Dietary microparticles are non-biological, bacterial-sized particles. Endogenous sources are derived from intestinal Ca and phosphate secretion. Exogenous sources are mainly titanium dioxide (TiO2) and mixed silicates (Psil); they are resistant to degradation and accumulate in human Peyer's patch macrophages and there is some evidence that they exacerbate inflammation in Crohn's disease (CD). However, whether their intake differs between those with and without CD has not been studied. We aimed to identify dietary microparticle sources and intakes in subjects with and without CD. Patients with inactive CD and matched general practice-based controls (ninety-one per group) completed 7d food diaries. Intake data for dietary fibre and sucrose were compared as positive controls. All foods, pharmaceuticals and toothpastes were examined for microparticle content, and intakes of Ca and exogenous microparticles were compared between the two groups. Dietary intakes were significantly different between cases and controls for dietary fibre (12 (SD 5) v. 14 (sd 5) g/d; P=0.001) and sucrose (52 (sd 27) v. 45 (sd 18) g/d; P=0·04) but not for Ca. Estimated median TiO2 and Psil intakes (2·5 and 35mg/individual per d respectively, totalling 1012–1013 microparticles/individual per d) were broadly similar to per capita estimates and while there was wide variation in intakes between individuals there was no significant difference between subjects with CD and controls. Hence, if exposure to microparticles is associated with the inflammation of CD, then the present study rules out excess intake as the problem. Nonetheless, microparticle-containing foods have now been identified which allows a low-microparticle diet to be further assessed in CD.

Background and Aims: During the long-term treatment of patients with hereditary haemochromatosis (HH) the authors observed that proton pump inhibitors (PPI) reduced the requirement for maintenance phlebotomy. Gastric acid plays a crucial role in non-haem iron absorption and the authors performed a case review and intervention study to investigate if PPI-induced suppression of gastric acid would reduce dietary iron absorption in C282Y homozygous patients. Methods: Phlebotomy requirements to keep serum ferritin ,50 mg/l before (mean 6.1 (SE 0.6) years) and during (3.8 (0.9) years) administration of a PPI were evaluated in seven patients and a post-prandial study was performed to determine whether PPIs reduce absorption of non-haem iron (14.5 mg) from a test meal in a further 14 phlebotomised patients with normal iron stores. Results: There was a significant reduction (p,0.001) in the volume of blood removed annually before (2.5 (0.25) l) and while taking (0.5 (0.25) l) a PPI. Administration of a PPI for 7d suppressed absorption of nonhaem iron from the meal as shown by a significant reduction (all p,0.01) in: area under the serum curve (2145 (374) versus 1059 (219)), % recovery of administered iron at peak serum iron (20.5 (3.2) versus 11.0 (2.0)%) and peak serum iron (13.6 (2.4) vs 6.1 (1.2) mmol/l) (all values are before vs during PPI). Conclusions: Administration of a PPI to patients with HH can inhibit the absorption of non-haem iron from a test meal and the habitual diet.

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Patients with Crohn's disease (CD) often experience Fe deficiency (ID) and frequently alter their diet to relieve abdominal symptoms. The present study set out to assess whether patients with CD have dietary habits that lead to low Fe intakes and/or reduced bioavailable Fe compared with control subjects. Patients with asymptomatic CD were matched to controls (n91/group). Dietary intakes of Fe and contributions from different food groups were compared using a 7 d food diary. Promoters and inhibitors of non-haem Fe absorption were investigated and a recently published algorithm was applied to assess bioavailable Fe. Fewer patients than controls met the reference nutrient intake for Fe (32 % CD patientsv. 42 % controls). Overall, patients had significantly lower mean Fe intakes (by 2·3 mg/d) and Fe density (by 0·26 mg/MJ (1·1 mg/1000 kcal)) compared with controls (bothP<0·001). Differences were mainly due to a preference among CD patients for low-fibre non-Fe fortified cereals, particularly breakfast cereals. In particular, control subjects had higher Fe intakes than matched CD subjects for men (P<0·001) and women less than 50 years (P=0·03). Intakes of both ascorbic acid (P<0·001) and phytic acid (P<0·01), but not animal tissue (P=1·0), were lower in patients with CD, but these had no overall effect on the predicted percentage of bioavailable Fe. Thus total bioavailable Fe was reduced in patients with CD due to lower intakes (P<0·01). Dietary Fe intakes are low in CD patients, which may contribute to an increased risk of ID and anaemia. Changing dietary advice may compromise perceived symptoms of the disease so the need for Fe supplementation should be carefully considered.

Background/Aim: To report our experience of paediatric renal transplantation at Great Ormond Street and Royal Free Hospitals since the inception of the programme. Methods: Retrospective review of the patient and transplant survival and influencing factors in the 300 children transplanted between 1973 and 2000. Results: 300 children had received a total of 354 transplants; 56 were living-related donations. The median age at transplantation was 10.3 (range 1.4–17.9) years. Forty-four percent had congenital structural abnormalities of the urinary tract. Forty-six children required a second and 8 a third transplant before transfer to an adult unit. The overall patient survival at 5, 10, and 20 years was 97, 94, and 72%, respectively. In the overall cohort, the donor type (deceased donor or living-related donor) did not affect mortality, nor did age at transplantation, but those transplanted before 5 years of age had a significantly shorter post-transplant survival time (p < 0.0001). Transplant survival (first transplant) for deceased and living-related donors was 66 and 87% at 5 years (p < 0.01), 51 and 54% at 10 years, and 36% at 20 years (deceased-donor transplants only). Although the overall transplant survival was inferior in children transplanted before 2 years of age (p < 0.03), in the most recent cohort (1990–2000), age did not affect the outcome. On multiple regression analysis, the only predictor of transplant survival was the era of transplantation (p < 0.001). The median final height was within the normal range for males and females; 7 patients received growth hormone after transplantation. Conclusions: The outlook for successful transplantation is improving, and in the last decade was unaffected by age at transplantation. The survival of living-related donor transplants is superior to deceased-donor transplants for the first 5 years. From the above data, we can predict that a 10-year-old child receiving a renal transplant in 2000 and on ciclosporin-based immunosuppression can expect a transplant half-life of 13.1 years from a living-related donor and one of 10.8 years from a deceased-donor transplant.

As the prevalence of children on renal replacement therapy (RRT) increases world wide and such therapy comprises at least 2% of any national dialysis or transplant programme, it is essential that paediatric nephrologists are able to advise families on the possible outcome for their child on dialysis. Most children start dialysis with the expectation that successful renal transplantation is an achievable goal and will provide the best survival and quality of life.

Graft thrombosis is an important cause of early (<4 weeks) renal graft loss. Reports show that heparin reduces the incidence of early renal allograft thrombosis. Routine peri-operative administration of unfractionated heparin was introduced in our unit in 1994. We conducted a retrospective study of 254 transplants, undertaken in children, between 1987 and 2000. There were 126 children who did not receive heparin (group 1) and 128 who did (group 2). Recipient characteristics and immunosuppression were similar in both groups. The incidence of graft loss secondary to thrombosis was compared between the groups. Variables previously identified with increased risk of graft loss, including donor age, recipient age, cold ischaemia time (CIT), multiple donor vessels, surgical complications, and side of graft donation, were examined using logistic regression. Thrombosis occurred in 14 grafts in group 1 and 11 grafts in group 2 (odds ratio 0.7, 95% confidence interval 0.3-1.6, P=not significant). The mean time to graft loss was similar in groups 1 and 2 (6.6, SD 3.9, range 2-12 days and 7.9, SD 4.4, range 1-14 days, respectively) ( P=0.445). Young recipient age ( P=0.006), young donor age ( P=0.009), increasing CIT ( P=0.007), and surgical complications ( P=0.002) increased the risk of graft thrombosis. A reduction in the incidence of early renal allograft thrombosis upon introduction of heparin was not demonstrated.

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