胆红素对新生儿脐血单核细胞凋亡的影响

目的 探讨胆红素对新生儿脐血单核细胞(CBMC)凋亡的影响.方法 采用纤维连接蛋白结合法分离新生儿CBMC.经含有不同浓度胆红素(6 mG/dl、9 mg/dl、12.9 mg/dl和18 mg/dl)的牛血清白蛋白溶液孵育1 h,再给予脂多糖(LPS,1μg/m1)刺激48 h,收集细胞.采用TUNEL法检测细胞的凋亡率.结果 LPS和低浓度(6 mg/dl)胆红素单独作用对CBMC的凋亡率均无影响.低浓度胆红素(6 mg/dl)与LPS共同作用不升高CBMC的凋亡率;较高浓度和高浓度胆红素(9 mg/dl、12.9 mg/dl、18 mg/dl)与LPS共同作用可升高CBMC的凋亡率,且这种作用随胆红索浓度的升高而增加.结论 较高浓度和高浓度胆红素可以升高CBMC的凋亡率,此种抑制作用可能与胆红素引起细胞膜破坏、Ca2+内流增多、线粒体功能障碍有关.     

Reliability of plasma creatinine measurement in infants and children

Plasma creatinine (Pcr, mg/dl) is often used to estimate glomerular filtration rate (GFR) in children. To establish whether the clinician can rely on the commonly used methods for measuring Pcr, the authors analyzed data from their own modified Technicon Autoanalyzer reference method and compared them to those obtained simultaneously from a Beckman Astra 8 kinetic Jaffe technique or a Technicon continuous flow Jaffe endpoint SMAC method. The SMAC method consistently overestimated Pcr by 0.1 mg/dl, whereas the kinetic method resulted in a large spread around the reference values. Neither laboratory gave consistent results for Pcr below 0.55, the normal range for infants and young children. The SMAC technique tended to underestimate GFR by 20 to 30 percent, whereas the kinetic method resulted in a great deal of scatter (only 37% of the measurements fell within +/- 25% of the values for GFR obtained by the reference method). The results suggest that the subtraction of 0.1 mg/dl from the Pcr measured on the SMAC system would give a value similar to that obtained with the reference method. This correction would permit the use of an estimate of GFR from kL/Pcr, where L is body length in cm and k is a constant (equalling 0.45 in term infants, 0.55 in children, and 0.7 in adolescent boys). The kinetic method requires repetitive determinations of Pcr before any firm conclusions can be drawn about GFR because of the scatter. The reliability of the clinician's laboratory can be tested by sending half the plasma to the laboratory on one day and the other half the next.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of bilirubin on the surface charge and aggregation tendency of platelets in cord blood

Unbound unconjugated bilirubin markedly increased the negative electrophoretic mobility of washed platelets from cord blood, even at concentration as low as 1.5 mg/dl. The increase in negativity could be abolished by washing the platelets. Aggregation of platelets was observed in parallel with the increase in negativity. These actions of bilirubin required calcium ions, which could not be replaced by magnesium ions. The results suggest attachment of the negative bilirubin molecules onto the platelet surface, probably through calcium ions, leading to platelet aggregation.Plasma components inhibited the actions of bilirubin on platelets up to 19.5 mg/dl bilirubin concentration.The effect of bilirubin on platelets was also investigated in the presence of albumin. When the saturation of albumin with bilirubin was exceeded, platelet negativity increased. However, the fraction of free bilirubin exceeding the albumin saturation point has not the same effect as truly free bilirubin at that concentration in the complete absence of albumin. The results indicate that albumin molecules loosly adsorbed onto the surface may protect the platelets against the attachment of free bilirubin. This protection, however, might be impaired by acidosis, which is frequently combined with hyperbilirubinaemia in the sick newborn. It is suggested that bilirubin could contribute to the haemostatic abnormalities in sick babies by acting on the platelet surface.     

Transcutaneous bilirubinometry: serum bilirubin measurement using transcutaneous bilirubinometer (TcB). A preliminary study

While the transcutaneous bilirubinometer (TcB) was originally developed for use as a jaundice meter, we have shown that it can also be used as a bedside instrument for direct measurement of serum bilirubin. An analysis of 130 samples indicates that total serum bilirubin measurement using the TcB is simple and accurate. A comparison with the AO bilirubinometer showed a highly significant coefficient or correlation (r = 0.99) for total serum bilirubin concentration. The addition of hemolysates caused no effect on TcB reading obtained by the TcB instrument, even at levels above those usually encountered in sera of newborn infants. The AO cuvette is very suitable for use in this measurement, since this method requires less than 15 microliters of serum. One of the disadvantages of this method may be that it yields somewhat lower (5%) than actual serum bilirubin concentrations in the range above 20 mg/dl, and somewhat higher (20%) than actual serum bilirubin concentrations in the range below 10 mg/dl. Our study demonstrated the TcB instrument to be a useful device for bedside determination of serum bilirubin in the screening of neonatal hyperbilirubinemia. However, though useful as a screening test, it does not provide such an accurate determination of serum bilirubin concentration as the AO bilirubinometer.     

Formation of bilirubin conjugates in human newborns

Bilirubin conjugates in the serum of newborn human infants were investigated using the alkaline methanolysis-high-performance liquid chromatography method, a specific and sensitive method for measurement of unconjugated bilirubin and bilirubin mono- and diester conjugates. Serum samples were analyzed from 13 premature infants, 11 full term newborns, 22 healthy adults, seven pregnant women at term and their corresponding infants cord blood at delivery, 46 cord blood specimens obtained at unselected deliveries, three cord bloods from infants with maternal-fetal blood group incompatibility, and two cord bloods from infants with intrauterine hypoxia. Bilirubin conjugates were not detectable in the healthy adults, maternal blood, or in the cord blood specimens except from infants with blood group incompatibility or intrauterine hypoxia. The two isomeric monoconjugates of bilirubin appeared in serum during the first 24 to 48 postnatal h in both premature and full term infants, followed by the diconjugate on the 3rd day. Conjugated esters accounted for 2 to 5% of the total bilirubin, with the diconjugate constituting 21% of total conjugated pigment (day 3). In all instances, the unconjugated serum bilirubin concentration had increased to at least 2 mg/dl in the course of physiologic neonatal hyperbilirubinemia before bilirubin conjugates became detectable. Both premature and full term human infants displayed the identical pattern of bilirubin conjugation in serum.     

The occurrence and significance of the bilirubin species, including delta bilirubin, in jaundiced infants

An improved technique for bilirubin analysis, using high-performance liquid chromatography, has enabled us to study the occurrence and significance of four species of bilirubin (unconjugated, monoconjugated, diconjugated, and delta bilirubin) in 40 infants with jaundice of various etiologies. We found that: (a) infants with indirect hyperbilirubinemia showed greater than 90% of their total serum bilirubin as unconjugated bilirubin. The small remaining fraction consisted of conjugated bilirubin; predominantly delta bilirubin (5%); (b) infants with elevated direct serum bilirubin (greater than or equal to 2 mg/dl) showed almost twice more monoconjugated than diconjugated bilirubin fractions; (c) the standard diazo test for bilirubin analysis underestimates the direct bilirubin by as much as 34%; and (d) delta bilirubin, a tightly protein bound bilirubin, was observed in significant amounts in infants with elevated direct bilirubin. Its concentration, which ranged from 10-73% of the total bilirubin, was related to the duration rather than to the cause of the jaundice. It was also observed at birth in an infant with giant-cell hepatitis. It is concluded that the identification of more specific bilirubin species in jaundiced infants, especially in those with elevated direct serum bilirubin, will further help in the understanding and management of their disease.     

Plasma concentrations of urea and creatinine in primary school children in Ujung Pandang.

A study of plasma concentrations of urea creatinine in 202 primary school children aged between 6 to 15 years was carried out in Ujung Pandang from November 1, 1988 through February 28, 1989. Sampling was done using multi-stage random sampling method. Plasma urea concentrations were not affected by sex, age and nutritional status. Normal distribution of plasma urea concentrations in P2.5 and P97.5 were 8.13 mg/dl and 24.09 mg/dl respectively (95% confidence level). There was no difference of creatinine concentration between the two sexes. The overall mean creatinine concentrations was significantly higher in the well-nourished group (0.73 +/- 0.081) mg/dl) as compared to PEM group (0.63 +/- 0.066 mg/dl). This study revealed a correlation between age and plasma creatinine concentrations in the well-nourished (r = 0.46, p less than 0.01) as well as in PEM (r = 0.37, p less than 0.01) group. Hence, normal distribution of plasma creatinine concentrations should be base on values in each age group. This study showed no correlation between plasma urea and creatinine concentrations.     

Use of intravenous lipid and hyperbilirubinemia in the first week.

Serum triglycerides, free fatty acids, unconjugated bilirubin, and albumin were evaluated in 40 neonates receiving 0.5-3.5 g/kg/day of a 50/50 soybean-safflower lipid emulsion infused during 18 h. The purpose of the study was to evaluate lipid tolerance and unconjugated hyperbilirubinemia according to our total parenteral nutrition protocol, which initiates lipid on postnatal day 4. Mean serum triglycerides and free fatty acids were within the range of prelipid infusion values at all dosages, and no statistically significant differences were noted between very-low-birth-weight neonates and those greater than 1,500 g birth weight. Mean free fatty acid:albumin molar ratio was less than 1.0 at all dosages and no individual patient values exceeded a ratio of 3.0. Mean peak serum unconjugated bilirubin of 5.8 mg/dl on postnatal day 3 was stable or fell the next 10 days of lipid-inclusive total parenteral nutrition. Initiating intravenous lipid on the 4th postnatal day at 0.5 g/kg/day and increasing at 0.5 g/kg/day increments at the end of the 1st postnatal week appears to be tolerated well. However, 5% of serum triglyceride levels exceeded 200 mg/dl. Therefore, in view of the unpredictability of a given patient's tolerance to lipid infusion, there should be monitoring for lipemia.     

Determination of bilirubin in capillary plasma by a direct photometric method (DPM, bilirubinometer) and the chemical determination of bilirubin in the bilirubin determination (2,5-dichlorophenyldiazonium method) in serum of venous blood samples

The determination of bilirubin in serum was performed by the 2.5-dichlorphenyldiazonium method (DPD) and in capillary plasma by the direct photometric method (DPM). Both methods showed a good precision and accuracy. The investigation was carried out in 135 samples with a bilirubin concentration up to 25 mg/dl. The comparison of the two methods in 62 samples with a bilirubin concentration up to 10 mg/dl showed a correlation coefficient of r = 0.862 and in 73 samples with a bilirubin concentration between 10 and 25 mg/dl a correlation coefficient of r = 0.893. In 29 cases (21.5%) we found differences between the two methods of 1.5-4.0 mg/dl. Most of them were in the critical higher range. Discussion of the DPD and DPM methods.     

Transcutaneous measurement of bilirubin in Turkish newborns: comparison with total serum bilirubin

Routine use of transcutaneous bilirubin (TcB) measurement in the newborn nursery could reduce costs, readmission rates for hyperbilirubinemia and the need for total serum bilirubin (TSB) measurements. The aim of this study was to examine the correlation between TcB measurement, as performed using BiliCheck, and TSB, measured with high-pressure liquid chromatography (HPLC) and with standard laboratory methods, and to determine the TcB cutoff points with desirable sensitivity and specificity values for various clinically relevant TSB levels by HPLC. Fifty-four infants of > or = 30 weeks of gestational age were enrolled in the study. Near simultaneous blood collection for TSB analysis by three methods--bedside bilirubinometer, diazo method and HPLC--and TcB measurement were performed. There was good correlation between TcB and HPLC-bilirubin (B) (r = 0.85), TSB by bilirubinometer and HPLC-B (r = 0.91) and TSB by diazo method and HPLC-B (r = 0.91). The cut-off limits providing a sensitivity of 100% for TcB measurements were TcB > or = 9 mg/dl for HPLC-B > 17 mg/dl and TcB > or = 8 mg/dl for HPLC-B > 15 mg/dl and HPLC-B > 13 mg/dl. Despite having good correlation with HPLC, BiliCheck showed worse performance than bilirubinometer and diazo method at various clinically relevant cut-off values. Since BiliCheck required relatively lower thresholds with false-positive results for having a sensitivity of 100%, it cannot be recommended as a complete substitute for serum bilirubin measurements.     

Transcutaneous bilirubinometry. Evaluation of accuracy and reliability in a large population

A total of 576 transcutaneous bilirubin measurements were performed on 336 Japanese full-term breast-fed newborn infants during the first twelve days of life. Our present study revealed that transcutaneous bilirubin measurements obtained from the forehead, chest, and sternum correlated well with serum bilirubin concentrations measured by AO bilirubinometer (0.910-0.922, p less than 0.001, n = 576). The 95% confidence limits were +/- 3.04 mg/dl for the forehead, +/- 2.85 mg/dl for the chest, and +/- 2.84 mg/dl for the sternum readings. The overall mean of values from the forehead, chest and sternum, when compared with individual means, was found to correlate better with serum bilirubin concentrations (r = 0.930, p less than 0.001, n = 576) and improve the 95% confidence limits to +/- 2.68 mg/dl. These results demonstrated that the accuracy and reliability of TcB measurement could be increased further with multiple site measurement. The study clearly indicates that transcutaneous bilirubinometry is useful for clinical screening of serum bilirubin levels in Japanese full-term newborn infants.     

Clofibrate as an Adjunct to Phototherapy for Unconjugated Hyperbilirubinemia in Term Neonates

Objective

To evaluate the efficacy of oral clofibrate as an adjunct to phototherapy for unconjugated hyperbilirubinemia in term neonates.

Methods

This randomized controlled trial was done in the level III neonatal intensive care unit (NICU) of a tertiary care hospital. Ninety term neonates with unconjugated hyperbilirubinemia with serum bilirubin 15–25 mg/dl were randomized to either intervention group (single dose of clofibrate in a dose of 50 mg/kg prior to starting phototherapy) or standard care group (only phototherapy). Primary outcome was absolute fall in bilirubin by 48 h. Secondary outcomes were duration of phototherapy, absolute fall in bilirubin levels at 12, 24, 36, 48 h, need for exchange transfusion and incidence of side-effects.

Results

After 48 h of intervention, significantly lower bilirubin levels were noted in the intervention group compared to standard care group with a mean difference of 7 mg/dl (95% CI 6.7 mg/dl to 7.2 mg/dl). Duration of phototherapy required was less in the intervention group compared to standard care group with mean difference of 23.82 h (95% CI 30.46 h to 17.18 h). Exchange transfusion was needed for 4 neonates in the standard care group and none in the intervention group. No side-effects were noted with clofibrate.

Conclusions

Single dose clofibrate prior to starting phototherapy in term neonates with uncomplicated unconjugated hyperbilirubinemia reduces the duration of phototherapy significantly.

     

Transcutaneous Bilirubinometry

ABSTRACT. A total of 576 transcutaneous bilirubin measurements were performed on 336 Japanese full-term breast-fed newborn infants during the first twelve days of life. Our present study revealed that transcutaneous bilirubin measurements obtained from the forehead, chest, and sternum correlated well with serum bilirubin concentrations measured by AO bilirubinometer (0.910–0.922, p <0.001, n =576). The 95% confidence lmits were ±3.04 mg/dl for the forehead, ±2.85 mg/dl for the chest, and ±2.84 mg/dl for the sternum readings. The overall mean of values from the forehead, chest and sternum, when compared with individual means, was found to correlate better with serum bilirubin concentrations ( r =0.930, p <0.001, n =576) and improve the 95% confidence limits to ±2.68 mg/dl. These results demonstrated that the accuracy and reliability of TcB measurement could be increased further with multiple site measurement. The study clearly indicates that transcutaneous bilirubinometry is useful for clinical screening of serum bilirubin levels in Japanese full-term newborn infants.     

Rapid intravenous rehydration by means of a single polyelectrolyte solution with or without dextrose

We compared the efficacy and safety of a single polyelectrolyte solution, Dhaka solution (DS), containing 133 mmol/L sodium, 13 mmol/L potassium, 98 mmol/L chloride, and 48 mmol/L acetate with and without 139 mmol/L (25 gm/L) dextrose in the rapid (4 hours) rehydration of 67 patients with diarrhea and moderate or severe dehydration requiring parenteral fluid therapy. Of the 67 patient, 31 were randomly assigned to receive the dextrose-containing solution (DS + D) and 36 DS without dextrose. On admission to the hospital, the two groups of patients were similar with respect to enteric pathogens detected, proportion with hyponatremia, magnitude of dehydration as assessed by clinical criteria, serum protein or creatinine concentration, and plasma glucose levels. At the end of the 4-hour infusion, both groups of patients had similar decreases in serum creatinine and protein levels and similar volume of urine output, but patients receiving DS + D had a significantly higher plasma glucose level than patients receiving DS (7.8 mmol/L (140 mg/dl) vs 5.39 mmol/L (97 mg/dl), P less than 0.01). One patient in the DS group had hypoglycemia (plasma glucose 2.0 mmol/L (36 mg/dl) at 4 hours. No other complications were noted. Serum protein values 24 hours after admission were little changed from 4-hour values, suggesting that rehydration was complete at the end of 4 hours. We conclude that, in our patients, rehydration can be carried out safely and rapidly with the use of a single solution and that adding 139 mmol/L (25 gm/L) of dextrose to the solution can prevent hypoglycemia without producing an osmotic diuresis.     

Development of bilirubin transport and metabolism in the newborn rhesus monkey.

Hepatic transport and metabolism of bilirubin have been examined in term, premature, and postmature newborn Macaca mulatta (rhesus) monkeys with and without prior phenobarbital treatment of pregnant mother and neonate. In untreated neonates a biphasic pattern of physiologic unconjugated hyperbilirubinemia has been observed. Phase I was characterized by a rapid increase in serum bilirubin concentration to 4.5 mg/dl by 19 hours and an equally rapid decline to 1.0 mg/dl by 48 hours of age. Phase II was characterized by a stable elevation at 1.0 mg/dl (four times greater than in the adult) from 48 to 96 hourse of age, followed by a decline to normal adult concentrations thereafter. An identical pattern was observed in 29 normal, term human neonates, but the duration of each phase was approximately three times as long as that in the monkey. Phase I hyperbilirubinemia appears to result from a sixfold increase in bilirubin load presented to the liver in the neonatal period, combined with marked deficieny in hepatic bilirubin conjugation, the rate-limiting step during Phase I. Hepatic uptake of bilirubin is not rate limiting during Phase I but may contribute to Phase II hyperbilirubinemia. An increased bilirubin load persists throughout the first 19 days of life in the monkey. Phase I physiologic jaundice in the monkey neonate was completely eliminated by prenatal maternal and neonatal administration of phenobarbital. A threefold enhancement of hepatic conjugation of bilirubin (glucuronyl transferase activity) during Phase I entirely accounted for the prevention of hyperbilirubinemia. The bilirubin load was unaffected by administration of phenobarbital. Whereas in control neonates the bilirubin load slightly exceeded hepatic bilirubin conjugating capacity and resulted in retention of bilirubin, in phenobarbital-treated neonates, hepatic conjugating capacity slightly exceeded that required for the bilirubin load. Administration of phenobarbital failed to alter Phase II hyperbilirubinemia and did not enhance either maximal hepatic uptake or excretion of bilirubin. Hepatic glucuronly transferase activity was increased threefold during Phase II and during the remainder of the neonatal period. Premature birth retarded maturation of hepatic glucuronyl transferase activity. In one phenobarbital-treated premature monkey neonate, there was no apparent response to treatment. Accelerated maturation of bilirubin uptake, conjugation, and excretion of bilirubin was observed in one postmature monkey neonate.     

Effects of Chichorium intybus on bilirubin

Objective  To evaluate the in vitro effects of chichorium intybus on bilirubin levels. Methods  In this study the bilirubin levels in the serum of thirty neonates staying in the NICU and suffering from clinical jaundice was determined three times: first without any alterations, second after adding chichorium intybus extract and third after adding the same amount of distilled water. The results were compared using SPSS statistical software. Results  Of the patients evaluated 76.7% were male and 23.3% were female. The average age was 7.35 days. The mean difference observed in unconjugated bilirubin levels in the specimens containing chichorium intybus extract was 3.84 ± 2.38 mg/dl and in the ones containing distilled water was 2.85 ± 2.00 mg/dl. The mean difference observed in conjugated bilirubin levels was 0.29 ± 0.32 mg/dl in specimens containing distilled water and 0.35 ± 0.26 in the ones containing chichorium intybus. In none of the cases the results were found to be significant. Conclusion  In this study chichorium intybus was found to have no significant in vitro effect on the bilirubin level reported by the laboratory. The in vivo effects of this herbal medicine must be evaluated more closely.     

Determination of Serum Unbound Bilirubin for Prediction of Kernicterus in Low Birthweight infants

Serum unbound bilirubin concentrations (UBC) and serum total bilirubin concentrations (TBC) were measured serially in 138 low birthweight (LBW) infants treated with phototherapy for non-hemolytic hyperbilirubinemia. We attempted to assign the suitable critical UBC levels for predicting bilirubin encephalopathy into two different birthweight groups: a very low birthweight (VLBW) group (birthweight < 1,500 g) and an LBW group (birthweight between 1,500 g and 2,499 g). Twelve infants were diagnosed as 'at risk' for kernicterus, of whom 11 had signs of acute bilirubin encephalopathy and exchange transfusion. One VLBW infant had neurological sequelae at a 3 year follow-up, although exchange transfusion was not carried out because of low TBC.
Sensitivity and specificity for predicting kernicterus were calculated at different UBC levels between 0.6μg/dl and 1.5μg/dl and TBC levels between 8 mg/dl and 26 mg/dl. The receiver-operating characteristic (ROC) curves plotted for UBC as a predictor of kernicterus were clearly shifted up and to the left compared with the curves for TBC in the VLBW and LBW groups. Thus, the UBC measurement may well provide a more rational basis for evaluating the risk of kernicterus in LBW infants. The optimal cut-off points were derived from these curves. In the VLBW group, the sensitivity was 100% and the specificity was 96% for a UBC of 0.8μg/dl, and 80% and 64% for a TBC of 11 mg/dl. In the LBW group, the sensitivity was 100% and the specificity was 98% for a UBC of 1.0μg/dl and 71% and 78% for a TBC of 16 mg/dl. These results suggest that UBC determination is more suitable for predicting kernicterus than TBC in LBW infants with non-hemolytic hyperbilirubinemia.     

Transcutaneous Bilirubinometry in Normal Japanese Infants

We performed TcB readings in healthy full-term breast-fed Japanese infants from birth to seven days, and attempted to establish the normal range. TcB readings from Japanese infants were significantly higher over a longer period compared with Caucasian infants. The age of peak TcB readings in Japanese newborn infants was day 6, significantly later than that of Caucasian infants, day 3–4. We also attempted to estimate the total serum bilirubin concentrations using regression line relating TcB readings to serum bilirubin concentrations. Our study demonstrated that estimated total serum bilirubin concentration from forehead TcB readings was 0.56 ± 0.35 mg/dl at birth, thereafter increasing to 6.8 ±0.5 mg/dl on day 1 and reaching a maximum of 12.6 ± 2.5 mg/d on day 6.These values and pattern in Japanese neonatal jaundice were significantly different from those of Caucasian children, but were similar to values and patterns from American Indians, Alaskan Eskimo, and other Asian full-term newborn infants. Thus TcB measurement may be useful for observation of the course of neonatal jaundice.     

Acute management of extreme neonatal jaundice–––the potential benefits of intensified phototherapy and interruption of enterohepatic bilirubin circulation

Abstract Increasing numbers of neonates are being admitted to hospital because of extreme jaundice. Phototherapy should be very effective in such infants, because the efficacy of phototherapy is proportional to the concentration of bilirubin in the skin. Here, I report on four infants who were admitted for indirect serum bilirubin levels of >500 µmol/1 (>>30mg/dl). In one of them, unrecognized Rhesus immunization was the main cause of hyperbilirubinemia, while in the other three increased enterohepatic circulation of bilirubin was thought to be an important contributory factor. In all four infants phototherapy (11–14 µW/cm²/nm) with whole body exposure plus ad lib feeding with milk were initiated immediately upon admission to the nursery. After 2h serum bilirubin values were reduced by 170–185 µmol/1 (10-11mg/dl) in the first three infants, while in the fourth infant a reduction of 195 µmol/1 (11.3mg/dl) was seen in the 5h interval between the first and second bilirubin measurement. This experience suggests that in some infants with extreme jaundice, intensified phototherapy plus feeding with milk may be very effective in reducing serum bilirubin levels. Even if an exchange transfusion is performed, using this strategy in the waiting period may be beneficial, as both the rapid reduction in serum bilirubin levels as well as the conversion of significant amounts of bilirubin into water-soluble isomers may reduce the risk of neurotoxicity.     

Serum bilirubin levels in 1-month-old,healthy, term infants from southern Turkey

This study investigated bilirubin levels in 282 1-month-old, healthy, term infants from the Adana region in southern Turkey. Total bilirubin was > 5 mg/dl in 20.2% of the infants and > 10 mg/dl in 6% of the group. Thyroid function and levels of alanine aminotransferase, aspartate aminotransferase and glucose-6-phosphate dehydrogenase were determined in babies with bilirubin levels > 5 mg/dl. The results were normal in all but one case, an infant with a bilirubin level of > 10 mg/dl and glucose-6-phosphate dehydrogenase deficiency. The results indicate that in this population a 5-mg/dl cut-off level for further investigation would mean that 20% of all infants would require further evaluation. This is not cost-effective. Based on our findings, we suggest that the cut-off level for investigating prolonged jaundice in term, 1-month-old, healthy infants in the Turkish population should be > 5 mg/dl.