There are currently no evidence‐based initiation strategies for performing renal replacement therapy (RRT) for pediatric patients with end‐stage renal disease. We retrospectively examined the timing of RRT initiation and choice of the modality in patients with hypo/dysplastic kidney, which is the major cause of end‐stage renal disease in children. Fourteen patients were included in this study. At the time of the initiation of RRT, the mean age was 11.5±5.8 years, and the mean estimated GFR (eGFR) was 10.1±3.1ml/min/1.73m². The mean time from the diagnosis of hypo/dysplastic kidney to the initiation of RRT was 6.7±3.7 years. In all patients, the urine volume and serum levels of potassium, phosphate, and bicarbonate were well maintained within the normal limits at the time of the initiation of RRT.
 Of the 14 patients, dialysis was initiated in 7 patients and preemptive kidney transplantation (PEKT) was performed in the remaining 7 patients. The mean eGFR at the time of RRT initiation was significantly higher in the PEKT group than in the dialysis group (eGFR 12.0±2.9 and 8.6±2.3ml/min/1.73m², respectively). Four patients in the dialysis group started dialysis following unexpected clinical events, although these events were not seen in any of the PEKT group patients. Since patients with hypo/dysplastic kidney showed a constant slope of progression, PEKT was considered to be a reliable therapeutic option for these patients. In addition, our results suggested that it is safe to start dialysis when the eGFR is around 10m/min/1.73m², even if asymptomatic, in pediatric patients with hypo/dysplastic kidney.

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 Concurrently with implementation of the school urinalysis program introduced in 1973, a handy “School Life Regulation Table" providing physical exercise and diet instructions for school children was issued. Furthermore, the “School Life Management Guidance Table" has come to be extensively used since 2002. The actual management category is determined employing a “yardstick of management categories" established by the Japan School Health Association, whereby data found are entered in the “School Life Management Guidance Table." The program, nevertheless, has encountered problems such as some of the relevant limitations failing to suit the actual state, whereby eventually the problem is coped with in most instances via commentary. As regards practical use of management categories, there is no consensus even among nephrologists;therefore, it is not uncommon that the management category judgment must be dependent on that by on―site physicians.
 In drafting the current revision entitled the “New All about School Urinalysis Program," it was necessary to review the “yardstick of management categories." To this end, the questionnaire was conducted among the councilors of the Japanese Society for Pediatric Nephrology to determine the actual status of exercise management currently being carried out by pediatric nephrologists. Although the results regarding selection of management categories varied significantly even among pediatric nephrologists, there was a wide gap between the “yardstick of management categories" and those actually employed. Thus, the overall results showed a need to change the yardstick. Furthermore, because the problems of the “School Life Regulation Table" are coped with in most instances via commentary, the current table may not be suitable for practical applications.

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 Exercise has been shown to enhance physical motor performance and improve quality of life (QOL). However, because of concerns that exercise may exacerbate proteinuria or renal function in patients with chronic kidney disease (CKD), traditionally a style based on rest has been adopted. Recently the trend has shifted toward the attitude that exercise should not be restricted excessively in CKD patients, but there is still no clear scientific evidence as to whether exercise in CKD will exacerbate kidney disease, or conversely, whether it will have a renal protective effect. We reviewed the literature on exercise restriction in CKD and examined the evidence. There are no reports of exercise having an adverse effect on long―term prognosis;rather, there is a fairly high level of evidence that exercise does not exacerbate proteinuria or renal function, improves exercise tolerance, and raises patient QOL. Rest and exercise restriction may inhibit the healthy physical and mental development of children in particular, and so exercise should not be restricted unnecessarily.

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 Although most children with idiopathic nephrotic syndrome (INS) respond initially to steroid therapy, considerable number of patients demonstrate frequent relapses, steroid―dependency and steroid―resistance and show significant steroid toxicity.
 Recently, several non―controlled clinical trials have suggested that rituximab, a chimeric monoclonal antibody inhibiting CD20―mediated B―cell proliferation and differentiation, is effective for children with refractory INS, though an established regimen does not exist.
 We are in process of clinical trial to evaluate the efficacy and safety of repeated administration of rituximab (375 mg/m² body surface area, four times every three months) for patients with refractory nephrotic syndrome. In this article, literature review of the rituximab treatment for refractory nephrotic syndrome in children and our first successful case treated with repeated administration of rituximab will be introduced.

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 We report the case of a 3―year―old female patient with steroid―resistant nephrotic syndrome. Although mizoribine (MZR) was administered at a dose of 9.5 mg/kg body weight/day, the peak MZR serum concentration (Cmax) was 1.07 μg/ml, which was low and clinically inefficacious. By the investigation of this issue, it was revealed that the apparent volume of distribution (Vd/F) was extremely high (5.97l/kg), the urinary excretion rate of MZR (fu) was low (17.4%), and the absolute volume of distribution (Vd) was 1.04l/kg, which value was consistent with that of a water―soluble drug. Hence, the reason for the low Cmax was the decreased absorption of MZR. The fu of MZR is considered to indicate the bioavailability or absorption rate of MZR. When fu is low, an extremely high Vd/F will be obtained. If Vd/F is high or Cmax or fu is low, the decreased absorption of MZR might result in an insufficient concentration of MZR in serum even after the administration of a high dose of MZR.

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 Diarrhea―associated hemolytic syndrome (D+HUS) is the disease that causes acute severe renal failure and often requires dialysis therapy. However, in many cases, renal function can be recovered. Oliguria is an absolute indication of dialysis therapy in the guideline of Japanese Society of Pediatric Nephrology for D+HUS. We report a case of D+HUS with oliguria who could avoid dialysis therapy. The case is a 5―year―old boy with fever, hematochezia and diarrhea. He went to see a regional hospital and pointed out the renal dysfunction and thrombocytopenia. He also developed oliguria and referred to our hospital. On the day of admission, He developed anuria without showing any electrolyte abnormalities and symptoms suggesting overhydration, so we did not perform dialysis therapy. On the fifth hospital day, urinary output started to increase and the patient was managed without dialysis therapy until discharge. If restrict monitoring and immediate performing of dialysis therapy can be done, it may be possible to treat the patient with oliguria without performing dialysis therapy.

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 When he was 5 years old, he was diagnosed having type 1 diabetes mellitus and started insulin therapy. At 9 years old, he had stomachache, vomiting and edema, and severe proteinuria and hypoproteinemia were elucidated. His illness was diagnosed as nephrotic syndrome, and oral prednisolone (PSL) was administered. Subsequently his blood glucose level rose. We increased the number of times of the blood sugar determination and increased insulin. Two weeks later from the start of treatment, his proteinuria did not decrease. We administered cyclosporine (CyA) with steroid. Four weeks later from the start of treatment, his nephrotic syndrome completely remitted. During alternate―day PSL administration, the basic insulin doze was increased only on the day when he took PSL. HbA1c at one month later from the start of the treatment was 7.7%, and at two month later was 7.8%. Early induction of immunosuppressant and the adjustment of the insulin dose during PSL alternate―day administration enabled early reduction of steroid and stable blood glucose level.

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 Introduction: Although rituximab (Rit) is a greatly effective salvage therapy for refractory nephrotic syndrome (NS), the duration of the efficacy is limited in many cases after the cessation of Rit. We experienced 2 cases of refractory NS successfully treated with re―starting the combination therapy of cyclosporin A (CyA) and mizoribine (MZR) after Rit treatment.
 Case 1: The patient is a 10―year―old boy with MCNS, who was first diagnosed at the age of 2 in 2003. Since then, he has experienced 16 relapses even under the combination therapy of CyA and MZR. In 2007, 4 series of Rit administrations were performed at the age of 7. Five months after the last Rit administration, he began to suffer from relapses again. After the combination therapy of CyA and MZR was restarted, he has been free from relapses for 1 year.
 Case 2: The patient is a 19―year―old boy with MCNS, who was first diagnosed at the age of 6 in 1997, and underwent 43 relapses under various treatments including the combination therapy of CyA and MZR. In 2009, 4 series of Rit administrations were carried out at the age of 18. He showed another relapse again 8 months after the last Rit administration, and the combination therapy was started again. Since then, no relapse has occurred to date.
 Discussion: After Rit treatment, there is a possibility that the effectiveness of the combination therapy of CyA and MZR may change for the better, although this mechanism is not proven. The long―term and recurrent use of CyA certainly increases a risk of CyA nephrotoxicity and repeated renal biopsy might be necessary to detect irreversible drug―induced adverse effects. MZR is also reported to have a function of reducing CyA nephrotoxicity.
 Conclusion: Re―starting the combination therapy of CyA and MZR might be one of the choices for the patients with refractory NS after Rit treatment failure.

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 It has been reported that nonadherence to immunosuppressive drugs is associated with increased organ rejection episodes leading to graft loss.
 We report here a case of 13―year old boy who received kidney transplantation at the age of 7. He developed antibody―mediated rejection and graft failure due to nonadherence in the fourth year after renal transplantation.
 To evaluate nonadherence of kidney transplant patients in our hospital, we carried out a questionnaire survey with five questions. Adolescent kidney transplant recipients (n＝8) at the Niigata University Medical and Dental Hospital were enrolled in the study. Of the total 8 patients, 67.5% (5 patients) reported missing their immunosuppressive drugs over the past 1 month.
 It is necessary to perform education and support for adolescent patient continuously.

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