Clinical Characteristics of Pediatric Parainfluenza Virus Infections: A Comparative Analysis of Parainfluenza Virus Serotypes 1-4 From April 2021 to October 2023 in Hokkaido, Japan.

BACKGROUND: Parainfluenza virus (PIV) is widely known as a causative virus of acute respiratory tract infections in children, and 4 serotypes (PIV-1-PIV-4) have been identified. The purpose of the present study was to clarify the clinical characteristics of the PIV serotypes in pediatric PIV infections in Japan. METHODS: Between April 2021 and October 2023, 8821 children aged <16 years who presented with respiratory symptoms underwent multiplex polymerase chain reaction analyses at the Department of Pediatrics, NTT Medical Center Sapporo. All 1490 cases in which PIV was detected were analyzed for their clinical characteristics by PIV serotypes. RESULTS: Of the 1490 cases, 608 were positive for a single PIV serotype: 91 (13.5%) for PIV-1, 54 (4.8%) for PIV-2, 361 (62.1%) for PIV-3 and 102 (19.6%) for PIV-4. The median ages were 3.5 years for PIV-1, 5.4 years for PIV-2, 1.9 years for PIV-3 and 2.2 years for PIV-4, with a significantly older age for PIV-2. Compared with the other serotypes, croup was significantly more common in PIV-1 and lower respiratory tract infection was significantly more common in PIV-4. Of the 608 cases with a single PIV serotype, 114 were hospitalized. The proportion of hospitalized patients was higher for PIV-4 than for the other PIV serotypes, but the difference was not significant. CONCLUSIONS: Lower respiratory tract infection was more frequent in PIV-4 than in the other PIV serotypes, and PIV-4 infection may increase the risk of hospitalization.

Neonatal suppurative parotitis: Case reports and literature review.

BACKGROUND: Neonatal suppurative parotitis is a rare disease, characterized mainly by unilateral parotid swelling with erythema and tenderness, and often purulent discharge from the Stensen's duct into the oral cavity. Only 44 cases were reported in the English literature between 1970 and 2013. METHODS: A MEDLINE search was conducted using the terms acute, neonatal, newborn, suppurative, bacterial, purulent, parotitis, parotid swelling, and parotid abscess, limited to the English-language literature starting from 2011. We reviewed all reported cases, together with two more managed cases in our hospital. We also describe the magnetic resonance imaging findings of the early stage of this disease. RESULTS: We identified 26 new cases since 2011. The total number of patients reviewed was 72, including our patients. The infection was unilateral in 83% of patients, and 67% of the affected patients were males. The serum amylase levels were generally not elevated despite marked parotid swelling. Of the causative agents of this disease, 65% were Staphylococcus aureus, of which 19% were methicillin-resistant S. aureus. As the rate of cesarean section was high in patients with this disease, it was considered a risk factor. The diffusion-weighted magnetic resonance images showed multiple punctate hyperintensity regions with reduced apparent diffusion coefficient, suggesting microabscess formation in the affected gland. CONCLUSIONS: Acute suppurative parotitis should be considered in cases of swelling and tenderness in the parotid gland during the neonatal period. Multiple punctate hyperintensities in the parotid gland on the diffusion-weighted images may indicate a retrograde bacterial infection from the Stensen's duct.

S100a9 Protects Male Lupus-Prone NZBWF1 Mice From Disease Development.

Systemic lupus erythematosus (SLE) is an autoimmune disorder disproportionally affecting women. A similar sex difference exists in the murine New Zealand Black/White hybrid model (NZBWF1) of SLE with all females, but only 30-40% of males, developing disease within the first year of life. Myeloid-derived suppressor cells (MDSCs) are prominent in NZBWF1 males and while depletion of these cells in males, but not females, promotes disease development, the mechanism of suppression remains unknown. S100a9, expressed by neutrophils and MDSCs, has previously been shown to exert immunosuppressive functions in cancer and inflammation. Here we investigated if S100a9 exerts immunosuppressive functions in NZBWF1 male and female mice. S100a9+/+, S100a9+/- and S100a9-/- NZBWF1 mice were followed for disease development for up to 8 months of age. Serum autoantibody levels, splenomegaly, lymphocyte activation, glomerulonephritis and proteinuria were measured longitudinally or at the time of harvest. In accordance with an immunosuppressive function of MDSCs in male mice, S100a9-deficient male NZBWF1 mice developed accelerated autoimmunity as indicated by increased numbers of differentiated effector B and T cells, elevated serum autoantibody levels, increased immune-complex deposition and renal inflammation, and accelerated development of proteinuria. In contrast, female mice showed either no response to S100a9-deficiency or even a slight reduction in disease symptoms. Furthermore, male, but not female, S100a9-/- NZBWF1 mice displayed an elevated type I interferon-induced gene signature, suggesting that S100a9 may dampen a pathogenic type I interferon signal in male mice. Taken together, S100a9 exerts an immunosuppressive function in male NZBWF1 mice effectively moderating lupus-like disease development via inhibition of type I interferon production, lymphocyte activation, autoantibody production and the development of renal disease.

Mosaic Turner syndrome with improved Chiari type 1 malformation after growth hormone therapy: A case report.

We described a three-year-old girl whose Chiari type 1 malformation associated with mosaic Turner syndrome disappeared after GH therapy. She was diagnosed with mosaic Turner syndrome at the age of 1 yr and 7 mo by a chromosomal analysis (G-band) for short stature and was treated with GH. Sagittal T1-weighted magnetic resonance imaging (MRI) performed before the start of GH demonstrated herniation of the cerebellar tonsils 7 mm below the foramen magnum into the cervical spinal cord. After the initiation of GH therapy, the growth in height was favorable and improved from 70.6 cm (-3.5 SD) to 92 cm (-1.5 SD) in 2 yr. An MRI examination 19 mo later showed the disappearance of Chiari type 1 malformation. GH therapy either exacerbates or ameliorates Chiari type 1 malformations associated with GH deficiency (GHD). Since Turner syndrome uses more GH than GHD, careful follow-up is required if the disease is associated with Chiari type 1 malformation.

Clinical significance of subcutaneous fat and fascial involvement in juvenile dermatomyositis.

Objectives: Subcutaneous involvement, including calcinosis and panniculitis, is a more common complication in juvenile dermatomyositis (JDM) than in adult dermatomyositis. Magnetic resonance imaging (MRI) is useful for evaluating disease distribution. We investigated the clinical significance of subcutaneous involvement in JDM. Methods: Thighs and hips in 18 newly diagnosed JDM patients were evaluated with fat-suppression MRI. Bilateral muscle, fascial and subcutaneous fat involvement were scored from 0 to 8 points according to the severity of distribution on MRI. Associations between clinical manifestations, serum muscle enzymes, and MRI scores were also evaluated. Results: Abnormal MRI findings in muscle, fascia and subcutaneous fat were observed in 18, 18, and 10 patients, respectively. Subcutaneous fat scores were significantly higher in early-diagnosed JDM patients (diagnosed less than 2 months from onset) than in late-diagnosed JDM patients (diagnosed later) (p = .025). Serum aldolase was elevated in all patients, although only eight demonstrated elevated serum creatine phosphokinase. Serum aldolase was significantly correlated with MRI scores for subcutaneous fat (p < .0001, ρ = .787) and fascia (p = .013 ρ = 0.574), but not muscle. Additionally, serum aldolase was significantly correlated with serum triglycerides (p = .009, ρ = 0.629). Conclusion: Subcutaneous fat involvement is a characteristic finding in early-diagnosed JDM and correlates with elevated serum aldolase.

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.

Usefulness of two interferon-γ release assays for rheumatic disease.

BACKGROUND: The aim of this study was to evaluate the performance of two interferon-γ release assays (IGRA), QuantiFERON-TB Gold In-Tube (QFT-GIT) and T-SPOT.TB, for pediatric patients with rheumatic disease in Japan and to analyze the frequencies of indeterminate test results with these kits. METHODS: An IGRA was performed in 108 patients <20 years old in order to exclude tuberculosis infection at the time of first application of or change of biological agents and immunosuppressants in Yokohama City University Hospital. RESULTS: None of the 108 patients tested had active tuberculosis during the 50 month observation period. Indeterminate results of QFT-GIT and T-SPOT.TB tests were obtained in 9.9% and in 0% of cases, respectively. Indeterminate results were obtained significantly more frequently in patients on prednisolone >0.5 mg/kg and in patients with active underlying disease. Use of biologicals and other immunosuppressants had no effect on these measurements. CONCLUSIONS: IGRA are very useful for excluding tuberculosis infection in patients with rheumatic disease before starting new immunosuppressant therapy. Furthermore, the T-SPOT.TB test was suitable for evaluating latent tuberculosis infection even under immunosuppression, when TB tests are generally hard to perform.

Loss of interleukin-21 leads to atrophic germinal centers in multicentric Castleman's disease.

Both multicentric Castleman's disease (MCD) and immunoglobulin (Ig)G4-related disease (IgG4-RD) are systemic diseases, presenting with hypergammaglobulinemia and elevated serum levels of IgG4. However, with regard to histopathological findings, MCD shows atrophic germinal centers. On the other hand, expanded germinal centers are detected in IgG4-RD. We extracted germinal centers from specimens of each disorder by microdissection and analyzed the expression of mRNAs by real-time polymerase chain reaction to clarify the mechanisms underlying atrophied germinal centers in MCD. This analysis disclosed loss of interleukin (IL)-21 and B cell lymphoma (Bcl)-6 in the germinal centers of MCD. Loss of IL-21 is considered to be involved in the disappearance of Bcl-6 and leads to atrophied germinal centers in MCD.

A national survey on current use of mycophenolate mofetil for childhood-onset systemic lupus erythematosus in Japan.

PURPOSE: To conduct a national survey of systemic lupus erythematosus (SLE) patients treated with mycophenolate mofetil (MMF). Based on current information on the use of MMF, we aimed to evaluate its efficacy and safety for childhood-onset (c-) SLE. TARGET: We evaluated 115 patients by questionnaire on MMF use for c-SLE in medical facilities specializing in pediatric rheumatic and renal diseases. RESULTS: Average age at SLE onset was 10.6 (range, 2-15) years; average age at the time of starting MMF was 12.3 (range, 2-15) years. Average dose per body surface area was 1,059.3 mg/m(2)/day. Corticosteroid dosing was 20.9 mg/day before treatment but 7.7 mg/day after treatment. Laboratory values before and after MMF treatment were as follows: C3 increased from 67.0 to 84.9 mg/dl (p < 0.001), C4 increased from 10.2 to 15.1 mg/dl (p < 0.001), and anti-DNA antibody decreased from 154.2 to 18.4 IU/ml (p < 0.001). 24 adverse events in 21 cases were reported, but MMF was not discontinued in any. CONCLUSIONS: The amount of MMF for c-SLE in Japan is similar to the standard dose in other countries. Reduction of corticosteroid dose and improvement of laboratory values represent efficacy of MMF. The side effects recorded here indicated tolerability of the drug.

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.

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.