Fever Responses Are Enhanced with Advancing Age during Respiratory Syncytial Virus Infection among Children under 24 Months Old.

The most important risk factor for severe respiratory syncytial virus (RSV) infection is considered young age due to the immature immune system. The risk at young age is reported greater for RSV than for other respiratory infectious agents. Based on the strong association between young age and severity of RSV infection due to immature immunity, we aimed to assess whether there were any age-related differences in fever responses, as one clinical aspect of the immune response. In our observational study over two seasons (2014-2015 and 2015-2016), daily body temperatures of children under 3 years old with RSV infection were recorded from the first medical visit during the acute phase to defervescence. The body temperature records were analyzed among 171 children of four age groups (< 6, < 12, < 24 and ≥ 24 months), in terms of fever development, degrees of fever onset, the highest fever during the period, and fever duration. There were 54 patients in the group of < 6 months, 41 in the group of < 12 months, 58 in the group of < 24 months, and 18 in the group of ≥ 24 months. We thus found the correlation between age and fever responses under 24 months old; namely, the more the age advanced, the more frequently high and prolonged fever was experienced. Importantly, infants under 6 months old tend to show the suppressed fever responses. In conclusion, young infants with reduced fever response during RSV infection do not implicate less severity and needs attentive management.

Characteristics of FDG-PET findings in the diagnosis of systemic juvenile idiopathic arthritis.

OBJECTIVE: To examine and delineate inflammatory focus in patients with juvenile idiopathic arthritis (JIA), (18)F-Fluoro-deoxy-glucose (FDG)-positron emission tomography (PET) ((18)F-FDG-PET) was applied to patients with JIA, and the images of these patients were compared. METHODS: Sixty-eight children (59 with systemic JIA (s-JIA) and 9 with polyarticular JIA) were included. The diagnosis of JIA was done to meet the International League of Associations for Rheumatology (ILAR) criteria. After 6-h fasting, whole-body positron emission tomography (PET) scans were acquired 60 min after intravenous injection of 3-5 MBq/kg (18)F-FDG. The interpretation of (18)F-FDG uptake was based on visual characteristics. RESULTS: Two types of PET images were outstanding in s-JIA; one was (18)F-FDG uptake in red bone marrow, such as the spine, pelvis, and long bones as well as spleen (12 cases), and other type was the uptake in the major joints, such as hips, elbows, wrists, knees, and ankles (8 cases). The former findings were correlated with elevated levels of inflammatory markers, while the latter were with significantly increased levels of MMP-3 (p < 0.05). CONCLUSION: There was a noticeable accumulation of (18)F-FDG uptake in bone marrow of s-JIA patients which may indicate the inflammatory focus of this disease and play an important role in the pathogenic basis of arthritis and systemic inflammation of s-JIA.

Pathogenesis of systemic inflammatory diseases in childhood: "Lessons from clinical trials of anti-cytokine monoclonal antibodies for Kawasaki disease, systemic onset juvenile idiopathic arthritis, and cryopyrin-associated periodic fever syndrome".

Inflammation has often been considered to be a nonspecific response and to play a bridging role in the activation of adaptive immunity. However, it is now accepted that inflammation is the product of an independent innate immune system closely linked to the adaptive immune system. The key mediators of inflammation are inflammatory cytokines, as determined by multiple lines of evidence both in vitro and in vivo. Due to the crucial role of inflammatory cytokines in the pathogenesis of autoimmune disorders, anti-cytokine treatment has been developed as a therapy for rheumatoid arthritis, juvenile idiopathic arthritis (JIA), and inflammatory bowel diseases. We recently completed several clinical trials of anti-cytokine treatment for children with systemic inflammatory diseases: anti-IL-6 receptor monoclonal antibody (tocilizumab) for children with two subtypes of JIA (poly-JIA and systemic JIA), anti-TNF-α monoclonal antibody (infliximab) for children with Kawasaki disease, and anti-IL-1-ß monoclonal antibody (canakinumab) for children with cryopyrin-associated periodic syndrome. This review summarizes the basis of inflammation in terms of innate immunity and adaptive immunity in these systemic inflammatory diseases, clinical efficacy, and tolerability of these biologic agents, and attempts to determine the roles of individual inflammatory cytokines in disease pathogenesis.

[A case of severe systemic juvenile idiopathic arthritis introduced tocilizumab in early phase of the disease].

A 14-year-old boy was admitted in the former hospital with remittent fever, erythematous rash, joint pain, and muscle pain. Antibiotics were ineffectively administered and then, methylprednisolone (mPSL) pulse therapy with methotrexate was introduced under the diagnosis of suspected systemic juvenile idiopathic arthritis (JIA). However, he still had clinical symptoms and signs, and was transferred to our hospital. Re-examination revealed no malignancies including acute leukemia by bone marrow aspiration, no infectious agents by septic work, and no significant increases of antibodies against several viruses including CMV, EBV, HSV, Parvovirus B19, adenovirus, and so forth. FDG-PET demonstrated the accumulation of (18)F-FDG in bone marrows suggesting systemic JIA. Laboratory findings were leukocytosis and granulocytosis, elevated levels of C-reactive protein, D-dimer, ferritin, and interleukin-6. He was finally diagnosed as having severe systemic JIA. Thus, soon after the additional mPSL pulse therapy, tocilizumab (TCZ) was successfully introduced. In conclusion, for systemic JIA patients with severe systemic inflammation, it will be reasonable to introduce tocilizumab earlier than the guideline suggested to reduce side effects of long-term and large amounts of steroids and to protect the transition to macrophage activation syndrome. Further studies will be needed to recommend appropriate timing of tocilizumab introduction.

Analysis of gender differences in genetic risk: association of TNFAIP3 polymorphism with male childhood-onset systemic lupus erythematosus in the Japanese population.

BACKGROUND: Systemic lupus erythematosus (SLE) is a systemic multisystem autoimmune disorder influenced by genetic background and environmental factors. Our aim here was to replicate findings of associations between 7 of the implicated single nucleotide polymorphisms (SNPs) in IRF5, BLK, STAT4, TNFAIP3, SPP1, TNIP1 and ETS1 genes with susceptibility to childhood-onset SLE in the Japanese population. In particular, we focused on gender differences in allelic frequencies. METHODOLOGY/PRINCIPAL FINDINGS: The 7 SNPs were genotyped using TaqMan assays in 75 patients with childhood-onset SLE and in 190 healthy controls. The relationship between the cumulative number of risk alleles and SLE manifestations was explored in childhood-onset SLE. Logistic regression was used to test the effect of each polymorphism on susceptibility to SLE, and Wilcoxon rank sum testing was used for comparison of total risk alleles. Data on rs7574865 in the STAT4 gene and rs9138 in SPP1 were replicated for associations with SLE when comparing cases and controls (corrected P values ranging from 0.0043 to 0.027). The rs2230926 allele of TNFAIP3 was associated with susceptibility to SLE in males, but after Bonferroni correction there were no significant associations with any of the other four SNPs in IRF5, BLK, TNIP1 and ETS1 genes. The cumulative number of risk alleles was significantly increased in childhood-onset SLE relative to healthy controls (P = 0.0000041). Male SLE patients had a slightly but significantly higher frequency of the TNFAIP3 (rs2230926G) risk allele than female patients (odds ratio [OR] = 4.05, 95% confidence interval [95%CI] = 1.46-11.2 P<0.05). CONCLUSIONS: Associations of polymorphisms in STAT4 and SPP1 with childhood-onset SLE were confirmed in a Japanese population. Although these are preliminary results for a limited number of cases, TNFAIP3 rs2230926G may be an important predictor of disease onset in males. We also replicated findings that the cumulative number of risk alleles was significantly increased in childhood-onset SLE.

Guidance on the use of canakinumab in patients with cryopyrin-associated periodic syndrome in Japan.

Cryopyrin-associated periodic syndrome (CAPS) is an orphan disease with incidence of about one in 1,000,000 persons. This autoinflammatory disease develops in the neonatal period or early childhood, with various inflammatory symptoms occurring repeatedly throughout the patient's lifetime. It is caused by abnormality of the NLRP3 protein which mediates the intracellular signal transduction mechanism of inflammatory processes, resulting in continuous overproduction of interleukin (IL)-1ß, which induces chronic inflammation and progressive tissue damage. Definitive diagnosis of CAPS is difficult, and treatment has also been difficult because of a lack of effective medications in Japan. Clinical studies of human anti-human IL-1ß monoclonal antibody (canakinumab) treatment were conducted in Japan, and approval was granted for therapeutic use of canakinumab for CAPS in September 2011. Similar to other biological drugs, canakinumab is clinically highly effective. However, sufficient attention to the method of use and adverse drug reactions is necessary. This guidance describes the use of canakinumab in Japan for CAPS in relation to exclusion criteria, method of use, evaluation criteria, and adverse drug reactions.

2 cases of HLA-B27-positive seronegative spondylarthritides in pediatric age treated with adalimumab.

Seronegative spondyloarthritis is strongly correlated to HLA-B27, and in the long term, it causes limitations to the movements of vertebral joints. In recent years, the numbers of patients diagnosed with axial spondyloarthritis have increased due to the widespread use of magnetic resonance imaging (MRI) for diagnostic imaging. We report the cases of 2 pediatric patients diagnosed with axial spondyloarthritis, and whose disease activity was successfully controlled using adalimumab. In case 1, the patient was a 15-year-old boy. The onset of the disease was marked by neck pain ; HLA-B27 was positive, and the MRI revealed sacroiliac arthritis. After being diagnosed with axial spondyloarthritis, he began receiving oral steroid therapy. Gradual recurrence was observed, and adalimumab treatment was initiated. In case 2, the patient was a 9-year-old boy. Bilateral pain was present in the shoulder joints, ankles, and knee joints. The patient was diagnosed with polyarticular juvenile idiopathic arthritis, and treatment using oral steroids, immunosuppressants and tocilizumab. The arthralgia disappeared, but at the age of 12 years, pain recurred in the sacroiliac joint and the Achilles tendon, the HLA-B27 was positive, and the MRI revealed sacroiliac arthritis. The condition was diagnosed as axial spondyloarthritis; adalimumab treatment was initiated. Adalimumab was effective in the treatment of axial spondylitis occurring in childhood.

[An approach to the patients with cryopyrin-associated periodic syndrome (CAPS) : a new biologic response modifier, canakinumab].

Cryopyrin-associated periodic syndrome (CAPS) comprises a group of rare, but severe, autoinflammatory syndrome, and includes 3 distinct conditions, familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS), and neonatal-onset multisystem inflammatory disease (MONID). These syndromes are characterized by urticarial-like rash, periodic fever, central nervous system inflammation, an arthropathy, and the risk of amyloidosis. About 20% die by age 20 years in the most severe cases. The disease is associated with mutations in the NLRP3 gene that encodes for the protein cryopyrin, a component of the inflammasome complex that regulates the production and secretion of IL-1ß. Canakinumab is a human IgG monoclonal antibody targeting IL-1ß. The clinical trials of canakinumab for patients with CAPS in both western countries and Japan were well-tolerated in most patients, and provided significant advantages over existing competitive therapies. Although no serious adverse effects have been reported, the frequencies of common infectious diseases including nasopharyngitis, upper respiratory tract infections, and gastroenteritis were reported presumably due to the blockade of proinflammatory cytokine, IL-1ß. For us pediatrician, it will be important to be more careful for infectious diseases to provide the maximum safety of canakinumab for these patients.

[Febrile responses in patients with pediatric rheumatic diseases].

Fever is one of the critical symptoms of patients in pediatrics field. It indicates inflammatory focus somewhere in the body, and the major causes of fever are infectious diseases. Recent progresses of our knowledge about autoinflammatory syndrome promoted the investigation of the mechanism of fever, and suggested that the pro-inflammatory cytokines are the direct causative agents of fever. The basic science revealed that cooperation of IL-6 and IL-1ß induces febrile response. Fever of unknown origin (FUO) remains a challenging problem. Rheumatic diseases, rare infectious diseases, and benign tumors and malignancies are diagnoses to be differentiated. FDG-PET is recently proved a valuable tool for the identification of the etiology in patients with FUO. Since the introduction of biological response modifiers into the treatment of patients with pediatric rheumatic diseases has shifted the therapeutic paradigm, a new concept that the blockade of a unique pro-inflammatory cytokine brings cessation of whole inflammatory responses affected tremendously the clinical medicine. A more investigation of inflammation and its pathophisiology will be needed in pediatric rheumatology.