SBIR-STTR Award

Human serum albumin is capable of binding bilirubin with high affinity, thus sequestering it and mitigat- ing its harmful neurological effects in jaundiced newborns. Despite considerable work indicating that the level of bilirubin in the blood relative to the level of albumin binding sites is a key factor in assessing risk for bilirubin associated brain damage, management of neonatal jaundice remains based upon proxies, such as gestational age and birth weight along with the bilirubin level. A number of methods for assaying the bilirubin level now ex- ist. The common approaches determine the total serum bilirubin by wet chemical methods. Methods to assay reserve albumin binding capacity and unbound (mobilized) bilirubin levels in serum have been developed over the years but none have achieved routine use because they remain cumbersome laboratory tests. The pro- posed work is to develop a point-of-care system (a small fluorometer and disposables) that makes use of bili- rubin's natural fluorescence. Bilirubin bound to albumin produces a fluorescence signal that can be detected in raw blood. Assayed by fluorescence this albumin-bound bilirubin level equates to the total serum bilirubin by standard methods since the unbound bilirubin level is always much smaller until albumin binding approaches saturation. The reserve binding capacity for bilirubin can be measured by adding excess bilirubin to the blood, with the increase in fluorescence being due to the newly bound bilirubin. This approach measures the actual binding capacity and naturally takes into account factors such as albumin levels, competing binding by other solutes and weakened binding sites. The basic studies leading to this fluorometric approach were reported more than thirty years ago and prototype laboratory-bound instruments were devised and tested in clinical settings. At that time new manage- ment guidelines in the absence of binding data coupled with wide use of phototherapy obviated their use. With the current practice of very early release of apparently healthy newborns and susbsequent development of jaundice at home, management has become complicated. Interviews with pediatricians "on the ground" have indicated that an inexpensive and easy to use point-of-care system that requires only a "heel stick" quantity of blood and essentially no manipulation of the specimen, would provide for better management from the ability to provide a stat bilirubin level alone, and binding data would additionally provide guidance in management that may be more efficient and less costly. Use at crib-side should also benefit the management of the jaundiced hospitalized low-birth-weight and sick neonate. While apparently feasible with modern optoelectronic technology, several design and practical chal- lenges exist for the development of such a small point-of-care system. The proposed work will confront and overcome these challenges.

Public Health Relevance:
Kernicterus is a preventable brain injury in neonates, and it is reemerging in the USA (1-5). Present-day methods of assaying bilirubin do not take into account a child's ability to safely sequester bilirubin and must be interpreted in terms of gestational age, age, weight and other factors (6). The proposed hematofluorometer directly measures bilirubin binding and reserve bilirubin binding capacity, and has the potentials to be faster, less expensive and available at the point of care.

Thesaurus Terms:
0-11 Years Old; 0-6 Weeks Old; 21h-Biline-8,12-Dipropanoic Acid, 2,17-Diethenyl-1,10,19,22,23,24-Hexahydro-3,7,13,18-Tetramethyl-1,19-Dioxo-; Accounting; Acquired Brain Injury; Actinotherapy; Affinity; Age; Albumins; Assay; Attention; Bilirubin; Bilirubin Encephalopathy; Bilirubin Ix Alpha; Bilirubin, Total; Binding; Binding (Molecular Function); Binding Sites; Bioassay; Biologic Assays; Biological Assay; Birth Weight; Blood; Blood Sample; Blood Serum; Blood Specimen; Brain Injuries; Cell Communication And Signaling; Cell Signaling; Chemicals; Child; Child Youth; Children (0-21); Clinical; Colorimetry; Combining Site; Communities; Community Hospitals; Coupled; Data; Development; Devices; Erythrocyte Volume, Packed; Fatty Acids, Nonesterified; Fetal Age; Fetal Maturity, Chronologic; Fluorescence; Free Fatty Acids; Gestational Age; Guidelines; Hct; Heel; Hematocrit; Hematocrit Procedure; Home; Home Environment; Housing; Human; Human, Child; Human, General; Hyperbilirubinemic Encephalopathy; Icterus; Infant, Newborn; Interview; Intracellular Communication And Signaling; Jaundice; Kernicterus; Laboratories; Light Therapy; Low Birth Weight Infant; Man (Taxonomy); Man, Modern; Measurement; Measures; Memory; Method Loinc Axis 6; Methodology; Methods; Methods And Techniques; Methods, Other; Microprocessor; Molecular Interaction; Neonatal Jaundice; Neurologic; Neurological; Newborn Infant; Newborns; Nonesterified Fatty Acids; Operation; Operative Procedures; Operative Surgical Procedures; Optics; Packed Red-Cell Volume; Photoradiation Therapy; Phototherapy; Plastics; Point-Of-Care Systems; Power Sources; Power Supplies; Proxy; Reactive Site; Reagent; Relative; Relative (Related Person); Reporting; Research Specimen; Reticuloendothelial System, Blood; Risk; Sampling; Serum; Serum Albumin; Side; Signal Transduction; Signal Transduction Systems; Signaling; Site; Specimen; Surgical; Surgical Interventions; Surgical Procedure; System; System, Loinc Axis 4; Techniques; Technology; Testing; Time; Vlbw (Human); Whblood; Weight; Whole Blood; Work; Base; Biological Signal Transduction; Brain Damage; Brain Lesion (From Injury); Children; Computerized Data Processing; Cost; Data Processing; Design; Designing; Instrument; Low Birth Weight Infant Human; Low Birthweight; Neonate; Newborn Human (0-6 Weeks); Pediatrician; Point Of Care; Prototype; Public Health Relevance; Response; Signal Processing; Solute; Surgery; Youngster

Uncontrolled hyperbilirubinemia (jaundice) in neonates has long been known to lead to neurological dysfunction including irreversible athetoid cerebral palsy with speech, ocular and hearing impairments, and even death. Contemporary management is based upon monitoring the total serum bilirubin (TBS), taking into account other clinical parameters such as birth weight and gestational age, and administering effective treatment (phototherapy and/or the rare exchange transfusion), if dictated. Unfortunately, the trend towards discharge of apparently healthy neonates from the hospital very soon after birth has made the management of subsequent jaundice more difficult in that population. A long suggested, but not used, better predictor of the neonate's risk for neurological sequelae due to elevated bilirubin is a measure of the capacity to sequester bilirubin in the blood compartment by its binding to serum albumin. The concentration of unbound bilirubin, the driver for bilirubin escaping from the vasculature, can be calculated from the TBS and binding capacitl. Presently existing methods for assaying binding capacity and unbound bilirubin are not facile. However, all these parameters can be directly measured simply in a very small volume of whole blood with a special purpose fluorometer, the hematofluorometer, first described years ago, by making use of the natural fluorescence of bilirubin bound to albumin. This technology is amenable to point-of-care use. The aims of this project are to transform the modernized and miniaturized hematofluorometer developed in Phase I into a product suitable for operation in various point-of-care environments, including the intensive care and healthy baby nurseries, the neonatal inpatient clinic, and the pediatrician's office. The first aim is to optimize the basic optical and electronic design: redesin the electronics to support the hospital information management requirements, such as a bar code reader, printer, and interface with a computer, either directly or via the local internet. The second aim is to develop a reagent kit that is easy to use and inexpensive. Phase I work demonstrated that significantly more work is needed to design a kit meeting these requirements, and then scaling this design up into a product that can be mass produced. The third aim is to test the instrument with neonate blood samples in a clinical environment to demonstrate that it well suited to meet the needs. With this goal in mind, Stanford University's Medical School and Children's Hospital has agreed to participate as a subcontractor to evaluate the new technology. With these proposed improvements, the instrument will be ready for the next stages: releasing it to the market for immediate R&D uses and clinical studies, and eventual approval by the FDA for general use.

Public Health Relevance:
A long suggested, but not used, better predictor of the neonate's risk for neurological sequelae due to elevated bilirubin is a measure of the capacity to sequester bilirubin in the blood compartment by its binding to serum albumin. The concentration of unbound bilirubin, the driver for bilirubin escaping from the vasculature, can be calculated from the TBS and binding capacitl. Presently existing methods for assaying binding capacity and unbound bilirubin are not facile. However, all these parameters can be directly measured simply in a very small volume of whole blood with a special purpose fluorometer, the hematofluorometer, first described years ago, by making use of the natural fluorescence of bilirubin bound to albumin. This technology is amenable to point-of-care use.The aims of this project are to transform the modernized and miniaturized hematofluorometer developed in Phase I into a product suitable for operation in various point-of-care environments, to complete development of easy-to-use sample handling disposables, and to verify the performance of the system for samples from a specified population of neonates.

Public Health Relevance Statement:
A long suggested, but not used, better predictor of the neonate's risk for neurological sequelae due to elevated bilirubin is a measure of the capacity to sequester bilirubin in the blood compartment by its binding to serum albumin. The concentration of unbound bilirubin, the driver for bilirubin escaping from the vasculature, can be calculated from the TBS and binding capacitl. Presently existing methods for assaying binding capacity and unbound bilirubin are not facile. However, all these parameters can be directly measured simply in a very small volume of whole blood with a special purpose fluorometer, the hematofluorometer, first described years ago, by making use of the natural fluorescence of bilirubin bound to albumin. This technology is amenable to point-of-care use.The aims of this project are to transform the modernized and miniaturized hematofluorometer developed in Phase I into a product suitable for operation in various point-of-care environments, to complete development of easy-to-use sample handling disposables, and to verify the performance of the system for samples from a specified population of neonates.

Project Terms:
Accounting; Albumins; Athetoid cerebral palsy; Bar Codes; base; Bilirubin; Binding (Molecular Function); Biological Assay; Birth; Birth Weight; Blood; Blood capillaries; Blood specimen; Calibration; capillary; Cessation of life; Clinic; Clinical; Clinical Research; Computer software; Computers; Contracts; cost; Data; design; Development; Documentation; effective therapy; Electronics; Environment; Evaluation Studies; experience; Fluorescence; Gestational Age; Glass; Goals; hearing impairment; Heating; Hospitals; Hyperbilirubinemia; Icterus; improved; Information Management; Informed Consent; Inpatients; Institutional Review Boards; instrument; Intensive Care; Internet; Laboratories; Lead; Life; Marketing; Measures; medical schools; meetings; Memory; Methods; Mind; miniaturize; Molds; Monitor; Neonatal; neonate; Neurologic; Neurologic Dysfunctions; new technology; Noise; Nurseries; operation; Optics; Pediatric Hospitals; pediatrician; Performance; Phase; Phototherapy; Plastics; point of care; Point-of-Care Systems; Population; Privacy; Production; Protocols documentation; prototype; Reader; Reading; Reagent; research and development; response; Risk; Sampling; scale up; Serum; Serum Albumin; Signal Transduction; Slide; Solid; Specific qualifier value; Speech; Staging; System; Technology; Temperature; Testing; Transfusion; trend; Tube; Universities; user-friendly; Whole Blood; Work; Writing;