Rituximab (RTX) is a chimeric monoclonal antibody that inhibits CD20-mediated B-cell proliferation and differentiation. Several studies have examined its use in intractable nephrotic syndrome (NS) with some positive results. However, those studies examined such effects for a short-term period of 1 year, and some patients continued to relapse after a lapse in RTX treatment. Our use of RTX as a maintenance therapy (RTX injection when the CD19 cell count exceeded $100-200/{\mu}L$ before relapse) showed some noticeable efficacy. We used RTX in 19 patients with steroid-dependent NS (SDNS). In 12 patients treated with RTX maintenance therapy, only one relapse occurred. The mean treatment period was $23.4{\pm}12.7months$, and the mean number of RTX administrations was $3.9{\pm}1.6$. The relapse rates were decreased (from 2.68/year to 0.04/year), and the drug-free period also increased (from 22.5 days/year to 357.1 days/year) during maintenance therapy. The other seven patients were treated with one cycle of RTX or additional cycles in case of relapse (non-maintenance therapy). Relapse rates were significantly decreased after RTX treatment (from 1.76/year to 0.96/year, P=0.017). The relapse-free period was $15.55{\pm}7.38$ (range, 5.3-30.7) months. No severe side effects of RTX were found except for a hypersensitivity reaction such as fever and chills during its infusion. In conclusion, RTX is considered an effective and safe option to reduce the relapse rate by a single- or maintenance-interval therapy in SDNS.

Significant advances in the diagnosis and medical care of children with chronic kidney disease (CKD) are major reasons for the better survival rates of children and adolescents with CKD than the survival rates reported in previous decades. These patients are reaching adulthood, and therefore require a transition to adult medical care. This transition phase is well-recognized to be associated with considerably increased morbidities and medical problems, such as non-adherence, graft loss after transplantation, and loss to follow-up. Low adherence increases morbidity and medical complications and contributes to poorer qualities of life and an overuse of the health care system. However, these tragic outcomes may be avoidable through a structured and well-defined transition program. In the last decade, there has been increasing interest to resolve these medical and psychological problems that occur during the transfer of young adult patients from pediatric to adult renal units. The aims of a successful transition from pediatric to adult medical care include enhancing the individual development of better health-competence and stabilizing, or even improving, the state of health. This review will focus on various aspects of the transition phase of adolescents who have CKD or who underwent kidney transplantation from pediatric to adult nephrology care.

Herlyn-Werner-Wunderlich (HWW) syndrome is a rare congenital malformation syndrome that is characterized by a triad of uterine didelphys, blind hemivagina, and ipsilateral renal agenesis. There is a wide variety of phenotypic presentation which is recognized as a spectrum of disease rather than a separate entity. The exact incidence and pathogenesis of HWW syndrome are yet to be investigated. While this disease typically involves adolescent girls who present with abdominal pain or a pelvic mass that is secondary to hematocolpos, nowadays, a majority of potential patients with HWW are being prenatally screened for renal anomalies. Therefore, it is recommended to search for uterovaginal anomalies whenever a multicystic dysplastic kidney or the absence of a kidney is noted in a newborn female, and the role of pediatric nephrologists has become ever more important for early recognition of the disease.

Thymic stromal lymphopoietin (TSLP) is an interleukin-7-like cytokine that is an important trigger and initiator of many allergic diseases. TSLP promotes a T-helper type 2 (Th2) cytokine response that can be pathological. A relationship is formed both at the induction phase of the Th2 response through polarization of dendritic cells to drive Th2 cell differentiation and at the effector phase of the response, by promoting the expansion of activated T cells and their secretion of Th2 cytokines and TSLP. In transgenic mice with TSLP overexpression, it has been reported that TSLP leads to the development of mixed cryoglobulinemic membranoproliferative glomerulonephritis. In addition, TSLP can play an important role in the pathogenesis of IgA nephropathy and systemic lupus erythematosus-related nephritis. From our knowledge of the role of TSLP in the kidney, further studies including the discovery of new therapies need to be considered based on the relationship between TSLP and glomerulonephritis.

Purpose: Podocytes are important architectures that maintain the crucial roles of glomerular filtration barrier functions. Despite this structural importance, however, the mechanisms of the changes in podocytes that can be an important pathogenesis of minimal change nephrotic syndrome (MCNS) are not clear yet. The aim of this study was to investigate whether apoptosis is induced by interleukin (IL)-13 in cultured human podocytes. Methods: Human podocytes were treated with different IL-13 doses and apoptotic cells were analyzed using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL assay) and fluorescence-activated cell sorting (FACS). Results: The IL-13 increased the number of TUNEL-positive cells in a dose-dependent manner at 6 and 18 hours (P<0.05 and P<0.05, respectively). The apoptosis rate was appeared to be increased slightly in the IL-13-stimulated podocytes (8.63%, 13.02%, and 14.46%; 3, 10 and 30 ng/mL, respectively) than in the control cells (7.66%) at 12 hours by FACS assay. Conclusion: Our study revealed that IL-13 expression may increase podocyte apoptosis. Blocking the IL-13 signal pathway can potentially play an important role in regulating the apoptosis of podocytes.

Ureteropelvic junction obstruction is one of the common causes of hydronephrosis in infancy and childhood. Most cases of ureteropelvic junction obstruction are diagnosed prenatally and are usually asymptomatic. Although less common, older children can experience ureteropelvic junction obstruction that presents with symptoms including flank or abdominal pain. Here, we present the case of a nine-year-old healthy girl who had repeated flank pain and abdominal symptoms, with mild left hydronephrosis, for several months. Computed tomography that was performed during the period of acute flank pain revealed aggravated hydronephrosis on her left kidney, which was secondary to an ureteropelvic junction obstruction. She underwent laparoscopic pyeloplasty, and a crossing vessel that passed the ureteropelvic junction was identified. In addition, we reviewed the current literature of this rare entity.

Acute idiopathic scrotal edema (AISE) is a self-limiting condition that is characterized by acute scrotal swelling and erythema. AISE is a very rare cause of acute scrotum, especially in neonates. We report a case of AISE in a 26-day-old infant who was admitted to the outpatient clinic with swelling and erythema of the penis and scrotum for a week. His vital signs were stable, and laboratory findings were non-specific. A diagnosis of AISE was made using scrotal ultrasonography with color Doppler. His symptoms resolved within four days after the onset of supportive treatment, and he was discharged from the hospital. In neonates with an acute scrotum, AISE should be considered to prevent unnecessary surgical exploration.