Epidemiology conduction of paediatric rheumatic diseases based on the registry database of the Pediatric Rheumatology Association of Japan.

OBJECTIVES: Although epidemiological surveys of paediatric rheumatic diseases in Japan have been conducted, they were single surveys with no continuity. This is the first report of the Pediatric Rheumatology Association of Japan registry database, which was established to continuously collect data for paediatric rheumatic diseases. METHODS: Pediatric Rheumatology International Collaborate Unit Registry version 2 (PRICUREv2) is a registry database established by the Pediatric Rheumatology Association of Japan. The registry data were analysed for the age of onset, time to diagnosis, sex differences, seasonality, and other factors. RESULTS: Our data showed the same trend regarding rates of paediatric rheumatic diseases reported in Japan and other countries. The age of onset was lower in juvenile idiopathic arthritis (JIA) and juvenile dermatomyositis and higher in systemic lupus erythematosus and Sjögren's syndrome. The time to diagnosis was relatively short in JIA and systemic lupus erythematosus but longer in juvenile dermatomyositis and Sjögren's syndrome. Rheumatoid factor-positive polyarticular JIA showed a seasonality cluster with regard to onset. CONCLUSION: PRICUREv2 aided the retrieval and evaluation of current epidemiological information on patients with paediatric rheumatic diseases. It is expected that the data collection will be continued and will be useful for expanding research in Japan.

Clinical practice guidance for childhood-onset systemic lupus erythematosus-secondary publication.

Childhood-onset systemic lupus erythematosus (cSLE) has been recognised as a more acute and severe autoimmune disease than adult-onset SLE. With the development of medications for the disease and supportive therapy, the mortality rate associated with cSLE has drastically improved; the 10-year survival rate among patients with cSLE between 1995 and 2006 in Japan was 98.3%. However, the 10-year survival rate without any permanent functional impairment remained low at 66.1%. Therefore, the current treatment goal for cSLE is to ensure that they can perform normal daily activities throughout their lives by preventing the occurrence and/or progression of organ damage. For this purpose, appropriate treatments and evaluations are required according to the severity and risk of organ damage; however, there are no established guidelines for cSLE. Therefore, the Pediatric Rheumatology Association of Japan and the Pediatric Rheumatology Subcommittee in the Japan College of Rheumatology developed a comprehensive guidance for clinical practice based on cSLE-related data collected from Japanese national surveys and relevant articles from both domestic and international sources. However, due to the lack of indications for defined and objective evidence quality levels, this guidance should be used on the basis of the judgement of the attending physicians for individual patients.

Clinical practice guidance for Sjögren's syndrome in pediatric patients (2018) - summarized and updated.

There are a considerable number of pediatric patients with Sjögren's syndrome (SS); however, SS is generally considered rare among children. Pediatric patients with SS report fewer sicca symptoms; therefore, many are under-diagnosed and cannot access appropriate medical management. Therefore, we propose a newly developed guidance for the diagnosis, treatment, and management of pediatric SS, including epidemiology, clinical features, and diagnostic examination methodology. The aim of this guidance was to standardize the medical care of pediatric SS in Japan, and we published the Japanese version by YODOSHA in 2018. This article is the English version, which is summarized and updated. This guidance will need to be revised in the near future as additional clinical data become available.

2019 Diagnostic criteria for mixed connective tissue disease (MCTD): From the Japan research committee of the ministry of health, labor, and welfare for systemic autoimmune diseases.

OBJECTIVE: To update and revise the diagnostic criteria for mixed connective tissue disease (MCTD) issued by the Japan Research Committee of the Ministry of Health, Labor, and Welfare (MHLW), a round table discussion by experts from rheumatology, dermatology, and pediatric medicine was conducted in multiple occasions. METHODS: The definition of MCTD, and items included in the diagnostic criteria were generated by consensus method and evaluation using clinical data of typical and borderline cases of MCTD, by applying to the diagnostic criteria for MCTD proposed in 1996 and 2004 by the Research Committee of MHLW. RESULTS: To the end, all committee members reached consensus. Then, the criteria were assessed in an independent validation cohort and tested against preexisting criteria. The revised criteria facilitate an understanding of the overall picture of this disease by describing the concept of MCTD, common manifestations, immunological manifestation and characteristic organ involvement. Conditions with characteristic organ involvement include pulmonary arterial hypertension, aseptic meningitis and trigeminal neuropathy. Even if the overlapping manifestations are absent, MCTD can be diagnosed based on the presence of the characteristic organ involvement. Furthermore, the criteria were validated for applicability in actual clinical cases, and public comments were solicited from the Japan College of Rheumatology and other associated societies. CONCLUSION: After being reviewed through public comments, the revised diagnostic criteria have been finalized.

Adipose tissue-derived stem cells suppress coronary arteritis of Kawasaki disease in vivo.

BACKGROUND: Kawasaki disease (KD) is a systemic inflammatory disease resulting in an acute febrile syndrome commonly affecting children younger than 5 years. Coronary arteritis in KD is occasionally non-responsive to several treatments. Recently, adipose tissue-derived stem cells (ADSCs) have been shown to have anti-inflammatory, immunosuppressive, and tissue-repair characteristics and are considered a useful treatment for inflammatory disease. The present study aimed to elucidate whether the administration of ADSCs can suppress KD-associated vasculitis in vivo. METHODS: Candida albicans water-soluble fraction is often used to model KD via the induction of severe coronary arteritis. Kawasaki disease model mice were intravenously administered ADSCs and phosphate-buffered saline (PBS). On day 29, the mice were sacrificed and hearts from mice in each group were dissected. This was followed by serum collection. Cardiac tissue sections were subjected to histopathological examination to evaluate the inflammatory area. The levels of pro-inflammatory cytokines in the serum were analyzed at days 15 and 29. The survival rates of both groups were compared. RESULTS: The mean inflammatory area in coronary arteritis was significantly lower in the ADSC group compared to the PBS group (P < 0.01). Furthermore, the levels of pro-inflammatory cytokines, such as IL-1ß, IL-12, IL-17, RANTES, INF-γ, and TNF-α, in the ADSC group were significantly lower than those in the PBS group. Moreover, the ADSC group had a significantly higher survival rate than the PBS group. CONCLUSIONS: These findings highlight that ADSCs have anti-inflammatory and immune regulatory functions that could provide novel cell-based therapeutic strategies for severe KD.

M1 macrophage is the predominant phenotype in coronary artery lesions following Kawasaki disease.

Kawasaki disease (KD) is a systemic inflammatory process that affects the medium-sized arteries, causing various cardiovascular complications. However, it is not clear if the vascular sequelae following KD can predispose to the development of atherosclerosis later in life. Our aim was to examine the macrophage phenotypes in the coronary arteries forming giant aneurysms after KD to gain insight into the pathogenesis of vascular lesions in KD. We examined histological sections of the coronary arteries from five patients with KD who underwent coronary bypass grafting procedure as treatment for giant aneurysms and subsequent stenosis. Immunohistochemical expression of M1- and M2-macrophage markers was assessed to determine the macrophage phenotype of KD to compare with that of atherosclerosis in eight adult patients. All the KD specimens showed a mild to moderate degree of intimal thickening consisting of mature fibrous tissue and distortion of elastic fibers, mimicking the histological features of atherosclerosis. The total number of CD68 positive macrophages was higher in atherosclerosis than in KD specimens. Among the CD68 positive macrophages, the proportion of M1 phenotype, detected by CD86 or SOCS3, was higher in KD than in atherosclerosis. In contrast, the proportion of M2 phenotype, detected by CD163 or MRC1, was higher in patients with atherosclerosis. Despite similar histological features, KD and atherosclerosis appear to have a different immunological etiology for progression of the chronic vascular lesions. A further study enrolling a larger number of cases is required to delineate underlying mechanisms of vascular complications in KD.

Treating juvenile idiopathic arthritis to target: recommendations of an international task force.

Recent therapeutic advances in juvenile idiopathic arthritis (JIA) have made remission an achievable goal for most patients. Reaching this target leads to improved outcomes. The objective was to develop recommendations for treating JIA to target. A Steering Committee formulated a set of recommendations based on evidence derived from a systematic literature review. These were subsequently discussed, amended and voted on by an international Task Force of 30 paediatric rheumatologists in a consensus-based, Delphi-like procedure. Although the literature review did not reveal trials that compared a treat-to-target approach with another or no strategy, it provided indirect evidence regarding an optimised approach to therapy that facilitated development of recommendations. The group agreed on six overarching principles and eight recommendations. The main treatment target, which should be based on a shared decision with parents/patients, was defined as remission, with the alternative target of low disease activity. The frequency and timeline of follow-up evaluations to ensure achievement and maintenance of the target depend on JIA category and level of disease activity. Additional recommendations emphasise the importance of ensuring adequate growth and development and avoiding long-term systemic glucocorticoid administration to maintain the target. All items were agreed on by more than 80% of the members of the Task Force. A research agenda was formulated. The Task Force developed recommendations for treating JIA to target, being aware that the evidence is not strong and needs to be expanded by future research. These recommendations can inform various stakeholders about strategies to reach optimal outcomes for JIA.

Survey of attitudes of non-pediatric rheumatologists among councilors of the Japan College of Rheumatology regarding transitional care.

OBJECTIVES: The transition from pediatric to adult healthcare systems has recently received worldwide attention. Surveys of the attitudes of Japanese non-pediatric rheumatologists regarding transitional care were conducted. METHODS: Non-pediatric rheumatologists among councilors of the Japan College of Rheumatology were enrolled in the surveys. Experiences of adult patients with childhood-onset rheumatic diseases, ideal medical care for these patients, and factors that made the transition to adult care difficult were examined via e-mail. RESULTS: Overall, 201 non-pediatric rheumatologists (21.2%) responded to the surveys. Ninety-one percent had previous experience with patients with childhood-onset rheumatic disorders. Transition to non-pediatric institutes was supported by about 90% of respondents. However, only 32% of non-pediatric rheumatologists had no hesitation about caring for adults with childhood-onset rheumatology disorders. Two main factors prevented smooth transitions to non-pediatric care: inadequacy of non-pediatric care (57%) and lack of independence from parents/family (53%). The majority of non-pediatric rheumatologists hesitated about medical care for patients with autoinflammatory syndromes, whereas they became familiar with articular juvenile idiopathic arthritis without hesitation (86.6%); 93% of respondents requested more opportunities to learn about pediatric rheumatology disorders. CONCLUSIONS: Sharing additional knowledge about pediatric rheumatology within the non-pediatric rheumatology field is required.

Characterization of a murine model with arteritis induced by Nod1 ligand, FK565: A comparative study with a CAWS-induced model.

OBJECTIVE: Kawasaki disease (KD) occurs via activation of the innate immune system. Nucleotide oligomerization domain-1 (NOD1) is a pattern recognition receptor regulating the innate immunity. We characterized histopathology of arteritis induced by FK565, a ligand for NOD1, in mice, compared with Candida albicans water-soluble fraction (CAWS)-induced model. METHODS: Vasculitis was induced by injection of FK565 or CAWS into C57BL6/J mice (n = 9 and n = 11, respectively). At 4 weeks, they were sacrificed, and plasma cytokines and chemokines were measured. RESULTS: FK565 injection induced vasculitis mainly involving bilateral coronary arteries whereas the aortic root was diffusely affected in CAWS mice. In FK565 animals, the abdominal aorta and its branching arteries also exhibited inflammation with atherosclerosis. IL-1α, IL-1ß, IL-5 and RANTES were increased in FK565 group whereas IL-6, IL-13, G-CSF, IFN-γ, and TNF-α were higher in CAWS animals (p < .05 for all variables). The total area of inflammation in FK565 mice appeared to correlate with IL-1ß levels (r = 0.71, p = .05). CONCLUSIONS: Histopathology of FK565-induced model demonstrated 'site-specific' coronary arteritis mimicking KD. This histopathological difference from CAWS model may be due to different cytokine expression profiles.

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.

Adipose-derived stromal cells grown on a hydroxyapatite scaffold can support hematopoiesis in regenerated bone marrow in vivo.

Osteoblastic cells are a key component of the bone marrow (BM) stem cell niche and help regulate hematopoietic stem cells (HSCs). We have previously demonstrated that adipose-derived stromal cells (ADSCs) can differentiate into both osteogenic and chondrogenic cells in vitro. The current study examined whether the anatomical architecture of the BM could be regenerated in vivo by using ADSCs cultured on a hydroxyapatite (HA) scaffold. ADSCs from GFP transgenic mice were cultured in vitro on an HA scaffold. The scaffold with the attached cells was implanted subcutaneously onto the backs of C57/BL6 (Ly5.2) recipient mice. Lineage-negative (Lin-) Ly5.1 BM cells transduced with a lentiviral vector containing the luciferase (Luc) gene were intravenously administered to the recipient mice after lethal irradiation. Eight weeks after BM transplantation, the scaffolds were removed from the first recipient mice and subcutaneously implanted into lethally irradiated second recipient mice. The biodistribution and kinetics of Luc(+) Ly5.1 cells were monitored by bioluminescence imaging and flow cytometry. Luc(+) hematopoietic cells were present in the scaffolds of the secondary implanted mice for at least 8 months. Subcutaneous injection of G-CSF resulted in wide distribution of bioluminescence signals from the original scaffolds to the whole body. Therefore, BM regenerated using ADSCs grown on an HA scaffold can support HSC populations in vivo, suggesting that a functional BM niche is reconstituted. These results may have a significant impact on the development of therapeutic strategies for various hematopoietic diseases.

Use of Fever Duration to Guide Management of Urinary Tract Infection.

BACKGROUND: The appropriate duration of antimicrobial therapy for febrile urinary tract infection (fUTI) in children has not been established. This study examined the optimal duration of treatment for fUTI in children. METHODS: We created a protocol that used fever duration to determine the duration of antibiotic administration. Transvenous antibiotics were administered until 3 days after resolution of fever, followed by oral antibiotics for 1 week. Diagnosis of fUTI was based on a fever of 37.5°C or higher and a quantitative culture of catheterized urine yielded a bacteria count of ≥5 × 104. Acute focal bacterial nephritis (AFBN) and pyelonephritis (PN) were diagnosed on the basis of contrast-enhanced computed tomography (eCT) findings. We retrospectively reviewed treatment outcomes. RESULTS: Of the 78 patients treated according to our protocol, data from 58 were analyzed-49 children (30 boys) had PN and nine (three boys) had AFBN. Blood test results showed that patients with AFBN had significantly higher white blood cell counts and C-reactive protein levels than did those with PN; however, urinary findings and causative bacteria did not differ between groups. Time to resolution of fever and duration of intravenous antibiotic administration were significantly longer in patients with AFBN than in those with PN. However, average duration of AFBN treatment was 14.2 days, which was shorter than the previously reported administration period of 3 weeks. No recurrence was observed in AFBN patients. CONCLUSIONS: A protocol that used fever duration to determine the duration of antimicrobial treatment was useful. Invasive examinations, such as eCT, were not required.

Candesartan Attenuates Vasculitis in a Mouse Model of Kawasaki Disease Induced by Candida albicans Water-Soluble Fraction.

BACKGROUND: The standard treatment for Kawasaki disease is immunoglobulin therapy, but the high frequency of coronary sequelae in immunoglobulin-refractory cases indicates a need for further improvement in treatment. METHODS: Kawasaki disease-like vasculitis was induced in 5-week-old DBA/2 mice by intraperitoneal administration of 0.5 mg Candida albicans water-soluble fraction (CAWS) daily for 5 days followed by daily administration of candesartan, an angiotensin receptor blocker. The vasculitis suppression effect was confirmed histologically and serologically in mice sacrificed at 28 days after the start of candesartan. RESULTS: The area of inflammatory cell infiltration at the aortic root was 2.4±1.4% in the Control group, 18.1±1.9% in the CAWS group, and 7.1±2.3%, 5.8±1.4%, 7.6±2.4%, and 7.9±5.0% in the CAWS+candesartan 0.125-mg/kg, 0.25-mg/kg, 0.5-mg/kg, and 1.0-mg/kg groups, respectively (p=0.0200, p=0.0122, p=0.0122, and p=0.0200 vs. CAWS, respectively). The low-dose candesartan group also showed significantly reduced inflammatory cell infiltration. A similar trend was confirmed by immunostaining of macrophages and TGFß receptors. Measurement of the inflammatory cytokines IL-1ß, IL-6, and TNF-α confirmed the anti-vasculitis effect of candesartan. CONCLUSIONS: Candesartan inhibited vasculitis even at clinical doses used in children, making it a strong future candidate as an additional treatment for immunoglobulin-refractory Kawasaki disease.

Evaluation of Coronary Circulation by 13N-Ammonia Myocardial Perfusion Positron Emission Tomography in Patients with Right Coronary Artery Occlusion Due to Kawasaki Disease.

BACKGROUND: Although occlusion of the right coronary artery (RCA) is common in the remote stages of Kawasaki disease, revascularization of the RCA is challenging in children and is usually managed by observation without intervention. METHODS: Using adenosine-stress 13N-ammonia myocardial perfusion positron emission tomography, we evaluated coronary circulation in 14 patients (12 males) with RCA occlusion to identify ischemia (myocardial flow ratio < 2.0) in the RCA region and examined hemodynamics, cardiac function, and coronary aneurysm diameter. These variables were also compared in patients with/without RCA segmental stenosis (SS). RESULTS: There were five cases of ischemia in the RCA region. RCA myocardial blood flow (MBF) at rest was higher in patients with ischemia than in those without ischemia, but the difference was not significant (1.27 ± 0.21 vs. 0.82 ± 0.16 mL/min/g, p = 0.2053). Nine patients presented with RCA SS, and age at onset of Kawasaki disease tended to be lower in those with SS. The maximum aneurysm diameter of RCA was significantly smaller in patients with SS (10.0 ± 2.8 vs. 14.7 ± 1.6, p = 0.0239). No significant differences in other variables were observed between patients with/without ischemia and SS. CONCLUSIONS: At rest, MBF in the RCA region was relatively well preserved, even in patients with RCA occlusion, and there was no progressive deterioration in cardiac function. Adenosine stress showed microcirculatory disturbances in only half of the patients, indicating that it is reversible in children with Kawasaki disease.

Human Adipose Tissue-Derived Stem Cells Inhibit Coronary Artery Vasculitis in a Mouse Model of Kawasaki Disease.

BACKGROUND: Adipose tissue-derived mesenchymal stem cells (ADSCs) are used for the treatment of various diseases because of their rapid proliferation and high anti-inflammatory and tissue repair properties. Kawasaki disease is a systemic vasculitis with coronary arteritis and aneurysms occurring in pediatric patients. In this study, we examined serologically and pathologically whether the administration of human ADSCs (hADSCs) to a mouse model of Kawasaki disease could suppress vasculitis. METHODS: Candida albicans water-soluble fractions were intraperitoneally injected into DBA/2 mice for 5 consecutive days to generate a mouse model of Kawasaki disease. The model mice were intravenously administered hADSCs or phosphate-buffered saline (PBS). Serum samples collected on days 15 and 29 were used to compare cytokine levels. Mouse hearts dissected on day 29 were subjected to hematoxylin and eosin and immunohistological staining using Galectin-1 (Gal-1), a protein involved in cardiovascular homeostasis, and CD44, a cell-surface marker of hADSCs. RESULTS: Comparison of inflammation-related cytokines showed a significant decrease in IL-1α expression at day 15 (P<0.05) and IL-6 expression at day 29 (P<0.01) in the hADSCs-treated group compared to the PBS group. Evaluation by hematoxylin and eosin staining showed decreased inflammatory cell infiltration and a tendency towards increased Gal-1 expression in the hADSCs group. CD44 expression was not observed in both the groups. The survival curve showed that the hADSCs group had a significantly longer survival time (P<0.05). CONCLUSIONS: The present experimental results indicate that hADSCs have an early anti-inflammatory effect, and that Gal-1 may be involved in preventing inflammation and reducing tissue damage.

Use of tocilizumab to treat arthritis associated with mixed connective tissue disease complicated by ovarian teratoma: a case report.

Mixed connective tissue disease (MCTD) is characterized by mixed features of systemic lupus erythematosus, systemic sclerosis, and polymyositis/dermatomyositis and is rare in children. Here, we report a case of MCTD in a 10-year-old girl who presented at our hospital with arthralgia, Raynaud's phenomenon, and fatigue. Blood tests were positive for anti-U1-ribonucleoprotein (RNP) antibodies and for rheumatoid factors (RFs) IgG-RF and anti-galactose-deficient IgG. Levels of myogenic enzymes and hypergammaglobulinemia were elevated. Macrophages were prominent in bone marrow, with scattered phagocytic macrophages. MCTD was diagnosed based on the patient's symptoms and laboratory findings. Methylprednisolone pulse therapy combined with oral tacrolimus was administered, which led to resolution of symptoms. Three months after pulse therapy, arthralgia worsened and methotrexate was administered. Arthralgia improved but did not resolve. Magnetic resonance imaging performed to investigate the hip pain revealed a mature ovarian teratoma, which was surgically removed. Because the pain persisted and interfered with her daily life, she was treated with tocilizumab for joint pain relief, which decreased the pain level. Tocilizumab is a candidate for additional treatment of juvenile idiopathic arthritis-like arthritis associated with childhood-onset MCTD.

Histological Analysis of Serial Renal Biopsy Specimens from Children with Immunoglobulin A Nephropathy Not Treated with Immunosuppressants.

BACKGROUND: Although pediatric immunoglobulin A nephropathy (IgAN) is considered to have a good prognosis, few studies have investigated histological changes over time in IgAN. Serial renal biopsies were performed during the course of the disease and histological changes were observed in patients who did not receive immunosuppressive treatment. To our knowledge, this is the first report of two or more histological evaluations of renal biopsies from patients with pediatric IgAN who did not receive immunosuppressive drugs. METHODS: Forty-two patients with biopsy-proven IgAN who did not receive immunosuppressive agents and underwent serial renal biopsies were followed in our hospital between 1990 and 2003. This retrospective study evaluated findings from renal biopsy specimens and medical records. RESULTS: Analysis of histological findings showed that 19 of 42 patients improved and 16 showed exacerbation of mesangial proliferation. Seven patients showed no obvious histological changes. Of the improved cases, 11 showed spreading of chronic lesions, and there was a significant difference between patients with and without segmental glomerular sclerosis or adhesion at the first biopsy. Of the exacerbated cases, only 5 of 16 patients showed strong active lesions at the first renal biopsy. CONCLUSIONS: Histological changes were investigated in pediatric IgAN patients not receiving immunosuppressive treatment. The results suggest that, even if mesangial hypercellularity improves, chronic lesions may spread during the natural history of the disease. Predicting histological changes by using findings from renal biopsies performed early after onset is difficult; therefore, patients should be carefully followed.

Methylation of PLK-1 Potentially Drives Bendamustine Resistance in Leukemia Cells.

BACKGROUND: Drug resistance remains a significant impediment in leukemia treatment. While Bendamustine hydrochloride (BH) stands out as a promising therapeutic agent for non-Hodgkin' s lymphoma and mantle cell lymphoma, the mechanisms of resistance to BH are not yet fully understood. Our study focuses on elucidating the mechanisms behind bendamustine resistance in leukemia cells, with a specific emphasis on epigenetics. METHODS: Bendamustine-resistant cells were cultivated from human B cell lymphoblastic leukemia cell lines through systematic and sustained exposure to bendamustine, using the limiting dilution method. Gene expression was assessed via real-time polymerase chain reaction, while the expression of the multidrug resistance protein 1 (MDR1) was evaluated using flow cytometry. RESULTS: Bendamustine-resistant leukemia cells exhibited a decreased RNA expression level for Polo-like kinase-1 (PLK-1). Notably, after treatment with the demethylating agent 5-aza-2'-deoxycytidine, PLK-1 gene expression surged significantly, enhancing bendamustine's cytotoxicity in the resistant leukemia cells. However, MDR1 expression, as determined by flow cytometry, remained consistent between parental and bendamustine-resistant leukemia cells. CONCLUSIONS: Our findings indicate that the methylation of the PLK-1 gene plays a pivotal role in modulating PLK-1 expression and is central to the development of bendamustine resistance in leukemia cells.

A case of seronegative primary Sjögren's syndrome complicated by Takayasu arteritis in a Japanese girl.

In paediatric primary Sjögren's syndrome (SS), the initial symptoms manifest systemically, such as fever, general fatigue, and lymphadenopathy, rather than sicca symptoms. Most children with primary SS have autoantibodies, such as antinuclear, anti-Ro/SS-A, and/or anti-La/SS-B antibodies; however, some patients are seronegative. Similar to paediatric patients with primary SS, those with Takayasu arteritis (TAK) initially only present constitutional symptoms, making it difficult to suspect, unless characteristic features are present. To our knowledge, there have been no reports of the coexistence of both diseases in children. We present a rare case of seronegative SS complicated by TAK in a 9-year-old girl who presented with a persistent low-grade fever, general fatigue, cervical lymphadenopathy, and multiple caries. Although blood examination revealed all autoantibodies to be negative, a lip biopsy revealed lymphocytic sialadenitis, and a sialoscintigraphy indicated hypofunctional salivary glands, leading to the diagnosis of seronegative SS. The patient was treated with low-dose glucocorticoid and immunosuppressant administration to inhibit persistent inflammation and the progression of salivary gland dysfunction; although the symptoms resolved, inflammatory markers remained elevated. When the patient was 14 years old, cervical bruits were incidentally found, and TAK was suspected based on cervical ultrasonography and magnetic resonance angiography findings. 18F-fluorodeoxyglucose-positron emission tomography/computed tomography results demonstrated increased fluorodeoxyglucose accumulation from the ascending to descending aorta. Therefore, she was diagnosed with SS complicated by TAK, which is rare. Aortitis should be suspected when the cause of persistent inflammation cannot be ascertained in patients with SS.