Establishing clinical remission criteria for giant cell arteritis: Results of a Delphi exercise carried out by an expert panel of the Japan Research Committee of the Ministry of Health, Labour, and Welfare for Intractable Vasculitis

OBJECTIVE

To develop a proposal for giant cell arteritis remission criteria in order to implement a treat-to-target algorithm.

METHODS

A task force consisting of 10 rheumatologists, 3 cardiologists, 1 nephrologist, and 1 cardiac surgeon was established in the Large-vessel Vasculitis Group of the Japanese Research Committee of the Ministry of Health, Labour and Welfare for Intractable Vasculitis to conduct a Delphi survey of remission criteria for giant cell arteritis. The survey was circulated among the members over four reiterations with four face-to-face meetings. Items with a mean score of ≥4 were extracted as items for defining remission criteria.

RESULTS

An initial literature review yielded a total of 117 candidate items for disease activity domains and treatment/comorbidity domains of remission criteria, of which 35 were extracted as disease activity domains (systematic symptoms, signs and symptoms of cranial and large-vessel area, inflammatory markers, and imaging findings). For the treatment/comorbidity domain, ≤5 mg/day of prednisolone 1 year after starting glucocorticoids was extracted. The definition of achievement of remission was the disappearance of active disease in the disease activity domain, normalization of inflammatory markers, and ≤5 mg/day of prednisolone.

CONCLUSION

We developed proposals for remission criteria to guide the implementation of a treat-to-target algorithm for giant cell arteritis.

Recommendations for the management of the vascular involvement in Behçet's disease by the Japanese National Research Committee for Behçet's disease-secondary publication

OBJECTIVES

This study aimed to develop clinical guidelines for the management of vascular Behçet's disease (BD) by the Behçet's Disease Research Committee of the Ministry of Health, Labour and Welfare of the Japanese Government.

METHODS

A task force proposed clinical questions (CQs) concerning vascular BD based on a literature search. After screening, draft recommendations were developed for each CQ and brushed up in three blinded Delphi rounds, leading to the final recommendations.

RESULTS

This study provides recommendations for 17 CQs concerning diagnosis and differential diagnoses, assessment of disease activity, and treatment. The guidelines recommend immunosuppressive treatments, for both arterial and venous involvement with active inflammation. Anticoagulation is also recommended for deep vein thrombosis except in high-risk patients. Surgical and endovascular therapies can be optional, particularly in patients with urgent arterial lesions undergoing immunosuppression. In addition, two sets of algorithms for diagnosis and treatment are shown for arterial and venous involvement.

CONCLUSIONS

These recommendations are expected to serve as useful tools in the daily clinical practice of BD. This content has already been published in Japanese in the Guideline for the Management of Behçet's Disease 2020 and is submitted with permission from both the primary and secondary publishers.

Nation-wide cohort study of remission induction therapy using rituximab in Japanese patients with antineutrophil cytoplasmic antibody-associated vasculitis: Effectiveness and safety in the first 6 months

OBJECTIVES

The aim of this article is to evaluate the effectiveness and safety of rituximab (RTX) for microscopic polyangiitis and granulomatosis with polyangiitis in Japan.

METHODS

In this prospective observational study, all patients with microscopic polyangiitis and granulomatosis with polyangiitis administered RTX were enrolled at each institution. During the observation period of 2 years, data up to 6 months were analysed. Cox proportional hazards analysis was used to assess the factors associated with an outcome.

RESULTS

Of the 75 patients who received RTX for remission induction therapy, 53 achieved remission by the sixth month and 50 were in remission at the sixth month. During therapy, 38 serious adverse events were observed in 24 patients, 21 serious infections in 16 patients, and 9 patients died. No factors were associated with remission; however, there was a significant difference between patients with and without remission in serious adverse events (22.6% vs. 54.5%), serious infections (11.3% vs. 45.4%), and death (1.9% vs. 36.4%). The hazard ratio (95% confidence interval) for serious infection was 3.49 (1.29-9.74) for patients aged ≥ 75 years and 3.53 (1.31-9.53) for pulmonary complications. Four patients maintained remission for 6 months.

CONCLUSIONS

The effectiveness and safety of RTX for microscopic polyangiitis and granulomatosis with polyangiitis for up to 6 months was demonstrated.

Association between glucocorticoid discontinuation and incidence of infection in older adults with rheumatoid arthritis: A retrospective cohort study

AIM

Old age and glucocorticoid (GC) use increase the susceptibility to infection in patients with rheumatoid arthritis (RA). Accordingly, we investigated whether GC discontinuation reduces the incidence of infection in older adults with RA and analyzed factors associated with GC discontinuation.

METHODS

Medical records of patients with RA aged ≥60 years were retrieved, and the association between GC use and the incidence of infection was investigated. The participants were divided into three groups: GC-continued, GC-discontinued, and non-GC; the incidence of infection was statistically analyzed. Furthermore, patient treatments and comorbidities were examined.

RESULTS

Among 389 patients with RA included in the study (n = 122, n = 126, and n = 141 in the GC-discontinued, GC-continued, and non-GC groups, respectively), 65 (16.7%) patients developed infection, and the incidence of infection was significantly higher in the GC-continued group than in the GC-discontinued (p = .021) and non-GC (p = .0003) groups; there was no significant difference between the non-GC and GC-discontinued groups (p = .659). The GC-discontinued group was more likely to require biologic use throughout the disease course than the other two groups. Comorbidities, especially malignancies (p = .004), were more common in the GC-continued group than in the GC-discontinued group (p = .007).

CONCLUSION

In patients with RA aged ≥60 years receiving GCs, GC discontinuation reduced the incidence of infection. Therefore, a further analysis of factors that help reduce GC use is necessary.

Long-term survival, causes of death, and prognostic factors for mortality in patients with microscopic polyangiitis and those with anti-neutrophil cytoplasmic antibody-positive interstitial lung disease: A single-center retrospective study

AIM

To elucidate the clinical features, long-term survival, and prognostic factors for mortality among patients with microscopic polyangiitis (MPA), including those with anti-neutrophil cytoplasmic antibody-positive interstitial lung disease (ILD) (ANCA-ILD), which could be a subset of its variant phenotype.

METHODS

We retrospectively included 76 consecutive patients between 2006 and 2014, diagnosed with MPA according to the European Medicines Agency algorithm using the Chapel Hill Consensus Conference definitions or ANCA-ILD. ILD was classified as usual interstitial pneumonia (UIP) or nonspecific interstitial pneumonia pattern using chest computed tomography.

RESULTS

The mean (standard deviation) age of the patients (female, 68%) was 69 (12) years. The median (interquartile range) follow-up period was 68 (33-95) months. Comorbid ILD and glomerulonephritis were observed in 44 (58%) (68% UIP) and 54 (71%) patients, respectively. Comorbid ILD was associated with low survival (P = .0563). There were 17 (39%) and 5 (16%) deaths in the ILD and non-ILD groups, respectively (P = .0404). In the ILD group, 6 and 5 of the deaths were attributed to infection and ILD progression, respectively. In the non-ILD group, 1 and 2 patients expired from subsequently developed ILD and aspiration pneumonia, respectively. Age ≥ 70 years (hazard ratio = 2.78; 95% confidential interval 1.15-6.70) and UIP (3.95; 1.60-9.77) were independent risk factors for mortality.

CONCLUSION

Age ≥ 70 years and ILD with a UIP pattern were associated with high mortality, owing to susceptibility to infection and ILD progression. A more effective and less toxic treatment is required for progressive ILD.

Reasons for discontinuation of methotrexate in the treatment of rheumatoid arthritis and challenges of methotrexate resumption: a single-center, retrospective study

Background

Methotrexate (MTX) is an anchor drug used for the treatment of rheumatoid arthritis (RA); hence, understanding the reasons for MTX discontinuation in RA can help improve its treatment. Therefore, this study aimed to investigate the reasons for MTX discontinuation and to identify future challenges in RA treatment regarding the discontinuation and resumption of MTX treatment.

Results

MTX administration was discontinued in 771 patients with RA. The reasons for MTX discontinuation were as follows: (1) infectious diseases (20.0%), (2) malignancy (14.1%), and (3) respiratory problems (10.2%). Some patients did not resume MTX therapy even after the infections were cured. Liver dysfunction (8.0%) did not improve with MTX discontinuation and was often associated with fatty liver disease. In addition to adverse events, MTX discontinuation was due to patient preference (4.3%), planning for pregnancy (5.1%), invalidity (5.7%), remission (5.6%), remission with biologics (4.7%), old age (2.6%), and poor compliance (1.6%).

Conclusions

This study revealed diverse reasons for the discontinuation of MTX; there are cases in which MTX is discontinued but should be considered for resumption. Furthermore, issues such as the indications for MTX discontinuation should still be debated, and multicenter evidence must be collected and examined in future studies.

Serum polyethylene glycol-specific IgE and IgG in patients with hypersensitivity to COVID-19 mRNA vaccines

BACKGROUND

The mechanism of allergic reactions to COVID-19 mRNA vaccines has not been clarified. Polyethylene glycol (PEG) is a potential antigen in the components of vaccines. However, there is little evidence that allergy after COVID-19 mRNA vaccination is related to PEG. Furthermore, the role of polysorbate (PS) as an antigen has also not been clarified. The objective of this study was to investigate whether PEG and PS allergies are reasonable causes of allergic symptoms after vaccination by detecting PEG-specific and PS-specific antibodies.

METHODS

Fourteen patients who developed immediate allergic reactions to BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna) vaccines and nineteen healthy controls who did not present allergic symptoms were recruited. Serum PEG-specific immunoglobulin E (IgE) and immunoglobulin G (IgG) and PS-specific IgE and IgG were measured by enzyme-linked immunosorbent assay. Skin tests using PEG-2000 and PS-80 were applied to five patients and three controls.

RESULTS

Serum levels of PEG-specific IgE and IgG in patients with immediate allergic reactions to the COVID-19 mRNA vaccine were higher than those in the control group. Serum levels of PS-specific IgE in patients with allergy to the vaccine were higher than those in patients of the control group. Intradermal tests using PEG verified the results for PEG-specific IgE and IgG.

CONCLUSIONS

The results suggest that PEG is one of the antigens in the allergy to COVID-19 mRNA vaccines. Cross-reactivity between PEG and PS might be crucial for allergy to the vaccines. PEG-specific IgE and IgG may be useful in diagnosing allergy to COVID-19 mRNA vaccines.

POS0794 PREGNANCY AND CHILDBIRTH IN TAKAYASU ARTERITIS IN JAPAN – A NATIONWIDE RETROSPECTIVE STUDY

Background

Takayasu arteritis (TAK), a granulomatous large vessel vasculitis, mainly involves the aorta and its proximal branches and commonly occurs in young females. However, studies of pregnancy in women with TAK are sparse and limited, probably due to the rarity of the disease.

Objectives

The purpose of this study was to understand the status quo of medical treatments of the primary disease and outcomes of pregnancy in patients with TAK, and birth outcomes of the children in Japan.

Methods

Patients with TAK who conceived after the onset of the disease and were managed at medical facilities participating in the Japan Research Committee of the Ministry of Health, Labour, and Welfare for Intractable Vasculitis (JPVAS) were retrospectively enrolled in this study. The following information was collected from patients who had a live-born baby: age at diagnosis of TAK, disease classification, age at delivery, treatments before and during pregnancy, complications during pregnancy, birth outcomes of the children, and changes in disease activity during pregnancy and after delivery.

Results

Fifty-one cases and 69 pregnancies from 19 ethics committee-approved centers were enrolled during the study period 2019–2021. Of these, 49 cases and 66 pregnancies (95.7%) resulted in delivery and live-born babies. The Numano classification of the 49 cases was as follows: type I, 11; type IIa, 15; type IIb,12; type III, 1; type IV, 1; type V, 9; with type IIa being the most common. The age of diagnosis was 22 years (13–37 years, year of diagnosis 1965–2017), the median age of the delivery of 66 pregnancies was 31 years (year of delivery 1969-2021), and the median duration of illness at delivery was nine years. There were 34 planned pregnancies (51.5%, including four pregnancies by artificial insemination/ovulation induction). Preconception therapy included prednisolone (PSL) in 51 pregnancies (77.3%, median dose 7.5 mg (range 4–30 mg)/day), immunosuppressive drugs in 18 pregnancies (27.3%, azathioprine 8, tacrolimus 7, methotrexate 4, cyclosporin A 1, and colchicine 1), biologics in 12 pregnancies (18.1%, infliximab 6, tocilizumab 5, and adalimumab 1), antihypertensive drugs in 5 pregnancies (7.6%). Surgical treatment had been performed before pregnancy in 6 cases (aortic root replacement 2, subclavian artery dilatation 1, subclavian artery bypass 1, subclavian artery stenting 1, and ascending aorta semicircular artery replacement 1). Medications used during the course of pregnancy included PSL in 48 pregnancies (72.7%, median dose 8 mg (range 4–30 mg)/day, increased in 13 pregnancies, decreased in 1 pregnancy), immunosuppressants in 13 pregnancies (19.7%, azathioprine 6, tacrolimus 6, and cyclosporin A 1), biologics 9 pregnancies (13.6%, infliximab 4, tocilizumab 4, and adalimumab 1). Immunosuppressants and biologics were discontinued in five and four pregnancies after conception. Complications during pregnancy were observed in 20 pregnancies (30.3%), with hypertension being the most common. Complications related to TAK or its treatment were severe infections in two pregnancies and aneurysm enlargement due to increased circulating plasma volume in one pregnancy. Aortic arch replacement was performed after delivery for the latter case. Relapse of TAK was observed in 4 pregnancies (6.1%) during pregnancy and in 8 pregnancies (12.1%) after delivery. One pregnancy resulted in restenosis of subclavian artery for which dilatation procedure was performed prior to the pregnancy. There were 13/66 (19.7%) preterm infants and 17/59 (28.8%) low birth weight infants; all but one had a birth weight of more than 2,000 g and no had serious postnatal abnormalities. Forty-three (82.7%) of the 52 confirmed infants were breastfeed fully or mixed.

Conclusion

Most of the pregnancies in patients with TAK were successfully delivered while they had low disease activity at a dose of less than 10 mg/day of PSL. Relapse occurred during pregnancy and after delivery in some cases. The babies tended to have low birth weight, but 82.7% of them were breastfed without serious complications.

Disclosure of Interests

Takako Miyamae: None declared, Yusuke Manabe: None declared, takahiko sugihara Speakers bureau: TS has received honoraria from Abbvie Japan Co., Ltd., AsahiKASEI Co., Ltd., Astellas Pharma Inc., Ayumi Pharmaceutical, Bristol Myers Squibb K.K., Chugai Pharmaceutical Co., Ltd., Eli Lilly Japan K.K., Mitsubishi-Tanabe Pharma Co., Ono Pharmaceutical, Pfizer Japan Inc., Takeda Pharmaceutical Co. Ltd., and UCB Japan Co., Grant/research support from: TS has received research grants from AsahiKASEI Co., Ltd., Daiichi Sankyo., Chugai Pharmaceutical Co., Ltd., and Ono Pharmaceutical., Natsuka Umezawa: None declared, Hajime Yoshifuji Speakers bureau: HY has received lecture fees from Janssen and Chugai., Naoto Tamura: None declared, Yoshiyuki Abe: None declared, Shunsuke Furuta Speakers bureau: Chugai Pharmaceutical Co.,Ltd.

DaiichiSankyo Co.,Ltd.

Asahi-Kasei Pharma Corporation, Manami Kato: None declared, Takashi Kumagai: None declared, Kaito Nakamura: None declared, Hiroko Nagafuchi: None declared, Jun Ishizaki: None declared, Naoko Nakano: None declared, Tatsuya Atsumi Speakers bureau: Mitsubishi Tanabe Pharma Co., Chugai Pharmaceutical Co., Ltd., Astellas Pharma Inc., Takeda Pharmaceutical Co., Ltd., Pfizer Inc., AbbVie Inc., Eisai Co. Ltd., Daiichi Sankyo Co., Ltd., Bristol-Myers Squibb Co., UCB Japan Co. Ltd., Eli Lilly Japan K.K., Novartis Pharma K.K., Eli Lilly Japan K.K., Kyowa Kirin Co., Ltd.,TAIHO PHARMACEUTICAL CO., LTD., Consultant of: AstraZeneca plc., MEDICAL & BIOLOGICAL LABORATORIES CO., LTD., Pfizer Inc., AbbVie Inc., ONO PHARMACEUTICAL CO. LTD.,

Novartis Pharma K.K., Nippon Boehringer Ingelheim Co., Ltd., Grant/research support from: Astellas Pharma Inc., TAIHO PHARMACEUTICAL CO., LTD.AbbVie Inc., Nippon Boehringer Ingelheim Co., Ltd.,Takeda Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Chugai Pharmaceutical Co., Ltd., Daiichi Sankyo Co. Ltd., Otsuka Pharmaceutical Co., Ltd. and Pfizer Inc. Alexion Inc., TEIJIN PHARMA LIMITED., Kohei Karino: None declared, Koichi Amano Speakers bureau: AbbVie GK, Asahi-Kasei Pharma, Astellas, Chugai Pharmaceutical Co.Ltd., Eisai, Eli Lilly, GlaxoSmithKlein, Janssen Pharma, Pfizer Japan, Grant/research support from: Asahi-Kasei Pharma,Chugai Pharmaceutical Co.Ltd., Takahiko Kurasawa: None declared, Shuichi Ito: None declared, Ryusuke Yoshimi: None declared, Noriyoshi Ogawa: None declared, Shogo Banno: None declared, Taio Naniwa Speakers bureau: Chugai, Tanabe, Abbbvie, Eisai, Grant/research support from: Chugai, Tanabe, Abbbvie, Eisai, Satoshi Ito Speakers bureau: SI has received speaker’s fees from pharmaceutical companies., Akinori Hara: None declared, Shinya Hirahara: None declared, Haruhito A. Uchida: None declared, Yasuhiro Onishi: None declared, Yohko Murakawa Speakers bureau: Astellas, UCB, Chugai, AbbVie, Grant/research support from: Chugai, AbbVie, Yoshinori Komagata: None declared, Yoshikazu Nakaoka: None declared, Masayoshi Harigai Speakers bureau: MH has received speaker’s fee from AbbVie Japan GK, Ayumi Pharmaceutical Co., Boehringer Ingelheim Japan, Inc., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Janssen Pharmaceutical K.K., Kissei Pharmaceutical Co., Ltd., Novartis Japan, Pfizer Japan Inc., Mitsubishi Tanabe Pharma Co., Teijin Pharma Ltd and UCB Japan., Consultant of: MH is a consultant for AbbVie, Boehringer-Ingelheim, Kissei Pharmaceutical Co., Ltd., and Teijin Pharma.

Clinical Features of Behçet's Disease Patients with Joint Symptoms in Japan: A National Multicenter Study

OBJECTIVES

Approximately 30%-60% of Behçet's disease patients exhibit joint symptoms. The aim of this study was to determine the clinical characteristics of such patients in Japan.

METHODS

This study retrospectively analyzed 151 Behçet's disease patients with joint symptoms who had been treated at seven cooperative medical institutions from 2007 to 2017. We investigated their clinical characteristics and treatments.

RESULTS

The most commonly affected joints were the knee, ankle, and proximal interphalangeal joints. Of the cases with pain and swelling, 18 of 293 joints (11 cases) displayed narrowing of the cleft or deformity by Xray analysis. Improvement in their arthritis was observed in 80% of the patients who received steroids as initial treatment; however, the rate of improvement was lower in patients who had received prednisolone (PSL) at <10 mg/day. The recurrence of joint symptoms was significantly less common in the colchicine group than in the PSL group.

CONCLUSIONS

These results suggest that PSL is effective for remission induction for the treatment of joint symptoms of Behçet's disease, though it may not be effective at low doses. Additionally, colchicine is effective in preventing the recurrence of joint symptoms in Behçet's disease. Furthermore, joint damages like joint space narrowing or with any deformity can often be observed in Behçet's disease patients in Japan.

Establishing Clinical Remission Criteria and the Framework of a Treat-To-Target Algorithm for Takayasu arteritis: Results of a Delphi Exercise Carried out by an Expert Panel of the Japan Research Committee of the Ministry of Health, Labour, and Welfare for intractable vasculitis

OBJECTIVE

To develop a proposal for remission criteria and a framework for a treat-to-target (T2T) algorithm for Takayasu arteritis (TAK).

METHODS

A study group of the large-vessel vasculitis group of the Japanese Research Committee of the Ministry of Health, Labour, and Welfare for Intractable Vasculitis (JPVAS) consists of 10 rheumatologists, 5 cardiologists, 1 nephrologist, 1 vascular surgeon, 1 cardiac surgeon, and 2 pediatric rheumatologists. A Delphi survey of remission criteria items was circulated among the study group over 4 reiterations. To develop the T2T algorithm, the study group conducted four face-to-face meetings and two rounds of Delphi together with 3 patients.

RESULTS

Initial literature review resulted in a list of 117 candidate items for remission criteria, of which 56 items with a mean score of ≥4 (0-5) were extracted including disease activity domains and treatment/comorbidity domains. The study group provided six overarching principles for the T2T algorithm, two recommendations on treatment goals, five on evaluation of disease activity and imaging findings including PET-CT, and two on treatment intensification.

CONCLUSIONS

We developed a T2T algorithm and proposals for standardized remission criteria by means of a Delphi exercise. These will guide future evaluation of different TAK treatment regimens.

Pregnancy outcomes in patients with rheumatoid arthritis who discontinue methotrexate treatment to conceive

INTRODUCTION/OBJECTIVES

Rheumatoid arthritis (RA) develops at reproductive age. Methotrexate (MTX), the anchor drug for RA treatment, is contraindicated during pregnancy. We investigated pregnancy outcomes in RA patients in whom MTX was withdrawn.

METHOD

Pregnancy outcomes, RA treatment, and infertility factors were examined in patients with RA who discontinued MTX prior to attempting conception. The Mann-Whitney U test and Fisher's exact test were used to evaluate differences between the groups.

RESULTS

Of the 52 patients enrolled in this study, 33 gave birth after discontinuing MTX and 19 did not. The age at MTX discontinuation was significantly different between the childbirth and non-childbirth groups (p = 0.0258). The use of non-steroidal anti-inflammatory drugs (NSAIDs) and salazosulfapyridine was significantly different between the groups (p = 0.0079 and p = 0.0438, respectively). Patients whose time from MTX discontinuation to pregnancy was longer than 12 months had a longer previous MTX administration period (p = 0.0182) and were older at the time of pregnancy (p = 0.0128) than those whose was shorter.

CONCLUSIONS

The results suggest that to ensure successful childbirth in women with RA, the decision to conceive should be made at the youngest possible age, NSAIDs should not be used, and a shorter duration of MTX treatment should be considered before pregnancy. Nevertheless, additional studies with larger sample sizes are warranted to analyse the effects of other factors on pregnancies in patients with RA.

KEY POINTS

• Patients with RA who plan to conceive must discontinue MTX therapy. • To achieve successful pregnancy outcomes, female patients with RA should become pregnant when they are young, discontinue NSAIDs prior to conception, and shorten their durations of MTX therapy before attempting pregnancy.

Rheumatoid arthritis relapse in patients with other iatrogenic immunodeficiency-associated lymphoproliferative disorders and its treatment

OBJECTIVES

Rheumatoid arthritis (RA) in patients undergoing immunosuppressive therapy (IS) is sometimes involved with other iatrogenic immunodeficiency-associated lymphoproliferative disorders (LPD). We aimed to clarify the effects of LPD treatment on RA and the current status of RA treatment options after LPD onset and subsequent IS withdrawal.

METHODS

We retrospectively analyzed data of patients who had RA with LPD and examined the relationship between LPD course and RA treatment as well as that between RA relapse and LPD treatment.

RESULTS

LPD patients were categorized into two groups: patients who regressed spontaneously (n = 19) and those who needed chemotherapy (n = 12). The chemotherapy group had significantly less RA relapse than the spontaneous regression group (p = .041). RA almost relapsed early in the spontaneous regression group and needed treatment for RA. Chemotherapy with rituximab prevented long-term RA relapse, and RA did not relapse for long even after rituximab monotherapy. The total dose of rituximab in monotherapy correlated with the time to RA relapse. Six patients with RA relapse received biologics and had no LPD relapse for more than 1 year.

CONCLUSIONS

Rituximab in chemotherapy for LPD may help prevent RA relapse with LPD. Large-scale studies are required in the future for verification.

Recurrent Bilateral Focal Myositis

This report describes a rare case of recurrent bilateral focal myositis and its successful treatment via methotrexate. A 38-year-old man presented myalgia of the right gastrocnemius in May 2005. Magnetic resonance imaging showed very high signal intensity in the right gastrocnemius on short-tau inversion recovery images. A muscle biopsy revealed inflammatory CD4+ cell-dominant myogenic change. Focal myositis was diagnosed. The first steroid treatment was effective. Tapering of prednisolone, however, repeatedly induced myositis relapse, which progressed to multiple muscle lesions of both lower limbs. Initiation of methotrexate finally allowed successful tapering of prednisolone, with no relapse in the past 4 years.

Psoriatic Arthritis with Annular Pustular Psoriasis

We herein present the case of a 56-year-old woman who presented with symptoms of psoriatic arthritis (PsA) with erythema that progressed to annular pustular psoriasis. The patient had a 15-year history of polyarthritis. Annular pustular psoriasis is not typically observed in cases of arthritis. This is the first reported case of PsA with annular pustular psoriasis.

Retrospective analysis of long-term outcome of chronic progressive neurological manifestations in Behcet's disease

OBJECTIVES

Chronic progressive neuro-Behcet's disease (CPNBD) is characterized by progressive deterioration leading to disability and death. Although methotrexate has been found effective for CPNBD, its influences on the long-term outcome remain unclear. We therefore explored the effects of various treatments on the prognosis.

METHODS

Thirty-seven patients, who met the international classification criteria for BD and developed chronic progressive neuropsychiatric manifestations after 1988, were followed up until October 2013. The effects of various treatments on prevention of death or severe disability of bedridden state were examined by Kaplan-Meier analysis and Cox's proportional hazard model.

RESULTS

Twenty-eight of 37 patients with CPNBD (75.7%) received methotrexate. Among the 28 patients, none died and only 5 patients progressed to disability with bedridden state. By contrast, among the 9 patients without methotrexate, 5 patients died and 3 patients progressed to bedridden state. Thus, methotrexate significantly improved the survival of patients with CPNBD (HR 0.0507, p=0.020) as well as reduced the rate of progression into bedridden state or death (HR 0.2082, p=0.0126), but none of high doses of steroids, azathioprine or cyclophosphamide did.

CONCLUSION

The results indicate that methotrexate, but not high doses of steroids, azathioprine or cyclophosphamide, is effective to prevent the progression of CPNBD.

Long-term safety and efficacy of rituximab in 7 Japanese patients with ANCA-associated vasculitis

OBJECTIVES

The safety and efficacy of rituximab were examined in a multicenter open-label pilot study in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) in Japan.

METHODS

Patients with refractory AAV were administered a rituximab infusion at a weekly dose of 375 mg/m(2) for 4 weeks. All patients also received oral daily prednisolone. The primary outcome was complete remission, which was defined as a Birmingham Vasculitis Activity Score (BVAS) of 0 or 1.

RESULTS

The mean age of the 7 patients was 57 (range, 34-71) years. The mean follow-up period after rituximab treatment was 62.9 (range, 4.8-81) months. The mean BVAS at entry was 16.7 (range, 2-34). Complete remission occurred in all cases, except in 1 case in which the patient died, with a significant decline in BVAS from baseline at 12 months after initiation of rituximab. Rituximab reduced granulomatous orbital involvement in a patient with granulomatosis with polyangiitis. Relapse occurred in five patients. Adverse events included de novo hepatitis B in one patient, cancer (hepatocellular carcinoma and prostate cancer) in two patients, and transient visual disturbance, atypical mycobacterial infection, urinary tract infection, sepsis, and cytomegalovirus infection. Two patients died due to recurrent infections and airway obstruction, caused by an AAV lesion.

CONCLUSIONS

Rituximab had a beneficial effect on refractory AAV in Japanese patients, but several adverse effects occurred during rituximab treatment.

Serum level of soluble triggering receptor expressed on myeloid cells-1 as a biomarker of disease activity in relapsing polychondritis

OBJECTIVES

We aimed to identify a serum biomarker for evaluating the disease activity of relapsing polychondritis (RP).

METHODS

We measured and compared serum levels of 28 biomarkers potentially associated with this disease, including soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), high-sensitivity C-reactive protein (hs-CRP), and cartilage oligomeric matrix protein (COMP), in 15 RP patients and 16 healthy donors (HDs). We divided the 15 RP patients into active RP (n = 8) and inactive RP (n = 7) groups, depending on the extent of the disease, and compared candidate markers between groups. The localization of membrane-bound TREM-1 in the affected tissue was examined by immunohistochemistry.

RESULTS

Serum levels of sTREM-1, interferon-γ, chemokine (C-C motif) ligand 4, vascular endothelial growth factor, and matrix metalloproteinases-3 were significantly higher in RP patients than HDs. Among these markers, sTREM-1 had the highest sensitivity and specificity (86.7 and 86.7 %, respectively). Furthermore, the serum level of sTREM-1 was significantly higher in active RP patients than inactive RP patients (p = 0.0403), but this was not true for hs-CRP or COMP. TREM-1 was expressed on endothelial cells in RP lesions.

CONCLUSIONS

The serum level of sTREM-1 may be a useful marker of disease activity in RP.

Analysis of various factors on the relapse of acute neurological attacks in Behçet's disease

OBJECTIVES

To investigate the influences of various factors on the relapse of acute neurological attacks in patients with Behçet's disease (BD).

METHODS

Sixty-one patients, who met the international classification criteria for BD, had attacks of acute neuro-Behçet's disease (NBD) and could be followed up at least for 2 months, including 60 patients in our multicenter retrospective survey on BD patients in 2011. The factors associated with relapse of acute neurological attacks were assessed.

RESULTS

Twenty-one of 61 patients had been taking cyclosporine A (CyA) at the onset of acute NBD. All the 21 patients with CyA and 33 of the 40 patients without CyA had eye involvement. There were no significant differences in demographic features, clinical symptoms, MRI findings, the need for, and responses to corticosteroid therapy including pulse therapy between patients with CyA and those without CyA. CyA was withdrawn in 19 of 21 patients with CyA. Of note, patients with CyA showed significantly lower relapse rates than those without CyA (HR 0.1283, 95% CI: 0.0788-0.7836, p = 0.0186 as calculated by log-rank test). Moreover, colchicine was found to reduce the relapse rates in patients with acute NBD without CyA (HR 0.2771, 95% CI: 0.0827-0.9422, p = 0.0450 [log-rank test]).

CONCLUSION

These results indicate that CyA-related acute neurological manifestations are almost identical with CyA-unrelated acute events of NBD, except for the paucity of relapse on withdrawal of CyA. The data also demonstrate that colchicine is effective to prevent relapses of acute neurological attacks especially in patients with CyA-unrelated acute NBD.

Comparison of phenotype and outcome in microscopic polyangiitis between Europe and Japan

OBJECTIVE

There are differences between Europe and Japan in the incidence and antineutrophil cytoplasmic antibody (ANCA) serotype of patients with microscopic polyangiitis (MPA). However, differences in phenotype or outcome have not been explored. We aimed to identify differences in phenotype and outcome of MPA between Europe and Japan.

METHODS

Sequential cohorts of patients with MPA and renal limited vasculitis were collected from European and Japanese centers (n = 147 and n = 312, respectively). Trial databases from the European Vasculitis Society and the Japanese patients with Myeloperoxidase (MPO)-ANCA-Associated Vasculitis (JMAAV) trial were studied (n = 254 and n = 48, respectively). We evaluated baseline characteristics including ANCA status and organ involvement, treatment, survival, and renal survival. Differences in survival and renal survival were studied using multivariate analysis.

RESULTS

The non-trial cohorts showed patients with MPA in Japan had a higher age at onset, more frequent MPO-ANCA positivity, lower serum creatinine, and more frequent interstitial pneumonitis than those in Europe (all p < 0.01). Comparisons between the trial databases demonstrated similar results. Cumulative patient survival and renal survival rates were not different between Europe and Japan (p = 0.71 and p = 0.38, respectively). Multivariate analysis identified age at onset, serum creatinine, gastrointestinal, and respiratory involvement as factors with higher risk of death. For endstage renal failure, serum creatinine and use of plasma exchange were identified as factors with higher risk, and immunosuppressant use as lower risk factors.

CONCLUSION

Phenotypes in patients with MPA were different between Europe and Japan. However, the outcomes of patient survival and renal survival were similar.

Assessment of the Birmingham vasculitis activity score in patients with MPO-ANCA-associated vasculitis: sub-analysis from a study by the Japanese Study Group for MPO-ANCA-associated vasculitis

OBJECTIVES: In the study cohort enrolled in a prospective open-label, multicenter trial conducted by the Japanese Study Group for MPO-ANCA-associated vasculitis (JMAAV), we conducted this sub-analysis to establish the validity of the Birminghan vasculitis activity score (BVAS) for Japanese patients with MPO-ANCA-associated vasculitis. METHODS: We recorded the BVAS at the time of diagnosis, at 6 weeks after the diagnosis, and at 3, 6, 9, 12, 15 and 18 months after the diagnosis in this study. RESULTS: The most frequently involved organs in the patients were the lungs, kidneys and the nervous system. The kidney (BVAS; new/worse 69.2 %, persistent 40.4 %), general (BVAS; new/worse 67.3 %, persistent 53.8 %), chest (BVAS; new/worse 36.5 %, persistent 46.2 %) and nervous system (BVAS; new/worse 38.5 %, persistent 25.0 %) were the organ systems most frequently involved by the disease at the baseline. The BVAS for new/worse disease decreased immediately after induction therapy, while improvement of the BVAS for persistent disease after therapy differed among the organ systems. CONCLUSIONS: BVAS was demonstrated to be a valuable guide for selection of the optimal treatment. Thus, BVAS was also found to be a useful tool in Japanese patients for the assessment of disease activity and degree of organ damage in patients with MPO-ANCA-associated vasculitis.

AC13, a C-terminal fragment of apolipoprotein A-I, is a candidate biomarker for microscopic polyangiitis

OBJECTIVE

Microscopic polyangiitis (MPA) is necrotizing vasculitis of unknown etiology. We analyzed the serum peptide profile of MPA to find a biomarker for this disease.

METHODS

Serum peptides from 33 patients with MPA, 7 with granulomatosis with polyangiitis (Wegener's), 7 with Churg-Strauss syndrome, 6 with giant cell arteritis, and 25 with systemic lupus erythematosus (SLE) were comprehensively analyzed by mass spectrometry. Peptide function on human microvascular endothelial cells (HMVECs) was examined by enzyme-linked immunosorbent assay and real-time polymerase chain reaction.

RESULTS

A total of 102 serum peptides were detected from the 78 patients. One of the peptides, peptide 1,523, showed significantly higher ion intensity in MPA (mean ± SD 46.8 ± 39.3 arbitrary units [AU]) than in the other systemic vasculitides (14.1 ± 12.2 AU) (P < 0.05) or in SLE (17.0 ± 12.1 AU) (P < 0.05). In MPA, peptide 1,523 showed significantly higher ion intensity before treatment than 1 week (P < 0.05) and 6 weeks (P < 0.05) after the initiation of treatment. Peptide 1,523 was identified as 13 C-terminal amino acid residues of apolipoprotein A-I (Apo A-I) and was designated "AC13." Validation of AC13 ion intensity using another MPA cohort (n = 14) similarly showed significantly higher ion intensity (90.1 ± 167.9 AU) compared to 14 patients with rheumatoid arthritis (8.6 ± 5.4 AU) (P < 0.01) and 14 healthy subjects (11.8 ± 6.1 AU) (P < 0.01). Serum concentrations of Apo A-I and high-density lipoprotein cholesterol were down-regulated in MPA before treatment and returned to their normal ranges 6 weeks after the initiation of treatment (both P < 0.01). Stimulation of HMVECs with AC13 significantly up-regulated secretion of interleukin-6 (IL-6) (P < 0.05) and IL-8 (P < 0.01).

CONCLUSION

AC13, a candidate biomarker for MPA, may be useful for monitoring disease activity and may exacerbate vascular inflammation through up-regulation of proinflammatory cytokines.

Cutaneous polyarteritis nodosa associated with HLA-B39-positive undifferentiated spondyloarthritis in a Japanese patient

We present the case of a 43-year-old man diagnosed with HLA-B39-positive spondyloarthritis who developed cutaneous lesions consistent with cutaneous polyarteritis nodosa (CPN). Previous studies indicated an elevated incidence of HLA-B39 in HLA-B27-negative Japanese patients with spondyloarthritis. This case suggested that CPN may also occur in association with forms of HLA-B39-positive spondyloarthritis. The rarity of this association is emphasized. Therapy with corticosteroid and methotrexate improved both the cutaneous lesions and the clinical symptoms of spondyloarthritis.

[Hypersensitivity vasculitis]

Hypersensitivity vasculitis (HSV) is characterized by palpable purpura and arthralgia, the existence of precipitating factors(medications or infections), and leukocytoclastic vasculitis in the skin lesion. It is known by a variety of names, including leukocytoclastic vasculitis, cutaneous small-vessel vasculitis (CSVV), allergic vasculitis. Patients are classified as HSV according to the criteria proposed by a subcommittee of the American College of Rheumatology (ACR) in 1990. HSV is distinguished from Henoch-Schönlein purpura that has a higher risk of gastrointestinal and renal involvement. Systemic involvement in HSV is rare and its prognosis is excellent. Most cases in HSV are self-limited if the precipitant can be removed.

[Coagulation and fibrinolysis system in pediatric cardiopulmonary bypass]

Coagulation and fibrinolysis system was evaluated during and after pediatric cardiopulmonary bypass (CPB. Twenty-two atrial septal defect (ASD) patients were surgically repaired under CPB and aortic cross-clamp through right thoracotomy. Drainage was established by gravity, CPB flow was kept 2.4 l/min/m2 and ACT was controlled over 400 seconds. HCT, PLT, fibrinogen, AT-III, D-dimer, thrombin-antithrombin complex (TAT), alpha2 plasmin inhibitor-plasmin complex (PIC), and plasminogen activator inhibitor (PAI-1) were measured at 6 points [after induction of anesthesia, 10 minutes after initiating CPB, end of CPB, on the entrance of intensive care unit (ICU), postoperative day (POD) 1, and at outpatient division]. Both fibrinogen and AT-III showed low values during CPB (121.9 +/- 22.0 mg/dl, 57.6 +/- 10.6%). D-dimer increased at 1 week postoperatively in all patients (5.57 +/- 3.45 microg/ml). There were significantly positive correlations between CPB duration and TAT value at the end of CPB (r = 0.88, p < 0.01), on the entrance of ICU (r = 0.71, p < 0.01). There was also a positive correlation between CPB duration and PIC value on the entrance of ICU (r = 0.53, p < 0.01). Five patients showed high PAI-1 value on the entrance of ICU, which remained high in 2 of them on POD 1. The outcomes from the current study suggest that there is a potential of coagulation-dominant disseminated intravascular coagulation (DIC) during pediatric CPB even in ASD patients who do not need long CPB. Longer CPB and severe hemodilution might become risk factors.

The role of HMGB-1 on the development of necrosis during hepatic ischemia and hepatic ischemia/reperfusion injury in mice

BACKGROUND

High-mobility group 1 (HMGB-1) is a late mediator of endotoxin lethality in mice. The release of HMGB-1 is delayed compared to other proinflammatory cytokines that mediate shock and tissue injury. The purpose of this study was to investigate the role of HMGB-1 levels in response to hepatic ischemia, hepatic I/R injury, and the relationship between changes in HMGB-1 and other cytokines.

MATERIALS AND METHODS

Three murine models were employed: our robust model of segmental hepatic warm ischemia (SHWI), a model of partial hepatic ischemia/reperfusion injury (PHIRI), and a model of total hepatic ischemia/reperfusion injury (THIRI). Over a 48-h period following ischemic insult and reperfusion using these models, serum HMGB-1 concentrations, concentrations of HMGB-1 in ischemic and nonischemic lobes, and serum concentrations of TNF-alpha and IL-6 levels were determined in mice. An anti-HMGB-1 antibody treatment was used in SHWI and THIRI to evaluate what aspects of response to ischemia and reperfusion were potentially mediated by HMGB-1.

RESULTS

Hepatic HMGB-1 tissue concentrations exhibited biphasic changes in SHWI mice, which were increased in the ischemic lobes relative to nonischemic lobes at 12 h but decreased relative to nonischemic lobes at 24 h after ischemic insult. These results suggested that HMGB-1 was released into the systemic circulation by necrotic cells over the first 12 h but this process may be complete by 24 h postischemia. By 6 to 12 h after SHWI, serum TNF-alpha began to increase significantly and continued to increase for 18 h, followed by a sudden decline. Similarly, serum IL-6 increased over 1-3 h after SHWI and then decreased over the next 6 h. Treatment with an anti-HMGB-1 antibody significantly prolonged survival time in SHWI and THIRI.

CONCLUSIONS

HMGB-1 plays a significant role in the response to hepatic ischemia and hepatic ischemia/reperfusion injury. The present study demonstrated a time-dependent production of HMGB-1 following hepatic warm ischemia in mice. The inherent HMGB-1 in ischemic areas was exhausted and HMGB-1 may be released by necrotic cells. HMGB-1 activation is involved in immediate proinflammatory stress response to I/R and anti-HMGB-1 antibody treatment remarkably improved survival. We demonstrated that systemic HMGB-1 accumulation was measured at an earlier phase of the hepatic ischemia and ischemia/reperfusion injury model than LPS-induced endotoxemia.

Excessive expression of Txk, a member of the Tec family of tyrosine kinases, contributes to excessive Th1 cytokine production by T lymphocytes in patients with Behcet's disease

Excessive Th1 cell function is importantly involved in the pathogenesis of Behcet's disease (BD). We previously found that Txk, a member of the Tec family of tyrosine kinases, acts as a Th1 cell specific transcription factor. To investigate immune aberration in the pathogenesis of BD, we studied the expression of Txk and Th1 cytokines in peripheral blood lymphocytes (PBL) and skin lesions in patients with BD. Cytokine production by the lymphocytes was assessed using ELISA. PBL produced excessive Th1 associated cytokines including IFN-gamma and IL-12 spontaneously and in response to exogenous HSP60-derived peptide stimulation, which was shown to induce proliferation of PBL, in patients with BD. Circulating CD4+ T cells expressed excessive Txk protein. A majority of cells infiltrating into skin lesions expressed IFN-gamma in the BD specimens. IL-12 and IL-18 were also expressed in the mononuclear cell aggregates. Lymphocytes accumulating in the skin lesion expressed higher levels of Txk as compared with atopic dermatitis lesions, a typical Th2 disease. IFN-gamma, IL-18 and Il-12 were detected in the BD skin lesions, which may induce preferential development of Th1 cells in patients with BD. The mononuclear cell aggregates contained Txk expressing cells in such skin lesions. Collectively, Txk expressing Th1 cells and the Th1 associated cytokines may play a critical role in the development of skin lesions in BD.

Abnormal killer inhibitory receptor expression on natural killer cells in patients with Behçet's disease

Viral infection has been assigned some role in the pathogenesis of Behçet's disease (BD). Defects in natural killer (NK) cell repertoire may be involved in impaired antiviral immunity, leading to the development of BD. We studied killer inhibitory receptor (KIR) expression in 40 patients with BD. CD94 and CD158b expression of NK cells was normal in a great majority of BD patients. NKB1 expression was reduced in eight and increased in six. Twelve of these 14 patients (86%) had severe eye disease. Some had reduced NKB1 and enhanced CD158a expression simultaneously, or enhanced NKB1 and reduced CD158a simultaneously, suggesting a skewed NK cell repertoire in BD. Collectively, KIR expression was abnormal in the BD patients with severe eye disease. This may result from genetic predisposition, or certain viruses may affect the KIR repertoire formation in BD patients. Abnormal KIR expression of NK cells may be associated with the development of BD.

Recombination activating genes (RAG) induce secondary Ig gene rearrangement in and subsequent apoptosis of human peripheral blood circulating B lymphocytes

Recombination activating gene (RAG) re-expression and secondary Ig gene rearrangement in mature B lymphocytes have been reported. Here, we have studied RAG expression of peripheral blood B lymphocytes in humans. Normal B cells did not express RAG1 and RAG2 spontaneously. More than a half of circulating B cells expressed RAG proteins, when activated with Staphylococcus aureus Cowan I (SAC) + IL-2. DNA binding activity of the RAG complex has been verified by a gel shift assay employing the recombination signal sequence (RSS). Secondary Ig light chain rearrangement in the RAG-expressing B cells was confirmed by linker-mediated (LM)-PCR. Highly purified surface kappa+ B cells activated by SAC + IL-2 became RAG+, and thereafter they started to express lambda chain mRNA. 2 colour immunofluorescence analysis disclosed that a part of the RAG+ cells derived from the purified kappa+ B cells activated by SAC + IL-2 turned to lambda+ phenotype in vitro. Similarly, apoptosis induction was observed in a part of the RAG+ B cells. Our study suggests that a majority of peripheral blood B cells re-expresses RAG and the RAG+ B lymphocytes could be eliminated from the B cell repertoire either by changing Ag receptor specificity due to secondary rearrangement or by apoptosis induction. Thus, RAG expression of mature B cells in peripheral blood would contribute to not only receptor revision for further diversification of B cell repertoire but in some cases (or in some B cell subsets) to prevention or induction of autoAb responses at this differentiation stage in humans.

Anatomical and functional recovery by embryonic stem cell-derived neural tissue of a mouse model of brain damage

We have treated undifferentiated mouse embryonic stem (ES) cells with all-trans retinoic acid (RA) to induce differentiation in vitro into neuron-like cells with good cell viability for use as a graft. Furthermore, we asked whether the RA-induced neuron-like cells restored neurological dysfunction. To this end, the cells were transplanted into right hemiplegia model of mice, developed by a cryogenic injury of motor cortex. Motor function of the recipients was gradually improved, whereas little improvement was observed in control mice. The lesion showed clustering of mature and almost mature neuron-like cells in mice transplanted with the RA-treated cells. The grafted cells had synaptic vesicles. This finding may suggest their maturation and synaptic connection in the recipient brain. Even though further study is necessary to elucidate molecular and cellular mechanisms responsible for the functional recovery, we consider that the ES cells may have advantage for use as a donor source in various neurological disorders including motor dysfunction.

Preferential expression of B7.2 (CD86), but not B7.1 (CD80), on B cells induced by CD40/CD40L interaction is essential for anti-DNA autoantibody production in patients with systemic lupus erythematosus

OBJECTIVE

B7 (CD80/CD86) molecules are over-expressed in patients with SLE. However, it is not clear whether CD80/CD86 molecules are involved in the pathogenic autoantibody production specifically or in the polyclonal antibody production in human SLE. The present study was carried out to characterize B7 molecules on B cells in autoantibody production.

METHODS

Expression of costimulatory molecules was analyzed by RT-PCR and two-color immunofluorescence staining. Purified B cells were co-cultured with T cells in the presence of anti-costimulatory molecule antibody.

RESULTS

Excessive expression of CD86 and CD80 molecules was evident on freshly isolated B cells in patients with SLE. Normal B cells did not express CD86 molecules spontaneously and expressed it after co-culture with activated T cells. CD86 expression on normal and SLE B cells induced by the activated T cells was inhibited by the addition of anti-CD40L into the cell culture. Furthermore, CD40L expression on T cells upon activation was enhanced in SLE patients. Anti-DNA antibody production by SLE B cells in the presence of activated T cells was markedly inhibited by anti-CD86, but not anti-CD80. Anti-CD86 treatment inhibited polyclonal Ig and anti-SS-A antibody production of SLE B cells, suggesting the preferential involvement of CD86 in polyclonal antibody production.

CONCLUSION

SLET T cells express CD40L excessively, and the CD40/CD40L pathway is involved in the CD86 over-expression of SLE B cells; thus T cell abnormality is at least partially involved in B cell hyperactivity. Enhanced CD86 expression of B cells by CD40L is essential for polyclonal antibody production.

Flk1+ cells derived from mouse embryonic stem cells reconstitute hematopoiesis in vivo in SCID mice

OBJECTIVE

Embryonic stem (ES) cells are pluripotent and can differentiate into any cell type, including the hematopoietic lineage. We examined whether hematopoietic progenitor cells derived from ES cells reconstitute hematopoiesis in irradiated SCID mice.

MATERIALS AND METHODS

ES cells (E14.1, H2K(b)) were cultured for 4 days in semisolid medium containing methylcellulose. Irradiated SCID mice were used as recipients of hematopoietic progenitor cells. Cell surface antigen expression was analyzed by flow cytometry. The spleens of the recipient mice were studied by hematoxylin and eosin staining and immunohistochemical staining.

RESULTS

After cell culture of ES cells in methylcellulose for 4 days, the cells expressing Flk1 (VEGF receptor 2), a tentative marker of hemangioblasts, were increased, whereas cells expressing CD31 (PECAM-1) and E-cadherin (nonmesodermal adhesion molecule) were dramatically reduced. Flk1+ cells expressed c-kit predominantly. Circulating leukocytes and thrombocytes were increased in irradiated SCID (H2K(d)) mice transplanted with ES cell-derived Flk1+ cells compared with vehicle-injected control mice. H2K(b+) and VE-cadherin(+) vascular endothelial cells were prominent in spleens of the recipient mice. Flow cytometric analysis demonstrated that H2K(b+) cells were increased in the bone marrow of recipient mice. In addition, Flk1+ cells accompanying enhanced c-kit expression preferentially repopulated in the bone marrow, and leukopoiesis and thrombopoiesis of the recipient mice were evident.

CONCLUSION

The Flk1+ hematopoietic cells derived from ES cells reconstitute hematopoiesis in vivo and may become an alternative donor source for bone marrow transplantation.

Aberrant expression of Fas ligand on anti-DNA autoantibody secreting B lymphocytes in patients with systemic lupus erythematosus: "immune privilege"-like state of the autoreactive B cells

BACKGROUND

Fas/Fas ligand (FasL) system has been assigned a pivotal role in the development and maintenance of peripheral tolerance, and mice with defects in their Fas/FasL system develop lupus-like symptoms. In this study we examined FasL expression of peripheral blood lymphocytes in patients with systemic lupus erythematosus (SLE).

METHODS

We assessed FasL mRNA and protein expression by reverse transcription (RT)-PCR and immunoblotting and immunocytochemical staining, respectively, in patients with SLE. Anti-DNA antibody secreting B cells were purified using biotin labeled DNA and streptavidin-bead.

RESULTS

Expression of FasL protein was not or very weakly detected in freshly isolated PBMC in normal individuals. In contrast, freshly isolated SLE PBMC exhibited the enhanced expression of FasL protein without in vitro stimulation. Not only purified T cells but also purified B cells expressed FasL on their cell surface spontaneously. In addition, freshly isolated anti-DNA autoantibody secreting B cells express FasL without in vitro stimulation.

CONCLUSION

The results suggest that autoreactive B lymphocytes which aberrantly express FasL may kill Fas+ immunoregulatory T lymphocytes. Thus aberrantly expressed FasL may facilitate escape of the autoreactive B cells from the immune tolerance system, and may contribute to the sustained secretion of autoantibodies in patients with SLE.