Screening for glucose-6-phosphate dehydrogenase deficiency in neonates: a comparison between cord and peripheral blood samples.

BACKGROUND: The use of cord blood in the neonatal screening for glucose-6-phosphate dehydrogenase (G6PD) deficiency is being done with increasing frequency but has yet to be adequately evaluated against the use of peripheral blood sample which is usually employed for confirmation. We sought to determine the incidence and gender distribution of G6PD deficiency, and compare the results of cord against peripheral blood in identifying G6PD DEFICIENCY neonates using quantitative enzyme activity assay. METHODS: We carried out a retrospective and cross-sectional study employing review of primary hospital data of neonates born in a tertiary care center from January to December 2008. RESULTS: Among the 8139 neonates with cord blood G6PD assays, an overall incidence of 2% for G6PD deficiency was computed. 79% of these were males and 21% were females with significantly more deficient males (p < .001). Gender-specific incidence was 3.06% for males and 0.85% for females. A subgroup analysis comparing cord and peripheral blood samples (n = 1253) showed a significantly higher mean G6PD value for peripheral than cord blood (15.12 ± 4.52 U/g and 14.52 ± 4.43 U/g, respectively, p = 0.0008). However, the proportion of G6PD deficient neonates did not significantly differ in the two groups (p = 0.79). Sensitivity of cord blood in screening for G6PD deficiency, using peripheral G6PD assay as a gold standard was 98.6% with a NPV of 99.5%. CONCLUSION: There was no difference between cord and peripheral blood samples in discriminating between G6PD deficient and non-deficient neonates. A significantly higher mean peripheral G6PD assay reinforces the use of cord blood for neonatal screening since it has substantially low false negative results.

Herb-induced acute bone marrow intoxication and interstitial nephritis superimposing glomerular C1q deposition in a patient with paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria is a rare disease of the red blood cell membrane that renders it lyzable by the complement system, leading to chronic intravascular hemolysis. Renal hemosiderosis is a well-known complication of intravascular hemolytic anemia and can lead to acute kidney injury and renal failure. The use of herbal medicine is common worldwide. The nephrotoxicity of herbal remedies can take several forms, which include acute kidney injury and acute and chronic interstitial nephritis. In addition, the use of herbal remedies can result in bone marrow toxicity and suppression. C1q nephropathy is an uncommon form of glomerular disease characterized by dominant or co-dominant glomerular immunofluorescence positivity for C1q in the absence of clinical and serological evidence of systemic lupus erythematosus, and has various clinical presentations and outcome. Here, we report a patient of undiagnosed paroxysmal nocturnal hemoglobinuria who consumed herbal medicine of unknown constituents and clinically presented with anemia and acute kidney injury. The pathological findings of bone marrow and renal biopsies that include bone marrow intoxication, severe renal hemosiderosis and acute interstitial nephritis and kidney injury, as well as co-dominant glomerular deposition of C1q, are discussed. In addition, we discuss and hypothesize the possible pathogenesis of glomerular C1q deposition in the setting of paroxysmal nocturnal hemoglobulinuria.