Early formation of bilirubin isomers during phototherapy for neonatal jaundice: effects of single vs. double fluorescent lamps vs. photodiodes

Neuropathological implication of high blood bilirubin in patients and model rats with depression

PURPOSE

Elevated bilirubin levels have been associated with major depressive disorder (MDD); however, the exact impact of bilirubin on MDD and the underlying molecular mechanisms remain unclear. Here, we explored the influence of bilirubin on MDD and sought to identify the mechanisms via which bilirubin induces depressive-like behavior.

PATIENTS AND METHODS

Forty patients who were diagnosed with MDD and received treatment with selective serotonin reuptake inhibitors (SSRIs) were included, with 43 healthy volunteers serving as controls. Clinical symptoms were evaluated using Hamilton depression rating scale-24 (HAMD-24) and the Hamilton anxiety rating scale. Serum concentrations of total bilirubin (TBIL) and indirect bilirubin (IBIL) were measured at baseline and after treatment using an automated biochemical analyzer. The connection between clinical symptoms and TBIL or IBIL was examined using Pearson correlation. Chronic restraint stress (CRS) was employed to generate a rat model of depression. TBIL, IBIL in rat serum were measured by ELISA. Reactive oxygen species (ROS) contents in rat hippocampal tissues were quantified by flow cytometry. The levels of microglial markers and the extent of neuronal damage in the rat hippocampus were assessed by immunofluorescence and transmission electron microscopy, respectively.

RESULTS

Serum TBIL and IBIL levels were higher in patients with MDD than in the healthy controls. After treatment with SSRIs, the serum levels of TBIL and IBIL in MDD patients were significantly reduced. The levels of TBIL and IBIL were associated with HAMD-24 in MDD patients. Compared with the controls, the serum levels of TBIL, IBIL and the hippocampal ROS contents were elevated in CRS-exposed rats. Fluoxetine lowered inflammatory factor levels, mitigated oxidative stress.

CONCLUSION

Our findings indicate a possible correlation between elevated serum bilirubin and depressive symptoms. Increases in ROS levels, along with neuronal damage, may represent pathological mechanisms underlying MDD.

Spicy Recipe for At-Home Diagnostics: Smart Salivary Sensors for Point-of-Care Diagnosis of Jaundice

Even though significant advances have been made, there is still a lack of reliable sensors capable of noninvasively monitoring bilirubin and diagnosing jaundice as the most common neonatal disease, particularly at the point-of-care (POC) where blood sampling from infants is accompanied by serious challenges and concerns. Herein, for the first time, using an easy-to-fabricate/use assay, we demonstrate the capability of curcumin embedded within paper for noninvasive optical monitoring of bilirubin in saliva. The highly selective sensing of the developed sensor toward bilirubin is attributed to bilirubin photoisomerization under blue light exposure, which can selectively restore the bilirubin-induced quenched fluorescence of curcumin. We also fabricated an IoT-enabled hand-held optoelectronic reader to measure and quantify the fluorescence and color signals of our sensor. Clinical analysis on the saliva of 18 jaundiced infants by using our developed smart salivary sensor proved that it is amenable to be widely exploited in POC applications for bilirubin monitoring as there are good correlations between its results with those of reference methods in saliva and blood. Meeting all WHO's REASSURED criteria by our developed sensor makes it a highly promising sensor for smart noninvasive diagnosis and therapeutic monitoring of jaundice, hepatitis, and other bilirubin-induced neurologic diseases at the POC.

Effectiveness of phototherapy with and without probiotics for the treatment of indirect hyperbilirubinaemia in preterm neonates: a randomised controlled trial

INTRODUCTION

Raised serum bilirubin levels can cause kernicterus, and premature infants are at increased risk owing to metabolic immaturity. The standard treatment for neonatal jaundice is phototherapy, but probiotics alone can reduce the duration of phototherapy and hospitalisation.

OBJECTIVES

To determine the effectiveness of phototherapy with and without probiotics for the treatment of indirect hyperbilirubinaemia in preterm neonates.

PATIENTS AND METHODS

The open-labelled randomised controlled trial was conducted from January 2022 to January 2023 in the neonatal unit of the University of Lahore Teaching Hospital, Pakistan. A total of 76 preterm neonates who fulfilled the selection criteria were included and divided into two groups. Both groups received standard phototherapy. In Group B, a probiotic (Saccharomyces boulardii) 125 mg, twice daily, orally (in 5 cc of whichever milk the infant was receiving) was given until discharge from hospital. The primary outcome measurements were the duration of phototherapy and the length of hospitalisation.

RESULTS

The mean (SD) duration of phototherapy was 36.55 (14.25) hours in Group A and 24.61 (9.25) hours in Group B (p <0.05). The mean (SD) duration of hospital stay was 47.36 (16.51) hours in Group A and 33.13 (8.93) hours in Group B (p <0.05).

CONCLUSION

Oral probiotics (Saccharomyces boulardii) have a significant effect on the duration of phototherapy for neonatal hyperbilirubinaemia, and they decrease the chances of nosocomial infection. Exploration of clinical outcomes by investigating faecal flora and undertaking large randomised controlled trials of various probiotics are needed.

ABBREVIATIONS

ABE: acute bilirubin encephalopathy; CNS: central nervous system; GA: gestational age; IVIG: intravenous immunoglobulin; KSD: kernicterus; NNU: neonatal unit; RCT: randomised controlled trial; S. boulardii: Saccharomyces boulardii.

A zebrafish model for studying the mechanisms of newborn hyperbilirubinemia and bilirubin-induced neurological damage

Unresolved neonatal hyperbilirubinemia may lead to the accumulation of excess bilirubin in the body, and bilirubin in neural tissues may induce toxicity. Bilirubin-induced neurological damage (BIND) can result in acute or chronic bilirubin encephalopathy, causing temporary or lasting neurological dysfunction or severe damage resulting in infant death. Although serum bilirubin levels are used as an indication of severity, known and unknown individual differences affect the severity of the symptoms. The mechanisms of BIND are not yet fully understood. Here, a zebrafish newborn hyperbilirubinemia model is developed and characterized. Direct exposure to excess bilirubin induced dose- and time-dependent toxicity linked to the accumulation of bilirubin in the body and brain. Introduced bilirubin was processed by the liver, which increased the tolerance of larvae. BIND in larvae was demonstrated by morphometric measurements, histopathological analyses and functional tests. The larvae that survived hyperbilirubinemia displayed mild or severe morphologies associated with defects in eye movements, body posture and swimming problems. Interestingly, a plethora of mild to severe clinical symptoms were reproduced in the zebrafish model.

Phototherapy in dermatological maladies (Review)

Since the introduction of modern phototherapy in 1903 by Nobel Prize-winner Niels Ryberg Finsen, the usage of this therapy in the medical field has grown, techniques have been refined and developed, and it has gained widespread acceptance. Psoriasis vulgaris, parapsoriasis, lichen planus, atopic dermatitis, neonatal jaundice, urticaria, morphea, vitiligo, granuloma annulare and cutaneous T cell lymphoma are only a few dermatological indications that come along with satisfactory results. Most often, it is a 2nd or 3rd line therapy being an alternative in more severe or refractory diseases. Despite the side effects that may occur after phototherapy, which are often minor, the benefits can be significant. Unfortunately, the absolute contraindications limit the use of this type of treatment and implicitly the management of these patients. The current review aimed to combine the recommendations of phototherapy in dermatology, the types of phototherapy that can be suitable for certain dermatological diseases and to emphasize its importance in certain conditions that are associated with significant remission rates.

Association between type of phototherapy management and hospital and patient-related outcomes in neonates with non-haemolytic jaundice at an Australian community hospital

AIM

To evaluate the associations between type of light-emitting diode phototherapy intervention and hospital and patient related outcomes in term neonates with non-haemolytic jaundice.

METHODS

A retrospective observational study in a community hospital within a disadvantaged area in Australia was conducted. Data was extracted from hospital systems and medical records regarding the use of three types of phototherapy surface-area exposure for term neonates ≤28 days with non-haemolytic neonatal jaundice. Associations between type of phototherapy management and length of stay (LOS), rate of serum bilirubin (SBR) decline and duration of phototherapy were estimated using the general linear mixed model or linear regression.

RESULTS

Of 102 neonates diagnosed with non-haemolytic jaundice between 1 June 2016 and 31 August 2017, 82 were included in final analyses. Neonates treated for jaundice during their first (birth) admission had a median LOS of 118 h for single-sided and 125 h for maximal double-sided phototherapy. Differences by phototherapy type were not statistically significant (P = 0.06). SBR rate of decline increased as surface-area of phototherapy increased (P < 0.001) with the fastest decline seen in maximal double-sided phototherapy. Estimated duration of phototherapy did not vary by phototherapy type but did vary by age at initiation of phototherapy (P = 0.006), with 16 fewer hours of phototherapy if commenced at ≥72 to <96 h versus ≥24 to 48 h of age (difference -16.4 h, 95% confidence interval -29.1 to -3.7 h).

CONCLUSIONS

LOS and phototherapy duration were not associated with phototherapy type. Older neonates with neonatal jaundice required shorter phototherapy duration. Double-sided phototherapy was associated with faster reduction in SBR.

LED Photo-polymerization, a Novel Strategy for Triggered Release Liposomes

LED light is used for many medical and cosmetic applications such as phototherapy and skin rejuvenation. Such physical methods can be combined with drug therapy, such as LED-responsive drug delivery system, the subject of present investigation.

To perform this investigation, a nanoliposome composed of DPPC, DSPE-PEG2000, and DC_8,9PC, was prepared as LED-sensitive systems. Calcein was loaded in the liposomes as a fluorescent probe for drug release studies. Different LED wavelengths (blue, green and red) were used for triggering release of calcein from nanoliposome. Indoor daylight, darkness, and sunlight were applied as controls.

Results showed that liposomes do not release their cargo in darkness, but they released it in response to indoor daylight, sunlight and LEDs, with the blue light showing the highest effect. Results also showed that release of calcein was sensitive to wavelength.

Our results reveal potential of LED-sensitive liposomes for medical and cosmetic applications and that such system can be combined with phototherapy. Such concomitant therapies can increase medical/cosmetic effects and decrease adverse reactions to phototherapy.

Sixty years of phototherapy for neonatal jaundice - from serendipitous observation to standardized treatment and rescue for millions

A breakthrough discovery 60 years ago by Cremer et al. has since changed the way we treat infants with hyperbilirubinemia and saved the lives of millions from death and disabilities. "Photobiology" has evolved by inquiry of diverse light sources: fluorescent tubes (wavelength range of 400-520 nm; halogen spotlights that emit circular footprints of light; fiberoptic pads/blankets (mostly, 400-550 nm range) that can be placed in direct contact with skin; and the current narrow-band blue light-emitting diode (LED) light (450-470 nm), which overlaps the peak absorption wavelength (458 nm) for bilirubin photoisomerization. Excessive bombardment with photons has raised concerns for oxidative stress in very low birthweight versus term infants treated aggressively with phototherapy. Increased emphasis on prescribing phototherapy as a "drug" that is dosed cautiously and judiciously is needed. In this historical review, we chronicled the basic to the neurotoxic components of severe neonatal hyperbilirubinemia and the use of standardized interventions.

Pruritus secondary to primary biliary cholangitis: a review of the pathophysiology and management with phototherapy

BACKGROUND

Primary biliary cholangitis (PBC) is an autoimmune hepatobiliary disorder characterized by destruction of liver bile ducts leading to intrahepatic cholestasis. It causes intractable pruritus for which ultraviolet (UV)B phototherapy is an experimental treatment when alternative therapies fail. The pathophysiology of cholestatic itch and the mechanism of action of narrowband UVB in this condition remains poorly understood.

OBJECTIVES

To summarize the current literature and propose testable hypotheses for the mechanism of action of phototherapy in attenuating itch.

METHODS

A focused PubMed search for articles relating to the pathogenesis of itch in cholestatic disease was performed. A total of 3855 articles were screened and 50 were found suitable for literature review. Evidence from this literature review was combined with author expertise in the area.

RESULTS

Formulated hypotheses focus on the role of bile salts, autotaxin and specific receptors including G-protein-coupled bile acid receptor, Gpbar1 (also known as TGR5) and the nuclear transcription factor farnesoid X receptor.

CONCLUSIONS

Several testable mechanisms through which phototherapy may exert its effects are discussed in this review. The next steps are to carry out an objective assessment of the efficacy of phototherapy in cholestatic pruritus, gain further knowledge on the underlying pathways, and subsequently trial its use against current licensed therapies. Such studies could lead to increased mechanistic understanding, identification of novel therapeutic targets and the potential to refine phototherapy protocols, leading to improved control of itch and quality of life in patients with PBC. What's already known about this topic? Primary biliary cholangitis (PBC) is frequently associated with intractable pruritus for which current treatment options are often unsuccessful. Phototherapy is used as an experimental treatment for PBC-associated pruritus when alternative better-studied treatments fail. What does this study add? This study reviews the current literature on the pathophysiology and management of cholestatic pruritus, an area which remains poorly understood. We propose testable hypotheses of the mechanisms behind the attenuation of cholestatic pruritus with phototherapy.

Easy Diagnosis of Jaundice: A Smartphone-Based Nanosensor Bioplatform Using Photoluminescent Bacterial Nanopaper for Point-of-Care Diagnosis of Hyperbilirubinemia

One of the concerns of parents in the first days of their baby's birth is the baby's risk of jaundice/hyperbilirubinemia. This is because more than 60% of babies are born with jaundice that, if not timely diagnosed and subsequently treated, can lead to serious damage to their health. On the other hand, despite recent progress in sensor technology for clinical applications, the development of easy-to-use, cost-effective, sensitive, specific, and portable diagnostic devices, which use nontoxic and biodegradable materials in their design and fabrication, is still in high demand. Herein we present an easy-to-use, cost-effective, selective, nontoxic, and disposable photoluminescent nanopaper-based assay kit with a smartphone readout for easy diagnosis of neonatal jaundice through visual determination of Bilirubin (BR) in infants' blood samples. The developed BR assay kit comprises highly photoluminescent carbon dot (CD) sensing probes embedded in a bacterial cellulose (BC) nanopaper substrate (CDBN). The photoluminescence (PL) of the developed BR sensor is quenched in the presence of BR as a PL quencher and then selectively recovered upon blue light (λ = 470 nm) exposure, due to conversion of the unconjugated BR to the colorless oxidation products (non-PL quencher) through BR photoisomerization and photooxidation, that subsequently leads to selective PL enhancement of CDBN. The recovered PL intensity of the developed BR assay kit, which was monitored by integrated smartphone camera, was linearly proportional to the concentration of BR in the range of 2-20 mg dL^-1. The feasibility of real application of the fabricated smartphone-based BR assay kit was also confirmed via comparing the results of our method with a clinical reference method for determination of BR concentration in infant's blood samples. With the advantages of nontoxicity and the extraordinary physicochemical properties of photoluminescent BC nanopaper as the sensing substrate, along with those of smartphone technology, we believe that our developed smartphone-based BR assay kit, as an easy-to-use, cost-effective (∼0.01 Euro per test), portable and novel sensing bioplatform, can be potentially exploited for sensitive, specific, rapid, and easy BR detection and jaundice diagnosis at the point of care (POC) and in routine clinical laboratories as well.

Analysis of therapeutic effect of intermittent and continuous phototherapy on neonatal hemolytic jaundice

Clinical efficacy and adverse reaction rates of ABO hemolytic jaundice in patients with continuous and intermittent blue light irradiation were compared, to provide reference for clinical treatment of neonatal ABO hemolytic jaundice. A retrospective analysis of 307 patients with neonatal hemolytic jaundice admitted to Qilu Hospital of Shandong University (Qingdao) from January 2010 to December 2017 was undertaken. A total of 165 cases of children with continuous blue light irradiation and 142 cases of intermittent blue light irradiation were analyzed. Also the serum bilirubin levels, phototherapy time and frequency, treatment efficiency and adverse reaction rates were compared between the groups. The phototherapy time of children in the continuous phototherapy group was significantly higher from the intermittent phototherapy group, and the difference was statistically significant (t=26.800, P<0.001). Before treatment, there was no significant difference in serum bilirubin levels between continuous and intermittent phototherapy groups (P>0.050). Serum bilirubin levels of patients in continuous and intermittent phototherapy groups were lower than both previous and before treatment period, and differences were statistically significant (P<0.001). The overall effective rate of the continuous phototherapy group was higher than that of the intermittent phototherapy group (P>0.050). The adverse reaction rates after treatment in the continuous phototherapy group was significantly higher than the intermittent phototherapy group (P<0.050). After the symptomatic treatment in children, the adverse reactions ceased. The therapeutic effect of intermittent blue light irradiation on neonatal ABO hemolytic jaundice was consistent with the continuous blue light irradiation treatment, and the intermittent blue light irradiation treatment has a low adverse reaction rate, and is worth promotion in clinical practice.

Uniform national guidelines do not prevent wide variations in the clinical application of phototherapy for neonatal jaundice

AIM

This study compared the use of phototherapy for neonatal jaundice in all 21 Norwegian neonatal intensive care units (NICUs) from 2013-2014 to improve practice.

METHODS

Information on all types of phototherapy devices was collected, and irradiance was measured from random units at 20 cm and 50 cm from the light source. We gathered information on local practice rules, including the use of single, double or triple phototherapy, how infants were positioned, the frequency of blood sampling, rules for using reflective surfaces and interrupting phototherapy. In every NICU, we asked one nurse with more than five years of experience and one with less than one year to set up phototherapy equipment, then measured the irradiance and distance.

RESULTS

Photodiodes were the most common of the eight types of phototherapy devices used. Rules for the distance from the device to the infant varied from 10 to 40 cm and in practice they varied from 15 to 48 cm, with irradiance ranging from 11.1-56.1 W/m² . There were significant variations between NICUs with regard to the overall treatment duration and duration in most birthweight categories.

CONCLUSION

There were considerable variations in phototherapy practices among Norwegian NICUs. In particular, the significant variations in duration need to be addressed.

Double versus single intensive phototherapy with LEDs in treatment of neonatal hyperbilirubinemia

OBJECTIVE

We investigate whether double phototherapy reduces total serum bilirubin concentration faster than single light during intensive phototherapy with high levels of irradiance using light-emitting diodes.

STUDY DESIGN

Eighty-three infants with gestational age ⩾33 weeks and uncomplicated hyperbilirubinemia were randomized to either double (n=41) or single phototherapy (n=42) for 24 h. The mean irradiance was 64.8 μW cm^-2 nm^-1 from above and 39 μW cm^-2 nm^-1 from below.

RESULTS

The percentage decreases of total serum bilirubin after 12 h of double vs single phototherapy were (mean (95% confidence interval (CI))) 39% (37 to 42) vs 30% (27 to 32), respectively (P<0.001). After 24 h, the decreases were 58% (56 to 61) vs 47% (44 to 50), respectively (P<0.001). The results were still significant after adjustment for confounding. The only side effect was loose stools.

CONCLUSION

Even with intensive phototherapy increasing spectral power by increasing the irradiated body surface area, the efficacy of phototherapy is improved.

The impact of hemoglobin on the efficacy of phototherapy in hyperbilirubinemic infants

BackgroundPhototherapy is the routine treatment for neonatal hyperbilirubinemia. Absorption of light in the skin transforms the native Z,Z-bilirubin to photobilirubins. This study investigates whether the hemoglobin concentration has an impact on efficacy of phototherapy, expressed by the decline of total serum bilirubin concentration (TsB).MethodsA trial was conducted on 93 infants, gestational age ≥33 weeks, with uncomplicated hyperbilirubinemia. The infants were treated with conventional phototherapy using LED light for 24 h. The median light irradiance was 66.8 μW/cm²/nm.ResultsThe median decrease in TsB after 24 h was 121 (57-199) μmol/l; the median hemoglobin was 12.0 (7.0-14.7) mmol/l. There was a significant effect of hemoglobin concentration on the decrease in TsB of -3.61 μmol/mmol hemoglobin (P=0.022), after adjusting for initial TsB and postnatal age. That is, assuming the same initial TsB and postnatal age, for each mmol/l increase in hemoglobin, the decrease in TsB was 3.61 μmol/l smaller. In our hemoglobin range, the decrease in TsB is reduced by 28 μmol/l (23%).ConclusionIncreasing hemoglobin levels led to a decrease in the efficacy of phototherapy. Our data provide additional support for the conclusion that the transformation of bilirubin to photobilirubins takes place mainly in the superficial capillaries of the skin.

Bilirubin isomer distribution in jaundiced neonates during phototherapy with LED light centered at 497 nm (turquoise) vs. 459 nm (blue)

BACKGROUND

Phototherapy using blue light is the treatment of choice worldwide for neonatal hyperbilirubinemia. However, treatment with turquoise light may be a desirable alternative. Therefore, the aim of this randomized, controlled study was to compare the bilirubin isomer distribution in serum of jaundiced neonates after 24 h of therapy with narrow-band (LED) light centered at 497 nm (turquoise) vs. 459 nm (blue), of essentially equal irradiance.

MATERIALS

Eighty-three neonates (≥33 wk gestational age) with uncomplicated hyperbilirubinemia were included in the study. Forty neonates were exposed to light centered at 497 nm and 43 infants with light centered at 459 nm. Irradiances were 5.2 × 10(15) and 5.1 × 10(15) photons/cm(2)/s, respectively.

RESULTS

After 24 h of treatment no significant differences in serum concentrations of total bilirubin isomers and Z,Z-bilirubin were observed between the 2 groups. Interestingly, concentrations of Z,E-bilirubin, and thus also total bilirubin isomers formed during therapy, were highest for infants receiving light centered at 459 nm, while the concentration of E,Z-bilirubin was highest for those receiving light centered at 497 nm. No significant difference was found between concentrations of E,Z-lumirubin.

CONCLUSION

Therapy with LED light centered at 497 nm vs. 459 nm, applied with equal irradiance on the infants, resulted in a different distribution of bilirubin isomers in serum.

A Pharmacologic View of Phototherapy

A pharmacologic view of phototherapy for neonatal jaundice is presented. By considering the photons of therapy light as molecules of a drug, this view connects therapeutic efficacy with photon wavelength, photon dose, dose rate and regimen, efficiency of photon absorption by bilirubin, quantum yields of photoproducts, and their metabolic courses. Based on this view, recommendations to ultimately improve efficacy and safety are presented. Special attention is given to phototherapy regimens for low gestational age, low birthweight infants.

Biology of Bilirubin Photoisomers

Phototherapy is the main treatment for neonatal hyperbilirubinemia. In acute treatment of extreme hyperbilirubinemia, intensive phototherapy may have a role in 'detoxifying' the bilirubin molecule to more polar photoisomers, which should be less prone to crossing the blood-brain barrier, providing a 'brain-sparing' effect. This article reviews the biology of bilirubin isomers. Although there is evidence supporting the lower toxicity of bilirubin photoisomers, there are studies showing the opposite. There are methodologic weaknesses in most studies and better-designed experiments are needed. In an infant acutely threatened by bilirubin-induced brain damage, intensified phototherapy should be used expediently and aggressively.

The effect of hematocrit on in vitro bilirubin photoalteration

BACKGROUND

Phototherapy using light in the spectral range of 410-500 nm, which overlaps the absorption of bilirubin, is the common treatment for neonatal hyperbilirubinemia. Hemoglobin (Hb) absorbs light strongly throughout this same range and thus can compete with bilirubin for this light and consequently reduce the efficacy of phototherapy. Here, we determined the effect of hematocrit (Hct) on in vitro bilirubin photoalteration using narrow-band blue (450 nm) light-emitting diodes (LEDs).

METHODS

Suspensions with Hcts from 0 to 80% and 16 ± 1 mg/dl bilirubin were prepared by mixing red blood cells (RBCs), bilirubin (30 mg/dl) in 4% human serum albumin, and normal saline. Aliquots of each suspension were exposed to blue light at equal irradiances. Before and after 60 min of exposure, bilirubin levels in supernatants (n = 46) were measured using a diazo-dye method.

RESULTS

Bilirubin photoalteration steeply decreased by ~60% as Hct increased from 0 to 10%. Over the clinically relevant range of 30-70% Hct, the decrease was significant, but less drastic, exhibiting a quasi-linear dependence on Hct.

CONCLUSION

Bilirubin photoalteration under blue light in vitro is significantly reduced as Hct increases. Clinical studies are warranted to confirm these in vitro observations that Hct can affect the efficacy of phototherapy.