The first pilot study of expanded newborn screening for inborn errors of metabolism and survey of related knowledge and opinions of health care professionals in Hong Kong

INTRODUCTION

Newborn screening is important for early diagnosis and effective treatment of inborn errors of metabolism (IEM). In response to a 2008 coroners' report of a 14-year-old boy who died of an undiagnosed IEM, the OPathPaed service model was proposed. In the present study, we investigated the feasibility of the OPathPaed model for delivering expanded newborn screening in Hong Kong. In addition, health care professionals were surveyed on their knowledge and opinions of newborn screening for IEM.

METHODS

The present prospective study involving three regional hospitals was conducted in phases, from 1 October 2012 to 31 August 2014. The 10 steps of the OPathPaed model were evaluated: parental education, consent, sampling, sample dispatch, dried blood spot preparation and testing, reporting, recall and counselling, confirmation test, treatment and monitoring, and cost-benefit analysis. A fully automated online extraction system for dried blood spot analysis was also evaluated. A questionnaire was distributed to 430 health care professionals by convenience sampling.

RESULTS

In total, 2440 neonates were recruited for newborn screening; no true-positive cases were found. Completed questionnaires were received from 210 respondents. Health care professionals supported implementation of an expanded newborn screening for IEM. In addition, there is a substantial need of more education for health care professionals. The majority of respondents supported implementing the expanded newborn screening for IEM immediately or within 3 years.

CONCLUSION

The feasibility of OPathPaed model has been confirmed. It is significant and timely that when this pilot study was completed, a government-led initiative to study the feasibility of newborn screening for IEM in the public health care system on a larger scale was announced in the Hong Kong Special Administrative Region Chief Executive Policy Address of 2015.

Chronic peritoneal dialysis in Chinese infants and children younger than two years

OBJECTIVE

To review the outcome for Chinese infants and young children on chronic peritoneal dialysis.

METHODS

The Paediatric Nephrology Centre of Princess Margaret Hospital is the designated site offering chronic dialysis to children in Hong Kong. Medical records of children who started chronic peritoneal dialysis before the age of 2 years, from 1 July 1995 to 31 December 2013, were retrieved and retrospectively reviewed.

RESULTS

Nine Chinese patients (male-to-female ratio, 3:6) were identified. They were commenced on automated peritoneal dialysis at a median age of 4.7 (interquartile range, 1.1-13.3) months. The median duration of chronic peritoneal dialysis was 40.9 (interquartile range, 22.9-76.2) months. The underlying aetiologies were renal dysplasia (n=3), pneumococcal-associated haemolytic uraemic syndrome (n=3), ischaemic nephropathy (n=2), and primary hyperoxaluria I (n=1). Peritonitis and exit-site infection rate was 1 episode per 46.5 patient-months and 1 episode per 28.6 patient-months, respectively. Dialysis adequacy (Kt/Vurea>1.8) was achieved in 87.5% of patients. Weight gain was achieved in our patients although three required gastrostomy. Four patients were delayed in development. All patients survived except one patient with primary hyperoxaluria I who died of acute portal vein thrombosis following liver transplantation. One patient with pneumococcal-associated haemolytic uraemic syndrome had sufficient renal function to be weaned off dialysis. Four patients received deceased donor renal transplantation after a mean waiting time of 76.7 months. Three patients remained on chronic peritoneal dialysis at the end of the study.

CONCLUSIONS

Chronic peritoneal dialysis is technically difficult in infants. Nonetheless, low peritonitis rate, low exit-site infection rate, and no chronic peritoneal dialysis-related mortality can be achieved. Chronic peritoneal dialysis offers a promising strategy to bridge the way to renal transplantation.