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.     

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.     

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.     

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.     

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.     

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.     

Effect of cephalosporins on bilirubin-albumin binding

The effect of parenterally administered cephalosporins on bilirubin-albumin binding was measured in vitro by means of the peroxidase method with human serum albumin and by means of a dialysis rate method with newborn infants' serum. Ceftriaxone and cefoperazone have been shown to affect bilirubin-albumin binding. In this study, 13 additional cephalosporins were tested. Cefonicid, cefotetan, and cefmetazole competed with bilirubin for albumin binding and, at reported mean peak serum levels, decreased the reserve albumin concentration by 75%, 56%, and 40%, respectively. We suggest that these five cephalosporins may increase the risk of bilirubin encephalopathy in jaundiced neonates.     

STUDIES ON PHOTOTHERAPY IN NEWBORN INFANTS

ABSTRACT: Windorfer, A., Faxelius, G. and Boréus, L. O. (Departments of Clinical Pharmacology and Paediatrics, Karolinska Hospital, Stockholm, Sweden). Studies on phototherapy in newborn infants: Influence on protein binding of bilirubin and salicylate and on activity of acetylsalicylic acid esterase. Acta Paediatr Scand 64:293, 1975.– Phototherapy of newborn infants with hyperbilirubinemia was shown to result in an increase in hematocrit values and in the activity of the erythrocyte enzyme acetylsalicylic acid esterase. The elevation of the enzyme activity also could be produced in light-treated rabbits and in vitro after illumination of blood from adult volunteers. The binding of bilirubin to serum albumin and of salicylate to plasma proteins did not alter, nor did the concentrations of albumin or total proteins in plasma. It is concluded that light does not increase the unbound fraction of bilirubin in blood.     

RESERVE ALBUMIN AND BILIRUBIN TOXICITY INDEX IN INFANT SERUM

ABSTRACT. Reserve albumin concentration (the concentration of albumin available for binding of unconjugated bilirubin) was determined in 95 sera from 76 subjects by dialysis with ¹⁴C-monoacetyl diamino diphenyl sulfone (MADDS). An index, I of bilirubin toxicity in the plasma was calculated for each subject, based on the bilirubin and reserve albumin concentrations, the affinity of bilirubin for serum albumin, and the pH-dependent solubility of bilirubin in the plasma. The values of reserve albumin and of I varied significantly with gestational age, clinical condition (whether sick or well), and serum bilirubin level. The value of reserve albumin was decreased and I was increased in association with clinical factors (e. g., hyperbilirubinemia, hypoxia, acidosis, or sepsis) recognized as increasing the risk for bilirubin encephalopathy. The lowest values of reserve albumin and the highest values of I were found in the least mature and sickest infants.     

Bilirubin-albumin binding affinity and serum albumin concentration during intensive phototherapy (blue double light) in jaundiced newborn infants

Thirty newborn infants with normal birth weights and uncomplicated hyperbilirubinaemia were studied. Twenty three of these were treated continuously for 24h with intensive phototherapy (blue double light), and seven untreated infants served as controls. During the treatment the serum concentrations of total bilirubin and unbound bilirubin in diluted serum measured by the peroxidase method were markedly reduced. The binding affinity of bilirubin to its high affinity site on serum albumin was not affected. During the treatment a slight decrease of the serum albumin concentration occurred, and the possible causes of this observation are discussed.     

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.     

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.     

Incidence and predicting factors of hypozincemia in very-low-birth-weight infants at near-term postmenstrual age

We prospectively investigated serum zinc (Zn) concentrations and clinical factors in 118 very-low-birth-weight infants with a gestational age of 29.5 +/- (SD) 2.5 weeks and a birth weight of 1,194 +/- 254 g at near-term postmenstrual age. The 25th percentile of the serum Zn concentration was 7.0 micromol/l. The infants whose serum Zn concentrations were less than 7.0 micromol/l (defined as hypozincemia) did not have apparent symptoms of Zn deficiency. Multivariate logistic regression analyses demonstrated that hypozincemia was associated with factors such as weight gain (1-g/kg/day increase of weight; OR 1.1762, 95% CI 1.0414-1.3286) and serum albumin concentration (1-g/dl increase of serum albumin; OR 0.0816, 95% CI 0.0152-0.4372). The types of milk feeding did not affect the serum Zn concentrations in the study subjects. This study suggests that hypozincemia in very-low-birth-weight infants at near-term postmenstrual age is associated with greater weight gain and lower serum albumin concentration. Nutritional supply of Zn by human milk fortifier and preterm formula does not appear to meet the demands of rapidly growing very-low-birth-weight infants.     

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.     

Albumin binding properties in relation to bilirubin and albumin concentrations during the first week of life

In 19 non-jaundiced and 22 jaundiced neonates, the serum albumin and bilirubin concentrations were measured during the first week of life. Some of the neonates were followed longitudinally. The albumin binding properties were evaluated by determining the reserve albumin concentration for monoacetyldiaminodiphenyl sulphone (MADDS), a deputy ligand for bilirubin. The reserve albumin concentration for MADDS increased with postnatal age. The reason for this increase is still unexplained. There was an inverse relation between the bilirubin and the reserve albumin concentrations, but when the bilirubin concentration increased by 1 mumol/l, the reserve albumin concentration for MADDS decreased by only 0.2 mumol/l. This shows that the reserve albumin concentration for MADDS does not give a direct measure of the bilirubin binding ability of the serum albumin molecule. In spite of this, it is still possible that a low reserve albumin concentration for MADDS is a risk factor for bilirubin encephalopathy.     

Bilirubin binding and acid-base equilibrium in newborn infants with low birthweight

Acidosis is known as a risk factor for the development of bilirubin encephalopathy in neonatal jaundice. However, few attempts have been made to evaluate the influence of acid-base state on bilirubin-albumin binding state in blood of newborn infants. Therefore, in 171 appropriate and 83 small for gestational age newborns (birthweight less than 2,500 g) the acid-base state in blood and bilirubin (BR) binding state in serum was measured at the ages of 3, 4, 5, and 8 days. There is a weak but significant correlation between standard base deficit and the ratio BR/reserve albumin as well as the toxic potential of serum BR. The results suggest that the higher risk in acidosis is not only caused by increased tissue binding of BR but also--at least partially--attributable to decreased BR binding in serum.     

Effects of albumin infusion therapy on total and unbound bilirubin values in term infants with intensive phototherapy

BACKGROUND: The purpose of the present study was to evaluate the effect of intravenous albumin administration on the serum total and unbound bilirubin values in term non-hemolytic hyperbilirubinemic neonates during intensive phototherapy. METHODS: Fifty-eight infants (gestational age 39.4 +/- 1.4 weeks; birth weight 3,245 +/- 435 g) were given phototherapy with similar light energy. Twenty infants (control group) received only phototherapy, while 38 others (albumin-treated group) were also given human albumin at 1 g/kg bodyweight, i.v., during the first 2 h of phototherapy. RESULTS: When comparing changes in total and unbound bilirubin values 0, 2, 6 and 24 h after entering the study between the albumin-treated group and the control group, there was a significant reduction in the serum unbound bilirubin values at the end of albumin treatment and at 6 and 24 h. However, there was no significant reduction in total serum bilirubin values during the study period. In the albumin-treated group, the mean serum unbound bilirubin reduction from the baseline level at the end of albumin treatment and at 6 and 24 h was 0.40 +/- 0.19, 0.41 +/- 0.20 and 0.43 +/- 0.20 microg/dL, respectively. CONCLUSIONS: The results suggest that albumin priming may be effective for an immediate reduction in serum unbound bilirubin values, the fraction that is potentially neurotoxic.     

Effect of lactate, pyruvate, acetone, acetoacetate, and beta-hydroxybutyrate on albumin binding of bilirubin

Lactate, pyruvate, acetone, acetoacetate, and beta-hydroxybutyrate were tested for their bilirubin-displacing effect on human serum albumin. Only lactate had a significant effect at levels found in asphyxiated infants (up to 20 mM). The reserve albumin equivalent for binding bilirubin was determined, using the deputy ligand monoacetyldiaminodiphenyl sulfone (MADDS), in adult human serum albumin solution, neonatal serum, and neonatal albumin solution. Twenty mM lactate caused a 23% decrease of reserve albumin when adult albumin was used, but did not cause any change of binding when neonatal serum or neonatal albumin solution was used. It is unlikely that endogenous substances, acting as competitive ligands, cause the low binding affinity of albumin for bilirubin in sick, premature infants.     

Albumin Binding Properties in Relation to Bilirubin and Albumin Concentrations during the First Week of Life

ABSTRACT. In 19 non-jaundiced and 22 jaundiced neonates, the serum albumin and bilirubin concentrations were measured during the first week of life. Some of the neonates were followed longitudinally. The albumin binding properties were evaluated by determining the reserve albumin concentration for monoacetyldiaminodiphenyl sulphone (MADDS), a deputy ligand for bilirubin. The reserve albumin concentration for MADDS increased with postnatal age. The reason for this increase is still unexplained. There was an inverse relation between the bilirubin and the reserve albumin concentrations, but when the bilirubin concentration increased by 1 μmol/l, the reserve albumin concentration for MADDS decreased by only 0.2 μmol/l. This shows that the reserve albumin concentration for MADDS does not give a direct measure of the bilirubin binding ability of the serum albumin molecule. In spite of this, it is still possible that a low reserve albumin concentration for MADDS is a risk factor for bilirubin encephalopathy.