Cases of Pediatric Pyelonephritis: A Single-Center Retrospective Study from an Extended-Spectrum ß-Lactamase-Producing Escherichia coli Endemic Area in Japan.

Background: Extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli has been increasingly recognized as the cause of upper urinary tract infection (UTI) in children. We have been using flomoxef at our department since 2017 as the first-line empiric therapy for children diagnosed with UTIs, and we avoid using carbapenems, which are considered the first-line treatment for ESBL-producing E. coli. However, reports on the use of flomoxef for UTIs are limited, especially for pediatric patients. The presence of vesicoureteral reflux at the onset of pyelonephritis is a concern. Severe vesicoureteral reflux can lead to repeated UTI and future deterioration of renal function, but the indication for voiding urethrography, which closely examines the presence of vesicoureteral reflux complications, is controversial. Methods: We retrospectively reviewed the laboratory findings, treatment, and clinical course of 96 pyelonephritis cases experienced at our department over a 7-year period from April 2014 to March 2021. Results: ESBL-producing E. coli were identified as the cause of pyelonephritis in 51% of cases, and this value was significantly higher (88%) in 2017. No significant differences were found in the febrile period or recurrence rate between the flomoxef-initiated group and other antibiotics groups. We also examined clinical indicators to predict vesicoureteral reflux and found no significant differences in ultrasonographic findings of hydronephrosis. Conclusion: In the present series, 51% of all pyelonephritis cases were found to be caused by ESBL-producing E. coli, with a significant increase in recent years. Flomoxef may be a useful alternative to carbapenem for ESBL-producing E. coli and the initial antibiotic of choice for upper UTIs in children. The indication for voiding cystourethrography should be carefully determined.

Juvenile Granulosa Cell Tumor with Elevated Peripheral Interleukin-6 Level Shows Prolonged Fever and Delayed Puberty.

Juvenile granulosa cell tumor (JGCT), classified as a sex cord-stromal tumor, is a rare neoplasm. This is an instructive case report of JGCT accompanied by augmented interleukin (IL)-6 secretion. A 13-year-old girl with prolonged fever and delayed puberty was diagnosed with JGCT of the left ovary based on an imaging study and pathological investigation. Although it was not clear whether IL-6 was secreted from the tumor cells, her serum level of IL-6 was very high. After tumorectomy, the patient's symptoms immediately disappeared, her IL-6 level decreased, and she entered puberty. Therefore, augmented IL-6 secretion production induced by tumors should be considered a potential cause of prolonged fever and/or delayed puberty.

Production of thyrotropin receptor antibodies in acute phase of infectious mononucleosis due to Epstein-Barr virus primary infection: a case report of a child.

Various autoantibodies have been reported to be detected during the progression of infectious mononucleosis. We observed a case of infectious mononucleosis due to Epstein-Barr virus primary infection for 2 months, and noticed the transiently increased titer of thyrotropin receptor autoantibodies detected at the acute phase on the 3rd day after admission. At that time, real-time quantitative PCR also revealed the mRNA expressions of an immediate early lytic gene, BZLF1, and a latent gene, EBNA2. The expression of BZLF1 mRNA means that Epstein-Barr virus infects lytically, and EBNA2 protein has an important role in antibody production as well as the establishment of Epstein-Barr virus latency. These results suggest that Epstein-Barr virus lytic infection is relevant to thyrotropin receptor autoantibody production. Thyrotropin receptor autoantibodies stimulate thyroid follicular cells to produce excessive thyroid hormones and cause Graves' disease. Recently, we reported the thyrotropin receptor autoantibody production from thyrotropin receptor autoantibody-predisposed Epstein-Barr virus-infected B cells by the induction of Epstein-Barr virus lytic infection in vitro. This case showed in vivo findings consistent with our previous reports, and is important to consider the pathophysiology of Graves' disease and one of the mechanisms of autoimmunity.

Successful treatment of lipoprotein glomerulopathy in a daughter and a mother using niceritrol.

We report two patients, a daughter and a mother, with lipoprotein glomerulopathy (LPG) who were successfully treated with niceritrol. Both patients carried a mutation in the apolipoprotein E (apoE) gene known as ApoE Tokyo/Maebashi. The daughter was found to have proteinuria at the age of 4 years. Four years later, she was diagnosed as having LPG based on a renal biopsy. She was treated with several medications including pravastatin, ethyl icosapentate, enalapril, warfarin and cyclophosphamide, all of which failed to reduce her proteinuria. At the age of 17 years, she exhibited an increase in proteinuria and a decline in renal function, despite ongoing treatment with pravastatin and enalapril. After switching from pravastatin to niceritrol, a marked reduction in the proteinuria and an improvement in renal function were observed. Her mother was found to have proteinuria at the age of 57 years and was diagnosed as having LPG based on a renal biopsy. She was also treated with niceritrol, resulting in an improvement in her proteinuria and renal function. These cases suggest that niceritrol might be a useful therapeutic option for LPG.