nm) and is accompanied by Franck-Condon activity involving the hindered methyl rotor. The frequencies and intensities are fit to a one-dimensional methyl rotor potential, using the calculated form of the ground state potential. The methyl rotor reports sensitively on the local electronic environment and how it changes with electronic excitation, shifting from a preferred ground state orientation with one CH in-plane and anti to the furan oxygen, to an orientation in the excited state in which one CH group is axial to the plane of the furan ring. Ground and excited state alkyl CH stretch infrared spectra are recorded using resonant ion-dip infrared (RIDIR) spectroscopy, offering a complementary view of the methyl group and its response to electronic excitation. Dramatic changes in the CH stretch transitions with electronic state reflect the changing preference for the methyl group orientation.

Anharmonic modeling of the conformation-specific IR spectra of ethyl, n-propyl, and n-butylbenzene.

Conformation-specific UV-IR double resonance spectra are presented for ethyl, n-propyl, and n-butylbenzene. With the aid of a local mode Hamiltonian that includes the effects of stretch-scissor Fermi resonance, the spectra can be accurately modeled for specific conformers. These molecules allow for further development of a first principles method for calculating alkyl stretch spectra. Across all chain lengths, certain dihedral patterns impart particular spectral motifs at the quadratic level. However, the anharmonic contributions are consistent from molecule to molecule and conformer to conformer. This transferability of anharmonicities allows for the Hamiltonian to be constructed from only a harmonic frequency calculation, reducing the cost of the model. The phenyl ring alters the frequencies of the CH2 stretches by about 15 cm(-1) compared to their n-alkane counterparts in trans configurations. Conformational changes in the chain can lead to shifts in frequency of up to 30 cm(-1).

The spectroscopy and photochemistry of quinioline structural isomers: (E)- and (Z)-phenylvinylnitrile.

In Titan's atmosphere, photochemical pathways that lead to nitrogen heteroaromatics may incorporate photoisomerization of their structural isomers as a final step. (E)- and (Z)-phenylvinylnitrile ((E)- and (Z)-PVN, C6H5-CH=CHCN) are structural isomers of quinoline that themselves possess extensive absorptions in the ultraviolet, and thus may engage in such photoisomerization pathways. The present study explores the vibronic spectroscopy and photo-induced isomerization of gas-phase (E)- and (Z)-PVN in the 33,600-35,850 cm(-1) region under jet-cooled conditions. The S0-S1 origins for (E)- and (Z)-PVN have been identified at 33 827 cm(-1) and 33 707 cm(-1), respectively. Isomer-specific UV-UV hole-burning and UV depletion spectra reveal sharp vibronic structure that extends over almost 2000 cm(-1), with thresholds for fast non-radiative decay identified by a comparison between hole-burning and UV depletion spectra. Dispersed fluorescence spectra of the two isomers enable the assignment of many low frequency transitions in both molecules, aided by harmonic frequency calculations (B3LYP/6-311++G(d,p)) and a comparison with the established spectroscopy of phenylvinylacetylene, the ethynyl counterpart to PVN. Both isomers are proven to be planar in both the S0 ground and S1 electronic excited states. (E)-PVN exhibits extensive Duschinsky mixing involving out-of-plane modes whose frequencies and character change significantly in the ππ* transition, which modulates the degree of single- and double-bond character along the vinylnitrile substituent. This same mixing is much less evident in (Z)-PVN. The spectroscopic characterization of (E)- and (Z)-PVN served as the basis for photoisomerization experiments using ultraviolet hole-filling spectroscopy carried out in a reaction tube affixed to the pulsed valve. Successful interconversion between (E) and (Z)-PVN was demonstrated via ultraviolet hole-filling experiments. Photoexcitation of (E)- and (Z)-PVN at their respective S0-S1 origins failed to produce quinoline, a simple polycyclic aromatic nitrogen heterocylcle, within the detection sensitivity of our experiments. Stationary points along the potential energy surface associated with (Z)-PVN → quinoline isomerization showed a barrier of 93 kcal/mol associated with the first step in the isomerization process, slowing the interconversion process at the excitation energies used (96 kcal/mol) to timescales beyond those probed in the present experiment.

Vibronic spectroscopy of a nitrile/isonitrile isoelectronic pair: para-diisocyanobenzene and para-isocyanobenzonitrile.

The ultraviolet spectroscopy of isoelectronic pair para-diisocyanobenzene (pDIB) and para-isocyanobenzonitrile (pIBN) has been studied under gas-phase, jet-cooled conditions. These molecules complete a sequence of mono and disubstituted nitrile/isonitrile benzene derivatives, enabling a comparison of the electronic effects of such substitution. Utilizing laser-induced fluorescence (LIF) and resonant two-photon ionization (R2PI) spectroscopy, the S0-S1 electronic origins of pDIB and pIBN have been identified at 35,566 and 35,443 cm(-1), respectively. In pDIB, the S0-S1 origin is very weak, with b(3g) fundamentals induced by vibronic coupling to the S2 state dominating the spectrum at 501 cm(-1) (ν17, isocyano bend) and 650 cm(-1) (ν16, ring distortion). The spectrum extends over 5000 cm(-1), remaining sharp and relatively uncongested over much of this range. Dispersed fluorescence (DFL) spectra confirm the dominating role played by vibronic coupling and identify Franck-Condon active ring modes built off the vibronically-induced bands. In pDIB, the S2 state has been tentatively observed at about 6100 cm(-1) above the S0-S1 origin. In pIBN, the S0-S1 origin is considerably stronger, but vibronic coupling still plays an important role, involving fundamentals of b2 symmetry. The bending mode of the nitrile group dominates the vibronically-induced activity. Calculations carried out at the TD-DFT B3LYP/6-31+G(d) level of theory account for the extremely weak S0-S1 oscillator strength of pDIB and the larger intensity of the S0-S1 origins of pIBN and pDCB (para-dicyanobenzene) as nitrile groups are substituted for isonitrile groups. In pDIB, a nearly perfect cancellation of transition dipoles occurs due to two one-electron transitions that contribute nearly equally to the S0-S1 transition. The spectra of both molecules show no clear evidence of charge-transfer interactions that play such an important role in some cyanobenzene derivatives.

Ground and excited state infrared spectroscopy of jet-cooled radicals: exploring the photophysics of trihydronaphthyl and inden-2-ylmethyl.

The alkyl and aromatic CH stretch infrared spectra of inden-2-ylmethyl (I2M, C10H9) and trihydronaphthyl (THN, C10H11) radicals have been recorded under jet-cooled conditions in the ground (D0) and first electronically excited (D1) states using resonant ion-dip infrared (RIDIR) spectroscopy. Previously, the vibronic spectroscopy of a series of C10H9 and C10H11 hydronaphthyl radicals were investigated and their thermochemical properties were evaluated with isomer specificity [J. A. Sebree et al., J. Phys. Chem. A 11, 6255-6262 (2010)]. We show here that one of the m/z 129 spectral carriers characterized in that work was misidentified as 2-hydronaphthyl (2-HN) radical, appearing in a discharge of 1,2-dihydronaphthalene in close proximity to 1-hydronaphthyl radical. The D0-RIDIR spectrum in the alkyl CH stretch region positively identifies the m/z 129 isomer as I2M, whose two-color resonant two-photon ionization (2C-R2PI) spectrum was recently reported by Schmidt and co-workers [T. P. Troy et al., Chem. Sci. 2, 1755-1765 (2011)]. Here, we further characterize the I2M and THN radicals by recording their gas phase IR spectra in the alkyl and aromatic CH stretch regions, and explore the spectroscopic consequences of electronic excitation on the CH stretch absorptions. A local-mode CH stretch Hamiltonian incorporating cubic stretch-bend coupling between anharmonic CH stretches and CH2 scissor modes is utilized to describe their Fermi resonance interactions. Excellent agreement between the experimental and theoretical results facilitates the interpretation of the D0- and D1-state RIDIR spectra of I2M, revealing that upon excitation the alkyl CH stretches decrease in frequency by 70 cm(-1), while the allyl-like CH stretches experience a modest blueshift. In comparison, the photophysics of THN are strikingly different in that the IR transitions that possess vibrational motion along the CßH and CδH bonds are absent in the D1-RIDIR spectrum yet are predicted to be present from the theoretical model. Several hypotheses are considered to account for the perturbations to these vibrations.

Bosentan treatment of digital ulcers related to systemic sclerosis: results from the RAPIDS-2 randomised, double-blind, placebo-controlled trial.

OBJECTIVES: Ischaemic digital ulcers (DUs) are common in patients with systemic sclerosis (SSc) and are a cause of disease-related morbidity. In an earlier trial, treatment with bosentan, an oral endothelin receptor antagonist, reduced the occurrence of new DUs by 48%. The present study (RAPIDS-2, for 'RAndomized, double-blind, Placebo-controlled study with bosentan on healing and prevention of Ischemic Digital ulcers in patients with systemic Sclerosis') was conducted to more fully evaluate the effects of bosentan treatment on DUs associated with SSc. METHODS: This double-blind, placebo-controlled trial conducted at 41 centres in Europe and North America randomised 188 patients with SSc with at least 1 active DU ('cardinal ulcer') to bosentan 62.5 mg twice daily for 4 weeks and 125 mg twice daily thereafter for 20 weeks (n=98) or matching placebo (n=90; total 24 weeks). The two primary end points were the number of new DUs and the time to healing of the cardinal ulcer. Secondary end points included pain, disability and safety. RESULTS: Over 24 weeks, bosentan treatment was associated with a 30% reduction in the number of new DUs compared with placebo (mean ± standard error: 1.9±0.2 vs 2.7±0.3 new ulcers; p=0.04). This effect was greater in patients who entered the trial with more DUs. There was no difference between treatments in healing rate of the cardinal ulcer or secondary end points of pain and disability. Peripheral oedema and elevated aminotransferases were associated with bosentan treatment. CONCLUSIONS: Bosentan treatment reduced the occurrence of new DUs in patients with SSc but had no effect on DU healing. Bosentan was well tolerated and may be a useful adjunct in the management of patients with SSc with recurrent DUs.

Use of a medication control officer to reduce bias in a clinical trial: lessons learned from the scleroderma lung study.

BACKGROUND: Scleroderma Lung Study (SLS) was designed to evaluate the efficacy and safety of oral cyclophosphamide (CYC) versus placebo taken for 1 year for scleroderma-associated interstitial lung disease. An independent medication control officer (MCO), usually a physician, at each center was assigned to monitor laboratory and clinical toxicity of study medication and regulate its dosing based on these results. By having an MCO who watched and managed toxicity, the study investigators were free to care for study patients and to assess study outcomes without the potential bias of knowing toxicity data (toxicity from cyclophosphamide is distinctive - cytopenias and hematuria in particular). PURPOSE: To assess the usefulness of an MCO, whose chief role was to maintain safety while retaining the blinding in the clinical trial. METHODS: Patients had safety laboratory testing every 2-4 weeks and results were sent directly to the MCO within 2 days of the test. Other clinical adverse events (AEs) were reported by the patient to a nurse coordinator who reported them to the MCO who then managed the AEs to preserve the blinding of investigators caring for the patients. The MCO was provided pre-determined algorithms for dose adjustments of test medication based on the presence and severity of laboratory abnormalities. RESULTS: Safety monitoring by the MCO was effective in the early detection of drug toxicity with provision of appropriate medical intervention on a timely basis. At the same time, investigator blinding appeared to be maintained. LIMITATIONS: The testing of MCO effectiveness in maintaining blinding and consistency was not defined as an a priori hypothesis and thus complete data relating to the efficacy of the MCO were not collected in a prospective fashion. CONCLUSION: An MCO and pre-specified monitoring and dosing guidelines, coupled with uniform pre-specified responses to AEs, may be used effectively to preserve investigator blinding and provide consistency in response to AEs in a clinical trial setting, even when AEs of the test medication are distinctive.

Recombinant human relaxin in the treatment of systemic sclerosis with diffuse cutaneous involvement: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: A phase II randomized controlled trial of recombinant human relaxin suggested that a dosage of 25 microg/kg/day was safe and clinically effective in improving skin disease and reducing functional disability in scleroderma (systemic sclerosis; SSc). We undertook a large randomized, double-blind, placebo-controlled clinical trial to compare placebo with 10 microg/kg/day and 25 microg/kg/day recombinant human relaxin, given for 24 weeks in patients with stable, diffuse, moderate-to-severe SSc. METHODS: Men and women ages 18-70 years with diffuse cutaneous SSc (dcSSc) were administered recombinant human relaxin (10 microg/kg/day or 25 microg/kg/day) or placebo for 24 weeks as a continuous subcutaneous infusion. There was a followup safety visit at week 28. RESULTS: The primary outcome measure, the modified Rodnan skin thickness score, was similar among the 3 groups at baseline and at weeks 4, 12, and 24. Secondary outcomes such as functional disability were similar in all 3 groups, while the forced vital capacity decreased significantly in the relaxin groups. The discontinuation of both doses of relaxin at week 24 led to statistically significant declines in creatinine clearance and serious renal adverse events (defined as doubling of serum creatinine, renal crisis, or grade 3 or 4 essential hypertension) in 7 patients who had received relaxin therapy but in none who had received placebo. CONCLUSION: Recombinant relaxin was not significantly better than placebo in improving the total skin score or pulmonary function or in reducing functional disability in patients with dcSSc. In addition, relaxin was associated with serious renal adverse events, the majority of which occurred after stopping the infusion. If relaxin is used therapeutically for any conditions other than scleroderma, close monitoring of blood pressure and renal function must be performed.

A multicenter, randomized, double-blind, placebo-controlled trial of oral type I collagen treatment in patients with diffuse cutaneous systemic sclerosis: I. oral type I collagen does not improve skin in all patients, but may improve skin in late-phase disease.

OBJECTIVE: To investigate the safety and efficacy of oral bovine type I collagen (CI) treatment in patients who have had diffuse cutaneous systemic sclerosis (dcSSc; scleroderma) for

Validity, reliability, and feasibility of durometer measurements of scleroderma skin disease in a multicenter treatment trial.

OBJECTIVE: To determine the validity, reliability, and feasibility of durometer measurements of skin hardness as an outcome measure in clinical trials of scleroderma. METHODS: Skin hardness was measured during a multicenter treatment trial for scleroderma using handheld digital durometers with a continuous scale. Skin thickness was measured by modified Rodnan skin score (MRSS). Other outcome data collected included the Scleroderma Health Assessment Questionnaire. In a reliability exercise in advance of the trial, 9 investigators examined the same 5 scleroderma patients by MRSS and durometry. RESULTS: Forty-three patients with early diffuse cutaneous systemic sclerosis were studied at 11 international centers (mean age 49 years [range 24-76], median disease duration 6.4 months [range 0.3-23], and median baseline MRSS 22 [range 11-38]). The reliability of durometer measurements was excellent, with high interobserver intraclass correlation coefficients (ICCs) (0.82-0.92), and each result was greater than the corresponding skin site ICCs for MRSS (0.54-0.85). Baseline durometer scores correlated well with MRSS (r = 0.69, P < 0.0001), patient self-assessments of skin disease (r = 0.69, P < 0.0001), and Health Assessment Questionnaire (HAQ) disability scores (r = 0.34, P = 0.03). Change in durometer scores correlated with change in MRSS (r = 0.70, P < 0.0001), change in patient self-assessments of skin disease (r = 0.52, P = 0.003), and change in HAQ disability scores (r = 0.42, P = 0.017). The effect size was greater for durometry than for MRSS or patient self-assessment. CONCLUSION: Durometer measurements of skin hardness in patients with scleroderma are reliable, simple, accurate, demonstrate good sensitivity to change compared with traditional skin scoring, and reflect patients' self-assessments of their disease. Durometer measurements are valid, objective, and scalable, and should be considered for use as a complementary outcome measure to skin scoring in clinical trials of scleroderma.

Human collagen Krox up-regulates type I collagen expression in normal and scleroderma fibroblasts through interaction with Sp1 and Sp3 transcription factors.

Despite several investigations, the transcriptional mechanisms that regulate the expression of both type I collagen genes (COL1A1 and COL1A2) in either physiological or pathological situations, such as scleroderma, are not completely known. We have investigated the role of hc-Krox transcription factor on type I collagen expression by human dermal fibroblasts. hc-Krox exerted a stimulating effect on type I collagen protein synthesis and enhanced the corresponding mRNA steady-state levels of COL1A1 and COL1A2 in foreskin fibroblasts (FF), adult normal fibroblasts (ANF), and scleroderma fibroblasts (SF). Forced hc-Krox expression was found to up-regulate COL1A1 transcription through a -112/-61-bp sequence in FF, ANF, and SF. Knockdown of hc-Krox by short interfering RNA and decoy strategies confirmed the transactivating effect of hc-Krox and decreased substantially COL1A1 transcription levels in all fibro-blast types. The -112/-61-bp sequence bound specifically hc-Krox but also Sp1 and CBF. Attempts to elucidate the potential interactions between hc-Krox, Sp1, and Sp3 revealed that all of them co-immunoprecipitate from FF cellular extracts when a c-Krox antibody was used and bind to the COL1A1 promoter in chromatin immunoprecipitation assays. Moreover, hc-Krox DNA binding activity to its COL1A1-responsive element is increased in SF, cells producing higher amounts of type I collagen compared with ANF and FF. These data suggest that the regulation of COL1A1 gene transcription in human dermal fibroblasts involves a complex machinery that implicates at least three transcription proteins, hc-Krox, Sp1, and Sp3, which could act in concert to up-regulate COL1A1 transcriptional activity and provide evidence for a pro-fibrotic role of hc-Krox.

Outcome measurements in scleroderma: results from a delphi exercise.

OBJECTIVE: To obtain a consensus on the minimal clinically relevant treatment effect in various scleroderma disease outcome measures to be used in future clinical trials. METHODS: A Delphi consensus building exercise using a survey was sent out to members of the Scleroderma Clinical Trials Consortium (SCTC). The 65 SCTC members were divided into 2 groups. Group 1 was informed, in a cover letter, of the usual American College of Rheumatology 20% response results in randomized trials using effective biologic treatments for rheumatoid arthritis, while Group 2 was not. The first round of the exercise presented the scleroderma experts with a survey composed of 95 questions/clinical scenarios divided into 8 categories. These included situations where the treatment group improved, or worsened, or where some outcome measures improved, while others worsened. From the responses of this first round, a mean, mode, median, and range of responses for each of the 95 questions was obtained. This information was sent out, in the second round of the Delphi exercise, only to those respondents who answered the first round. The respondent's previous answer and the mean and range from the first round were provided for each question. It gave respondents the option to change any of their initial responses. The median of their responses in the second round was used to calculate the values for the minimal clinically relevant treatment effect. RESULTS: Thirty-two of the 65 SCTC members returned the first round of the Delphi exercise. Twenty-eight members returned the second round. Intraclass correlation coefficients between responses to round 1 and 2 were calculated for the questions. These varied from 0.99 (excellent agreement) to 0.02 (poor agreement). The p value was under 0.09 for 9 questions and under 0.19 for 20 questions. Standard deviations (SD) were calculated and were found to be lesser for each of the questions in round 2 when compared to the SD in responses from round 1, thus indicating a movement towards a consensus by the second round. An average of 33% of the responses were changed by the respondents in the second round of the Delphi exercise to a value closer to the median/average of the first round's responses. A range in required values for the minimal clinically relevant treatment effect for Modified Rodnan skin score is 3 to 7.5 units, Health Assessment Questionnaire Disability Index (HAQ-DI) 0.2 to 0.25 units, HAQ pain 0.2 to 0.3 units, MD global (100 mm visual analog scale) 8 to 13, patient global assessment 10 to 12, and diffusing capacity (percentage predicted) 9 to 10. The scenarios were especially weighted towards overall disease modification, thus organ-specific measures, such as 6 minute walk time (which has been used in many pulmonary artery hypertension trials), forced vital capacity, and a dyspnea rating (which may be important in scleroderma lung trials), were not included in the survey. CONCLUSION: Our study begins to address the current deficiency in our knowledge of appropriate values for the minimal clinically relevant treatment effect in various scleroderma disease outcome measures. A consensus could be achieved, or at least a range of minimal clinically relevant treatment effect values could be found for several outcome measurements. Of course, this consensus statement will be modified by evidence as it accrues in each consensus area.

Recombinant human anti-transforming growth factor beta1 antibody therapy in systemic sclerosis: a multicenter, randomized, placebo-controlled phase I/II trial of CAT-192.

OBJECTIVE: To evaluate CAT-192, a recombinant human antibody that neutralizes transforming growth factor beta1 (TGFbeta1), in the treatment of early-stage diffuse cutaneous systemic sclerosis (dcSSc). METHODS: Patients with SSc duration of <18 months were randomly assigned to the placebo group or to 1 of 3 CAT-192 treatment groups: 10 mg/kg, 5 mg/kg, 0.5 mg/kg. Infusions were given on day 0 and weeks 6, 12, and 18. The primary objective of this study was to evaluate the safety, tolerability, and pharmacokinetics of CAT-192. Secondary outcomes included the modified Rodnan skin thickness score (MRSS), the Scleroderma Health Assessment Questionnaire, assessment of organ-based disease, serum levels of soluble interleukin-2 receptor, collagen propeptides (N propeptide of type I [PINP] and type III collagen), and tissue levels of messenger RNA for procollagens I and III and for TGFbeta1 and TGFbeta2. RESULTS: Forty-five patients were enrolled. There was significant morbidity and mortality, including 1 death in the group receiving 0.5 mg/kg of CAT-192 and 3 deaths in the group receiving 5 mg/kg of CAT-192. There were more adverse events and more serious adverse events in patients receiving CAT-192 than in those receiving placebo, although these events were not more frequent in the high-dose treatment group. The MRSS improved in all groups during the study, but there was no evidence of a treatment effect for CAT-192. Improvement in the MRSS correlated with the disease duration (r = -0.54, P = 0.0008). Changes in the PINP level from baseline correlated with changes in the MRSS (r = 0.37, P = 0.027). CONCLUSION: We report the first evaluation of a systemically administered and repeatedly dosed anti-TGFbeta1 drug. In this pilot study, CAT-192, in doses up to 10 mg/kg, showed no evidence of efficacy. The utility of clinical and biochemical outcome measures and the feasibility of multicenter trials of early dcSSc were confirmed.

Durometry for the assessment of skin disease in systemic sclerosis.

OBJECTIVE: To examine the validity of a durometer to objectively measure skin hardness in systemic sclerosis (SSc), and to compare digital durometry with the modified Rodnan skin score (MRSS) and ultrasonography. METHODS: Patients with SSc and healthy controls underwent durometry measurements in 3 assessments: a Latin square experiment to establish durometry's intra- and interobserver reliability compared with skin scoring (5 SSc, 1 control); a longitudinal cohort to assess sensitivity to change in skin hardness (13 SSc, 5 controls); and an ultrasound cohort to evaluate correlation between durometry, ultrasound-measured skin thickness, and clinical skin scoring (30 SSc, 12 controls). RESULTS: Intraobserver reproducibility was higher for durometry than for clinical skin scoring (intraclass correlation coefficient [ICC] 0.97 versus 0.85), whereas interobserver reproducibility was similar (0.75 versus 0.73). Interobserver reproducibility of durometry was good for all body areas (ICC 0.61-0.85), but for skin scoring it was moderate in the legs (0.51) and poor in the abdomen (0.08), feet (0.09), and fingers (0.27). Durometry scores correlated with clinical skin scores (Latin square: r = 0.44, P = 0.03; longitudinal cohort: r = 0.81, P < 0.001) and ultrasound-measured skin thickness (hands: r = 0.58, forearms: r = 0.63, upper arms: r = 0.40; P < or = 0.001 for all). Uninvolved skin in patients with SSc was harder than skin from controls (mean +/- SD 23 +/- 7 durometer units [DU] versus 19 +/- 6 DU; P < 0.0001). Finally, there was a strong correlation between change in MRSS and change in durometry score (r = 0.77, P = 0.002). CONCLUSION: Durometer-measured skin hardness correlates well with MRSS and ultrasound-measured skin thickness, provides greater reliability than MRSS, and is sensitive to changes in skin hardness over time. Durometry should be considered for use in clinical therapeutic SSc trials.

Cartilage oligomeric matrix protein is overexpressed by scleroderma dermal fibroblasts.

Cartilage oligomeric matrix protein (COMP) is an extracellular glycoprotein that belongs to the thrombospondin gene family. It is found predominantly in cartilage, tendon, ligament, and bone. Mutations in the COMP gene have been linked to the development of pseudoachondroplasia and multiple epiphysial dysplasia. COMP influences the organization of collagen fibrils by interacting with collagens I, II and IX. Gene expression profiling of cultured skin fibroblasts suggested that COMP mRNA levels were elevated in scleroderma. We therefore examined COMP expression in SSc and normal skin biopsies. Immunohistochemistry confirmed that COMP protein accumulates in SSc but not normal skin, with SSc skin showing striking deposition in the papillary and deeper dermis. Significant staining was also seen in non-lesional skin from patients. Due to its involvement in the development of fibrosis, TGFbeta was examined for a possible role in regulating COMP expression. Cultured SSc fibroblasts demonstrated greater staining for COMP compared to normal controls prior to stimulation, and TGFbeta-1 induced a large increase in mRNA and protein. Murine fibroblasts engineered to overexpress human COMP demonstrated increased levels of fibronectin and collagen in the extracellular matrix. Taken together, these data demonstrate that COMP is overexpressed in SSc skin and cultured fibroblasts possibly due to autocrine TGFbeta stimulation, and COMP overexpression is sufficient to stimulate excess matrix deposition. By interactions with other matrix proteins and cells, COMP may play a role in pathogenic matrix deposition.