We report the outcome of our single-center, long-term follow-up study of tacrolimus therapy in children with steroid-resistant nephrotic syndrome (SRNS). All cases of nephrotic syndrome (NS) with kidney biopsies treated at our center between January 2000 and July 2008 were reviewed. Children with systemic lupus erythematosus and steroid-dependent NS were excluded. Nineteen children with SRNS received tacrolimus. Histopathological analysis of the biopsy revealed the underlying conditions of these 19 patients to be focal segmental glomerulosclerosis (ten patients), C1q nephropathy (four), membranous nephropathy (two), minimal change disease (one), membranoproliferative glomerulonephritis (one), and immunoglobulin A nephropathy (one). The mean follow-up was 55 months, and the median age of the patient cohort was 10 years. We observed complete remission in 11 (58%) patients, partial remission in six (32%), and failure to respond in two (9%). The median time to response was 8 weeks. Side effects were mild and transient (one case of acute kidney injury and three cases of hyperglycemia). The initial rate for combined partial and complete remission of the NS in children with SRNS was 81%, which was sustained in 58% of the patients on follow-up. Among children with FSGS, the sustained remission rate was 50%, while 40% progressed to end-stage renal disease (ESRD) (mean time 52 months). Based on the results of this study, we conclude that tacrolimus is an effective and well-tolerated therapeutic option for the treatment of SRNS in children. However, the occurrence of relapses of the NS with progression to ESRD during the long-term follow-up indicates the need for careful monitoring of such patients.

Systemic vasculitic syndromes are rare in childhood. Vasculitis is the predominant feature of a large number of different clinical entities that are linked by the presence of inflammatory changes in the blood vessels. The nature of these diseases and their relationship to each other remain unclear. The clinical presentation associated with the size of the affected vessels and epidemiological data are very helpful for the diagnosis of those diseases. Recent advances are beginning to shed some light on the etiology and pathogenetic mechanisms involved in the various vasculitides. There is good evidence to support roles for circulating immune complexes, cell-mediated immunity, anti-neutrophil cytoplasmic antibodies and anti-endothelial cell antibodies in the pathogenesis. Renal involvement in vasculitis in children is commonly seen in Henoch-Schönlein purpura, microscopic polyarteritis, Wegener's granulomatosis, Churg-Strauss syndrome and polyarteritis nodosa. However, kidney disease can also be part of the clinical picture of Kawasaki disease and Takayasu arteritis. Recently, with the institution of early and aggressive immunosuppressive treatment of severe cases, significant improvement in the long-term survival of patients has been achieved. This review article addresses the pathological and clinical features (particularly renal involvement), therapeutic intervention and prognosis of the above-mentioned diseases.

C1q nephropathy (C1qN) is a rare idiopathic glomerulopathy typically seen in adolescents and young adults. All kidney biopsies done from 2002 to 2007 were analyzed (264). Thirteen cases of C1qN from 212 (6.6%) native biopsies and one case out of 52 (1.9%) transplant biopsies were reviewed regarding demographic features, clinical presentation, histopathology, treatment, and outcome. Age varied from 1 to 18 years; half were boys. Ten children (71.4%) presented with nephrotic syndrome (NS). The most common histopathology found was diffuse mesangial proliferative glomerulonephritis (DMP) by light microscopy (LM), with diffuse granular staining for C1q predominantly in the mesangium. Children with either NS or persistent gross hematuria received prednisone and angiotensin-converting enzyme inhibitors (ACEi) (11). Median follow-up was 36 months. Steroid response was complete in 6 patients (54.5%). Those with steroid resistance (5) or steroid dependence (2) received further immunosuppression with mycophenolate mofetil (MMF) or tacrolimus (Tac). Three children achieved complete remission and four partial remission. Frequent relapses were seen in 4/14 patients. Renal survival was 100%. Our report reveals a high incidence of C1qN in pediatric patients, with variable clinical presentation. Despite a high incidence of steroid resistance among those with NS, an excellent response was observed with the addition of further immunosuppression.

Mycophenolate mofetil (MMF) is a new immunosuppressive drug used in combination with cyclosporin A (CsA) or tacrolimus and prednisone to prevent rejection of renal allografts in both adult and pediatric recipients. It has been shown in several large studies that MMF significantly decreases the incidence of acute rejection in adults and has acceptable adverse effects. In this retrospective study, we compare the incidence of adverse events between pediatric and adult renal allograft recipients. Twenty-two children and 37 adult renal allograft recipients were included in the study. The initial dose of MMF was 1.5 g b.i.d. for the adult patients and ranged from 15 to 30 mg/kg/d for the pediatric patients. All patients received p.o. acyclovir as prophylaxis for cytomegalovirus (CMV). The two groups were similar regarding gender distribution and graft source. Acute rejections occurred in 10 of the 22 pediatric patients (45%) and in nine of the 37 adults (24%), p = NS. The incidence of infections was similar in both groups except for the occurrence of CMV (n = 5), which was seen only in adults. The incidence of GI symptoms was significantly higher in the pediatric population (54.5% vs. 21.6%; p = 0.02). Significant weight loss was seen more often in the smaller pediatric patients (weight < or = 15 kg) compared to the larger pediatric patients, 60% vs. 11.7%, p = 0.05. Among the patients who had significant GI symptoms 50% of the adults and 75% of the pediatric recipients required either dose reduction or, most commonly, discontinuation of the MMF. The need to discontinue MMF was significantly higher in the pediatric patients, especially in those that weighed less than 15 kg. We suggest the possibility that the optimum dose, dosing interval or preparation of MMF has not yet been established for pediatric patients. One should therefore monitor pediatric patients closely, especially the small ones, to avoid significant nutritional problems and other adverse GI events.

Serial monitoring of urine sediments by UFC was predictive of the requirement for antilymphocytic therapy and irreversible graft damage.