Pediatric Nephrology最新文献

Lesch-Nyhan syndrome (LNS) is a rare X-linked recessive disorder caused by complete deficiency of hypoxanthine-guanine phosphoribosyltransferase (HPRT). While the disease is classically characterized by severe neurological manifestations and self-injurious behavior, kidney involvement is an underrecognized but important aspect of the clinical spectrum.

Background: Tacrolimus is a cornerstone of lifelong immunosuppressive therapy to prevent acute rejection post-kidney transplantation. Tacrolimus intra-patient variability (IPV) is characterized by several pharmacokinetic metrics, including the standard deviation (SD) of tacrolimus troughs, coefficient of variation (CV%), dose-normalized concentration (DNC), and time in therapeutic range (TTR). This study aimed to investigate the influence of TTR, alongside other IPV metrics, on the incidence of acute rejection in the first year after kidney transplantation.

Methods: This single-center retrospective study evaluated the relationship between IPV measures including coefficient of variation (CV%), standard deviation (SD), dose-normalized concentration (DNC), time in therapeutic range (TTR), and acute rejection during the first post-transplant year in 100 pediatric kidney recipients.

Results: Patients were stratified by TTR into two subgroups: TTR < 78% (n = 80) and TTR ≥ 78% (n = 20). The mean CV% of tacrolimus concentration was 37.1 ± 16.6%, with significantly higher variability observed in those with rejection (p = 0.031). Longitudinal analysis showed that differences in trough levels between TTR groups became evident after 3 months (p < 0.001). Multivariable modeling demonstrated that rejection risk was independently associated with higher age (p = 0.002) and post-transplant period beyond 3 months (p = 0.004), rather than TTR itself.

Conclusions: In pediatric kidney transplant patients, the rejection risk was significantly associated with the magnitude of CV% rather than TTR. Special attention is warranted for therapeutic drug monitoring, especially beyond 3 months post-transplant, due to the increased risk of rejection compared to earlier stages post-transplantation.

A 3-year-old boy presented with dark-colored urine for 4 months. His history was negative for infections, but he was taking oral methylcobalamin treatment for a persistent deficiency. His parents were first-degree cousins, and a female cousin had proteinuria of unknown etiology. A physical examination and laboratory examination revealed no abnormalities except for non-orthostatic nephritic proteinuria and low levels of vitamin B12. Albumin was the main protein in the urine. Kidney biopsy showed nonspecific changes. Genetic analysis identified a homozygous pathogenic AMN mutation, confirming Imerslund-Grâsbeck syndrome (IGS). Angiotensin-converting enzyme inhibitor was prescribed but discontinued due to stable protein levels. After 4 years, kidney function remained stable. Imerslund-Grâsbeck syndrome is a rare autosomal recessive disorder that affects vitamin B12 and protein, particularly albumin absorption. While typically presenting with megaloblastic anemia, AMN mutations show variable phenotypes. Proteinuria is resistant to ACE inhibitors, and currently, there is no specific treatment.

Background: Studies demonstrate that elevated renin is associated with adverse outcomes in critical illness. We aimed to evaluate whether serum renin enhances acute kidney injury (AKI) risk stratification in critically ill children.

Methods: A prospective, observational pilot study of PICU patients from the TAKING FOCUS 2 (TF2) study for whom direct renin levels were measured within 48 h of PICU admission. TF2 employed the Renal Angina Index (RAI) (RAI +  ≥ 8) and urine neutrophil gelatinase-associated lipocalin (uNGAL; uNGAL +  ≥ 150 ng/mL) to aid in the risk prediction of severe AKI (sAKI; ≥ KDIGO stage 2) at PICU day 2-4. We examined renin levels across TF2 algorithm branchpoints, assessed the additive predictive performance of renin ≥ 100 pg/mL for sAKI, and assessed associations between elevated renin and outcomes.

Results: Among 107 patients (53% male, median age 8 [2-15] years), 30 (28%) were RAI-, 77 (72%) were RAI+ , and 43 (40%) had sAKI. Median renin concentration was 61.3 [16.5-143.8] pg/mL, increasing progressively across sAKI risk strata: RAI+  > RAI- (70.4 [24.7-182.1] vs. 33.3 [11.2-93.9] pg/mL, p = 0.006) and RAI+ /uNGAL +  > RAI+ /uNGAL- (103.7 [47-507] vs. 42.1 [15.9-125] pg/mL, p = 0.01). Patients with sAKI had higher renin (102 [35.2-374] vs. 41.6 [11.4-111] pg/mL, p = 0.002), including after adjustment for covariates (p = 0.001). Renin ≥ 100 pg/mL was independently associated with mortality (aOR 4.0, 95% CI 1.06-14.9, p = 0.041). Adding renin ≥ 100 pg/mL to RAI+ /uNGAL+ improved specificity (93% from 84%) and PPV (81% from 77%) of day 2-4 sAKI prediction.

Conclusions: Serum renin levels increase progressively across sAKI risk strata and appear to enhance sAKI prediction.

Background: The percutaneous insertion of a peritoneal dialysis (PD) catheter by a nephrologist offers a plausible alternative to surgical insertion, improving access to dialysis. We report the experience of the paediatric nephrology unit in Dakar, Senegal, initiating PD for children with acute kidney injury (AKI), using a haemodialysis catheter inserted via a modified Seldinger technique. This approach was chosen due to its availability and cost-free provision, addressing resource constraints effectively.

Methods: This pilot case series study describes a cohort of nine children with AKI managed using this innovative technique between March and October 2024 in Dakar, Senegal.

Results: Nine children, including two neonates with life-threatening AKI, were included. Mean age was 4.5 years, with a male-to-female ratio of 1.25. Infections accounted for 44.4% (n = 4) of the cases. Catheter insertion in the peritoneal cavity was successful in eight out of nine cases; one mispositioned catheter (case 9) was removed and excluded from analysis. During the first week, no cases of bleeding or dialysate leakage occurred at the insertion site. Peritonitis was observed in two cases after > 2 weeks. Of the eight children with successful catheter placement, five stabilised on PD (62.5%); and of those five, two (40%) fully recovered kidney function. Three children (37.5%) succumbed to septic shock from the underlying infection.

Conclusions: Within the "Saving Young Lives" programme, our small case series showed that a haemodialysis catheter can feasibly deliver paediatric emergency PD in Dakar. Safety, efficacy, and programme-level impact must be confirmed in larger, multi-centre studies before wider training and implementation.

Intravascular contrast media plays an important role in improving tissue and vascular characterisation in diagnostic imaging and image-guided intervention. Iodinated contrast media are commonly used in imaging modalities which utilise ionising radiation and gadolinium-based contrast agents (GBCA) in magnetic resonance imaging. Intravascular use of iodinated contrast medium is associated with contrast-induced acute kidney injury and GBCA with nephrogenic systemic fibrosis, both of which can lead to potentially significant adverse outcomes in patients with kidney impairment. However, most studies in the literature focus on adults and the evidence in the paediatric population is scarce. In this review, we aim to examine the consensus guidelines and studies in the paediatric population who require intravascular iodinated contrast media and GBCA. At the end, we propose an algorithm to approach the use of intravascular contrast media in children who need to undergo diagnostic imaging or image-guided intervention.

Hemolytic uremic syndrome (HUS) associated with Shiga toxin-producing Escherichia coli (STEC) infection remains a major individual and public health challenge throughout the world causing substantial personal, social, and economic burdens. In Western countries, bloody diarrhea (BD) in children is related to STEC infection in at least 6% of cases (rising to 15-20% in summer). This infection may turn into STEC-HUS in about 15% of patients. The widespread use of molecular microbiology leads to the diagnosis of STEC infection before the onset of HUS in an increasing number of patients. The anticipation of the diagnosis creates a window of preventive and/or therapeutic opportunities that include rehydration of dehydrated patients and/or volume expansion that have both proven to mitigate the severity of HUS. Traditionally, antibiotics are not recommended in STEC infections, but recent data suggest a promising potential preventive role for bacteriostatic agents (e.g., azithromycin), if they are given early in the course of the infection. It is recommended to test all children with BD for Shiga toxin (Stx) encoding genes, actively infuse Stx-positive patients with isotonic crystalloid solutions and carefully monitor them with urine dipstick for hemoglobinuria to early identify those who might eventually develop HUS. The suggested approach will increase the detection of STEC-infected patients thus enhancing our knowledge of the mechanisms of disease spreading. The early diagnosis of STEC infection combined with the mentioned therapeutic opportunities will hopefully decrease the number of children suffering from HUS, its case fatality rate and/or improve its short- and long-term outcomes.

Background: Ultrasonography (US) is the preferred first-line imaging modality for suspected urinary calculi in children because it is non-invasive and avoids radiation exposure. However, its diagnostic accuracy compared with non-contrast computed tomography (CT) remains variable, depending on stone location and secondary findings. This study evaluated the diagnostic accuracy of US for pediatric urinary calculi, using CT as the reference, and explored the predictive role of secondary sonographic markers.

Methods: We retrospectively analyzed 47 children (0-18 years) who underwent both US and non-contrast CT for suspected urinary tract calculi (June 2023-2025). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of US were calculated separately for kidney and ureteral calculi. Logistic regression assessed whether hydronephrosis or ureteral dilatation predicted CT-confirmed stones.

Results: US showed moderate specificity (84.8%) and NPV (82.4%) overall but limited sensitivity (57.1%) and a high false-negative rate (42.9%) for kidney calculi. Performance was notably poorer for ureteral calculi, with very low sensitivity. Hydronephrosis was significantly associated with ureteral calculi, increasing stone likelihood nearly seven-fold (OR 7.02, 95% CI 1.25-39.40; p = 0.027), while it was not predictive for kidney stones. Ureteral dilatation was not predictive for either kidney (OR 0.34, 95% CI 0.03-3.18; p = 0.349) or ureteral calculi (OR 0.57, 95% CI 0.06-5.41; p = 0.628).

Conclusions: US remains a valuable first-line tool for pediatric urinary calculi but shows limited sensitivity, particularly for ureteral stones. CT should be reserved for cases with inconclusive or negative US but persistent clinical suspicion or secondary signs suggestive of obstruction, ensuring diagnostic accuracy while minimizing unnecessary radiation exposure.