Diabetes mellitus following paediatric renal transplantation: a single centre experience.

BACKGROUND/AIMS: Post-transplant diabetes mellitus (PTDM) has a variably reported incidence of 4-41% among adults and children. We describe our recent experience of four children with PTDM in a paediatric renal transplantation centre. METHODS: We undertook a retrospective analysis of the glycaemic status of all paediatric patients undergoing renal transplantation at our centre in the 2-year study period. The clinical features and investigations of those who developed PTDM were further reviewed. RESULTS: Five episodes of PTDM occurred in 4/32 children. There was a variable onset and a wide range of symptoms. Investigations revealed a combination of insulinopenia with peripheral insulin resistance. Insulin therapy was required for variable durations with resolution of PTDM in four episodes. PTDM did not adversely affect the renal graft function. CONCLUSION: PTDM requires increased awareness among paediatric nephrologists and endocrinologists for early recognition and prompt effective intervention.

The effects of intravenous tobramycin on renal tubular function in children with cystic fibrosis.

BACKGROUND: Tobramycin, used to treat respiratory exacerbations in cystic fibrosis (CF), is also a renal tubular toxin. Tubular dysfunction leads to increased urinary levels of the proximal tubular lysosomal enzyme, N-acetyl-beta-D-glucosaminidase (NAG) and the proximal tubular protein, retinol-binding protein (RBP). Hypermagnesuria and resulting hypomagnesaemia are indicative of more severe tubular damage, occasionally seen following repeated courses of intravenous tobramycin. Using these biochemical markers we studied the effect of a 2-week course of this agent on tubular function. METHODS: Twenty-two children (11 boys) with CF were studied. Median age = 10.9 years, range 3.1-16.4 years. All had a normal predicted glomerular filtration rate (pGFR). They received tobramycin 3 mg/kg/dose tds. Urinary NAG, RBP, creatinine and plasma magnesium and creatinine were assayed: a) immediately before commencing tobramycin, b) immediately following the course, c) 4 weeks after the end of the course. RESULTS: Mean log UrNAG and UrRBP rose significantly between time points a) and b) before falling to almost pre-treatment levels by time c). Using two way ANOVA analysis the results for UrNAG and UrRBP were both highly statistically significant (p<0.0001). Paired t-tests on the logged values revealed highly significant differences between all time points for UrNAG and in the case of UrRBP for all other than a) compared to c). In all patients plasma magnesium and pGFR remained within normal limits. CONCLUSIONS: Intravenous tobramycin produces acute tubular injury, which showed evidence of almost complete recovery after 4 weeks. The insult to the tubules was not sufficient to produce hypomagnesaemia in our study group. To assess cumulative tubular damage in more detail it would be necessary to repeat this study after further courses of tobramycin. We recommend monitoring plasma magnesium during courses of intravenous tobramycin.

Does antenatal pelvic dilation predict renal scarring?

Moderate antenatal renal pelvic dilation (5-15 mm) may suggest vesicoureteric reflux, but it is not known to predict renal scarring. Dimercaptosuccinic acid scans on such children aged over 4 years showed a scarring rate (0/133 boys, 1/56 girls) similar to our local population. Investigation and treatment of moderate dilation may not be required.

Selective renal embolisation for renovascular hypertension?

An 11 year old girl developed hypertensive encephalopathy and renal failure from reflux nephropathy. Resection of her shrunken left kidney did not control her hypertension. Two selective arterial embolisations of the scarred right lower pole produced only transient benefit, but a heminephrectomy gave good control. Embolisation may delay definitive treatment.

Oral health in children with renal disease.

Thirty-eight children (aged 2-16 years) attending a regional kidney unit had a full clinical and radiological dental examination. Twenty had previously undergone a renal transplant, 11 had chronic renal failure and 7 had other renal diseases. Periodontal disease was uncommon The presence of gingival hyperplasia (gum overgrowth), as recorded in 22 of the children, did not show any relationship with the use of immunosuppressant therapy. However, gingival overgrowth was so excessive in 2 patients that surgical removal was required. The prevalence of dental caries was low. Enamel defects were common, and of an unusual pattern, with a much higher prevalence of diffuse opacities and enamel hypoplasia than in the normal child population, 83% and 22%, respectively. This increased prevalence is probably due to disordered calcium and phosphate metabolism. The prevalence of these defects may reflect an early onset of renal disease, since there were a number of very young children in the programme. Dental and medical care should be closely integrated for children with renal disease to avoid the undesirable dental sequelae of, in particular, gingival overgrowth, carcinoma and enamel hypoplasia.

Hyperammonaemia due to Klebsiella infection in a neuropathic bladder.

A boy with a neuropathic bladder and a single hydronephrotic kidney developed hyperammonaemic encephalopathy during a urinary tract infection with Klebsiella oxytoca. Although particularly associated with Proteus infections and prune belly syndrome, hyperammonaemia can complicate infection with any urease-producing bacteria if there is urinary stasis.