Transportation is Pivotal to Newborn Screening of G6PD Deficiency - Abstract
This study aimed to evaluate the interferents in a quantitative technique for glucose-6 phosphate dehydrogenase (G6PD), deficiency diagnosis. Newborn blood samples were collected in filter paper from May 2016 to January 2017 in Sergipe state, Brazil. Samples were divided into three groups with different pre-analytical and analytical conditions: in the pilot group was evaluated sample quality and time between collection and examination; in the standard group
was analyzed the samples under regular conditions of newborn screening; and in the control group samples were transported with low temperature. We evaluated 11,677 samples, of which 8,213 (70.33%), were considered valid: 2,347 from Pilot Group, 5,766 from Standard Group, and 100 from Control Group. The prevalence obtained was 9.35% from the Standard Group. There was significant statistical difference among positive results of most groups. Prevalence decreased from 13.66% in Pilot Group to 1% in Standard Group, and the mean enzyme activity of samples from Pilot Group, Standard Group, and Control Group was 4.4, 4.3 and 7.5 U/g Hb, respectively. The optimal technical conditions observed were: completely filled filter paper (Pilot Group), three weeks between collection and examination (Standard Group), and refrigerated transport (Control Group). The confirmatory test was performed in 50
newborns from Standard Group, and the deficiency was confirmed in 20 patients. Among the established criteria, refrigerated transportation had the greatest impact in reducing prevalence. We suggest that quantitative measures of enzyme activity technique cannot be used to diagnose G6PD deficiency in regions with high temperature without refrigeration during transportation.