FRI0266 THE REAL-WORLD EFFICACY OF THE 2015 EULAR/ACR RECOMMENDATIONS FOR THE MANAGEMENT OF POLYMYALGIA RHEUMATICA WITH ADDITIONAL TOCILIZUMAB THERAPY

Background:

A Part of patients with polymyalgia rheumatica (PMR) are refractory to the 2015 EULAR/ACR algorism for the management of PMR. Recent reports have demonstrated that tocilizumab (TCZ) may be efficacious for refractory and relapsing PMR.

Objectives:

To determine the real-world efficacy of the 2015 EULAR/ACR algorism for the management of PMR plus introduction of TCZ for refractory and relapsing PMR.

Methods:

Patients who had been diagnosed with PMR according to the 2012 EULAR/ACR provisional classification criteria for PMR were recruited in the study. Registered variables included demographic data, disease characteristics, prednisolone (PSL) dosage and duration, addition of methotrexate (MTX) and TCZ, adverse effects, and clinical outcomes.

Results:

There were 101 patients who had originally diagnosed as PMR (50 males and 65 females) and followed up for at least one year; the mean ± SD age at onset was 73 ±11 years at onset, with the mean observational period being 44 ± 26 months. Their treatments were initiated with PSL of 15.5 ± 4.3 mg/day. 41 patients experienced disease recurrence after 9.6 ± 6.7 months (median 9 month) of GC therapy, while receiving PSL at 5 ± 4.5 mg/day (3.7 mg/day). Baseline factors that were associated with relapse in our cohort were higher-grade thrombocytosis and higher-dose of initial GC by multivariate analysis. In 30 of the 41 patients who failed GC monotherapy, MTX was added. Five patients reached GC-free remission, but 25 patients failed GC tapering. In such refractory patients to a combination of GC plus MTX, 8 patients agreed to add TCZ therapy, and 5 of them reached drug-free remission. At present, 67 of the total 101 patients maintained drug-free remission, but most others were still receiving low-dose GC and/or MTX (n=17). No significant adverse effects did not occur during therapy, except for GC-related adverse effects such as diabetes, dyslipidemia and osteoprotic fractures.

Conclusion:

Our experience indicated that there is notable heterogeneity across PMR patients in terms of drug response, and the patients with severe inflammation, e.g. thrombocytosis, may need higher-dose of initial GC and addition of biologics such as TCZ on the 2015 EULAR/ACR algorism.

Acknowledgments:

None

Disclosure of Interests:

None declared

Leak-free million-fold DNA amplification with locked nucleic acid and targeted hybridization in one pot

An isothermal cascade reaction that exponentially amplifies pre-designed, single-stranded DNA as a sensor and signal amplifier module for DNA-based computing and molecular robotics was developed. Taking advantage of the finding that locked nucleic acid can suppress problematic ab initio DNA synthesis, up to million-fold amplification rates and concurrent hybridization were achieved at a physiological temperature in a single reactor. Although the effect of locked nucleic acid introduction to the templates was complicated, undesired leak DNA amplification was generally suppressed in the amplification reaction for distinct DNA sequences. The present reaction that senses one DNA as an input and generates a large amount of another DNA as an output, exhibiting a high correlation between the molecular concentration and the amplification time, is applicable for nucleic acid quantification.

Relationship Between Initial Renal Function and the Inhibitory Effect of Dipeptidyl Peptidase-4 Inhibitor Treatment on Renal Function Decline

We retrospectively investigated the renal function index of patients with type 2 diabetes mellitus (T2DM) to examine the influence of dipeptidyl peptidase-4 (DPP-4) inhibitors on renal function between patients up to early nephropathy and after overt nephropathy. Patients with T2DM (>18 years old) who had been prescribed hypoglycemic agents for ≥3 months at Gifu Municipal Hospital between March 2010 and April 2014 were included in the study. Renal function was evaluated as the estimated glomerular filtration rate (eGFR) decline from baseline at 12 months. Patients in the DPP-4 inhibitor-treated and untreated groups with an eGFR ≥60 (358 [58.2 %] and 257 [41.8 %], respectively) and eGFR <60 (115 [60.2 %] and 76 [39.8 %], respectively) were subjected to multiple logistic regression analysis. Among patients with an eGFR ≥60, no significant differences were observed in eGFR decline rates over time. However, among patients with an eGFR <60, significant decreases were observed in eGFR decline rates >10 % (6 months; odds ratio, 0.476; P = 0.043, 12 months; odds ratio, 0.413; P = 0.010). Similar results were obtained for an eGFR decline rate >20 % (12 months; odds ratio, 0.369; P = 0.049). DPP-4 inhibitors are renoprotective in patients with T2DM and an eGFR <60.

An investigation of visual hallucinations associated with voriconazole administration to patients with hematological malignancies

Voriconazole (VRCZ) is commonly administered to treat fungal infections in patients with hematological malignancies. Some of these patients experience VRCZ-associated visual hallucinations. We conducted a retrospective survey to investigate the characteristic features of this side effect. Patients with hematological malignancies who were treated with VRCZ for a fungal infection after hospitalization at Ichinomiya municipal hospital between 1 October 2005 and 31 December 2015 were included in this study (n = 103). Fifteen of these (14.6%) reported visual hallucinations that started on day 1-7. Seven of these 15 patients developed this symptom rapidly (day 1 or 2). Three patients had transient symptoms (lasting 2-12 days), 6 patients experienced hallucinations throughout the treatment, and the duration was unknown in 6 patients. Eleven patients experienced visual hallucinations when their eyes were closed (73 %) and these disappeared when they opened their eyes. One patient had visual hallucinations with open eyes, while the state of the eyes was unknown in 3 patients. The patients saw a range of images including people, animals, landscapes, and foods; several reported seeing images like those found in movies. In addition, 9 of 15 patients (60%) with visual hallucinations had visual disturbances. This was a higher proportion than that observed in patients who did not develop hallucinations (17 of 88; 19.3 %; P < 0.05). However, we found no significant difference between the blood VCRZ concentrations of patients who developed or did not develop visual hallucinations. This study indicated that most of these patients had visual hallucinations that manifested on eye closure, and they did not progress to serious mental illness. Our findings emphasized the importance of fully explaining the features of this symptom to each patient prior to starting VRCZ administration in order to reduce anxiety. In addition, since VRCZ discontinuation will compromise patient management, therapeutic drug monitoring should be used to increase the likelihood of successful therapy.

Development of Collaterals to the Spinal Cord after Endovascular Stent Graft Repair of Thoracic Aneurysms

OBJECTIVES

In thoracic and thoraco-abdominal aortic aneurysm repair, spinal cord injury (SCI) is devastating. Detection of the Adamkiewicz artery might be important for preventing SCI. Although thoracic endovascular stent grafts often occlude the segmental artery, the incidence of SCI in thoracic endovascular aortic repair is thought to be low compared with open repair. This study aimed to evaluate how the Adamkiewicz artery is supplied after segmental arteries are occluded by stent grafts.

METHODS

From March 2007 to August 2015, 32 patients were enrolled whose segmental arteries that were connected to the Adamkiewicz arteries were occluded by stent grafts. Segmental arteries, Adamkiewicz arteries, collateral circulation into the Adamkiewicz arteries, and anterior spinal arteries were pre- and post-operatively evaluated by computed tomography angiography.

RESULTS

Post-operatively, Adamkiewicz arteries were detected in 24 (75%) patients, except for two patients with paraplegia and six without paraplegia. Post-operative Adamkiewicz arteries were the same as pre-operative Adamkiewicz arteries, except for one Adamkiewicz artery that was located at two vertebral levels below the pre-operative level. SCI occurred in two (6.3%) patients. The distribution of feeding arteries into the Adamkiewicz artery post-operatively was divided into three patterns as follows: a segmental artery below the distal landing zone of the stent graft (53%), branches of the left subclavian artery (33%), and a branch of the left external iliac artery (13%).

CONCLUSIONS

The length of the stent graft should be as short as possible. Blood supply to the left subclavian artery should be maintained because segmental arteries below the segmental artery occluded by the stent graft and branches of the left subclavian artery can become collaterals post-operatively.

Stable neutral radicals of planar N2O2-type dipyrrin platinum complexes: hybrid radicals of the delocalized organic π-orbital and platinum d-orbital

Neutral radicals of N2O2-dipyrrin platinum complexes were synthesized by the reaction of dipyrrin ligands with PtCl2(cod) and successive one-electron oxidation. The radicals are very stable even under aerobic and ambient conditions. X-ray crystallographic analysis revealed the stacking array of the planar dipyrrin complex moieties. The ESR signals were broadened and significantly downfield shifted. The absorption spectra exhibited NIR bands. These results indicated a delocalized radical character with a contribution by the platinum d-orbital.

Changes in axial alignment of the ipsilateral hip and knee after total hip arthroplasty

AIMS

We investigated changes in the axial alignment of the ipsilateral hip and knee after total hip arthroplasty (THA).

PATIENTS AND METHODS

We reviewed 152 patients undergoing primary THA (163 hips; 22 hips in men, 141 hips in women) without a pre-operative flexion contracture. The mean age was 64 years (30 to 88). The diagnosis was osteoarthritis (OA) in 151 hips (primary in 18 hips, and secondary to dysplasia in 133) and non-OA in 12 hips. A posterolateral approach with repair of the external rotators was used in 134 hips and an anterior approach in 29 hips. We measured changes in leg length and offset on radiographs, and femoral anteversion, internal rotation of the hip and lateral patellar tilt on CT scans, pre- and post-operatively.

RESULTS

The mean internal rotation increased by 11° (-15° to 46°) and was associated with underlying disease (OA), pre-operative range of internal rotation, gender, surgical approach, leg lengthening, and change of femoral anteversion (adjusted R(2) : 0.253, p < 0.001). The mean lateral patellar tilt increased by 4° (-5° to 14°) and was associated with age, leg lengthening, and increment of hip internal rotation (adjusted R(2): 0.193, p < 0.001).

CONCLUSION

Both internal rotation of the hip at rest and lateral patellar tilt are increased after THA. Changes in rotation after THA may affect gait, daily activities, the rate of dislocation of the hip, and ipsilateral knee pain.

TAKE HOME MESSAGE

Internal rotation of the hip at rest and lateral patellar tilt increase after THA.

Preliminary validation of an instrument to assess social support and tuberculosis stigma in patients' families

SETTING

Ribeirão Preto, São Paulo, Brazil.

OBJECTIVE

To develop and validate a preliminary instrument for assessing social support and tuberculosis (TB) stigma in families of TB patients.

DESIGN

A literature review on social support and TB stigma was used to generate the theoretical domains for the instrument. A focus group was then conducted with TB patients and their families to revise the domains. Reviewers were invited to judge the appropriateness of the items in the instrument. A cross-sectional survey was carried out among 110 family members to assess the factorial structure using principal component analysis and confirmatory factor analysis to assess construct validity. Reliability was assessed in terms of internal consistency using Cronbach's alpha.

RESULTS

After semantic validation and a pilot study, 23 items were selected for the scale. Examination of the factorial structure of the 16 items that were factorable using principal component analysis led to the extraction of two factors. The 16-item instrument was assessed for construct validity with confirmatory factor analysis, which confirmed a model with four items for each dimension.

CONCLUSION

The study analysed the psychometric properties of an instrument that is still in its preliminary stages. Other studies on a similar scale in the Brazilian setting are required.

Renal involvement in rheumatoid arthritis: analysis of renal biopsy specimens from 100 patients

Abstract  We analyzed renal biopsy specimens from 100 patients to evaluate the characteristics of renal involvement in patients with rheumatoid arthritis (RA). Membranous nephropathy (MN) was the most common renal histological pattern (31%). Mesangial proliferative glomerulonephritis (GN) was found in 21% of cases (IgA nephropathy 12%, non-IgA GN 9%), minor changes in 17%, renal amyloidosis in 11%, interstitial nephritis in 9%, sclerotic GN in 4%, and crescentic GN in 2%. MN was relatively more frequent in men than in women, and most developed nephrotic syndrome, while a few developed renal failure. Disease-modifying antirheumatic drugs (DMARDs) correlated with MN in 26 of 31 cases. Mesangial proliferative GN showed high-grade hematuria. Amyloidosis correlated with long duration of RA; approximately half of the cases with amyloidosis also had nephrotic syndrome, and 82% developed renal failure. Of the 100 patients, 82% showed some tubulo-interstitial changes, which might be related to non-steroidal anti-inflammatory drugs. Because renal lesions in RA are very diverse, and early stage cases of MN and amyloidosis can be detected only by histological examinations, renal biopsy should be performed in cases with continuous urinary abnormalities or progressive renal failure.

Stereospecific oxidation of the (S)-enantiomer of RS-8359, a selective and reversible monoamine oxidase A (MAO-A) inhibitor, by aldehyde oxidase

In a previous paper by the authors on RS-8359, a new selective and reversible monoamine oxidase A (MAO-A) inhibitor, it was reported that the (S)-enantiomer of RS-8359 is rapidly eliminated from rats, monkeys and humans as a result of the formation of a 2-oxidative metabolite. The present study investigates the properties of the enzyme responsible for the 2-oxidation of RS-8359. Subcellular localization, cofactor requirement and the inhibitory effects of typical compounds were studied using rat liver preparations. In addition, the enzyme was purified from rat liver cytosol for further characterization. The enzyme activity was localized in the cytosolic fraction without the need for any cofactor and was extensively inhibited by menadione, chlorpromazine and quinacrine. The purified enzyme was also a homodimer with a monomeric molecular weight of 140 kDa and it had an A280/A450 ratio of 5.1 in the absorption spectrum. The results suggest that the enzyme responsible for the biotransformation of RS-8359 to give the 2-keto derivative is aldehyde oxidase (EC 1.2.3.1). The reaction of aldehyde oxidase is highly stereoselective for the (S)-configuration of RS-8359 and the (9R)-configuration of cinchona alkaloids.

Asymmetric Surface Roughness Formationon Moving Non-isothermal Liquid Coatings

We present a lubrication model of thermo-capillary flows in moving volatile liquid film coatings. The forced air impingement from a slit nozzle onto the moving coating imposes an axi-symmetric surface temperature distribution, and thus the local surface-tension gradients on the liquid surface. Despite the symmetric temperature profile, local thickness variations became asymmetric and exhibited a particular ridge in downstream and a depression in upstream. The competing feature between the surface-tension-driven and the pressure-driven flows gives a characteristic growth and decay in the surface roughness as the temperature profile travels in the opposite direction to the moving coating. The model prediction showed that the surface roughness was first enhanced and then suppressed with increasing the impinging air velocity, suggesting some directions for achieving more uniform coatings at higher speeds.

[Aortic valve replacement presence of anti-Jr(a) antibody]

A 65-year-old female with a heart murmur developed progressive symptom of chest oppression. She was diagnosed severe aortic valve stenosis with echocardiogram. Antibody screening revealed anti-Jr(a) antibody. Preoperatively, erythropoietin was administered. Over 14 days, a total 1,000 ml of her blood was drawn and stored for autologous transfusion. The aortic valve was replaced with ATS mechanical valve [18 mm advanced performance (AP)]. Following surgery, her stored blood was administered to him. But her HCT was 17% on the 1st postoperative day. Frozen thawed red cells were transferred 7th postoperative day.

[Surgical treatment for left ventricular false aneurysm caused by infective endocarditis; report of a case]

A 24-year-old man who had left ventricular (LV) false aneurysm, which is caused by mitral valve infective endocarditis, underwent aneurysmectomy, direct closure of aneurysmal mouth and concomitant mitral valve replacement. Post-operative course was uneventful. It has been reported that the etiology of this false aneurysm was due to the vegetations' friction, which could have caused an initial endocardial ulceration that progressively expanded into the myocardium. The false aneurysmal wall should be completely removed in order to eliminate the possibility of recurrence of the infective endocarditis. We believe that the surgical treatment should be carried out as soon as possible after completion of diagnosis because the aneurysmal wall is usually quite thin and could rupture easily.

[Prosthetic valve endocarditis after aortic valve replacement with freestyle stentless xenograft]

A 52-year-old man underwent aortic valve replacement with freestyle stentless xenograft, using subcoronary technique for active infective endocarditis in June, 2001. Eighteen month later he had late prosthetic valve endocarditis associated with aortic annular abscess due to Staphylococcus epidermidis infection. The abscess was debrided and gelatin-resorcin-formalin glue (GRF glue) was injected into the abscess cavity. Abscess cavity was closed with continuous running suture of 3-0 polypropylene stitches. Finally the aortic valve was replaced with ATS mechanical valve (20 mmAP). After administration of vancomycin and gentamicin for 4 weeks, he discharged on 57th postoperative day in good condition. We strongly suggest that GRF glue is essential to close the aortic annular abscess of combined with aortic regurgitation due to active infective endocarditis.

[Thymic carcinoma (mixed small cell undifferentiated squamous cell carcinoma); report of a case]

A 52-year-old man was admitted to our hospital on October, 1997 with complains of left anterior chest pain. A chest X-ray and computed tomography on admission showed evidence of a mass in the left anterior mediastinum. The patient was treated with combination chemotherapy [cisplatin (CDDP), etoposide (VP-16)] and radiation therapy (2 gray x 25 days), preoperatively. Median sternotomy revealed a tumor invading into the left anterior chest wall, the pericardium, and partial pleura. The tumor was extirpated with combined resection of invaded organs. Microscopically and immunohistochemically, the tumor was diagnosed mixed small cell and undifferentiated squamous cell carcinoma documented by Snover et al. The patient was discharge on March 1998, but 2 years later after operation, he was dead by recurrent. We reported a rare case of thymic carcinoma.

Erythema multiforme associated with cytomegalovirus infection in nonimmunosuppressed patients

BACKGROUND

It is widely known that cytomegalovirus (CMV) primarily brings about subclinical and asymptomatic infection in the early stages of life and can cause various dermatological and systemic disorders under immunosuppressed conditions. Nonimmunosuppressed individuals very rarely present with cutaneous CMV involvement.

OBJECTIVE

In the present study, we described the clinical characteristics of 5 nonimmunosuppressed adult patients with positive IgM antibody to CMV.

METHODS

The systemic symptoms and dermatological features of these 5 patients were described. Laboratory examinations including blood cell counts, liver and renal functions were performed. IgG and IgM antibodies to CMV were also examined at the first consultation and 2-3 months after the skin eruption. Polymerase chain reaction for CMV DNA was performed in the skin samples of the patients.

RESULTS

All 5 patients had fever and complained of a sore throat. Multiple exudative erythema and target lesions with itching were observed mainly on the extremities. These symptoms and eruptions disappeared within 1 week after the onset and IgM antibody titers significantly decreased after 2-3 months. IgG antibody to CMV was already positive in 3 cases but was negative in 2 cases at the initial consultation.

CONCLUSION

We propose that CMV infection may cause erythema multiforme by primary, recurrent infections or reactivation of CMV even in nonimmunosuppressed adults.

Artificial ion channels showing rectified current behavior

Voltage-dependent artificial ion channels 3 and 4 were synthesized. Two cholic acid derivatives were connected through a m-xylylene dicarbamate unit at 3-hydroxyl groups. Asymmetries were introduced by terminal hydrophilic groups, carboxylic acid and phosphoric acid for 3 and hydroxyl and carboxylic acid for 4. Under basic conditions, these headgroups in 3 and 4 are expected to be dissociate into -1/-2 (pH 8.2) and 0/-1 (pH 7.2), respectively. Single ion channel properties were examined by a planar bilayer lipid membrane method under symmetrical 500 mM KCl at pH 8.2 or 7.2. When 3 and 4 were introduced into the bilayer membrane under application of positive voltage (a positive-shift method), the current values at positive applied voltage were larger than the corresponding ones at the negative applied voltage. The current-voltage plots were fitted by curves through a zero point to show clear rectification properties. The direction of rectification could be controlled by positive- or negative-shift methods. Vectorial alignment of terminal headgroup charges by the voltage-shift incorporation is essential for giving voltage-dependent rectified ion channels.

[A case of advanced gastric cancer producing alpha fetoprotein with multiple liver metastases responding to TS-1 after TAE]

We report a case of advanced gastric cancer producing Alpha Fetoprotein (AFP) with multiple liver metastases in which TS-1 is effective. Prognosis of gastric cancer producing AFP is well known to poor. A 74-year-old female was admitted complaining of anemia. She was diagnosed as having advanced gastric cancer with multiple liver metastases producing AFP by endoscopy, computed tomography and angiography. Her serum AFP level was 17,666 ng/ml and her serum CEA level was 5-2 ng/ml. After transarterial embolization (TAE), her family rejected her operation because it would not be curative. So, she was treated with TS-1, 40 mg, administered orally every day, followed by 14 days rest, as the first course. The next was TS-1, 80 mg orally administered for 6 courses. Her serum AFP level was down from 17,666 ng/ml to 94 ng/ml after 6 courses of TS-1. CT revealed that liver metastases did not change and endoscopy showed the primary lesion has diminished. Our report is the first to demonstrate that TS-1 is effective for patients with advanced gastric cancer producing AFP with multiple liver metastases.

Effects of chronic treatment with caffeine on behaviour and related parameters in male and female mice

The effects of chronic free access to caffeine (0.01% or 0.05%) in drinking water and subsequent withdrawal on spontaneous motor activity for 24 hours and some related parameters were examined in 8-week-old male and female ICR mice. In the males, the 0.01% group showed little response, but in the 0.05% group the activities in both light- and dark-phases and, consequently, in total increased and peaked on day 5 of treatment. The response gradually decreased on days 15 and 30 and reached the control level after 30 days of caffeine withdrawal. Meanwhile, in the females, the activity was stimulated by both 0.01% and 0.05% of caffeine, at the dark- and light-phases in the former and latter, respectively. The response peaked at 30 days and decreased near to the control level thereafter in both groups. Caffeine affected little the food intake; however, water intakes were higher and lower than the control in the 0.05% and 0.01% male groups, respectively, but the opposite was true in the females. Plasma component levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), cholesterol and glucose were higher than the control in the males and females treated with 0.05% of caffeine. The caffeine had little effect on the body weight change, organ weights and external appearance throughout the experiment. Thus, the sex- and dose-related differences in the responses to caffeine of spontaneous motor activity and related parameters were proved under physiological conditions.

Prevention and detection of spinal cord injury during thoracic and thoracoabdominal aortic repairs

BACKGROUND

Spinal cord injury is a most dreaded and unpredictable complication. In this study, based on our experimental results in dogs and early clinical results, we reviewed the incidence of paraplegia and the detection of spinal cord injury.

METHODS

Eighty-two patients who underwent elective surgical repair of the descending thoracic and thoracoabdominal aorta over 17 years were subjects for this study. Sixty-two patients were male and 20 were female. Their mean age was 61.6 years (range, 17 to 81 years). Monitoring somatosensory evoked potentials (SEP) and measurement of mean distal aortic pressure and cerebrospinal fluid pressure were performed perioperatively.

RESULTS

Sixty patients had no ischemic change in SEP. In 17 patients with significant ischemic changes of SEP, SEP recovered by increasing spinal cord perfusion pressure to more than 40 mm Hg. Two patients with complete loss of SEP experienced paraplegia. One patient had delayed paraplegia.

CONCLUSIONS

These results strongly suggest that SEP, mean distal aortic pressure, cerebrospinal fluid pressure should be monitored during aortic cross-clamping. Maintaining spinal cord perfusion pressure at more than 40 mm Hg by increasing mean distal aortic pressure or withdrawal of cerebrospinal fluid is valuable for preventing paraplegia.

Immunomodulation based on a two-way paradigm with deoxyspergualin alleviates graft-versus-host reaction in small-bowel transplantation in rats

In this study, we investigated whether or not deoxyspergualin used as donor pretreatment, with and without pretreatment using bone-marrow-cell injection, could alleviate graft-versus-host reaction (GVHR) following small-bowel transplantation in an unidirectional GVHR model with Lewis (LEW)-to-F1 rats. In addition, we studied the effect of deoxyspergualin plus bone-marrow-cell donor pre-operative treatment in combination with recipient postoperative treatment using deoxyspergualin. When the donor was pretreated with bone-marrow cells from recipient rats, the recipient died at 7.2+/-1.4 days, showing significantly shorter survival compared with the control group. Deoxyspergualin, when employed either alone as recipient post-treatment or as donor pretreatment, both with and without additional pretreatment with F1 recipient bone-marrow-cell injection, did not result in significant prolongation of recipient survival. The combination of donor pretreatment with deoxyspergualin plus F1 bone-marrow-cell injection followed by post-operative deoxyspergualin administration, however, resulted in significant prolongation in recipient survival compared with control (26.1+/-1.7 days). In addition, no severe cutaneous lesions on GVHR were seen throughout the observation period. This suggests that donor pretreatment with deoxyspergualin and recipient bone-marrow-cell injection combined with postoperative deoxyspergualin administration can lead to resistance to GVHR after parent-to-F1 small-bowel transplantation.

Levels of interleukin-18 and its binding inhibitors in the blood circulation of patients with adult-onset Still's disease

OBJECTIVE

Interleukin-18 (IL-18) is a proinflammatory cytokine that is involved in immunologically mediated tissue damage, but its bioactivity is regulated in vivo by its soluble decoy receptor, IL-18 binding protein (IL-18BP). This study was undertaken to determine levels of IL-18 and IL-18 binding inhibition in the blood of patients with adult-onset Still's disease (ASD).

METHODS

Serum concentrations of IL-18 in ASD patients were compared by enzyme-linked immunosorbent assay (ELISA) with those in patients with other systemic rheumatic diseases and healthy controls. The biologically active mature protein of IL-18 was detected by Western blot analysis with anti-IL-18 antibody and its induction of interferon-gamma (IFNgamma) secretion from IL-18-responding human myelomonocytic KG-1 cells. The inhibitory activity on IL-18 binding to its receptor was determined by 125I-IL-18 binding inhibition assay using the Chinese hamster ovary cell line transfected with a murine IL-18 receptor (CHO-K1/mIL-18R).

RESULTS

Concentrations of serum IL-18 were extremely elevated in patients with active ASD compared with those in patients with rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, polymyositis/dermatomyositis, Sjogren's syndrome, or healthy individuals. Levels of IL-18 were found to correlate with serum ferritin values and disease severity in ASD. Western blot analysis revealed that serum samples from patients with active ASD contained an 18-kd polypeptide of IL-18, corresponding in size to the mature form. Accordingly, the samples were able to induce IFNgamma secretion from KG-1 cells, which was largely abolished by neutralizing anti-IL-18 antibody. However, the level of IL-18 bioactivity was more than 10-fold weaker than the concentration of IL-18 protein measured by ELISA. Serum samples from patients with active ASD showed an inhibitory effect on the binding of 125I-IL-18 to CHO-K1/mIL-18R cells, and this activity was associated with elevation of IL-18.

CONCLUSION

These data indicate that systemic overproduction of IL-18 may be closely related to the pathogenesis of ASD, despite the restriction on its inflammatory activity by IL-18 binding inhibitors such as IL-18BP. The disease activity appears to be determined on the basis of the relative levels of IL-18 and its specific inhibitors.

Inhibitory effects of detergents on rat CYP1A1-dependent monooxygenase: comparison of mixed and fused systems consisting of rat CYP 1A1 and yeast NADPH-P450 reductase

Inhibitory effects of detergents Triton X-100 and Chaps on 7-ethoxycoumarin O-deethylation activity were examined in the recombinant microsomes containing both rat CYP1A1 and yeast NADPH-P450 reductase (the mixed system) and their fused enzyme (the fused system). Triton X-100 showed competitive inhibition in both mixed and fused systems with K(i) values of 24.6 and 21.5 microM, respectively. These results strongly suggest that Triton X-100 binds to the substrate-binding pocket of CYP1A1. These K(i) values are far below the critical micelle concentration of Triton X-100 (240 microM). Western blot analysis revealed no disruption of the microsomal membrane by Triton X-100 in the presence of 0-77 microM Triton X-100. On the other hand, Chaps gave distinct inhibitory effects to the mixed and fused systems. In the fused system, a mixed-type inhibition was observed with K(i) and K(i)' values of 1.2 and 5.4 mM of Chaps, respectively. However, in the mixed system, multiple inhibition modes by Chaps were observed. Western blot analysis revealed that the solubilized fused enzyme by Chaps preserved the activity whereas the solubilized CYP1A1 and NADPH-P450 reductase reductase showed no activity in the mixed system. Thus, the comparison of the mixed and fused systems appears quite useful to elucidate inhibition mechanism of detergents.

Interferon-gamma-inducing activity of interleukin-18 in the joint with rheumatoid arthritis

OBJECTIVE

To examine the levels of interleukin-18 (IL-18) bioactivity within the rheumatoid arthritis (RA) joint, and the differential effects of IL-12 and IL-18 on interferon-gamma (IFNgamma) production by T cell infiltrates.

METHODS

Expression of IL-18 protein and messenger RNA (mRNA) was determined by enzyme-linked immunosorbent assay and reverse transcriptase-polymerase chain reaction, respectively. The biologic activity of IL-18 was detected on the basis of IFNgamma secretion from IL-18-responding human myelomonocytic KG-1 cells. To determine the extent of inhibitory activity on binding of IL-18 to its receptor, a [125I]-IL-18 binding inhibition assay was performed, using a Chinese hamster ovary cell line transfected with a murine IL-18 receptor.

RESULTS

The amount of IL-18 protein detected in both the serum and synovial fluid of RA patients was markedly larger than that detected in the serum and synovial fluid ofosteoarthritis (OA) patients, and serum IL-18 levels correlated with the levels of serum C-reactive protein. IFNgamma production by KG-1 cells was more strongly stimulated in synovial fluid samples from RA patients than in samples from OA patients, and this activity was largely diminished in the presence of anti-IL-18 antibody. In contrast, the activity of IL-18 binding inhibition in the serum and synovial fluid of RA patients was not significantly elevated compared with that in OA patients. RA synovial tissues showed increased expression of IL-18 mRNA and increased IL-18 protein synthesis compared with that in OA tissues. Purified CD14+ macrophages, but not activated fibroblast cell lines, from RA synovium were able to release mature IL-18, although both cell types expressed its transcripts. IL-18 alone showed a negligible effect on IFNgamma production by RA synovial tissue cells, in contrast to IL-12, which was directly stimulatory. However, IL-12-induced IFNgamma production was synergistically enhanced by IL-18, and yet was >50% reduced by neutralization of endogenous IL-18 with anti-IL-18 antibody.

CONCLUSION

These results indicate that IL-18, produced predominantly by tissue macrophages, primarily potentiates IL-12-induced IFNgamma production by T cell infiltrates in RA synovium. Detection of significant IL-18 bioactivity in the joints, despite the presence of IL-18 binding inhibitors, supports an integral role of this cytokine in perpetuating the IFNgamma-dominant T cell cytokine response in RA.

Differential in vitro effects of IL-4, IL-10, and IL-13 on proinflammatory cytokine production and fibroblast proliferation in rheumatoid synovium

The purpose of this study was to compare the potential of interleukin-4 (IL-4), IL-10, and IL-13 to interrupt two major inflammatory pathways in rheumatoid arthritis (RA), i.e., overexpression of proinflammatory cytokines and cytokine-mediated fibroblast growth. IL-4, IL-10, and IL-13 were all able to significantly inhibit the production of IL-1beta, tumor necrosis factor-alpha (TNF-alpha), IL-6, and IL-8 by freshly isolated RA synovial tissue cells, IL-10 was most effective in terms of IL-1beta and TNF-alpha reduction. The IL-1 receptor antagonist was enhanced by IL-4 and IL-13, but only slightly enhanced by IL-10. Spontaneous interferon-gamma secretion was diminished by IL-4 and IL-10 but not by IL-13. Addition of anti-IL-10 neutralizing antibody to RA synovial tissue cells resulted in a substantial increase in IL-1beta and TNF-alpha levels, whereas neither anti-IL-4 nor anti-IL-13 antibody had a significant effect. IL-1beta-stimulated proliferation of RA synovial fibroblast cell lines was inhibited by IL-4 and IL-13, but not by IL-10; IL-4 was over tenfold more effective than IL-13. These results suggest that IL-4, IL-10, and IL-13 all have the therapeutic potential to regulate the disease activity mediated by proinflammatory cytokines in RA, but each cytokine may have different potencies.