Salicylate saturation index in neonatal jaundice.

30 serum samples from premature and newborn infants with non-haemolytic hyperbilirubinaemia were analyzed to prove the accuracy of determination of albumin binding capacity for bilirubin. The salicylate method of Odell was used to determine the saturation index of albumin indicated by a decrease in optical density through displaced bilirubin. Bilirubin is stoichometrically displaced from albumin by the addition of salicylate. The values of the sautration index correspond to free binding sites. Analysis of our data demonstrated that there is no direct correlation between the saturation index (SI) and total serum bilirubin/albumin concentration quotient. Methodical errors, problems in statistics and other theoretical concepts are discussed. The salicylate method is not suitable for accurate determination of albumin binding capacity for bilirubin.     

BILIRUBIN, RESERVE ALBUMIN FOR BINDING OF BILIRUBIN AND pH IN PLASMA DURING PHOTOTHERAPY (ORDINARY AND DOUBLE LIGHT) OF TERM NEWBORN INFANTS

ABSTRACT. Ebbesen, F. (Department of Neonatology, Rigshospitalet, Copenhagen, Denmark). Bilirubin, reserve albumin for binding of bilirubin and pH in plasma during phototherapy (ordinary and double light) of term newborn infants. Acta Paediatr Scand, 70:223, 1981. –Forty-five term newborn infants with uncomplicated hyperbilirubinaemia were treated continuously with phototherapy for 24 hours. Twenty-eight infants received double light treatment and 17 infants ordinary phototherapy. During both treatments a significant decrease in the serum unconjugated bilirubin concentration, a significant increase in the serum reserve albumin concentration for binding of bilirubin determined by the [¹⁴C] MADDS method, and a significant decrease in the index of serum bilirubin toxicity occurred. The changes in these parameters were significantly greater during the double light treatment than during the ordinary phototherapy. During the treatment the fall in index was constant. No significant change in plasma pH was seen. Thus, the study gives further evidence that the risk of bilirubin encephalopathy is reduced by phototherapy and that double light treatment is in the respect superior to ordinary phototherapy. Prior to phototherapy the molar ratio in serum of unconjugated bilirubin plus reserved albumin for binding of bilirubin to albumin was only 0.60, on average, and during the treatment the increase in the serum reserve albumin concentration was less than the decrease in the serum bilirubin concentration. This can be explained either by the presence in infant serum of an unknown ligand interfering competitively or allosterically in the binding of MADDS and bilirubin to albumin, or by the existence of a foetal albumin with a lower affinity for MADDS than adult albumin.     

Reserve albumin binding capacity,salicylate saturation index,and red cell binding of bilirubin in neonatal jaundice

105 blood samples from 72 infants, mostly with jaundice due to haemolytic disease, were analysed for reserve albumin binding capacity (HBABA method), salicylate saturation index (SI), and red cell binding of bilirubin. 2 infants with clinical symptoms of bilirubin encephalopathy had abnormally large amounts of red cell bound bilirubin, though the HBABA binding capacity and salicylate saturation index did not suggest a risk of bilirubin encephalopathy. On the other hand, 48 of the other samples showed `risk values'' for saturation index and 2 of the other samples showed such values as judged by the HBABA method. The discrepancies between these findings are discussed. It is suggested that determination of red cell bound bilirubin may have clinical value in patients with neonatal jaundice, especially in cases of suggested kernicterus.     

The effect of multiple exchange transfusions on bilirubin binding

Three bilirubin binding tests (hydroxybenzene-azobenzoic acid dye binding method, the estimation of unbound bilirubin by horseradish peroxidase assay and the saturation of albumin by the salicylate saturation index) were performed on pre-exchange samples of blood and repeated 24 hours after the procedure. No significant improvement in bilirubin binding was found even in infants receiving as many as four exchange transfusions. Based on these bilirubin binding tests, we find no evidence that the criteria for subsequent exchange transfusions should be different from the first exchange transfusion.     

The Effect of Multiple Exchange Transfusions on Bilirubin Binding

ABSTRACT. Three bilirubin binding tests (hydroxybenzene-azobenzoic acid dye binding method, the estimation of unbound bilirubin by horseradish peroxidase assay and the saturation of albumin by the salicylate saturation index) were performed on pre-exchange samples of blood and repeated 24 hours after the procedure. No significant improvement in bilirubin binding was found even in infants receiving as many as four exchange transfusions. Based on these bilirubin binding tests, we find no evidence that the criteria for subsequent exchange transfusions should be different from the first exchange transfusion.     

LOW RESERVE ALBUMIN FOR BINDING OF BILIRUBIN IN NEONATES WITH DEFICIENCY OF BILIRUBIN EXCRETION AND BRONZE BABY SYNDROME

ABSTRACT. The plasma reserve albumin concentration for binding of bilirubin was found to be low in four newborn infants with deficiency of bilirubin excretion, of whom two had the bronze baby syndrome. Thus, the risk of bilirubin encephalopathy was increased. Also the ratio of binding fraction of albumin, i. e. unconjugated bilirubin plus reserve albumin, to total albumin was low. Possible causes of the low reserve albumin concentration and the ratio are discussed.     

EFFECT OF EXCHANGE TRANSFUSION ON SERUM RESERVE ALBUMIN FOR BINDING OF BILIRUBIN AND INDEX OF SERUM BILIRUBIN TOXICITY

ABSTRACT. Ebbesen F. (Department of Neonatology, Rigshospitalet, Copenhagen, Denmark). Effect of exchange transfusion on serum reserve albumin for binding of bilirubin and index of serum bilirubin toxicity. Acta Paediatr Scand, 70:643,.–Seventeen newborn infants, who received their first exchange transfusion due to hyperbilirubinaemia and/or rhesus haemolytic disease, were studied. The exchange transfusions were performed with fresh, citrated blood. During the exchange transfusion a marked increase in the serum reserve albumin concentration for binding of bilirubin measured by the [^,4C]-MADDS method was observed, followed by a smaller decrease after the transfusion. Plasma pH increased both during and after the exchange transfusion. During the exchange transfusion a drastic fall in index of serum bilirubin toxicity was observed, followed by a smaller increase after the transfusion. Citrate was not found to interfere in the binding of bilirubin to albumin. The results are in agreement with the clinical finding that an exchange transfusion performed with fresh, citrated blood effectively reduces the risk of bilirubin encephalopathy. The ratio in serum of binding albumin, i.e. bilirubin plus reserve albumin, to total albumin failed to be increased by the exchange transfusion, and a decrease occurred after the transfusion. These findings indicate the presence in infant serum of non-binding albumin. Donor albumin with intact binding potential is partly transformed into the non-binding variety in the course of one hour after the transfusion. In the most severely rhesus sensitized infant a drastic decline of the serum albumin binding capacity was seen during the first day of life.     

Ceftriaxone effect on bilirubin-albumin binding

The effect of ceftriaxone on bilirubin-albumin binding was measured in vitro using the peroxidase method with human serum albumin and a dialysis rate method with adult and newborn serum. Ceftriaxone competes with bilirubin for binding to human serum albumin; the displacement constant is 1.5 X 10(4) L/mol. Therapeutic levels of ceftriaxone decrease the reserve albumin concentration in newborn serum by 39%. These results indicate that ceftriaxone may increase the risk of bilirubin encephalopathy in jaundiced premature infants.     

POSTNATAL CHANGES IN THE ABILITY OF PLASMA ALBUMIN TO BIND BILIRUBIN

ABSTRACT. The plasma concentrations of total albumin, unconjugated bilirubin and reserve albumin for bilirubin binding were determined in 407 healthy infants of various age up to eight days. The albumin reserve was measured using monoacetyldiaminodiphenyl-sulfone (MADDS) as a deputy ligand for bilirubin. The fraction of albumin capable of binding bilirubin was calculated as the sum of the concentrations of bilirubin and reserve albumin, divided by the total albumin concentration. Our data showed that this fraction was low (average 0.36) and did not change during the first 24 hours of life, and in this period it was independent of the maturity of the infant, as expressed by its birth weight or gestational age. From about 24 hours of life, the fraction began to increase. This increase came to an end about 60 hours after birth, and no further changes were seen during the following five days. The level of the bilirubin-binding fraction reached 60 hours after birth was related to the maturity of the infant: It increased with increasing birth weight up to 3000 g and with increasing gestational age up to 275 days, when on an average it was about 0.58. The fraction of binding albumin was independent of the sex.     

Postnatal changes in the ability of plasma albumin to bind bilirubin

The plasma concentrations of total albumin, unconjugated bilirubin and reserve albumin for bilirubin binding were determined in 407 healthy infants of various age up to eight days. The albumin reserve was measured using monoacetyldiaminodiphenyl-sulfone (MADDS) as a deputy ligand for bilirubin. The fraction of albumin capable of binding bilirubin was calculated as the sum of the concentrations of bilirubin and reserve albumin, divided by the total albumin concentration. Our data showed that this fraction was low (average 0.36) and did not change during the first 24 hours of life, and in this period it was independent of the maturity of the infant, as expressed by its birth weight or gestational age. From about 24 hours of life, the fraction began to increase. This increase came to an end about 60 hours after birth, and no further changes were seen during the following five days. The level of the bilirubin-binding fraction reached 60 hours after birth was related to the maturity of the infant: It increased with increasing birth weight up to 3000 g and with increasing gestational age up to 275 days, when on an average it was about 0.58. The fraction of binding albumin was independent of the sex.     

ALBUMIN ADMINISTRATION COMBINED WITH PHOTOTHERAPY IN TREATMENT OF HYPERBILIRUBINAEMIA IN LOW-BIRTH-WEIGHT INFANTS

ABSTRACT. Ebbesen, F., and Brodersen, R. (Department of Neonatology, Rigshospitalet, Copenhagen and Institute of Medical Biochemistry, Aarhus, Denmark). Albumin administration combined with phototherapy in treatment of hyperbilirubinaemia in low-birth-weight infants. Acta Paediatr Scand, 70:649,.–Fifty-nine jaundiced light treated newborn infants with low birth weight were studied. At onset of phototherapy 30 infants received 1 g human serum albumin per kg body weight as a 9 % solution containing sodium caprylate and N-acetyltryptophan as stabilizers. 29 infants did not receive human serum albumin and served as controls. Blood samples were taken before initiation of the therapy and again 24 and 48 h thereafter, and the following determinations were made: Serum concentrations of unconjugated bilirubin, albumin, reserve albumin for binding of bilirubin by the [^l4C]-MADDS method, packed cell volume and pH. Before infusion of albumin it was found that the binding fraction of serum albumin, i.e. the sum of the serum concentrations of bilirubin-albumin and reserve albumin, constituted about half of the total serum albumin concentration. The other half was non-binding, in agreement with previous findings in neonates. The effect of albumin therapy was mainly an unexpected increase of the non-binding fraction of serum albumin, while the increase of the serum reserve albumin concentration was small and the concentration of bilirubin-albumin was not changed.     

The possible risk of bilirubin encephalopathy as predicted by plasma parameters in neonates with previous severe asphyxia

The study group consisted of nine mature newborn infants with a previous history of severe asphyxia and a control group of 18 mature, healthy newborns with the same postnatal age and sex. The object of the investigation was to compare the possible risk of development of bilirubin encephalopathy between the two groups as estimated by plasma parameters. The asphyxia group had a significantly lower reserve albumin concentrations for binding of monoacetyldiaminodiphenyl sulphone (P=0.008), a measure of binding of unconjugated bilirubin, and significantly lower total albumin concentrations (P=0.02). No significant difference was observed in unconjugated bilirubin concentration. It is suggested that mature newborns with previous severe asphyxia are at a slightly increased risk of developing bilirubin encephalopathy over and above the well-known risk associated with increased permeability of the blood brain barrier.     

INCREASE IN BILIRUBIN BINDING TO ALBUMIN WITH CORRECTION OF NEONATAL ACIDOSIS

Abstract. Twenty-six serial measurements of free bilirubin concentration and apparent association constant of bilirubin for albumin (Ka) at a bilirubin: albumin molar ratio of 0.8 were performed and compared with baseline values in 11 newborn infants with acidosis before treatment and during recovery from acidosis. When arterial pH was corrected from 7.12±0.02 (Mean±S.E.M.) to 7.34±0.02, there was a significant decrease in serum free bilirubin concentration and a significant increase in the Ka at molar ratio 0.8. The data offer in vivo evidence that correction of acidosis in the neonate results in an improvement of the apparent bilirubin binding affinity of albumin.     

Increase in bilirubin binding to albumin with correction of neonatal acidosis.

Twenty-six serial measurements of free bilirubin concentration and apparent association constant of bilirubin for albumin (Ka) at a bilirubin: albumin molar ratio of 0.8 were performed and compared with baseline values in 11 newborn infants with acidosis before treatment and during recovery from acidosis. When arterial pH was corrected from 7.12 +/- 0.02 (Mean +/- S.EM.) to 7.34 +/- 0.02, there was a significant decrease in serum free bilirubin concentration and a significant increase in the Ka at molar ratio 0.8. The data offer in vivo evidence that correction of acidosis in the neonate results in an improvement of the apparent bilirubin binding affinity of albumin.     

Hematin and bilirubin binding to human serum albumin and newborn serum

In jaundiced newborn infants, hemolytic disease is considered a risk factor for kernicterus due to the suspected competition between bilirubin and other hemoglobin breakdown products for albumin binding. We have studied the effect of hematin on bilirubin-albumin binding using the peroxidase assay and a light-scattering technique for measuring unbound bilirubin. Our results show that hematin does not affect bilirubin-albumin binding. To determine if other albumin binding functions are affected by hematin, we used a microdialysis rate technique employing two ligands, diazepam and monoacetyldiaminodiphenyl sulfone (MADDS). Hematin does not utilize the diazepam binding function of albumin, but does decrease the albumin binding of MADDS. The results of this study indicate that the MADDS and bilirubin binding functions are not identical. The clinical usefulness of reserve albumin equivalent determination using MADDS is discussed.     

Risk of bilirubin acid precipitation in preterm infants with respiratory distress syndrome: considerations of blood/brain bilirubin transfer equilibrium

Twenty-six preterm infants with respiratory distress syndrome (RDS), were examined daily during the first 6 days of life. Twenty-six equally preterm but clinically well infants served as controls. In the RDS infants, plasma albumin concentration was low, hyperbilirubinemia was prolonged, plasma pH was decreased during the first two days, and the concentration of reserve albumin for binding of monoacetyldiaminodiphenylsulfone (MADDS), a deputy ligand for bilirubin, was decreased on the second throughout the sixth day, when compared with the controls. These factors concur in increasing the likelihood of bilirubin acid precipitation in RDS above the increased risk present in preterm infants. The plasma of the preterm controls was supersaturated with respect to crystalline bilirubin acid by an average factor 5 (index of plasma bilirubin toxicity = 0.7) on the first day of life, peaking at a factor 10 (index 1.0) on the third and fourth days while these factors were 10 and 20 (index 1.0 and 1.3), respectively, in the RDS infants. Two of the latter surpassed a level of 60 times supersaturation (index 1.8) where acute precipitation of amorphous bilirubin acid becomes possible.     

Hematin and Bilirubin Binding to Human Serum Albumin and Newborn Serum

ABSTRACT. In jaundiced newborn infants, hemolytic disease is considered a risk factor for kernicterus due to the suspected competition between bilirubin and other hemoglobin breakdown products for albumin binding. We have studied the effect of hematin on bilirubin-albumin binding using the peroxidase assay and a light-scattering technique for measuring unbound bilirubin. Our results show that hematin does not affect bilirubin-albumin binding. To determine if other albumin binding functions are affected by hematin, we used a microdialysis rate technique employing two ligands, diazepam and monoacetyldiaminodiphenyl sulfone (MADDS). Hematin does not utilize the diazepam binding function of albumin, but does decrease the albumin binding of MADDS. The results of this study indicate that the MADDS and bilirubin binding functions are not identical. The clinical usefulness of reserve albumin equivalent determination using MADDS is discussed.     

THE RELATIONSHIP BETWEEN SERUM BILIRUBIN AND RESERVE ALBUMIN FOR BINDING OF BILIRUBIN DURING PHOTOTHERAPY OF PRETERM INFANTS

ABSTRACT. Ebbesen, F. (Department of Neonatology, Rigshospitalet, Copenhagen, Denmark). The relationship between serum bilirubin and reserve albumin for binding of bilirubin during phototherapy of preterm infants. Acta Paediatr Scand, 70:405, 1981.–Thirty-four preterm newborn infants suffering from uncomplicated hyperbilirubinaemia were studied. The infants received ordinary phototherapy continuously during 48 hours. The serum unconjugated bilirubin concentration decreased significantly during the treatment, and a significant correlation between the changes in the serum bilirubin concentration and the changes in the serum reserve albumin concentration for binding of bilirubin measured by the [¹⁴C]MADDS method was found. The regression coefficients were -0.50 and -0.48 after 24 and 48 hours of treatment, respectively. Thus, it can be concluded that the risk of bilirubin encephalopathy is reduced by phototherapy in preterm infants.     

COMPARISON BETWEEN TWO PREPARATIONS OF HUMAN SERUM ALBUMIN IN TREATMENT OF NEONATAL HYPERBILIRUBINAEMIA

ABSTRACT. Thirty-six newborn infants with normal birth weights and with uncomplicated hyperbilirubinaemia, treated with light, were studied. At onset of phototherapy the infants received intravenously 1 g human serum albumin (HSA) per kg body weight as a 9 % solution. Two different preparations of HSA were used and compared. One of these, HSA_I, contained sodium caprylate and N-acetyltryptophan, 5 mmol/1 of each, as stabilizers. HSA_II contained only caprylate, 5 mmol/1. Nineteen infants received HSA_I and seventeen infants HSA_II. The reserve albumin for binding of bilirubin, measured by the [¹⁴C] MADDS method, was low in both preparations in vitro. During the infusion, the serum concentrations of albumin and reserve albumin increased and the serum unconjugated bilirubin concentration decreased, resulting in a fall in the index of plasma bilirubin toxicity in all infants. After completion of the infusion, the serum concentrations of albumin and reserve albumin declined, and a slight rise in index occurred. The increase in the serum reserve albumin concentration was markedly higher during infusion of HSA_II than of HSA_I. It is concluded that infusion of both HSA preparations during phototherapy provides an immediate protection against bilirubin encephalopathy. HSA_I is inferior to HSA_II, probably due to its content of N-acetyltryptophan.     

Binding capacity of some drugs to plasma proteins of newborns in comparison with adults (author's transl)

Comparative studies on binding capacity of some drugs to plasma proteins of newborns and adults were carried out. Plasma from the newborn and adult rabbits as well as human from 4 sources: a) from healthy adults, b) from cord blood, c) from 5 days old newborns, and 6 month old infants were used for the experiments. For methodological reasons in the first part of our studies we have chosen: two sulfonamides - sulfamethazine and sulfamethoxasole, chlorpromazine and sodium salicylate. In the experiments two different techniques were used 1) equilibrium dialysis, 2) ultrafiltration. On the basis of the results obtained in animals as well as in human beings it was noted that the degree of drug binding to plasma proteins in newborns was different from that observed in adults, it may be higher or lower according to the drug used. The knowledge of this fact is of great importance, and should be taken into consideration in the calculation of proper dosage of various drugs in the newborns and infants.