Diagnostic methods for neonatal hyperbilirubinemia: benefits, limitations, requirements, and novel developments.

Invasive bilirubin measurements remain the gold standard for the diagnosis and treatment of infants with severe neonatal hyperbilirubinemia. The present paper describes different methods currently available to assess hyperbilirubinemia in newborn infants. Novel point-of-care bilirubin measurement methods, such as the BiliSpec and the Bilistick, would benefit many newborn infants, especially in low-income and middle-income countries where the access to costly multi-analyzer in vitro diagnostic instruments is limited. Total serum bilirubin test results should be accurate within permissible limits of measurement uncertainty to be fit for clinical purposes. This implies correct implementation of internationally endorsed reference measurement systems as well as participation in external quality assessment programs. Novel analytic methods may, apart from bilirubin, include the determination of bilirubin photoisomers and bilirubin oxidation products in blood and even in other biological matrices. IMPACT: Key message: Bilirubin measurements in blood remain the gold standard for diagnosis and treatment of severe neonatal hyperbilirubinemia (SNH). External quality assessment (EQA) plays an important role in revealing inaccuracies in diagnostic bilirubin measurements. What does this article add to the existing literature? We provide analytic performance data on total serum bilirubin (TSB) as measured during recent EQA surveys. We review novel diagnostic point-of-care (POC) bilirubin measurement methods and analytic methods for determining bilirubin levels in biological matrices other than blood. Impact: Manufacturers should make TSB test results traceable to the internationally endorsed total bilirubin reference measurement system and should ensure permissible limits of measurement uncertainty.

Screening methods for neonatal hyperbilirubinemia: benefits, limitations, requirements, and novel developments.

Severe neonatal hyperbilirubinemia (SNH) is a serious condition that occurs worldwide. Timely recognition with bilirubin determination is key in the management of SNH. Visual assessment of jaundice is unreliable. Fortunately, transcutaneous bilirubin measurement for screening newborn infants is routinely available in many hospitals and outpatient settings. Despite a few limitations, the use of transcutaneous devices facilitates early recognition and appropriate management of neonatal jaundice. Unfortunately, however, advanced and often costly screening modalities are not accessible to everyone, while there is an urgent need for inexpensive yet accurate instruments to assess total serum bilirubin (TSB). In the near future, novel icterometers, and in particular optical bilirubin estimates obtained with a smartphone camera and processed with a smartphone application (app), seem promising methods for screening for SNH. If proven reliable, these methods may empower outpatient health workers as well as parents at home to detect jaundice using a simple portable device. Successful implementation of ubiquitous bilirubin screening may contribute substantially to the reduction of the worldwide burden of SNH. The benefits of non-invasive bilirubin screening notwithstanding, any bilirubin determination obtained through non-invasive screening must be confirmed by a diagnostic method before treatment. IMPACT: Key message: Screening methods for neonatal hyperbilirubinemia facilitate early recognition and timely treatment of severe neonatal hyperbilirubinemia (SNH). Any bilirubin screening result obtained must be confirmed by a diagnostic method. What does this article add to the existing literature? Data on optical bilirubin estimation are summarized. Niche research strategies for prevention of SNH are presented. Impact: Transcutaneous screening for neonatal hyperbilirubinemia contributes to the prevention of SNH. A smartphone application with optical bilirubin estimation seems a promising low-cost screening method, especially in low-resource settings or at home.

Maternal Instruction About Jaundice and the Incidence of Acute Bilirubin Encephalopathy in Nigeria.

OBJECTIVE: To evaluate whether teaching mothers about neonatal jaundice will decrease the incidence of acute bilirubin encephalopathy among infants admitted for jaundice. STUDY DESIGN: This was a multicenter, before-after and cross-sectional study. Baseline incidences of encephalopathy were obtained at 4 collaborating medical centers between January 2014 and May 2015 (Phase 1). Structured jaundice instruction was then offered (May to November 2015; Phase 2) in antenatal clinics and postpartum. Descriptive statistics and logistic regression models compared 3 groups: 843 Phase 1 controls, 338 Phase 2 infants whose mothers received both antenatal and postnatal instruction (group A), and 215 Phase 2 infants whose mothers received no instruction (group B) either because the program was not offered to them or by choice. RESULTS: Acute bilirubin encephalopathy occurred in 147 of 843 (17%) Phase 1 and 85 of 659 (13%) Phase 2 admissions, which included 63 of 215 (29%) group B and 5 of 338 (1.5%) group A infants. OR for having acute bilirubin encephalopathy, comparing group A and group B infants adjusted for confounding risk factors, was 0.12 (95% CI 0.03-0.60). Delayed care-seeking (defined as an admission total bilirubin ≥18 mg/dL at age ≥48 hours) was the strongest single predictor of acute bilirubin encephalopathy (OR 11.4; 6.6-19.5). Instruction decreased delay from 49% to 17%. Other major risk factors were home births (OR 2.67; 1.69-4.22) and hemolytic disease (hematocrit ≤35% plus bilirubin ≥20 mg/dL) (OR 3.03; 1.77-5.18). The greater rate of acute bilirubin encephalopathy with home vs hospital birth disappeared if mothers received jaundice instruction. CONCLUSIONS: Providing information about jaundice to mothers was associated with a reduction in the incidence of bilirubin encephalopathy per hospital admission.

Diagnostic Performance Analysis of the Point-of-Care Bilistick System in Identifying Severe Neonatal Hyperbilirubinemia by a Multi-Country Approach.

IMPORTANCE: The real prevalence and clinical burden of severe neonatal jaundice are undefined due to difficulties in measuring total serum bilirubin (TSB) outside secondary and tertiary clinical centers. OBJECTIVE: To assess the diagnostic performance of the point-of care Bilistick System (BS) in identifying neonatal jaundice patients requiring treatment. DESIGN: Between April 2015 and November 2016, 1911 neonates, were recruited to participate in the study. Blood samples were simultaneously collected for the TSB determination by BS and by hospital laboratory (Lab). Data were collected and sent to the Bilimetrix headquarter in Trieste where statistical analysis was performed. Newborns with neonatal jaundice were treated with phototherapy according to each center's guidelines. SETTING: 17 hospitals from Nigeria, Egypt, Indonesia, and Viet Nam. PARTICIPANTS: 1911 newborns were included, of which 1458 (76·3%) fulfilled the inclusion criteria. RESULTS: TSB level measured by BS agreed (p < .0001) with the lab result in all four countries. The diagnostic performance of BS showed a positive predictive value (PPV) of 92·5% and a negative predictive value (NPV) of 92·8%. CONCLUSIONS AND RELEVANCE: BS is a reliable system to detect neonatal jaundice over a wide range of bilirubin levels. Since Bilistick is a point-of-care test, its use may provide appropriate and timely identification of jaundiced newborns requiring treatment.

Neonatal Jaundice in Low- and Middle-Income Countries: Lessons and Future Directions from the 2015 Don Ostrow Trieste Yellow Retreat.

Severe neonatal hyperbilirubinemia, defined as total serum bilirubin (TSB) ≥20 mg/dl, is associated with a higher risk of permanent neurological sequelae and death. Jaundice can and should be promptly diagnosed and treated. Reliable methods for TSB assay are not always readily available, particularly in low- and middle-income countries, making the true incidence of severe neonatal jaundice (NNJ) difficult to estimate. To gather a more comprehensive picture, a symposium addressing NNJ worldwide was organized during the 2015 Don Ostrow Trieste Yellow Retreat. Data collected by several researchers in different regions of the world were presented and differences/similarities discussed. This report points out the need for: (1) a coordinated worldwide effort to define the burden and the causes of severe NNJ and its consequences; (2) aggressive educational programs for families and health personnel to facilitate timely care-seeking, and (3) accurate diagnostics and effective phototherapy.

Functional induction of the cystine-glutamate exchanger system Xc(-) activity in SH-SY5Y cells by unconjugated bilirubin.

We have previously reported that exposure of SH-SY5Y neuroblastoma cells to unconjugated bilirubin (UCB) resulted in a marked up-regulation of the mRNA encoding for the Na(+)-independent cystine∶glutamate exchanger System X(c)(-) (SLC7A11 and SLC3A2 genes). In this study we demonstrate that SH-SY5Y cells treated with UCB showed a higher cystine uptake due to a significant and specific increase in the activity of System X(c)(-), without the contribution of the others two cystine transporters (X(AG)(-) and GGT) reported in neurons. The total intracellular glutathione content was 2 folds higher in the cells exposed to bilirubin as compared to controls, suggesting that the internalized cystine is used for gluthathione synthesis. Interestingly, these cells were significantly less sensitive to an oxidative insult induced by hydrogen peroxide. If System X(c)(-) is silenced the protection is lost. In conclusion, these results suggest that bilirubin can modulate the gluthathione levels in neuroblastoma cells through the induction of the System X(c)(-), and this renders the cell less prone to oxidative damage.

Morphological and biochemical analysis of human cardiac valve allografts after an increment of the cryostorage temperature.

Cryopreserved human cardiac valve allografts could suffer lethal damages if the temperature is elevated during cryostorage. This work describes the functional and morphological alterations suffered by human cardiac valve allografts after a gradual increment of the cryostorage temperature from -147 degrees C to -47 degrees C due to a technical failure. Three experimental groups of human pulmonary and aortic allografts were compared: fresh, cryopreserved (-147 degrees C) and cryopreserved with temperature changes from -147 degrees C up to -47 degrees C and back to -147 degrees C. Fibroblast functionality was studied to asses the degree of valvular damages. Collagen network was also analyzed with bright light field and polarized microscopy; an immunohistochemistry for procollagen I was performed and the MTT colorimetric assay was used to evaluate fibroblast mitochondrial enzymatic activity. Porcine heart grafts valves were used to set the MTT colorimetric assay. With bright light field microscopy, disorganized collagen network was seen together with interstitial edema in cryopreserved groups. Polarized microscopy showed that fresh allografts had abundant collagen type I and III, cryopreserved group had less amount of collagen type I and in allografts that suffered cryopreservation temperature elevation collagen type I synthesis could not been demonstrated. Procollagen I was present in fibroblast cytoplasm of fresh group, but it was diminished in cryopreserved group and was absent in the group that suffered temperature elevation. Temperature changes during the cryopreservation period of human cardiac valve allografts induced fibroblast activity reduction. When the cryopreservation temperature is elevated during cryostorage, fibroblasts lost their functionality and the allografts may be not suitable for transplant.