Late first acute rejection in pediatric kidney transplantation: A North American Pediatric Renal Trials and Collaborative Studies special study.

Rates of early AR in pediatric kidney transplantation have declined in every era but the most recent NAPRTCS cohort has shown an increase in late first AR rates. We hypothesized this was due to an increased proportion of deceased donor utilization and early steroid taper utilization. Using the NAPRTCS database, we compared the most recent three cohorts of patients transplanted between 2002-2006, 2007-2011, and 2012-2017. To determine variables that predict late first AR, we used two multivariable models: a standard Cox regression model and LASSO model. From the LASSO model, deceased donor source (P = .002), higher recipient age (P = .019), black race (P = .010), and transplant cohort 2012-17 (P = .014) were all significant predictors of more late first AR. On standard Cox regression analysis, those same variables, minus donor source, were significant, in addition to mycophenolates usage (P = .007) and lower eGFR at 12 months (P = .02). The most recent 2012-2017 cohort remains an independently significant risk factor for late first AR, suggesting unmeasured variables. Further research is needed to determine whether these higher late first AR rates will impact long-term graft survival in the most recent cohort.

The light at the end of the tunnel: an unusual case of acute kidney injury in a pediatric patient: Answers.

Monoclonal gammopathies are a rare diagnosis in pediatric patients. A 19-year-old female patient with past medical history of hypogammaglobulinemia and natural killer cell deficiency and stage III follicular lymphoma, in remission, presented with a right-sided pneumonia, noted to have acute kidney injury and proteinuria. Complement C3 and C4 levels were normal. Anti-double-stranded DNA antibodies, antinuclear antibodies, anti-extractable nuclear antigen antibodies, and antineutrophil cytoplasmic antibodies were negative. A renal biopsy showed numerous fractured tubular casts that were periodic acid-Schiff and silver-stain negative and fuchsinophilic on trichrome stain, with associated giant cells, tubulitis, acute tubular injury, and tubular rupture. The tubular casts had 3+ staining for lambda light chains and 0-1+ staining for kappa light chains. These findings were consistent with light chain cast nephropathy (LCCN). Serum free light chains, serum immunofixation, urine protein electrophoresis, and urine immunofixation studies supported the renal biopsy diagnosis of LCCN. A bone marrow biopsy showed normal trilineage hematopoiesis and also revealed an atypical B cell population detected by flow cytometry. Pathology specimens from lesions in the distal small bowel were characteristic of diffuse large B cell lymphoma (DLBCL). Chemoreduction therapy followed by chemotherapy was initiated for the DLBCL. Three months after initiation of chemotherapy, the patient's creatinine has improved by > 50%. The likely cause of her LCCN was the new diagnosis of a DLBCL. Other risk factors include her history of hypogammaglobulinemia, natural killer (NK) cell deficiency, community-acquired pneumonia, and prior follicular lymphoma. Our patient may be the youngest reported case of LCCN. Treatment of LCCN is based on treating the underlying clonal plasma cell or B cell proliferation, typically with chemotherapy.

Amino acid clearance during acute metabolic decompensation in maple syrup urine disease treated with continuous venovenous hemodialysis with filtration.

OBJECTIVE: Assessment of amino acid clearances by continuous venovenous hemodialysis with filtration in treatment of a metabolic decompensation in acute maple syrup urine disease. DESIGN: Single patient assessment. SETTING: Pediatric intensive care unit. PATIENTS: A 10-yr-old male with known maple syrup urine disease (branched chain alpha-ketoacid dehydrogenase deficiency) with metabolic decompensation due to an acute viral illness, characterized by altered mental status, progressive obtundation, and severe acidosis. INTERVENTIONS: Continuous venovenous hemodialysis with filtration. MEASUREMENTS AND MAIN RESULTS: Continuous venovenous hemodialysis with filtration was instituted with both filtration (500 mL/m(2)/hr) and dialysis (1000 mL/m(2)/hr) utilized, allowing rapid correction of systemic ketoacidosis while providing amino acid clearance. Amino acid clearance was measured at initiation and at 24 hrs into therapy. The procedure was well tolerated, with near normal mental status within 12 hrs and resumption of enteral feedings. During the 24-hr period of continuous venovenous hemodialysis with filtration, serum leucine levels fell from 2352 to 381 micromoles/L, isoleucine fell from 626 to 164, and valine fell from 1117 to 228. Leucine, isoleucine, and valine clearance rates averaged 13.1, 12.8, and 13.2 mL/min, respectively, and were constant during the 24 hrs of treatment. Clearance of other amino acids during this period did not vary significantly between cationic, anionic, neutral, or hydrophobic amino acids. CONCLUSIONS: Continuous venovenous hemodialysis with filtration provides an effective therapeutic alternative to intermittent hemodialysis during acute metabolic decompensation in maple syrup urine disease.