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  We asked whether pediatric renal transplant recipients, subgrouped by age, differed in the percentage and number of hospital readmissions and in the incidence of infectious complications post transplant. Between 1 August 1985 and 31 October 1993, a total of 164 patients <18 years of age underwent primary transplants, with cyclosporine-based immunosuppression, at the University of Minnesota. The percentage of readmissions (P = NS), the mean number of readmissions (P = NS), and the length of hospital stay during readmission (P = NS) did not differ significantly among age groups. The overall incidence of acute rejection was greater in those ≥2 years than those <2 years (P = 0.002), and in living donor recipients ≥2 years versus those <2 years (P = 0.02). The incidence of bacterial infection (<2 years, 87%; 2 – 5 years, 72%; 6 – 12 years, 51%; 13 – 17 years, 40%) was greater in younger recipients (P = 0.0001). The most common bacterial infection in recipients ≤5 years was Clostridium difficile-associated diarrhea; in those >5 years, urinary tract infection. The overall incidence of viral infection did not differ among groups (P = NS). The most common viral infection in recipients ≤5 years was varicella and those >5 years, cytomegalovirus infection. Risk factors for infection in the first 6 months post transplant included age <2 years and Solu-Medrol treatment for acute rejection. In conclusion, young recipients <2 years of age at the time of transplant are at a higher risk for bacterial infection post transplant.

 Protein and energy requirements of children on automated peritoneal dialysis (APD) have still not been sufficiently well defined, although their adequacy is important to maintain a positive nitrogen (N) balance and prevent malnutrition. We carried out 42 studies to estimate N balance in 31 children over 3 years on APD for 19.8±15.7 months. Twenty metabolic studies were performed in patients dialysed for less than 1 year (7.2±3.3 months) and 22 in patients treated for more than 1 year (31.3±13.6 months). The mean estimated N balance of all metabolic studies was 57.5±62.8 mg/kg per day. In only 21 of 42 studies was N balance estimated to be over 50 mg/kg per day, which is considered adequate to meet N requirements for all metabolic needs and growth of uremic children. Estimated N balance correlated significantly with dietary protein intake (r=0.671, P=0.0001) and total energy intake (r=0.489, P=0.001). Using the equations of correlation, the values of dietary protein intake [=144% recommended dietary allowance (RDA)] and total energy intake (89% RDA) required to obtain an estimated N balance >50 mg/kg per day were calculated. Significantly lower estimated N balance values were obtained in the studies performed on patients on APD for over 1 year (36.09±54.02 mg/kg per day) than in patients treated for less than 1 year (81.11±64.70 mg/kg per day). In conclusion, based on the values of estimated N balance, we were able to establish adequate dietary protein and energy requirements for children on APD.

Renal hypertension causes left ventricular (LV) hypertrophy leading to cardiomyopathy. Nephrectomy has been utilized to improve blood pressure and prepare for kidney transplantation in the pediatric population. We sought to investigate antihypertensive medication (AHM) requirement and LV mass in patients undergoing nephrectomy with renal hypertension. We performed a single institution retrospective review from 2009 to 2021 of children who have undergone nephrectomy for hypertension. Primary outcome was decrease in number of AHM. Secondary outcomes included change in LV mass and elimination of AHM. LV mass was measured using echocardiogram area-length and linear measurements. Non-parametric analyses were utilized to assess significance. Thirty-one patients underwent nephrectomy. Median age was 12.5 years (0.8–19 years). Median of 3 AHM (range 1–5 medications) were used pre-operatively and patients had been managed for median 2.5 years. Twenty-nine had preoperative echocardiogram. Forty-eight percent of patients had LVH at nephrectomy. Median AHM after surgery was 1 (range 0–4 medications) at 30 days and 12 months, (p < 0.001). By 12 months after nephrectomy, 79.2% of patients had decreased the number of AHM. Eight (26%) patients were on no AHM 30 days after surgery, and 13 (43%) at 12 months. Systemic vascular disease and multicystic dysplastic kidney were the only factors associated with lack of improvement in AHM (p = 0.040). Fourteen patients had pre- and post-operative echocardiogram and 11 (79%) had improvement in LV mass (p = 0.016, 0.035). Nephrectomy is effective in improving LV mass and reducing AHM for children with renal hypertension. Improvement is less likely in patients with systemic vascular disease and multicystic dysplastic kidneys.

The pathogenesis of childhood-onset nephrotic syndrome (NS), disparity in incidence of NS among races, and variable responses to therapies in children with NS have defied explanation to date. In the last 20 years over 50 genetic causes of steroid-resistant nephrotic syndrome (SRNS) have been identified, and at least two disease loci for two pathologic variants of SRNS (focal segmental glomerulosclerosis and membranous nephropathy) have been defined. However, the genetic causes and risk loci for steroid-sensitive nephrotic syndrome (SSNS) remain elusive, partly because SSNS is relatively rare and also because cases of SSNS vary widely in phenotypic expression over time. A recent study of a well-defined modest cohort of children with SSNS identified variants in HLA-DQA1 as a risk factor for SSNS. Here we review what is currently known about the genetics of SSNS and also discuss how recent careful phenotypic and genomic studies reinforce the role of adaptive immunity in the molecular mechanisms of SSNS.

Steroid-resistant nephrotic syndrome (SRNS) is the most severe form of childhood nephrotic syndrome with an increased risk of progression to chronic kidney disease stage 5. Research endeavors to date have identified more than 80 genes that are associated with SRNS. Most of these genes regulate the structure and function of the podocyte, the visceral epithelial cells of the glomerulus. Although individuals of African ancestry have the highest prevalence of SRNS, especially those from Sub-Saharan Africa (SSA), with rates as high as 30–40% of all cases of nephrotic syndrome, studies focusing on the characterization and understanding of the genetic basis of SRNS in the region are negligible compared with Europe and North America. Therefore, it remains unclear if some of the variants in SRNS genes that are deemed pathogenic for SRNS are truly disease causing, and if the leading causes of monogenic nephrotic syndrome in other populations are the same for children in SSA with SRNS. Other implications of this lack of genetic data for SRNS in the region include the exclusion of children from the region from clinical trials aimed at identifying potential novel therapeutic agents for this severe form of nephrotic syndrome. This review underlines a need for concerted efforts to advance the genetic basis of SRNS in children in SSA. Such endeavors will complement global efforts at understanding the genetic basis of nephrotic syndrome.

The management of IgA vasculitis with nephritis (IgAVN) remains controversial because of the difficulty to identify prognostic factors. This study reports the prognosis of children with IgAVN in relation to histological parameters. All children with IgAVN diagnosed between 2000 and 2015 in three pediatric nephrology centers were included. The following histological parameters were analyzed: mesangial proliferation (MP), endocapillary proliferation (EP), crescents, active, or chronic tubular and interstitial lesions (TIa lesions/TIc lesions), and segmental glomerulosclerosis (GS). Clinical and biological data were collected at the time of renal biopsy. The primary endpoint was IgAVN remission defined as a proteinuria < 200 mg/l without renal failure. One hundred fifty-nine children were included with a median age of 7.6 years. Acute glomerular or TI lesions including MP, EP, crescents, and TIa lesions were observed, respectively, in 81%, 86%, 49%, and 21% of patients. Chronic glomerular lesions including GS and TIc lesions were observed in 6 and 7% of patients. Median initial proteinuria was 330 mg/mmol, albuminemia 32 g/l, and eGFR 110 ml/min/1.73 m2. One hundred twelve (70%) patients were in remission at the end of a median follow-up of 37.4 months. Chronic lesions were significantly associated with the absence of remission in multivariate analysis, whereas EP, crescents and TIa were not associated with a poor prognosis. Of children with IgAVN, 30% present a persistent renal disease at the end of a 3-year follow-up. Chronic histological lesions, but not EP or crescents, are associated with a bad prognosis and must be evaluated in IgAVN histological classification.

IgA nephropathy is the world's most common primary glomerulonephropathy. Recent evidence in a rat model implicated excessive production of oxygen-free radicals in the pathogenesis and suggested that vitamin E-treatment ameliorated progression. We studied this antioxidant therapy on the glomerular filtration rate (GFR), proteinuria and hematuria in biopsy-proven IgA nephropathy in children. The duration of treatment or placebo was 2 years, with vitamin E treatment consisting of 400 IU/day in children weighing <30 kg, and twice that dose for those >30 kg. We measured GFR at entry, midpoint and exit. At baseline and at 4-month intervals after randomization, urinary protein/creatinine ratios and urinalysis were examined. The mixed model procedure with log transformation was used in data analysis to test treatment difference as well as the potential time effect. Fifty-five patients were randomized and 38 completed at least 1 year of follow-up. At entry, the clinical characteristics were not different between the treatment and placebo groups. There was a trend toward better preservation of GFR in vitamin E-treated versus placebo patients, 127±50 vs. 112±31 ml/min/1.73 m2, respectively (P=0.09). The urinary protein/creatinine ratio was significantly lower in the vitamin E-treated group vs. placebo; 0.24±0.38 vs. 0.61±1.37 (P<0.013). However, there was no difference in the prevalence of hematuria between the groups. Vitamin E treatment in our study patients was associated with significantly lower proteinuria, but no effect on hematuria. While there was a trend toward stabilization of GFR in the vitamin E-treated patients, long-term treatment and follow-up are needed to determine whether antioxidant therapy is associated with preservation of renal function in IgA nephropathy.

We present a rare case of para-influenza type 1 virus-induced rhabdomyolysis, complicated by acute renal failure (ARF). The child underwent continuous venovenous haemofiltration and has shown full clinical and biochemical recovery. ARF due to rhabdomyolysis in para-influenza type 1 infection in a child has, to the best of our knowledge, not been previously reported.