Yasuhiko Itoh

Macrophage Activation Syndrome in Patients with Systemic Juvenile Idiopathic Arthritis under Treatment with Tocilizumab.

Objective. To identify macrophage activation syndrome (MAS) in patients with systemic juvenile idiopathic arthritis (sJIA) undergoing tocilizumab (TCZ) treatment, and to confirm laboratory marker changes and responses to treatment in patients with MAS receiving TCZ. Methods. In Japan, 394 patients with sJIA were registered in an all-patient registry surveillance of TCZ as of January 15, 2012. TCZ (8 mg/kg) was administered every 2 weeks to patients with sJIA. MAS, hemophagocytic lymphohistiocytosis, or Epstein-Barr virus–associated hemophagocytic syndrome (EB-VAHS) was reported in 23 of these patients (25 events). The Safety Evaluation Committee of Tocilizumab for JIA reviewed these cases and clinically evaluated the data and laboratory findings using their own therapeutic experience. Events were categorized into 4 groups: definitive MAS, probable MAS, EB-VAHS, and non-MAS. Results. The committee’s review revealed 3 events of definitive MAS in 3 patients, 12 events of probable MAS in 11 patients, 2 events of EB-VAHS in 2 patients, and 8 events of non-MAS in 8 patients. There were 2 patients who developed 2 events: 2 events in 1 patient were classified into definitive MAS and probable MAS, and 2 events in another patient were classified into probable MAS. In patients with definitive or probable MAS, common clinical manifestations and laboratory findings of MAS were observed. Changes in laboratory data observed in patients with EB-VAHS were similar to those observed in patients with MAS. Conclusion. These results suggest that the clinical/laboratory features in the course of MAS appear to be similar among patients regardless of whether TCZ is administered. Similarities in the pathophysiological background of MAS and EB-VAHS were also suggested.

Tocilizumab in systemic juvenile idiopathic arthritis in a real-world clinical setting: results from 1 year of postmarketing surveillance follow-up of 417 patients in Japan

Objectives To evaluate the safety and effectiveness of tocilizumab (TCZ) in patients with systemic juvenile idiopathic arthritis (sJIA) in real-world clinical settings in Japan. Methods Paediatric patients with sJIA initiating TCZ between April 2008 and February 2012 and those previously enrolled in clinical trials who initiated TCZ before April 2008 were enrolled in a Japanese registry surveillance programme. Safety and effectiveness parameters were collected for 52 weeks. Results Of 417 patients enrolled, mean age was 11.2 years and 48.0% were female. TCZ exposure was 407.0 patient-years (PYs). Baseline corticosteroid use was higher than in clinical trials. Rates of total adverse events (AEs) and serious AEs (SAEs) were 224.3/100 PYs and 54.5/100 PYs, respectively, with SAEs higher than previously reported. The most frequent AEs and SAEs were infections and infestations (69.8/100 PYs and 18.2/100 PYs, respectively). 74 serious infections occurred in 55 patients (18.2/100 PYs); higher than previously reported. 26 macrophage activation syndrome events were reported in 24 patients (6.4/100 PYs). Fever and rash symptoms improved from baseline to week 52 (54.6% to 5.6% and 43.0% to 5.6%, respectively). At 4 weeks, 8 weeks and 52 weeks, 90.5%, 96.2% and 99.0% of patients achieved normal C reactive protein levels (<0.3 mg/dL), respectively. Conclusions These first real-world data demonstrated that TCZ was well tolerated, with acceptable safety and effectiveness in patients with sJIA. Higher incidences of SAEs and serious infections may be due to differences, such as corticosteroid use and concomitant diseases, between patient populations enrolled in previously reported clinical trials and this study.

Stress-induced cell surface expression and antigenic alteration of the Ro/SSA autoantigen.

Recent studies have shown that Ro/SSA autoantigen is heterogeneous. There are two isoform families; the 60 kD forms (Ro60) and the 52 kD forms (Ro52). Recently we have found that autoantibodies to the Ro/SSA proteins are conformation dependent. Anti-Ro60 antibodies are mainly directed to the native protein and conversely anti-Ro52 antibodies are directed only to the denatured protein. It has been known that UV irradiation to cultured keratinocytes induces cell surface expression of Ro/SSA and this phenomenon has been thought to be related with photosensitivity in patients with anti-Ro/SSA antibodies. We studied the quantitative and qualitative changes of the Ro/SSA protein induced by stress, such as with heat shock and UV irradiation, and found that only Ro52 could be expressed on the cell surface of human peripheral lymphocytes by either heat shock or UV irradiation. Moreover, flow cytometric analysis revealed that HS-treated and UV-treated lymphocytes could be stained with patient sera, and by using a technique which combined immunoprecipitation and Western immunoblotting, it has been confirmed that Ro52 expressed on the cell surface can be recognized by anti-Ro/SSA antibodies in native form while cytoplasmic Ro52 cannot be recognized. These data suggest that Ro52 can be antigenic in vivo when expressed on the cell surface and may explain the mechanism of direct tissue damage by anti-Ro/SSA antibodies.

Antinuclear Antibodies in Children with Chronic Nonspecific Complaints

Children who are chronically complaining nonspecific symptoms such as headache, fatigue, abdominal pain, and low grade fever are commonly seen in daily pediatric outpatient clinics. Some of them are unable to go to school and are diagnosed as school refusal by physicians or educational staff. On the other hand, there are children who do not fulfill any criteria of collagen diseases and whose anti-nuclear antibodies (ANA) are found to be positive. Some of these children have chronic nonspecific complaints. We prospectively studied the prevalence of ANA in children who visited a pediatric outpatient clinic because of chronic nonspecific complaints. Surprisingly, 74 out of 140 symptomatic children (52.4%) were positive for ANA, while only 5 out of 82 healthy control children (6.1%) were positive (p < 0.0001). 39 of 74 ANA positive patients (52.1%) have low ANA titers < or = 1:80, nevertheless 36 patients (47.9%) have high ANA titers > or = 1:160. ANA fluorescent patterns were homogeneous and speckled in 75.3%, speckled in 17.6% and others in 6.8%. ANA positive patients tended to have general fatigue and low grade fever, while gastrointestinal problems such as abdominal pain and diarrhea and orthostatic dysregulation symptoms were commonly seen in ANA negative patients. Children who were unable to go to school more than 1 day a week were seen significantly more in ANA positive patients than in negative patients. Autoantibody analysis using Western immunoblot revealed that 26 out of 63 ANA positive sera (41.3%) had antibodies to the 62 kD protein which had not been previously noticed. These data suggest that autoimmune mechanism may play a role in childhood chronic nonspecific symptoms. We therefore propose a new disease entity of the autoimmune fatigue syndrome in children. When chronically complaining children visit a pediatric out-patient clinic, immunological approaches should be considered before they are discriminated as school refusal or having psychogenic disorders.

Autoantibodies to lens epithelium-derived growth factor/transcription co-activator P75 (LEDGF/P75) in children with chronic nonspecific complaints and with positive antinuclear antibodies

Autoimmune fatigue syndrome (AIFS) is characterized by chronic nonspecific complaints, consistently positive antinuclear antibodies (ANA), and lack of alternate medical explanations. A newly recognized antibody, named anti-Sa, was detected in approximately 40% of the patients by Western blot (WB) using HeLa extract. Some patients with AIFS later develop chronic fatigue syndrome (CFS), and most of them are positive for anti-Sa. On the other hand, Muro et al. reported anti-DFS70 in patients with CFS. Anti-Sa and anti-DFS70 were turned out to be same specificities by exchanging studies of blind sera. The target antigen of anti-DFS70 was identified as lens epithelium derived growth factor/transcription co-activator p75 (LEDGF/p75). The objectives of this study are to confirm whether the target antigen of anti-Sa is also LEDGF/p75, and to develop ELISA system by using recombinant protein. Recombinant protein of LEDGF/p75 was purchased from Protein One (Bethesda, MD, USA). We developed an ELISA system to detect anti-LEDGF/p75 by coating this recombinant protein. 226 sera of AIFS patients (including 36 CFS patients) were applied to this ELISA assay and Western immunoblot, and it was revealed that anti-Sa-positive sera defined by WB and sera positive for anti-LEDGF/p75 on ELISA were identical. Moreover, reactivities of anti-Sa on WB were inhibited by pre-incubating with recombinant LEDGF/p75, and eluted antibodies from the nitrocellulose membrane could react on the ELISA. These results confirm that the Sa antigen is LEDGF/p75. The ELISA assay using recombinant LEDGF/p75 could be a promising tool for measuring anti-Sa and consequently for diagnosing CFS.

Etanercept Suppresses Arteritis in a Murine Model of Kawasaki Disease: A Comparative Study Involving Different Biological Agents

Coronary arteritis, a complication of Kawasaki disease (KD), can be refractory to immunoglobulin (IVIG) treatment. To determine the most effective alternative therapy, we compared the efficacy of different agents in a mouse model of KD. Vasculitis was induced by injection of Candida albicans water-soluble fractions (CAWS) into a DBA/2 mouse, followed by administration of IVIG, etanercept, methylprednisolone (MP), and cyclosporine-A (CsA). At 2 and 4 weeks, the mice were sacrificed, and plasma cytokines and chemokines were measured. CAWS injection induced active inflammation in the aortic root and coronary arteries. At 2 weeks, the vasculitis was reduced only by etanercept, and this effect persisted for the subsequent 2 weeks. At 4 weeks, IVIG and CsA also attenuated the inflammation, but the effect of etanercept was more significant. MP exerted no apparent effect at 2 or 4 weeks. The suppressive effect exerted by etanercept on cytokines, such as interleukin- (IL-)6, IL-12, IL-13, and tumor necrosis factor-α (TNF-α), was more evident than that of others. The extent of arteritis correlated with the plasma TNF-α levels, suggesting a pivotal role of TNF-α in KD. In conclusion, etanercept was most effective in suppressing CAWS-induced vasculitis and can be a new therapeutic intervention for KD.

Fibromyalgia and chronic fatigue syndrome in children.

Background:  Fibromyalgia (FM) is characterized by widespread persistent pain and the presence of multiple discrete tender points. Chronic fatigue syndrome (CFS) is a syndrome characterized by debilitating fatigue associated with a variable number of non‐specific complaints. Because neither condition had necessarily been recognized in children until recently, those patients have been treated as having school refusal without being diagnosed as having either syndrome. There is a considerable overlap of clinical symptoms between these two syndromes. It is therefore controversial as to whether these syndromes have the same pathogenesis or not. The aim of the present study was to clarify the relationship between these syndromes in children.

Autoimmunity in chronic fatigue syndrome in children

We have reported that about half of children with chronic non-specific complaints were positive for antinuclear antibodies (ANA) and that the commonest complaint was fatigue in ANA-positive patients. Therefore, we have proposed a novel disease entity of autoimmune fatigue syndrome (AIFS). In order to investigate the relationship between AIFS and chronic fatigue syndrome (CFS) in children, all CFS patients seen in our clinic were immunologically assessed. Immunological examinations including ANA, autoantibody analysis by Western immunoblotting, lymphocyte subsets and NK activities were performed on 14 CFS patients. Clinical courses of these patients were reviewed retrospectively. None of the patients had fulfilled the CDC criteria for CFS at their first visit. They fulfilled the criteria in a relatively short time, with a 6 months to 6 years smoldering period. All patients had been diagnosed as school refusal by physicians or school teachers. Thirteen patients were positive for ANA and the other one was positive for rheumatoid factor. Twelve patients were positive for antibodies to the 62 kDa protein (anti-Sa) which had been detected in about 40% of AIFS patients. NK activity was not as low as reported in adult patients with CFS. Most of the children with CFS were positive for ANA, suggesting an autoimmune mechanism may play an important role in the pathogenesis of childhood CFS. AIFS patients should be carefully followed because of the possibility of later development of CFS.

Immunogenetic Background of Patients with Autoimmune Fatigue Syndrome

We have previously reported that approximately 50% of children with chronic nonspecific complaints were positive for antinuclear antibodies (ANA), and that a novel autoantibody to a 62kD protein (anti-Sa) was found in 40% of these ANA-positive patients. Therefore, we proposed a distinct disease entity termed autoimmune fatigue syndrome (AIFS). We hypothesized that if autoimmune mechanisms did play an important role in the pathogenesis of AIFS, it is possible that it is immunogenetically regulated as observed in other autoimmune disorders. In order to examine the immunogenetic background of AIFS patients, HLA-A, -B, -C, and -DR loci were analyzed serologically in 61 AIFS patients. AIFS was found to be positively associated with the class I antigen HLA-B61 and with the class II antigen HLA-DR9, with odds ratios of 2.77 (p = 0.015, Pcorr = 0.48) and 2.60 (p= 0.012, Pcorr = 0.17), respectively. A negative association was also found between AIFS and HLA-DR2 with odds ratio of 0.25 (p = 0.029, Pcorr = 0.041). When comparing anti-Sa positive AIFS patients with healthy controls, the odds ratios associated with HLA-B61, DR9, and DR2 were 3.42 (p = 0.021, Pcorr = 0.22), 3.96 (p = 0.0011, Pcorr= 0.015), and 0.16 (p = 0.0022, Pcorr= 0.031), respectively. Thus, the HLA associations observed in this study suggested that immunogenetic background might play a role in AIFS

Guidance on using tocilizumab for juvenile idiopathic arthritis

Medical care for rheumatic disease in children has been supported by advances in rheumatology. In the past few years and based on knowledge about cytokines, particularly marked advances have been made in treatments using biological products. The fact that patients showed a marked response to treatment with biological products also provided uniform direction to treatment choice, which had previously been chaotic. On the other hand, biological products inhibit the action of physiologically essential substances, such as inflammatory cytokines or their receptors. This led to concerns about the risk of fatal or life-threatening adverse reactions, and rheumatologists are now required to take a disciplined approach to the use of these products. Thus, we sincerely hope that this guidance on using tocilizumab for juvenile idiopathic arthritis serves as a desk reference for pediatric rheumatologists and other healthcare professionals treating children with rheumatic diseases by biological drugs.