Bilirubin: The yellow hormone?

Bilirubin is a tetrapyrrolic compound originating from heme catabolism. Although originally considered only a potentially dangerous waste product, it has become increasingly evident that this molecule represents an important modulator of various biological functions in the human body. Bilirubin appears to have versatile functions, from cell signaling (behaving almost like a "real" hormonal substance), modulation of metabolism, to immune regulation, affecting biological activities with apparent clinical and even therapeutic consequences. These activities may be the reason for the lower incidence of diseases of civilisation (cardiovascular diseases, arterial hypertension, diabetes, obesity, metabolic syndrome, certain cancers, autoimmune, and neurodegenerative diseases) observed in individuals with a chronic mild unconjugated hyperbilirubinemia, a typical sign of Gilbert's syndrome. While higher serum concentrations of unconjugated bilirubin may serve as an important protective factor against these diseases, low levels of bilirubin are associated with the opposite effect.

The influence of hyperbilirubinemia on indexes of kidney function in neonates.

BACKGROUND: To study the influence of hyperbilirubinemia on indexes of neonatal kidney function. METHODS: A prospective cohort study was conducted September 2019 to March 2020 in Neonatology Department of Xuzhou Central Hospital. Neonates with gestational age ≥ 35 weeks and aged ≤ 7 days were included and divided into mild, moderate, and severe groups according to total serum bilirubin level. Epidemiologic and demographic data and daily urine output were recorded. Total serum bilirubin, serum creatinine, serum cystatin C, serum neutrophil gelatinase-associated lipocalin (NGAL), urine NGAL, and kidney injury molecule-1 were tested before and 12~18 h after phototherapy. Parameters of kidney function were compared between groups. RESULTS: Fifty-three, 52, and 49 neonates were included in the mild, moderate, and severe groups, respectively. Urine NGAL was higher in severe (1.36 ± 0.24 µg/L) compared to moderate (1.22 ± 0.19 µg/L) and mild groups (1.16 ± 0.19 µg/L), and differences were statistically significant (P = 0.004 and < 0.001, respectively). Urine NGAL was not significantly different between moderate and mild groups (P > 0.05). No significant differences in other kidney function indexes were observed between the three groups (all P > 0.05). Significant reduction in urine NGAL levels 12~18 h after stopping phototherapy was found in severe group ((1.17 ± 0.28) µg/L vs. (1.35 ± 0.23) µg/L, P < 0.001). Urine NGAL positively correlated with total serum bilirubin (r = 0.575, P < 0.001). Among all cases, neither serum creatinine nor daily urine output met neonatal acute kidney injury diagnostic criteria. CONCLUSION: Severe hyperbilirubinemia may temporarily impair renal tubular reabsorption functions in full-term and near-term neonates, which is likely reversible. However, it has little effect on glomerular filtration function. A higher resolution version of the Graphical abstract is available as Supplementary information.

The Extent of Intracellular Accumulation of Bilirubin Determines Its Anti- or Pro-Oxidant Effect.

BACKGROUND: Severe hyperbilirubinemia can cause permanent neurological damage in particular in neonates, whereas mildly elevated serum bilirubin protects from various oxidative stress-mediated diseases. The present work aimed to establish the intracellular unconjugated bilirubin concentrations (iUCB) thresholds differentiating between anti- and pro-oxidant effects. METHODS: Hepatic (HepG2), heart endothelial (H5V), kidney tubular (HK2) and neuronal (SH-SY5Y) cell lines were exposed to increasing concentration of bilirubin. iUCB, cytotoxicity, intracellular reactive oxygen species (ROS) concentrations, and antioxidant capacity (50% efficacy concentration (EC50)) were determined. RESULTS: Exposure of SH-SY5Y to UCB concentration > 3.6 µM (iUCB of 25 ng/mg) and >15 µM in H5V and HK2 cells (iUCB of 40 ng/mg) increased intracellular ROS production (p < 0.05). EC50 of the antioxidant activity was 21 µM (iUCB between 5.4 and 21 ng/mg) in HepG2 cells, 0.68 µM (iUCB between 3.3 and 7.5 ng/mg) in SH-SY5Y cells, 2.4 µM (iUCB between 3 and 6.7 ng/mg) in HK2 cells, and 4 µM (iUCB between 4.7 and 7.5 ng/mg) in H5V cells. CONCLUSIONS: In all the cell lines studied, iUCB of around 7 ng/mg protein had antioxidant activities, while iUCB > 25 ng/mg protein resulted in a prooxidant and cytotoxic effects. UCB metabolism was found to be cell-specific resulting in different iUCB.

Cereblon gene variants and clinical outcome in multiple myeloma patients treated with lenalidomide.

Carfilzomib-lenalidomide-dexamethasone (KRd) therapy has yielded promising results in patients with newly diagnosed multiple myeloma (NDMM). Cereblon (CRBN) is the direct molecular target of lenalidomide and genetic polymorphisms in CRBN have been associated with lenalidomide efficacy. In this study, we assessed the correlation of five single nucleotide variants (SNVs) in the CRBN gene with clinical response and outcomes in patients with NDMM administered KRd therapy with lenalidomide maintenance, achieving favorable trial endpoints in a prospective Phase II study (NCT01402284). Of the observed SNVs, no associations with KRd therapy response were found in this patient cohort, although strong trends in hypoalbuminemia grade and hyperbilirubinemia grade emerged across the CRBN rs1672753 genotype (P = 0.0008) and the rs1714327 genotype (P = 0.0010), respectively. Our results do not provide conclusive support for the predictive utility of CRBN gene polymorphisms as potential biomarkers of clinical response to lenalidomide-based therapy in our patient population. However, these findings remain to be validated in prospective studies using larger patient populations.

Cholestasis affects enteral tolerance and prospective weight gain in the NICU.

BACKGROUND: Intestinal Failure-Associated Liver Disease is characterized by cholestasis and hepatic dysfunction due to parenteral nutrition (PN) therapy. We described key features of cholestatic infants receiving PN to assess overall outcomes in this population at our institution. METHODS: This is a retrospective single center study of 163 neonates grouped into cholestatic (n = 63) and non-cholestatic (n = 100) as defined by peak conjugated bilirubin of ≥2.0 mg/dL or < 0.8 mg/dL, respectively. Univariate and multiple regression models were used to study associations between variables and outcomes of interest. RESULTS: Lower Apgar scores (4 ± 3 vs. 6 ± 3, p-value = <0.005 at 1 min; 6 ± 2 vs. 7 ± 2, p < 0.005 at 5 min) and lower birth weight (adj ß [SE] = 0.62 [0.27], p-value = 0.024) were risk factors for developing cholestasis. Cholestatic infants were more likely to have had gastrointestinal surgery (31 [49%] vs. 15 [15%], p-value <0.005), received PN for a longer duration (40 ± 39 days vs. 11 ± 7 days, p-value <0.005), and started enteral feeds later in life (86 ± 23 days vs. 79 ± 20 days, p-value <0.005) when compared to non-cholestatic infants. Weight percentiles in cholestatic infants were lower both at hospital discharge (14 ± 19 vs. 24 ± 22, p-value <0.005) and at 6 months of age (24 ± 28 vs. 36 ± 31, p-value = 0.05). CONCLUSIONS: Cholestasis in the NICU is a multifactorial process, but it has a long lasting effect on prospective weight gain in infants who receive PN in the NICU. This finding highlights the importance of follow-up for adequate growth and the potential benefit from aggressive nutritional support.

Jaundice in the emergency department: meeting the challenges of diagnosis and treatment [digest].

There are approximately 52,000 visits a year to emergency departments for patients presenting with jaundice. While many of these patients will not have immediately life-threatening pathology, it is essential that the emergency clinician understands the pathophysiology of jaundice, as this will guide the appropriate workup to detect critical diagnoses. Patients who present with jaundice could require intravenous antibiotics, emergent surgery, and, in severe cases, organ transplantation. This issue will focus on the challenge of evaluating and treating the jaundiced patient in the ED using the best available evidence from the literature. [Points & Pearls is a digest of Emergency Medicine Practice.].

Jaundice in the emergency department: meeting the challenges of diagnosis and treatment.

There are approximately 52,000 visits a year to emergency departments for patients presenting with jaundice. While many of these patients will not have immediately life-threatening pathology, it is essential that the emergency clinician understands the pathophysiology of jaundice, as this will guide the appropriate workup to detect critical diagnoses. Patients who present with jaundice could require intravenous antibiotics, emergent surgery, and, in severe cases, organ transplantation. This issue will focus on the challenge of evaluating and treating the jaundiced patient in the ED using the best available evidence from the literature.

Impact of Postoperative Liver Dysfunction on Survival After Left Ventricular Assist Device Implantation.

BACKGROUND: Liver dysfunction in left ventricular assist device (LVAD) recipients is common both before and after implantation. Postoperative liver dysfunction (PLD) develops in some LVAD recipients without preoperative liver dysfunction. The aim of this study was to assess clinical outcomes in such patients. METHODS: Records of all patients undergoing implantation of a HeartMate II (HM II, St. Jude Medical, Inc, Minneapolis, MN) LVAD at a single center at the University of Minnesota from January 2005 through June 2014 were analyzed. PLD was defined by hypertransaminasemia or hyperbilirubinemia, or both, during the hospitalization for LVAD implantation. RESULTS: During the study period, 284 patients underwent HM II implantation. Excluded from analysis were 14 recipients with preoperative liver dysfunction. In the final cohort (n = 270), there were no major difference in preoperative characteristics among those patients with versus without PLD. PLD developed in 129 (47.8%) recipients: 16 (12.4%) had isolated hypertransaminasemia (group I), 76 (58.9%) had isolated hyperbilirubinemia (group II), and 37 (28.7%) had combined hypertransaminasemia and hyperbilirubinemia (group III). Group III LVAD recipients had significantly greater rates of 30-day, 90-day, and 1-year mortality, along with significantly higher transfusion requirements and higher rates of renal replacement therapy, prolonged ventilation, and vasopressor use. Moreover, their mortality risk was significantly higher than that of PLD-free LVAD recipients (hazard ratio, 4.6; 95% confidence interval, 2.1 to 10.1; p < 0.001). CONCLUSIONS: Isolated hyperbilirubinemia is common after LVAD implantation. In this study, it was not associated with an increase in early or midterm postoperative mortality. However, postoperative combined transaminasemia and hyperbilirubinemia was associated with a significant increase in early and midterm morbidity and mortality. Further research into the pathogenesis of post-LVAD PLD is necessary.

Hyperbilirubinemia and phototherapy in newborns: Effects on cardiac autonomic control.

BACKGROUND: Neonatal jaundice and its phototherapeutic treatment can lead to several side effects involving activation of autonomic control mechanisms. AIM: The aims of this study are to investigate the autonomic nervous system changes in icteric neonates using heart rate variability (HRV) and to assess the effect of phototherapy on short-term heart rate dynamics as an indicator of autonomic nervous control of cardiovascular system. METHODS: HRV recordings from 20 icteric full-term neonates before, during and after phototherapy and from 20 healthy controls were analyzed. In addition to traditional time and frequency domain measures, heart rate complexity parameters including normalized complexity index (NCI), normalized unpredictability index (NUPI), pattern classification indices (0V%, 1V%, 2LV%, 2UV%) and irreversibility index (P%) on four time scales were evaluated. All measures were derived from data segments of 1000 RR intervals. RESULTS: The analysis revealed higher values of 1V%, 2LV%, and lower P% in neonates with hyperbilirubinemia compared to controls. While HRV magnitude did not change, mean heart rate increased during and after the phototherapy. Nonlinear analysis showed a decrease of complexity, unpredictability and pattern classification measures 2LV% and 2UV%. In contrast, 0V% and irreversibility index P% were increased during and at least 30min after phototherapy. CONCLUSION: The results suggest a shifted autonomic balance in icteric neonates compared to the controls and its further alterations during phototherapy. As the nonlinear HRV parameters are independent of the linear methods, they can provide new information about the cardiac regulatory mechanisms and their changes in neonates.

Transient severe hyperbilirubinemia after hepatic arterial infusion of oxaliplatin in patients with liver metastases.

PURPOSE: We have observed severe, but rapidly reversible, hyperbilirubinemia in patients receiving hepatic arterial infusion (HAI) of oxaliplatin. We performed a retrospective analysis to characterize this unusual phenomenon. METHODS: We reviewed the electronic medical records of 113 consecutive patients receiving HAI oxaliplatin to describe the associated hyperbilirubinemia. RESULTS: Four of 113 patients (3.5 %) presented with transient, severe (grade 3/4) hyperbilirubinemia post-HAI oxaliplatin. Peak levels of total bilirubin within 10-16 h of starting HAI oxaliplatin were 4.6, 12.2, 12.8, and 21.2 mg/dL and declined rapidly (within 24 after stopping treatment). One out of four patients experienced severe abdominal pain, and another patient had an infusion reaction (hypertension and hypoxemia) that reversed after discontinuation of infusion. Total bilirubin was predominantly direct. No significant decline in hemoglobin or increase in alkaline phosphatase occurred. Increase in liver transaminases post-infusion was mild to moderate (grades 1-3) and was seen after HAI oxaliplatin regardless of the emerged hyperbilirubinemia. CONCLUSIONS: Severe hyperbilirubinemia is a rare but rapidly reversible adverse effect of HAI oxaliplatin and may be accompanied by an abdominal pain syndrome or infusion reaction. Treating physicians should be aware for the potential of this reaction. The mechanism of this unusual reaction merits further investigation.

Investigação de icterícia / Investigation of jaudice

Este trabalho é uma revisão da literatura sobre como investigar a icterícia no paciente adulto. Para isso, é imprescindível entender o metabolismo da bilirrubina, a fisiopatologia da hiperbilirrubinema e reconhecer os principais diagnósticos diferenciais de icterícia no adulto.

This article is a literature review on jaundice investigation in adult patients. Therefore, it is necessary for the understanding, knowing about the metabolism of bilirubin and the pathophysiology of hyperbilirrubinemia as well as recognizing the main differential diagnoses of jaundice in adults.

Conjugated hyperbilirubinemia in children.

A variety of anatomic, infectious, autoimmune, and metabolic diseases can lead to conjugated hyperbilirubinemia, both in the newborn period and later in childhood. The pediatric practitioner is most likely to encounter conjugated hyperbilirubinemia in the neonatal period.It is crucial to maintain a high degree of suspicion for cholestasis in the persistently jaundiced newborn. The goal is recognition of conjugated hyperbilirubinemia between 2 and 4 weeks after birth, allowing for the prompt identification and management of infants who have biliary atresia, which remains the most common cause of neonatal cholestasis.

Síntese e metabolismo da bilirrubina e fisiopatologia da hiperbilirrubinemia associados à Síndrome de Gilbert: revisão de literatura / Bilirubin synthesis and metabolism, and hyperbilirubinemia associated with Gilbert’s Syndrome: A review of the literature

A icterícia é sinal clínico comum a várias condições patológicas, podendo ser evidenciada em vários locais do organismo devido à grande capacidade de impregnação do pigmento biliar. A icterícia torna-se evidente quando a concentração plasmática encontra-se acima de 2,5 a 3,0 mg/dL. O presente trabalho retrata o metabolismo fisiológico dos pigmentos biliares concomitantemente com a síntese e metabolismo de bilirrubina, assim como processos fisiopatológicos causados pelo aumento da bilirrubina plasmática (hiperbilirrubinemia), como ocorre na síndrome de Gilbert, caracterizada pela deficiência enzimática, que se manifesta clinicamente como icterícia. Compreender os passos da formação e excreção da bilirrubina é fundamental para a compreensão das manifestações clínicas e que ocorrem na icterícia, facilitando o entendimento dos mecanismos fisiopatológicos da hiperbilirrubinemia, como ocorrem na síndrome de Gilbert.

Jaundice is a common clinical manifestation of several pathological conditions. It can be found in several parts of the body because of the high impregnation capacity of the bile pigment. Jaundice is evident when plasmatic concentration is higher than 2.5 ? 3.0 mg/dL. This paper describes the physiological metabolism of bile pigments concomitantly with bilirubin synthesis and metabolism, as well as the pathophysiological processes derived from increased plasmatic bilirubin (hyperbilirubinemia). This is a circumstance typical of the Gilbert?s syndrome, which causes enzymatic deficiency that is clinically manifested as jaundice. Knowledge of the steps of bilirubin formation and excretion is crucial to shed light into the clinical manifestations of jaundice and thus gain more understanding of the physiological mechanisms of hyperbilirubinema associated with Gilbert?s syndrome.

Primary graft dysfunction after living donor liver transplantation is characterized by delayed functional hyperbilirubinemia.

The purpose of this study is to propose a new concept of primary graft dysfunction (PGD) after living donor liver transplantation (LDLT), characterized by delayed functional hyperbilirubinemia (DFH) and a high early graft mortality rate. A total of 210 adult-to-adult LDLT grafts without anatomical, immunological or hepatitis-related issues were included. All of the grafts with early mortality (n = 13) caused by PGD in LDLT had maximum total bilirubin levels >20 mg/dL after postoperative day 7 (p < 0.001). No other factors, including prothrombin time, ammonia level or ascites output after surgery were associated with early mortality. Thus, DFH of >20 mg/dL for >seven consecutive days occurring after postoperative day 7 (DFH-20) was used to characterize PGD. DFH-20 showed high sensitivity (100%) and specificity (95.4%) for PGD with early mortality. Among the grafts with DFH-20 (n = 22), those with early mortality (n = 13) showed coagulopathy (PT-INR > 2), compared with those without mortality (p = 0.002). Pathological findings in the grafts with DFH-20 included hepatocyte ballooning and cholestasis, which were particularly prominent in the centrilobular zone. PGD after LDLT is associated with DFH-20 caused by graft, recipient and surgical factors, and increases the risk of early graft mortality.

Critical illness evokes elevated circulating bile acids related to altered hepatic transporter and nuclear receptor expression.

UNLABELLED: Hyperbilirubinemia is common during critical illness and is associated with adverse outcome. Whether hyperbilirubinemia reflects intensive care unit (ICU) cholestasis is unclear. Therefore, the aim of this study was to analyze hyperbilirubinemia in conjunction with serum bile acids (BAs) and the key steps in BA synthesis, transport, and regulation by nuclear receptors (NRs). Serum BA and bilirubin levels were determined in 130 ICU and 20 control patients. In liver biopsies messenger RNA (mRNA) expression of BA synthesis enzymes, BA transporters, and NRs was assessed. In a subset (40 ICU / 10 controls) immunohistochemical staining of the transporters and receptors together with a histological evaluation of cholestasis was performed. BA levels were much more elevated than bilirubin in ICU patients. Conjugated cholic acid (CA) and chenodeoxycholic acid (CDCA) were elevated, with an increased CA/CDCA ratio. Unconjugated BA did not differ between controls and patients. Despite elevated serum BA levels, CYP7A1 protein, the rate-limiting enzyme in BA synthesis, was not lowered in ICU patients. Also, protein expression of the apical bile salt export pump (BSEP) was decreased, whereas multidrug resistance-associated protein (MRP) 3 was strongly increased at the basolateral side. This reversal of BA transport toward the sinusoidal blood compartment is in line with the increased serum conjugated BA levels. Immunostaining showed marked down-regulation of nuclear farnesoid X receptor, retinoid X receptor alpha, constitutive androstane receptor, and pregnane X receptor nuclear protein levels. CONCLUSION: Failure to inhibit BA synthesis, up-regulate canalicular BA export, and localize pivotal NR in the hepatocytic nuclei may indicate dysfunctional feedback regulation by increased BA levels. Alternatively, critical illness may result in maintained BA synthesis (CYP7A1), reversal of normal BA transport (BSEP/MRP3), and inhibition of the BA sensor (FXR/RXRα) to increase serum BA levels.

Hemofiltration for hyperbilirubinemia after left ventricular assist system implantation: report of four cases.

We hypothesized that the use of hemofiltration (HF) to reduce cytokines may attenuate the hyperbilirubinemia that often develops after left ventricular assist system (LVAS) implantation. Four patients with hyperbilirubinemia after LVAS implantation underwent HF continuously for 7 days. Blood samples were collected and the serum concentrations of total bilirubin (T-Bil), interleukin (IL)-6, and IL-8 were measured. We also measured the serum concentrations of IL-6 and IL-8 in the blood flowing into and out of the filter. Two patients had reduced serum concentrations of IL-6, IL-8, and T-Bil, but the other two did not, despite the effective filtration of these cytokines. Our findings suggest that the reduction of cytokines by HF may assist in the treatment of hyperbilirubinemia after LVAS placement in some patients.

Surveillance of extreme hyperbilirubinaemia in Denmark. A method to identify the newborn infants.

AIM: To describe the incidence of infants born at term or near-term with extreme hyperbilirubinaemia. METHODS: The study period was between 1 January 2002 and 31 December 2005, and included all infants born alive at term or near-term in Denmark. Medical reports on all newborn infants with a total serum bilirubin concentration (TSB) > or = 450 micromol/L were obtained by linking laboratory data to the unique Danish personal identification number. RESULTS: In total, 113 infants were included, that is, an incidence of 45/100,000 live births. Thirty-seven infants presented in hospital, 2 after home birth and the others after having been discharged. The maximum TSB was 485 (450-734) micromol/L (median [range]) and appeared latest amongst those infants admitted from home, but was not different from the maximum TSB of the nondischarged infants. Forty-three infants had symptoms of early-phase acute bilirubin encephalopathy; one infant had advanced-phase symptoms. Four infants received an exchange transfusion. ABO blood group incompatibility was present in 52 infants. Thirty-seven infants were of non-Caucasian descent. CONCLUSION: A method to obtain the national epidemiological data is presented. The observed incidence of extreme hyperbilirubinaemia is higher than previously reported in Denmark. This is mainly due to a very sensitive method of identifying the study group.

NIM811, a mitochondrial permeability transition inhibitor, prevents mitochondrial depolarization in small-for-size rat liver grafts.

ATP decreases markedly in small-for-size liver grafts. This study tested if the mitochondrial permeability transition (MPT) underlies dysfunction of small-for-size livers. Half-size livers were implanted into recipients of about twice the donor weight, resulting in quarter-size liver grafts. NIM811 (5 microM), a nonimmunosuppressive MPT inhibitor was added to the storage solutions. Mitochondrial polarization and cell death were assessed by confocal microscopy of rhodamine 123 (Rh123) and propidium iodide (PI), respectively. After quarter-size transplantation, alanine aminotransferase (ALT), serum bilirubin and necrosis all increased. NIM811 blocked these increases by >70%. After 38 h, BrdU labeling, a marker of cell proliferation and graft weight increase were 3% and 5%, respectively, which NIM811 increased to 30% and 42%. NIM811 also increased survival of quarter-size grafts. In sham-operated livers, hepatocytes exhibited punctate Rh123 fluorescence. By contrast, in quarter-size grafts at 18 h after implantation, mitochondria of most hepatocytes did not take up Rh123, indicating mitochondrial depolarization. Nearly all hepatocytes not taking up Rh123 continued to exclude PI at 18 h, indicating that depolarization preceded cell death. NIM811 and free radical-scavenging polyphenols strongly attenuated mitochondrial depolarization. In conclusion, mitochondria depolarized after quarter-size liver transplantation. NIM811 decreased injury and stimulated regeneration, probably by inhibiting free radical-dependent MPT onset.

Visual evoked potentials in neonatal hyperbilirubinemia.

The management of neonatal hyperbilirubinemia is very standardized. However, there is a lack of an objective method to evaluate the cerebral effects of bilirubin apart from brainstem auditory evoked potentials. There were few studies evaluating the effects of hyperbilirubinemia or phototherapy on the visual pathway in infants with hyperbilirubinemia. Serial visual evoked potentials of two groups of term neonates (N = 24)--group 1 with moderate hyperbilirubinemia (n = 16) and group 2 with severe hyperbilirubinemia (n = 8)--were evaluated prospectively. All infants had regular physical, neurologic, visual, and auditory evaluations until 3 years. Four (16%) had abnormal visual evoked potentials before 1 year, and the abnormalities returned to normal thereafter. There was no significant difference in visual evoked potentials between the two groups. All had normal neurodevelopmental status by 3 years, with the exception of one child from the severe group with ABO incompatibility with transient mild motor delay, hypotonia, and abnormal visual evoked potential. There were no abnormal effects of phototherapy on visual evoked potentials in infants with neonatal hyperbilirubinemia after 1 year of age. Although our sample size was small, the results suggest that the effects of hyperbilirubinemia on visual evoked potentials might be transient. (J Child Neurol 2006;21:58-62).

[Characteristics of hearing loss in 299 high-risk neonates].

OBJECTIVE: To compare the occurrence of hearing loss in neonates with hyperbilirubinemia, hypoxic-ischemic encephalopathy (HIE) and very low-birth weight infant (VLBW) body mass, and to provide evidence for early intervention. METHODS: Totally 299 high-risk neonates (598 ears) were divided into six groups: pure hyperbilirubinemia group, pure HIE group, hyperbilirubinemia with HIE group, hyperbilirubinemia with VLBW group, HIE with LBWI group, hyperbilirubinemia with VLBW and HIE mass group. Auditory brainstem response (ABR) was detected in all groups. RESULTS: The hearing threshold of ABR and the abnormal rate of hyperbilirubinemia with LBWI and HIE were much higher than that of pure hyperbilirubinemia and pure HIE neonates. CONCLUSIONS: Of the three high-risk factors, hearing loss occurs more often and more serious in neonates with hyperbilirubinemia and with VLBW while as HIE body mass. So the babies should receive hearing screening with ABR and be treated in time or following up as early as possible.