Role of foetal kidney size on kidney function in childhood: the born in bradford cohort renal study.

BACKGROUND: Foetal and early childhood development contributes to the risk of adult non-communicable diseases such as hypertension and cardiovascular disease. We aimed to investigate whether kidney size at birth is associated with markers of kidney function at 7-11 years. METHODS: Foetal kidney dimensions were measured using ultrasound scans at 34 weeks gestation and used to derive kidney volume (cm3) in 1802 participants in the Born in Bradford (BiB) birth cohort. Blood and urine samples were taken from those who participated in the BiB follow-up at 7-11 years (n = 630) and analysed for serum creatinine, cystatin C, urea, and urinary albumin to creatinine ratio (ACR), protein to creatinine ratio (PCR) and retinol binding protein (RBP). Estimated glomerular filtration rate (eGFR) was calculated using Schwartz creatinine only and combined with cystatin C, and cystatin C only Zappitelli and Filler equations. Linear regression was used to examine the association between foetal kidney volume and eGFR, ACR, PCR and blood pressure, unadjusted and adjusted for confounders. RESULTS: Kidney volume was positively associated in adjusted models with eGFR calculated using Schwartz combined (0.64 ml/min diff per unit increase in volume, 95% CI 0.25 to 1.02), Zappitelli (0.79, 95% CI 0.38 to 1.20) and Filler (2.84, 95% CI 1.40 to 4.28). There was an association with the presence of albuminuria but not with its level, or with other urinary markers or with blood pressure. CONCLUSION: Foetal kidney volume was associated with small increases in eGFR in mid-childhood. Longitudinal follow-up to investigate the relationship between kidney volume and markers of kidney function as children go through puberty is required.

Smaller kidney size at birth in South Asians: findings from the Born in Bradford birth cohort study.

BACKGROUND: Rates of advanced chronic kidney disease and renal replacement therapy are higher in South Asian than in white British populations. Low birth weight is also more frequent in South Asian populations and has been associated with increased risks of kidney disease, perhaps due to a reduced nephron endowment. METHODS: Using ultrasound scans at 34 weeks of gestation, we measured fetal kidney dimensions (transverse and anteroposterior diameters, length and circumference) and derived volume in a random sample of 872 white British and 715 South Asian participants in the Born in Bradford cohort study. Kidney measurements were compared between ethnic groups. RESULTS: Birth weight for gestational age at 40 weeks was 200 g less in South Asian babies compared with white British babies. The mean kidney volume for gestational age was 16% lower in South Asian than in white British babies [8.79 versus 10.45 cm(3), difference 1.66 cm(3) (95% confidence interval 1.40-1.93, P < 0.001)]. The difference was robust after adjustment for maternal age, socio-economic factors, marital status, body mass index, smoking and alcohol use in pregnancy, parity, baby's gender and birth weight for gestational age [adjusted difference 1.38 cm(3) (0.97-1.84), P < 0.001]. There were smaller reductions in other fetal measures. CONCLUSION: South Asian babies have smaller kidneys compared with white British babies, even after adjusting for potential confounders including birth weight. This finding may contribute to increased risks of adult kidney disease in South Asian populations.

Ethnic differences in kidney function in childhood: the Born in Bradford Cohort Renal Study.

Background: Endstage kidney failure rates are higher in South Asians than in White Europeans. Low birth weight is associated with adult chronic kidney disease and is more common in South Asians. Foetal kidney size was smaller in South Asians in the Born in Bradford (BiB) birth cohort. As part of BiB follow up, we aimed to investigate if there were ethnic differences in kidney function and blood pressure in early childhood and whether this was different by foetal kidney size. Methods: Serum creatinine, cystatin C, urea, and urinary albumin to creatinine ratio (ACR), protein to creatinine ratio (PCR) and retinol binding protein (RBP) were analysed in blood and urine samples from those who participated in the BiB follow-up at 7-11 years. Ethnicity was categorised by parental self-report as White European and South Asian. Estimated glomerular filtration rate (eGFR) was calculated using Schwartz, and cystatin C Zappitelli and Filler equations. Linear regression was used to examine the association between ethnicity and eGFR, PCR and blood pressure. Results: 1591 children provided blood (n=1403) or urine (n=625) samples. Mean eGFR was 92 ml/min/1.73m 2 (standard deviation (SD) 9) using Schwartz (n=1156) and 94 (SD 11) using Zappitelli (n=1257). CKD prevalence was rare (1 with eGFR <60 ml/min/1.73m 2, 14 (2.4%) had raised ACR (>2.5 mg/mmol in boys/3.5 mg/mmol in girls). Diastolic blood pressure was higher in South Asian children (difference 2.04 mmHg, 95% CI 0.99 to 3.10) but was not significant in adjusted analysis. There was no evidence of association in adjusted models between ethnicity and any eGFR or urinary measure at this age. Conclusions: There was no evidence of significant ethnic differences in kidney function at pre-pubertal age despite differences in kidney volume at birth. Longitudinal follow-up is required to track ethnic patterns in kidney function and blood pressure as children develop through puberty.

Indo-Asian experience of renal transplantation in Yorkshire: results of a 10-year survey.

BACKGROUND: There is a significant Indo-Asian community in Yorkshire. The rate of end-stage renal failure is disproportionately high in this ethnic group. There have not been any large studies of this ethnic minority's access to and outcome after cadaveric renal transplantation. METHODS: Three local cohorts were studied: 846 adult patients (9.1% Asian) who started renal replacement therapy 1990-1994, 822 adult patients (11.4% Asian) registered on the transplant waiting list 1985-1994; and 608 adult patients (8.6% Asian) transplanted 1985-1994. RESULTS: At 1 year from the start of dialysis, 34% of Asian and 31% of non-Asian patients were registered onto the waiting list. After adjustment for age in a multifactorial model, Asian patients were less likely to be listed (relative risk, 0.68), although this did not reach statistical significance (P=0.06). There was a significant difference in graft rate between the groups: at 3 years 72% of non-Asians versus 55% of Asians had been transplanted from the waiting list (P<0.001). For those transplanted, HLA matching was superior for white patients: 34% versus 20% of pairings achieved a 000 mismatched or favorably matched graft (P<0.05). Transplant survival at 5 years was 71% in the non-Asian and 58% in the Asian patients (P=0.07). Asian cadaveric donation was identified in 2 of 608 transplants during a 10-year period. CONCLUSION: Asian patients gained access to the transplant waiting list at a similar rate to the non-Asian white majority. Because of difficulties with HLA matching, Asian patients were significantly disadvantaged in receiving a transplant once listed, and there was a trend towards reduced posttransplant survival. Cadaveric donation was uncommon from within the Asian community; the reasons for which are likely to be complex.

P-ANCA positive renal vasculitis in association with renal cell carcinoma and prolonged hydralazine therapy.

Renal cell carcinoma and hydralazine drug therapy has each been reported as rare associations with pauci-immune renal vasculitis. We report a patient in whom both factors were operative simultaneously. A middle-aged man on long term hydralazine therapy presented with advanced renal failure. Serum was strongly positive for P-ANCA with high anti-myeloperoxidase (MPO) titre and renal biopsy showed focal necrotizing glomerulonephritis. A renal mass was identified on scanning and at left nephrectomy a large renal cell carcinoma was removed. In spite of an apparently curative operation and discontinuation of hydralazine, P-ANCA remains strongly positive, he has had no recovery of renal function and has progressed to dialysis dependence.