Gad Kainer

Loss of appetite and poor growth are common in children with chronic kidney disease (CKD), and changes in smell and/or taste function may be responsible, but the hypothesis has not been proven. This aims of this prospective age- and gender-controlled study were to determine whether: (1) changes in smell and taste function occur in children with CKD; (2) smell or taste dysfunction are associated with estimated glomerular filtration rate (eGFR); (3) there is an association between smell or taste loss and body mass index (BMI). The study cohort consisted of 72 children of whom 20 were CKD stage 3–5 patients, 12 were CKD stage 2 patients, 20 were clinical controls (CC) and 20 were healthy children (HC). The CKD patients and clinical controls were recruited from Sydney Children’s Hospital and The Children’s Hospital, Westmead, and healthy controls were recruited from a local school. Scores for each group from taste and smell chemosensory function tests were compared, and their relationship with renal function and BMI investigated. The CKD stage 3–5 group had a significantly lower taste identification score (85.6%, P < 0.001) than the CC (94.8%) and HC (94.8%) groups, with almost one third of the children in the CKD stage 3–5 group exhibiting taste loss. Decreased taste function was associated with decreased eGFR (r = 0.43, P < 0.01), but no association between BMI and taste function was found (r = 0.001, P > 0.9). Odour identification scores were not different; however, there was a positive relationship with BMI (r = 0.427, P = 0.006). We conclude that a loss of taste can occur in children with CKD and that when it occurs, it worsens as eGFR declines and is found early in kidney disease.

A renal length discrepancy (RLD) of more than 10 mm by ultrasound (US) is accepted as a potential indicator of an underlying renal pathology; however, there are few supporting data for this in children. Our objective was to determine a cutoff at which RLD on US is a reliable predictor of dimercaptosuccinate acid (DMSA) scan abnormality. We present data from 90 patients who had both renal US and a DMSA scan, as well as DMSA scan results compared with bipolar RLD by US. Positive (PPV) and negative (NPV) predictive values were calculated for renal RLD from 6 to >10 mm. The left kidney was longer in 56%, whereas the right kidney was longer in 37%; their lengths were equal in 8%. For children at all ages, a left kidney longer than the right by ≥10 mm or a right kidney longer than the left by ≥7 mm gave a PPV for DMSA abnormality of 79% and 100%, respectively. In children older than 4 years, if the right kidney was longer by ≥7 mm or if the left kidney was longer by ≥10 mm, the PPVs for DMSA abnormality were 100% and 63%, respectively. In children younger than 4 years, when the right kidney was longer by ≥6 mm or the left was kidney longer by ≥10 mm, the PPV were 86% and 100%, respectively. Thus, children with a right kidney longer than the left by even <10 mm is a reliable predictor of an abnormal DMSA scan.

Objectives Hypertension in children may be defined by blood pressure elevated above the 95th percentile according to sex and age. Population data for ambulatory blood pressure provide different age-related and sex-related threshold limits to office-derived data. We sought to determine whether, when using ambulatory blood pressure monitoring in a clinical setting, changing 95th percentile threshold limit sets from office-derived to ambulatory blood pressure-derived would lead to different diagnostic decisions. Methods Three nephrologists who were blinded as to patient identity and limit setting method reported on 42 ambulatory blood pressure records from a mixed group of patients aged 5–18 years by using both office-derived threshold limits for the 95th centile of blood pressure and ambulatory blood pressure-derived limits. Decisions regarding the presence or absence of hypertension were compared for each patient according to the limit set. Results Thirty-five (83%) patients were considered to be hypertensive when office-derived threshold limits were used and 20% (P=0.005) fewer records were reported as showing hypertension when ambulatory blood pressure-derived threshold limits were used. When ambulatory blood pressure limits were applied, there were fewer records with an awake systolic blood pressure load >50% (P=0.004) and the average awake systolic blood pressure load was significantly lower (P<0.001). Conclusion Ambulatory blood pressure normative data tend to provide higher blood pressure limits for age and sex. Consequently, when ambulatory blood pressure data are used to set threshold limits, clinical decisions based on ambulatory blood pressure may be different than when office limits are used. These findings demonstrate the importance of using the most appropriate limit sets to analyze ambulatory blood pressure and when interpreting ambulatory blood pressure-based research.

The use of ambulatory blood pressure monitoring (ABPM) can improve the accuracy of paediatric BP measurement and may better correlate with end-organ injury than office BP measurement. However, the interpretation of ABPM may be influenced by several variables. We sought to ascertain the agreement among three paediatric nephrologists when reporting 92 ABPM sessions performed on patients aged 5 to 18 years. All three nephrologists were in agreement on the presence or absence of hypertension in 64% of cases. They were less likely to concur about records where hypertension was borderline or if the ABP record contained fewer BP readings. These results highlight the need for evidence-based consensus regarding the interpretation of ABPM in children.

Renal cortical studies were performed in 19 children with renal transplants. There were 10 normal studies and 9 abnormal studies, 8 of which showed multiple large focal peripheral cortical defects. The following factors showed a positive correlation: (a) the ischemia time of the transplant kidney was significantly shorter in patients with normal studies; (b) cadaver grafts were more likely to have abnormal scan appearances than living related donor grafts; and (c) in four of the five patients with double renal arteries, the scans were abnormal in multiple sites. A possible pathophysiologic mechanism to explain these scan appearances is asymptomatic segmental graft infarction secondary to progressive vascular disease. These infarcts may be a long-term sequela of ischemic insult at the time of or prior to the insertion of the renal allograft.

A 5-year-old girl suffered Campylobacter jejuni enteritis. Over the ensuing weeks she developed glomerulonephritis, pulmonary hemorrhage and anemia. Renal biopsy revealed immune-complex mediated, crescentic glomerulonephritis. Campylobacter jejuni antigen was identified in the glomeruli suggesting a causal role of Campylobacter jejuni in the disease process.