Search

Glucose-6-phosphate dehydrogenase (G6PD, D-glucose 6-phosphate: NADP oxidoreductase, E.C. 1.1.1.49) activity and the percentage of G6PD deficient erythrocytes was determined in 50 girls heterozygous for G6PD deficiency, 25 of whom had had hyperbilirubinaemia at birth and 25 who had normal bilirubin levels. The enzymatic activity was 2.32 +/- 0.87 I.U./g Hb in the first group and 3.31 +/- 0.92 I.U./g Hb in the second group. The percentage of G6PD deficient erythrocytes was 54.1 +/- 15.3 and 65.3 +/- 14.0, respectively. The level of enzymatic activity exceeded 4 I.U./g Hb and the percentage of G6PD deficient cells fell below 40% in only one of the subjects who had developed hyperbilirubinaemia. Levels of enzymatic activity below 4 I.U./g Hb, or percentages of G6PD deficient erythrocytes higher than 40% can therefore be considered to be associated with a high risk of developing neonatal hyperbilirubinaemia. In our opinion, these babies should receive prophylactic treatment with phenobarbital, as do G6PD deficient Mediterranean males.

40 full-term newborn infants with erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD) deficiency were used for a study concerning the effectiveness of agar per os in preventing severe hyperbilirubinemia. 20 randomly selected neonates were given agar (1 g/kg/day) orally in 4 daily doses from their 1st to their 5th day of life. 20 infants were not treated and served as controls. Three exchange transfusions were performed in the experimental as well as in the control group. According to these results, agar does not seem to be effective in preventing severe hyperbilirubinemia, which frequently occurs in newborn infants with erythrocyte G-6-PD deficiency.

The present paper reports the incidence from 1965 to 1979 of acute hemolytic anemia for a total of 948 cases in G-6-PD-deficient subjects due to the ingestion of fresh or dried fava beans or certain drugs and to viral infections. The highest percentage of hemolytic crises was due to fresh fava beans (94.4%). No cases of favism were observed in breast-fed babies whose mothers had eaten fava beans or from pollen inhalation. The male sex proved to be the hardest hit. Hemoglobin values were lower than or equal to 7 g/dl in about 75% of males and 50% of females. Total bilirubin values were lower than 103 mumol/l (6 mg/dl) in about 75% of males and 85% of females. Both the hemoglobin and bilirubin values were statistically significant. Mean transaminase values (SGPT) were significantly higher than those of normal controls. No correlation between favism and blood groups was found.

Hemolysis was studied in 40 G-6-PD-deficient newborn infants, half of whom had bilirubin blood levels within the normal range whereas the others, who were hyperbilirubinemic, underwent exchange transfusion. Hemoglobin, hematocrit, hemopexin and haptoglobin showed no or little differences between either of the two groups and the controls. The findings confirm the authors' assumption expressed elsewhere that this form of hyperbilirubinemia is not hemolytic in nature.

Hb A2 was determined in 50 subjects with erythrocyte G-6-PD deficiency who presented with hyperbilirubinemia in the neonatal period and in 100 non-hyperbilirubinemic G-6-PD deficient newborn infants, at the age of 12 months or more. Six subjects in the first group and 13 in the second were found to be carriers of the beta-thalassemia trait. Statistical analysis of the data did not show any significant difference between the two groups. It seems that the beta-thalassemia trait does not provide any protection against neonatal hyperbilirubinemia associated with G-6-PD deficiency.

Glucose 6-phosphate dehydrogenase (G6PD) activity was assayed quantitatively in red cells from 100 consecutive G6PD-deficient newborn male babies born in a city hospital in Sassari, Sardinia. In four cases G6PD activity was between 30% and 45% of normal: these appeared on electrophoresis to be identical with G6PD Seattle-like. In 65 cases G6PD activity ranged from 2% to 14% of normal, while in the remaining 31 samples no activity could be detected in crude hemolysates. G6PD was partiall purified from 39 samples having activity below 14% of normal (including 20 with zero activity). G6PD activity could now be determined in all, and it was fully characterized in nine samples. These were shown to belong to two distinct classes on grounds of the Michaelis constant for glucose 6-phosphate and the elution profile from DEAE-Sephadex columns. These properties were compared with those of G6PD-deficient samples from Greece and from Israel. We conclude that there are at least three polymorphic G6PD-deficient variants in Northern Sardinia: G6PD Seattle-like, G6PD Mediterranean, and a new variant, which we designate G6PD Sassari. The GdMediterranean and GdSassari genes have been shown to breed true in family studies. We also produce evidence that the definition of G6PD Mediterranean must be carefully reassessed.

Salicylamide glucuronide formation has been studied in 23 newborn babies with erythrocyte G-6-PD deficiency and in 15 normal newborns on the first day of life. Glucuronide formation was significantly lower (p less than 0.001) in the former in comparison with the controls. In the newborns with G-6-PD deficiency who subsequently became hyperbilirubinemic an even lower mean glucuronide formation was observed (p less than 0.01) in respect to the non-jaundiced G-6-PD-deficient newborns.

We have investigated the association of neonatal jaundice (NNJ) and G6PD deficiency in consecutive births in a Northern Sardinian hospital. After excluding known causes for NNJ, and after correcting for the incidence of NNJ from unknown causes, we estimated that 20% of G6PD deficient male newborns develop NNJ resulting from their enzyme deficiency. By analyzing in detail 100 G6PD deficient babies we found no differences in birth weight or haemoglobin level between those without and those with NNJ, four of whom required exchange transfusion. We further showed by an accurate quantitative method that the residual G6PD enzyme activity was not significantly lower in G6PD deficient babies with NNJ compared to G6PD deficient babies without NNJ.

Phototherapy was employed in treatment of newborn infants with erythrocyte G-6-PD deficiency whose serum bilirubin concentrations exceeded 10 mg/100 ml on the second or third day of life. Exchange transfusions were required for two of the 12 treated babies and for six of the 12 control infants. It is noteworthy that exposure to light did not affect the erythrocyte GSH content nor did it increase hemolysis.