Reye's syndrome in the United States from 1981 through 1997

Hyperammonemia in the Pediatric Emergency Department

ABSTRACT

Hyperammonemia is a serious clinical condition associated with significant morbidity and mortality. In the pediatric population, this is often caused by urea cycle disorders, acute liver failure, or other less common underlying etiologies. Children and teens with hyperammonemia can have a broad range of clinical findings, including vomiting, respiratory distress, and changes in mental status. As ammonia levels worsen, this presentation can progress to respiratory failure, encephalopathy, cerebral edema, seizures, and death. Given the risk of neurologic damage, timely identification and management of hyperammonemia is critical and includes initial resuscitation, early consultation with subspecialists, and initiation of appropriate therapies. It is important for pediatric emergency medicine providers to understand the clinical findings, causes, diagnosis, and management of hyperammonemia because they play a key role in the provision of effective, multidisciplinary care of these patients.

Influenza in Children and Adolescents: Epidemiology, Management, and Prevention

EDUCATION GAP

Influenza is among the most common infectious causes of pediatric emergency department visits and hospitalizations. Clinicians should use evidence-based guidelines to learn how to identify, manage, prevent, and treat influenza cases. Disease caused by influenza virus can be mitigated with appropriate treatment and prevention efforts.

OBJECTIVES After completing this article, readers should be able to:

1. Describe the virology and epidemiology of influenza.

2. List the clinical features and complications of influenza infections.

3. List the benefits and limitations of testing modalities for the diagnosis of influenza.

4. Appropriately apply American Academy of Pediatrics, Infectious Diseases Society of America, and Centers for Disease Control and Prevention (CDC) treatment guidelines for influenza or suspected influenza.

5. Describe the importance of influenza vaccination.

Medical Outcomes of Acute Aspirin Single Substance Poisoning in Pediatric Patients

BACKGROUND

A consensus guideline on salicylate poisoning recommends referring patients to the emergency department if they ingested 150 mg/kg of aspirin. The dose of aspirin associated with severe poisoning in pediatric patients has not been investigated.

OBJECTIVE

This study aims to associate medical outcomes with aspirin overdoses in patients 5 years old and younger.

METHODS

A retrospective review of data on pediatric patients with single substance aspirin exposures reported from poison centers across the country was conducted. The primary endpoint was to associate aspirin doses with medical outcomes. Secondary endpoints included evaluation of the signs, symptoms, and treatments of ingestion and their association with medical outcomes.

RESULTS

There were 26 488 included exposures with aspirin exposures resulting in no effect (92.5%), minor effect (6.0%), moderate effect (1.4%), major effect (0.2%), and death (0.02%). There were 8921 cases with available weight-based dosing information. Median doses associated with no effect, minor effects, moderate effects, major effects, and death ranged between 28.4 and 40.9 mg/kg, 52.5 and 82.3 mg/kg, 132.1 and 182.3 mg/kg, 132.3 and 172.8 mg/kg, and 142.2 and 284.4 mg/kg, respectively. Minor effect and moderate effect exposures were more likely to have alkalinization documented compared to no effect exposures (odds ratio [OR] = 1.75, 95% confidence interval [CI] = 1.41-2.17; OR = 1.79, 95% CI = 1.12-2.86). There was no difference in rates of alkalinization between minor and moderate exposures (OR = 1.02, 95% CI: 0.61-1.7).

CONCLUSIONS AND RELEVANCE

Reevaluation of the current recommendation of 150 mg/kg for referral to a healthcare facility is necessary for pediatric acute salicylate overdoses.

Trends in Influenza and Related Health Resource Use During 2005-2021 Among Children in Japan

BACKGROUND

To determine the epidemiological trends in pediatric influenza and changes in healthcare resource use from 2005 to 2021 using nationally representative outpatient database in Japan.

METHODS

We conducted a retrospective cohort study consisting of 3.5 million children with 177 million person-months during 2005-2021 using Japan Medical Data Center claims database in Japan. We investigated trends in incidence rates of influenza and changes in healthcare resource use (eg, use of antivirals) over 17 years. Generalized estimation equations were used to investigate the impact of the 2009 influenza pandemic and the coronaviral disease 2019 (COVID-19) pandemic on incidence rates of influenza and related healthcare utilization.

RESULTS

Annual incidence rates of influenza were estimated at 55 cases per 1000 person-years with a 93% relative increase [95% confidence interval (CI): 80%-107%] during the 2009 influenza pandemic and a 99.4% relative reduction (95% CI: 99.3%-99.4%) during the COVID-19 pandemic. Similar patterns were observed for health resource use, total healthcare costs, admission rates and antiviral agent use. Approximately 80% of children with influenza received prescriptions for antivirals. The most prescribed antivirals were oseltamivir, but we observed a temporal increase in zanamivir use during 2007-2009, an increasing trend in laminamivir use during 2010-2017, a temporal increase in baloxavir use in 2018. Symptomatic medications with serious side effects (codeine, salicylate, sedative antihistamine) showed decreasing trends over the study period.

CONCLUSIONS

Influenza incidence and healthcare resource use were largely affected by the 2009 influenza pandemic and the COVID-19 pandemic. Our study indicates improvement of quality in healthcare delivered to children.

Drug-induced hyperammonaemia

Hyperammonaemia (HA) as a consequence of numerous primary or secondary causes, gives rise to clinical manifestations due to its toxic effects on the brain. The neurological consequences broadly reflect the ammonia level, duration and age, with paediatric patients being more susceptible. Drug-induced HA may arise due to either decreased ammonia elimination or increased production. This is associated most frequently with use of valproate and presents a dilemma between ongoing therapeutic need, toxicity and the possibility of an alternative cause. As there is no specific test for drug-induced HA, prompt discussion with a metabolic physician is recommended, as the neurotoxic effects are time-dependent. Specific guidelines for managing drug-induced HA have yet to be published and hence the treatment approach outlined in this review reflects that outlined in relevant urea cycle disorder guidelines.

Genetic and environmental risk factors of acute infection-triggered encephalopathy

Acute encephalopathy is a constellation of syndromes in which immune response, metabolism and neuronal excitation are affected in a variable fashion. Most of the syndromes are complex disorders, caused or aggravated by multiple, genetic and environmental risk factors. Environmental factors include pathogenic microorganisms of the antecedent infection such as influenza virus, human herpesvirus-6 and enterohemorrhagic Escherichia coli, and drugs such as non-steroidal anti-inflammatory drugs, valproate and theophylline. Genetic factors include mutations such as rare variants of the SCN1A and RANBP2 genes, and polymorphisms such as thermolabile CPT2 variants and HLA genotypes. By altering immune response, metabolism or neuronal excitation, these factors complicate the pathologic process. On the other hand, some of them could provide promising targets to prevent or treat acute encephalopathy.

A tool for screening potentially inappropriate prescribing in Chinese children

Background: More than half of adverse drug events in pediatric patients are avoidable and blocking medication errors at the prescribing stage might be one of the most effective preventive measures.

Objective: To form a tool (a series of criteria) for detecting potentially inappropriate prescriptions in children, promote clinical rational drug use and reduce risks of medication in children.

Methods: Potentially inappropriate prescription propositions for children were collected through a systematic review. Then, the Delphi technique was adopted to form the final criteria. Panelists were asked to use a 5-point Likert scale to rate their agreement with each potentially inappropriate prescription proposition and were encouraged to add new propositions based on their clinical experience and knowledge. After 2 rounds of Delphi survey and propositions were fully revised and improved, the final criteria for identifying potentially inappropriate prescriptions in children were formed.

Results: The final criteria for identifying potential inappropriate prescriptions in children has 136 propositions, which were divided into “criteria for children with non-specific diseases/conditions” (71 propositions: 68 for potentially inappropriate medication, 3 for potential prescribing omission) and “criteria for children with specific diseases/conditions” (65 propositions: 55 for potentially inappropriate medication, 10 for potential prescribing omission), according to whether the proposition was about identifying specific risks associated with one drug in children with a specific other diseases/conditions that do not exist in children with other diseases/conditions.

Conclusion: A tool for screening potentially inappropriate prescriptions in children is formed to detect potentially inappropriate medication and prescribing omission in pediatrics and is available to all medical professionals liable to prescribe or dispense medicines to children.

Clinical Manifestations of Varicella: Disease Is Largely Forgotten, but It's Not Gone

After 25 years of varicella vaccination in the United States, classic varicella and its complications have become an uncommon occurrence. The clinical manifestation of varicella among vaccinated persons is usually modified, with fewer skin lesions, mostly maculopapular, and milder presentation. However, the potential for severe manifestations from varicella still exists among both vaccinated and unvaccinated persons, and thus healthcare providers should keep varicella in the differential diagnosis of a maculopapular or vesicular rash. The prompt recognition and diagnosis of varicella is important because when confirmed, clinical and public health measures need to be taken swiftly.

Real world study of children and young adults with myeloproliferative neoplasms identifying risks and unmet needs

In a contemporary cohort of 444 young MPN patients, risks of thrombosis, hemorrhage, and transformation were 1% pt/y.

Current risk scores had no utility. Uniquely, we identify that splenomegaly and hyperviscosity symptoms predict thrombosis and transformation.

Myeloproliferative neoplasms (MPNs) are uncommon in children/young adults. Here, we present data on unselected patients diagnosed before 25 years of age included from 38 centers in 15 countries. Sequential patients were included. We identified 444 patients, with median follow-up 9.7 years (0-47.8). Forty-nine (11.1%) had a history of thrombosis at diagnosis, 49 new thrombotic events were recorded (1.16% patient per year [pt/y]), perihepatic vein thromboses were most frequent (47.6% venous events), and logistic regression identified JAK2V617F mutation (P = .016) and hyperviscosity symptoms (visual disturbances, dizziness, vertigo, headache) as risk factors (P = .040). New hemorrhagic events occurred in 44 patients (9.9%, 1.04% pt/y). Disease transformation occurred in 48 patients (10.9%, 1.13% pt/y), usually to myelofibrosis (7.5%) with splenomegaly as a novel risk factor for transformation in essential thrombocythemia (ET) (P= .000) in logistical regression. Eight deaths (1.8%) were recorded, 3 after allogeneic stem cell transplantation. Concerning conventional risk scores: International Prognostic Score for Essential Thrombocythemia-Thrombosis and new International Prognostic Score for Essential Thrombocythemia-Thrombosis differentiated ET patients in terms of thrombotic risk. Both scores identified high-risk patients with the same median thrombosis-free survival of 28.5 years. No contemporary scores were able to predict survival for young ET or polycythemia vera patients. Our data represents the largest real-world study of MPN patients age < 25 years at diagnosis. Rates of thrombotic events and transformation were higher than expected compared with the previous literature. Our study provides new and reliable information as a basis for prospective studies, trials, and development of harmonized international guidelines for the specific management of young patients with MPN.

What are the clues for an inherited metabolic disorder in Reye syndrome? A single Centre study of 58 children

OBJECTIVES

Reye Syndrome is an acute encephalopathy with increased liver enzymes and blood ammonia, without jaundice. The prevalence of an underlying inherited metabolic disorder (IMD) is unclear, nor the clinical or biological factors directing toward this diagnosis. Our aims were to define these clues in a large series of patients.

PATIENTS AND METHODS

We retrospectively studied all patients with Reye admitted in our institution from 1995. We defined 3 groups: Group 1 with a confirmed IMD, Group 2 considered as free of IMD, Group 3 unclassified. Statistical analysis compared patients in Groups 1 and 2, to find criteria for a diagnosis of IMD.

RESULTS

Fifty-eight children were included; 41 (71%) had a confirmed IMD, 12 (20%) were free of IMD, and 5 remained unclassified. IMDs included Urea Cycle Disorders (51%), Fatty-Acid Oxidation Disorders (24%), ketogenesis defects (5%), other mitochondrial energy metabolism defects (10%), NBAS mutation (7%), Glycosylation Disorders (2%). In Group 2, the trigger was a viral infection, or a drug, deferasirox in three children. Univariate analysis showed that onset before 2 years-old, recurrent Reye and the association with rhabdomyolysis were significantly associated with IMD. Blood ammonia was a poor discriminating marker. All children were admitted into the intensive care unit, 23% needed continuous venovenous hemodialysis and one died from brain oedema.

CONCLUSION

Metabolic tests should be performed early in all cases of Reye, regardless of triggers. As they can be inconclusive, we suggest to systematically go to Next-Generation Sequencing study. These children should be transferred early to a specialized unit.

High occurrence of perinatal risk factors and more severe impairments in children with postneonatal cerebral palsy in Norway

AIM

To describe causal events, perinatal risk factors and clinical characteristics in children with postneonatal cerebral palsy (PNCP).

METHODS

Population-based registry study of Norwegian children born 1999-2013. Prevalence, causal events and clinical characteristics of PNCP were described. The occurrence of perinatal risk factors for CP was compared with the general population.

RESULTS

Among 1710 children with CP, 67 had PNCP (3.9%; 0.75 per 10,000 livebirths [95%CI: 0.59-0.96]). The prevalence of PNCP decreased during the study period. Leading causal events were cerebrovascular events (32.8%), head injuries/other accidents (22.4%), infections (19.4%) and hypoxic events (14.9%). Spastic hemiplegic (53.7%) or spastic quadriplegic/dyskinetic CP (31.3%) was more common in children with PNCP than non-PNCP (42.3% and 20.1%, respectively; p < 0.001). Children with PNCP had more severe motor and associated impairments. Perinatal risk factors for CP were more common in children with PNCP than in the general population.

CONCLUSION

The prevalence of PNCP among Norwegian children was low and decreasing. The main causes were cerebrovascular events and head injuries/other accidents. Although spastic hemiplegic CP was the dominating subtype, children with PNCP had more severe motor and associated impairments than children with non-PNCP, as well as a higher occurrence of perinatal risk factors than in the general population.

Mitochondria as the Target of Hepatotoxicity and Drug-Induced Liver Injury: Molecular Mechanisms and Detection Methods

One of the major mechanisms of drug-induced liver injury includes mitochondrial perturbation and dysfunction. This is not a surprise, given that mitochondria are essential organelles in most cells, which are responsible for energy homeostasis and the regulation of cellular metabolism. Drug-induced mitochondrial dysfunction can be influenced by various factors and conditions, such as genetic predisposition, the presence of metabolic disorders and obesity, viral infections, as well as drugs. Despite the fact that many methods have been developed for studying mitochondrial function, there is still a need for advanced and integrative models and approaches more closely resembling liver physiology, which would take into account predisposing factors. This could reduce the costs of drug development by the early prediction of potential mitochondrial toxicity during pre-clinical tests and, especially, prevent serious complications observed in clinical settings.

Influenza

Seasonal influenza epidemics of variable severity pose challenges to public health. Annual vaccination is the primary way to prevent influenza, and a wide range of vaccines are available, including inactivated or live attenuated standard-dose, recombinant vaccines, as well as adjuvanted or high-dose vaccines for persons aged 65 years or older. Persons at increased risk for influenza complications include young children, persons with underlying medical conditions, and older adults. Prompt diagnosis of influenza can facilitate early initiation of antiviral treatment that provides the greatest clinical benefit. This article summarizes recommendations for providers on influenza vaccination, diagnostic testing, and antiviral treatment.

Neuropathology Evaluation in Juvenile Toxicity Studies in Rodents: Comparison of Developmental Neurotoxicity Studies for Chemicals With Juvenile Animal Studies for Pediatric Pharmaceuticals

The developmental neuropathology examination in juvenile toxicity studies depends on the nature of the product candidate, its intended use, and the exposure scenario (eg, dose, duration, and route). Expectations for sampling, processing, and evaluating neural tissues differ for developmental neurotoxicity studies (DNTS) for chemicals and juvenile animal studies (JAS) for pediatric pharmaceuticals. Juvenile toxicity studies typically include macroscopic observations, brain weights, and light microscopic evaluation of routine hematoxylin and eosin (H&E)-stained sections from major neural tissues (brain, spinal cord, and sciatic nerve) as neuropathology endpoints. The DNTS is a focused evaluation of the nervous system, so the study design incorporates perfusion fixation, plastic embedding of at least one nerve, quantitative analysis of selected brain regions, and sometimes special neurohistological stains. In contrast, the JAS examines multiple systems, so neural tissues undergo conventional tissue processing (eg, immersion fixation, paraffin embedding, H&E staining only). An "expanded neurohistopathology" (or "expanded neuropathology") approach may be performed for JAS if warranted, typically by light microscopic evaluation of more neural tissues (usually additional sections of brain, ganglia, and/or more nerves) or/and special neurohistological stains, to investigate specific questions (eg, a more detailed exploration of a potential neuroactive effect) or to fulfill regulatory requests.

Neurological complications of cardiovascular drugs

Cardiovascular drugs are used to treat arterial hypertension, hyperlipidemia, arrhythmias, heart failure, and coronary artery disease. They also include antiplatelet and anticoagulant drugs that are essential for prevention of cardiogenic embolism. Most neurologic complications of the cardiovascular drugs are minor or transient and are far outweighed by the anticipated benefits of treatment. Other neurologic complications are more serious and require early recognition and management. Overtreatment of arterial hypertension may cause lightheadedness or fatigue but often responds readily to dose adjustment or an alternative drug. Other drug complications may be more troublesome as in myalgia associated with statins or headache associated with vasodilators. The recognized bleeding risk of the antithrombotics requires careful calculation of risk/benefit ratios for individual patients. Many neurologic complications of cardiovascular drugs are well documented in clinical trials with known frequency and severity, but others are rare and recognized only in isolated case reports or small case series. This chapter draws on both sources to report the adverse effects on muscle, nerve, and brain associated with commonly used cardiovascular drugs.

The role of aspirin desensitization followed by oral aspirin therapy in managing patients with aspirin-exacerbated respiratory disease: A Work Group Report from the Rhinitis, Rhinosinusitis and Ocular Allergy Committee of the American Academy of Allergy, Asthma & Immunology

Aspirin-exacerbated respiratory disease (AERD) is characterized by the clinical triad of chronic rhinosinusitis with nasal polyps, asthma, and an intolerance to medications that inhibit the cycloxgenase-1 enzyme. Patients with AERD on average have more severe respiratory disease compared with patients with chronic rhinosinusitis with nasal polyps and/or asthma alone. Although patients with AERD traditionally develop significant upper and lower respiratory tract symptoms on ingestion of cycloxgenase-1 inhibitors, most of these same patients report clinical benefit when desensitized to aspirin and maintained on daily aspirin therapy. This Work Group Report provides a comprehensive review of aspirin challenges, aspirin desensitizations, and maintenance aspirin therapy in patients with AERD. Identification of appropriate candidates, indications and contraindications, medical and surgical optimization strategies, protocols, medical management during the desensitization, and recommendations for maintenance aspirin therapy following desensitization are reviewed. Also included is a summary of studies evaluating the clinical efficacy of aspirin therapy after desensitization as well as a discussion on the possible cellular and molecular mechanisms explaining how this therapy provides unique benefit to patients with AERD.

Assessment of Reye's syndrome profile with data from the US Food and Drug Administration Adverse Event Reporting System and the Japanese Adverse Drug Event Report databases using the disproportionality analysis

Objectives:

Reye’s syndrome is a rare and potentially fatal illness that is defined as encephalopathy accompanied by liver failure. The aim of this study was to assess Reye’s syndrome profiles by analyzing data from the spontaneous reporting system database.

Methods:

We analyzed reports of Reye’s syndrome using the US Food and Drug Administration Adverse Event Reporting System and the Japanese Adverse Drug Event Report databases. The reporting odds ratio and proportional reporting rate were used to detect the pharmacovigilance signal.

Results:

The US Food and Drug Administration Adverse Event Reporting System contains 12,201,620 reports from January 2004 to June 2020, of which 186 are on Reye’s syndrome. The Japanese Adverse Drug Event Report contains 646,779 reports from April 2004 to September 2020, of which 30 are on Reye’s syndrome. In the US Food and Drug Administration Adverse Event Reporting System database, the reporting odds ratios (95% confidence interval, number of cases) of aspirin, diclofenac, ibuprofen, acetaminophen, and valproate sodium were 404.6 (302.6–541.0, n = 80), 15.1 (6.7–34.1, n = 6), 26.2 (16.1–42.6, n = 18), 10.7 (5.5–20.9, n = 9), and 47.1 (26.2–84.6, n = 12), respectively. In the Japanese Adverse Drug Event Report database, the reporting odds ratios (95% confidence interval, number of cases) of aspirin, diclofenac, ibuprofen, loxoprofen, acetaminophen, and valproate sodium were 14.1 (5.4–36.8, n = 5), 51.7 (22.2–120.5, n = 7), 135.0 (40.8–446.2, n = 3), 17.6 (6.7–46.0, n = 5), 24.0 (9.2–62.6, n = 5), and 13.8 (3.3–57.9, n = 2), respectively. The reported number of female patients aged 30–39 years was the highest in the Japanese Adverse Drug Event Report.

Conclusion:

Although the frequency of the occurrence of Reye’s syndrome is low, the possible risk of the disease occurring in adult females should be considered.

Evaluating the content validity of two versions of an instrument used in measuring pediatric pain knowledge and attitudes in the Ghanaian context

In this article, we compared the content validity of two instruments used in measuring pediatric pain knowledge and attitudes. This was considered necessary due to the universal differences in culture, semantics and healthcare resources in different parts of the globe. Thirteen (13) pediatric experts in Ghana assessed the content validity of two instruments: the 42-item Pediatric Nurses' Knowledge and Attitudes Survey Regarding Pain (PNKAS) and the 41-item Pediatric Healthcare Providers' Knowledge and Attitudes Survey Regarding Pain (PHPKASRP). The relevance and clarity of each item on these instruments were rated on a four-point likert scaled options from 1 (not relevant/ not clear) to 4 (very relevant/ very clear). The item-level content validity index (I-CVI) was calculated by dividing the number of experts who rated an item with 3 or 4 by the total number of experts. The average scale-level content validity index (S-CVI/Ave) was also estimated by summing up the I-CVIs of all items and dividing them by the total number of items. The I-CVIs on the PNKAS ranged from 0.62 to 1.00 for the relevance component and 0.69 to 1.00 for the clarity component. The I-CVIs on the PHPKASRP ranged from 0.62 to 1.00 for both the relevance and clarity components. The S-CVI/Ave were 0.87 and 0.89 for the relevance and clarity aspects on the PNKAS respectively. The S-CVI/Ave for the PHPKASRP instrument were 0.86 and 0.89 for the relevance and clarity aspects correspondingly. At the end of the validation process, 5 items were revised on both instruments whilst 37 and 36 items were maintained on the PNKAS and PHPKASRP instruments respectively. The PNKAS and PHPKASRP have an acceptable level of content validity in the Ghanaian context and recommended for educational and research purposes. Other forms of validity and reliability of these instruments should also be examined in future studies.

Essential thrombocythemia A retrospective case series

BACKGROUND

Essential thrombocythemia (ET) is rare in children, and pediatric guidelines are lacking. Therefore, we aimed to evaluate ET diagnosis and treatment in a pediatric cohort.

PROCEDURE

Data of patients with ET from three hospitals were reviewed. Molecular diagnosis included JAK2V617F, CALR, and MPL mutations. Patients were evaluated for acquired von Willebrand syndrome (AVWS). Follow-up included clinical symptoms, adverse events, and treatment.

RESULTS

Twelve children (median age: 8 years, range 1-14.5) were included. Mean lag period between the first documentation of thrombocytosis until ET diagnosis was 36 months. Six patients were positive for JAK2V617F and two for CALR mutations. In six of nine patients, AVWS was diagnosed. At diagnosis, only 33% of patients started therapy with aspirin (n = 4) and hydroxyurea (n = 2). In three of eight untreated patients, therapy was added during follow-up. The cohort was followed for a median of 32.5 months (range: 4-108 months). Clinical follow-up disclosed vascular complications in 4 of 12 patients (deep vein thrombosis, n = 1; transient ischemic attack, n = 3). Two females experienced excessive bleeding; both were diagnosed with AVWS. Neither leukemia nor myelofibrosis evolved in our cohort.

CONCLUSION

Increased awareness to pediatric ET is warranted, as delayed diagnosis is common. Compared to adults, AVWS may be more prevalent among children with ET.

Adjuvant herbal therapy for targeting susceptibility genes to Kawasaki disease: An overview of epidemiology, pathogenesis, diagnosis and pharmacological treatment of Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is a self-limiting acute systemic vasculitis occur mainly in infants and young children under 5 years old. Although the use of acetylsalicylic acid (AAS) in combination with intravenous immunoglobulin (IVIG) remains the standard therapy to KD, the etiology, genetic susceptibility genes and pathogenic factors of KD are still un-elucidated.

PURPOSE

Current obstacles in the treatment of KD include the lack of standard clinical and genetic markers for early diagnosis, possible severe side effect of AAS (Reye's syndrome), and the refractory KD cases with resistance to IVIG therapy, therefore, this review has focused on introducing the current advances in the identification of genetic susceptibility genes, environmental factors, diagnostic markers and adjuvant pharmacological intervention for KD.

RESULTS

With an overall update in the development of KD from different aspects, our current bioinformatics data has suggested CASP3, CD40 and TLR4 as the possible pathogenic factors or diagnostic markers of KD. Besides, a list of herbal medicines which may work as the adjunct therapy for KD via targeting different proposed molecular targets of KD have also been summarized.

CONCLUSION

With the aid of modern pharmacological research and technology, it is anticipated that novel therapeutic remedies, especially active herbal chemicals targeting precise clinical markers of KD could be developed for accurate diagnosis and treatment of the disease.

Key Potentially Inappropriate Drugs in Pediatrics: The KIDs List

OBJECTIVES

The safe use of medications in pediatric patients requires practitioners to consider the unique pharmacokinetics and pharmacodynamics of drugs prescribed in this age group. In an effort to create a standard of care for the safe use of medications in this population, a list of drugs that are potentially inappropriate for use in pediatric patients has been developed and titled the "KIDs List."

METHODS

A panel of 7 pediatric pharmacists from the Pediatric Pharmacy Association were recruited to evaluate primary, secondary, and tertiary literature; FDA Pediatric Safety Communications; the Lexicomp electronic database; and product information for drugs that should be considered potentially inappropriate for use in pediatric patients. Information was rated using predefined criteria. A PubMed search was conducted using the following terms: adverse drug events OR adverse drug reactions. The search was limited to humans; age <18 years; case reports, observational studies, or clinical trials; and English language. No date range was used. Results were used to create an evidence-based list of candidate drugs that was then peer-reviewed and subjected to a 30-day public comment period prior to being finalized.

RESULTS

A PubMed search yielded 4049 unique titles, of which 210 were deemed relevant for full review. Practitioner recommendations highlighted an additional 77 drugs. FDA Pediatric Safety Communications and the Lexicomp database yielded 22 and 619 drugs, respectively. After critical analysis, peer review, and public review the final KIDs List contains 67 drugs and/or drug classes and 10 excipients.

CONCLUSIONS

This extensive effort led to compilation of the first list of drugs that are potentially inappropriate for prescribing in all or in a select subgroup of pediatric patients. If avoidance is not clinically possible, the drug should be used with caution and accompanied by appropriate monitoring.

A rare case of Reye's syndrome induced by influenza A virus with use of ibuprofen in an adult

Background

Reye's syndrome (RS) is a rare but severe acute life‐threating disease characterized by encephalopathy and fatty liver damage. Reye's syndrome is most common in children and rarely occurs in adults.

Case presentation

A 56‐year‐old woman was admitted to the emergency department with disturbance of consciousness and respiratory failure. She had taken ibuprofen for headache. Her Glasgow Coma Scale score was E3V3M5 on admission. The laboratory findings revealed acute liver failure with prothrombin time – international normalized ratio of 3.16, aspartate aminotransferase 12,548 IU/L, alanine aminotransferase 5,725 IU/L, and blood ammonia 102 μg/dL. Head magnetic resonance imaging showed hyperintense signals on diffusion‐weighed images of globus pallidus.

We diagnosed the patient with RS induced by influenza A and use of ibuprofen. The patient received supportive care in the intensive care unit and her clinical outcome was favorable.

Conclusion

Ibuprofen might be a risk factor for RS.

Acute hepatitis and acute liver failure: Pathologic diagnosis and differential diagnosis

Acute hepatitis and acute liver failure are severe medical conditions that require early clinical intervention. Histopathologic findings on a liver biopsy or a liver explant may help identify the underlying etiology or provide an important direction for further clinical, laboratory and radiographical investigation. This review is divided into two main portions. The first portion concentrates on various etiologies and discusses unique histologic features that can be associated with specific etiologies. The second portion describes the general morphologic features based on which the diagnosis of acute hepatitis and acute liver failure are made. Histopathologic distinction between collapse and cirrhosis and limitations of histopathologic assessment for underlying etiologies are addressed in this portion. Another focus of this review is non-necrotic acute liver failure, which typically features diffuse microvesicular steatosis secondary to various etiologies causing mitochondrial dysfunction. Molecular testing serves an increasingly important role in the diagnosis and management of this group of disorders.

[Varicella (chickenpox) morbidity and mortality in hospital: about 19 cases collected at the Yalgado Ouedraogo University Hospital, Burkina Faso]

La varicelle est une virose dont l'épidémiologie est mal connue au Burkina Faso. Cette étude s'est donnée pour objectif de décrire le profil hospitalier de la pathologie dans le service des maladies infectieuses du Centre Hospitalier Universitaire Yalgado Ouedraogo (CHU-YO). Il s'est agi d'une série de 19 patients hospitalisés entre le 1^er janvier 2005 et le 31 décembre 2014. Ont été inclus, tous les patients avec un dossier complet et exploitable, dont le diagnostic positif de varicelle a été fait. La proportion périodique de varicelle était de 6,2% et a représenté 14,6% des éruptions fébriles. Elle était plus fréquente en 2011, de janvier à mars. L'âge médian était de 19 ans, et la moitié des patients avaient entre 6 et 30 ans. Les comorbidités étaient dominées par l'infection à VIH et l'herpès. Sur le plan clinique, la fièvre et le prurit étaient les symptômes communs et la vésicule la principale éruption. A l'admission, les principales complications étaient pulmonaires, hématologiques et cutanées. La durée médiane d'hospitalisation était de 5 jours, avec des extrêmes de 0 et 13 jours. Les principaux traitements étaient antiviral dans 9 cas, antipyrétique dans 19 cas, local dans 17 cas et antihistaminique dans 11 cas. Sur 19 cas de varicelle, 14 ont guéri et deux sont décédés, dont un adulte sur 10 et 1 enfant sur 9. Si la varicelle est une affection habituellement bénigne, elle peut être fatale chez l'adulte et l'enfant en cas de complications graves.

Characteristics and outcomes of patients with essential thrombocythemia or polycythemia vera diagnosed before 20 years of age: a systematic review

Although it is well known that myeloproliferative neoplasms occur in younger patients, few large cohorts of such patients have been reported. Thus, our knowledge about circumstances of diagnosis, outcome and treatment is limited, especially for children and young adults. We therefore performed a systematic review of cases, published since 2005, concerning patients aged below 20 years at the time of diagnosis of essential thrombocythemia or polycythemia vera. We identified 396 cases of essential thrombocythemia and 75 of polycythemia vera. The median age at diagnosis was 9.3 and 12 years, respectively, and females constituted 57.6% and 45% of the groups, respectively. Half of the patients were asymptomatic at diagnosis. The proportion of so-called triple negativity was high: 57% in essential thrombocythemia and 73% in polycythemia vera. The incidence of thrombosis during the follow-up was 9.3% in patients with polycythemia vera and less, 3.8%, in those with essential thrombocythemia. Venous events were predominant (84.2%), with hemorrhagic episodes being rarer (<5%). The risk of evolution also seemed low (2% to myelofibrosis and no reports of acute leukemia), but the median follow-up was only 50 months. Survival curves were not available. Half of the patients received an antithrombotic drug and 40.5% received a cytoreductive drug. All data should be analyzed with care because of the proportion of missing data (10.7% to 74.7%). This review highlights interesting points concerning this population of young patients with myeloproliferative neoplasms, including that such patients were identified as negative for all common driver mutations, but also shows the need for larger contemporary cohorts with longer follow-up to assess the true prognosis of these patients.

A Case of Reye Syndrome Caused by Influenza A Virus

Background

Reye syndrome is a rare and potentially life-threatening disease characterized by liver failure and hepatic encephalopathy. Multiple possible etiologies have been suggested, but only aspirin (acetylsalicylic acid) has been statistically proven to be a causative factor. We describe a case of Reye syndrome secondary to influenza A virus.

Case Report

A 2-year-old male with a recent history of influenza-like symptoms presented with neurologic deterioration. He had elevated liver enzymes, hyperammonemia, elevated creatinine, and hypoglycemia. Liver biopsy showed microvesicular steatosis consistent with Reye syndrome. He was given supportive care and recovered after 17 days with normalization of metabolic derangements. At 4-month follow-up, the patient had reached age-specific developmental milestones.

Conclusion

The incidence of Reye syndrome has decreased since 1980 when the Centers for Disease Control and Prevention issued a warning against aspirin use in children. Consequently, any new incidence of Reye syndrome warrants investigation of other etiologies. This case adds to the evidence that causes other than aspirin can result in Reye syndrome.

[Reye syndrome and sudden death symptoms after oral administration of nimesulide due to upper respiratory tract infection in a boy]

A boy aged 6 years and 3 months developed upper respiratory tract infection and pyrexia 2 months ago and was given oral administration of nimesulide by his parents according to directions. Half an hour later, the boy experienced convulsions and cardiopulmonary arrest, and emergency examination found hypoketotic hypoglycemia, metabolic acidosis, significant increases in serum aminotransferases and creatine kinase, and renal damage. Recovery of consciousness and vital signs was achieved after cardiopulmonary resuscitation, but severe mental and movement regression was observed. The boy had a significant reduction in free carnitine in blood and significant increases in medium- and long-chain fatty acyl carnitine, urinary glutaric acid, 3-hydroxy glutaric acid, isovalerylglycine, and ethylmalonic acid, suggesting the possibility of multiple acyl-CoA dehydrogenase deficiency. After the treatment with vitamin B2, L-carnitine, and bezafibrate, the boy gradually improved, and reexamination after 3 months showed normal biochemical parameters. The boy had compound heterozygous mutations in the ETFDH gene, i.e., a known mutation, c.341G>A (p.R114H), from his mother and a novel mutation, c.1484C>G (p.P495R), from his father. Finally, he was diagnosed with multiple acyl-CoA dehydrogenase deficiency. Reye syndrome and sudden death symptoms were caused by nimesulide-induced acute metabolic crisis. It is concluded that inherited metabolic diseases may be main causes of Reye syndrome and sudden death, and biochemical and genetic analyses are the key to identifying underlying diseases.

Safety of ibuprofen in infants younger than six months: A retrospective cohort study

Objective

We hypothesized (1) that gastrointestinal (GI) and renal adverse events (AE) would occur more often in infants first prescribed ibuprofen before rather than after six months of age and (2) that ibuprofen would be associated with more adverse effects than acetaminophen in infants younger than six months.

Methods

We created two partly overlapping retrospective cohorts of infants aged less than six months when California Medicaid first paid for ibuprofen or acetaminophen between 2004 and 2010. In the first cohort we compared the incidence rate ratio (RR) of GI and renal AE between those infants first prescribed ibuprofen before six months of age with those first prescribed ibuprofen after six months of age. In the second cohort we compared the RR of GI and renal AE between infants younger than six months prescribed ibuprofen (+/-acetaminophen) with those prescribed only acetaminophen.

Results

We identified 41,669 prescriptions for ibuprofen and 176,991 prescriptions for acetaminophen in 180,333 eligible infants (median age 2.1 months). We did not observe higher RR of any AE in infants first prescribed ibuprofen before rather than after six months of age. Most infants prescribed ibuprofen were also prescribed acetaminophen. Any GI (adjusted (a)RR 1.25, 95% CI 1.13–1.38) and moderate or severe GI AE (aRR 1.24, 95% CI 1.09–1.40) were more common in infants younger than six months who were prescribed ibuprofen versus acetaminophen alone. Severe GI (aRR 0.63, 95% CI 0.27–1.45) and renal AE (aRR 1.84 95% CI 0.66–5.19) were not different between the ibuprofen (+/-acetaminophen) and acetaminophen-only groups.

Conclusions

GI and renal AEs were not higher in infants younger than six months who were prescribed ibuprofen compared with those aged six to 12 months. AEs were increased in infants younger than six months who were prescribed ibuprofen compared with infants who were prescribed acetaminophen alone.

Cancer prevention by aspirin in children with Constitutional Mismatch Repair Deficiency (CMMRD)

Constitutional MisMatch Repair Deficiency (CMMRD) is caused by homozygous or compound heterozygous germline variants in one of the mismatch repair (MMR) genes (MSH2, MSH6, PMS2, MLH1). This syndrome results in early onset colorectal cancer, leukemia and lymphoma, brain tumors and other malignancies. Children with CMMRD are at high risk of developing multiple cancers and cancer surveillance does not guarantee detection of cancer at a curable stage. The development of a preventive treatment strategy would be a major step forward. Long-term daily use of acetylsalicylic acid (ASA) has been shown to reduce cancer risk in individuals with Lynch syndrome (LS). LS is caused by heterozygous germline variants of MSH2, MSH6, PMS2 and MLH1 and characterized by an increased risk of developing colorectal and endometrial cancer at adult age. Here we discuss the potential use of ASA for cancer prevention in patients with CMMRD.

Neuroinfluenza: evaluation of seasonal influenza associated severe neurological complications in children (a multicenter study)

PURPOSE

Although influenza primarily affects the respiratory system, in some cases, it can cause severe neurological complications. Younger children are especially at risk. Pediatric literature is limited on the diagnosis, treatment, and prognosis of influenza-related neurological complications. The aim of the study was to evaluate children who suffered severe neurological manifestation as a result of seasonal influenza infection.

METHODS

The medical records of 14 patients from six hospitals in different regions of the country were evaluated. All of the children had a severe neurological manifestations related to laboratory-confirmed influenza infection.

RESULTS

Median age of the patients was 59 months (6 months-15.5 years) and nine (64.3%) were male. Only 4 (28.6%) of the 14 patients had a comorbid disease. Two patients were admitted to hospital with influenza-related late complications, and the remainder had acute complication. The most frequent complaints at admission were fever, altered mental status, vomiting, and seizure, respectively. Cerebrospinal fluid (CSF) analysis was performed in 11 cases, and pleocytosis was found in only two cases. Neuroradiological imaging was performed in 13 patients. The most frequent affected regions of nervous system were as follows: cerebellum, brainstem, thalamus, basal ganglions, periventricular white matter, and spinal cords. Nine (64.3%) patients suffered epileptic seizures. Two patients had focal seizure, and the rest had generalized seizures. Two patients developed status epilepticus. Most frequent diagnoses of patients were encephalopathy (n = 4), encephalitis (n = 3), and meningitis (n = 3), respectively. The rate of recovery without sequelae from was found to be 50%. At discharge, three (21.4%) patients had mild symptoms, another three (21.4%) had severe neurological sequelae. One (7.1%) patient died. The clinical findings were more severe and outcome was worse in patients <5 years old than patients >5 years old and in patients with comorbid disease than previously healthy group.

CONCLUSION

Seasonal influenza infection may cause severe neurological complications, especially in children. Healthy children are also at risk such as patients with comorbid conditions. All children who are admitted with neurological findings, especially during the influenza season, should be evaluated for influenza-related neurological complications even if their respiratory complaints are mild or nonexistent.

What are pharmacists recommending for infant teething treatment?

OBJECTIVES

In 2011, the Food and Drug Administration issued a warning to avoid the use of any benzocaine-containing products for infant teething treatment owing to a risk of methemoglobinemia. Several benzocaine-containing products targeted for infant teething are currently available over the counter. Pharmacists are commonly asked for medical advice in the community, and there is no current literature evaluating what pharmacists are recommending for infant teething. The objectives of this study were to evaluate what pharmacists are currently recommending for infant teething treatment and assess what percentage would inappropriately recommend a benzocaine-containing product.

METHODS

From March to June 2016, a 16-item in-person paper-and-pen questionnaire was administered to 200 pharmacists in the San Francisco Bay area at 115 outpatient over-the-counter pharmacies. Questions included demographic information, work and educational background, infant teething recommendations, and preferred educational resources.

RESULTS

The overall response rate was 94.3%. One-half (50.5%) of the pharmacists' approaches to infant teething treatment was to recommend a nondrug option first and then, if needed, an over-the-counter medication. A majority (63.0%) of the pharmacists surveyed would inappropriately select a benzocaine-containing product.

CONCLUSION

Despite warnings, the majority of pharmacists would still inappropriately recommend a benzocaine-containing product for treatment of infant teething. Further education is warranted to ensure that all pharmacists, health care providers, and consumers are aware of the potential harm of benzocaine use in infants.

Peak hyperammonemia and atypical acute liver failure: The eruption of an urea cycle disorder during hyperemesis gravidarum

Inborn urea cycle disorders are under-recognised metabolic causes of hyperammonemia in adults. A 28-year-old primigravida, seven weeks pregnant, affected by hyperemesis gravidarum developed acute liver injury (ALI) and then acute liver failure (ALF) in less than 48 h. Because the patient developed atypical features, especially mildly elevated aminotransferases contrasting with very high blood ammonia levels (281 μmol/L), concomitant with normal serum creatinine, an inborn error of metabolism was suspected. We performed emergency metabolic analyses, stopped all protein intake and started with intravenous (i.v.) high caloric intake, nitrogen scavenger drugs and haemodialysis. The neurological and hepatic status of the patient quickly improved together with normalisation of her ammonemia levels. High plasma glutamine and urinary orotic acid, alongside low plasma arginine, citrulline and ornithine were suggestive of an ornithine transcarbamylase deficiency, later confirmed by molecular analyses. Foetal sex was female, as determined by foetal DNA analysis in maternal blood, and foetal development was unremarkable throughout the pregnancy. Delivery was induced at 39 weeks with a close monitoring of ammonemia levels and i.v. perfusion of carbohydrates and lipids during labour and immediately post-partum to avoid hypercatabolism. Delivery was uneventful and the patient delivered a healthy female baby. Urea cycle disorders should be contemplated in non-jaundiced patients with ALI or ALF, severe hyperammonemia and normal serum creatinine regardless of serum aminotransferase levels. The prompt recognition of this rare condition and the rapid initiation of adequate metabolic therapy are mandatory to prevent irreversible neurological sequelae and to avoid liver transplantation.

Kawasaki disease and coronary artery aneurysms: from childhood to adulthood

Kawasaki disease is an acute, systemic vasculitis of childhood and confers a 25% risk of developing coronary artery aneurysms. Its etiology is unknown, but the incidence is increasing rapidly with linked gene polymorphisms having been identified. A constellation of symptoms, epidemics and seasonality all implicate an unidentified infective or environmental cause. Intravenous immunoglobulin therapy, aspirin and steroids all form the mainstay of acute treatment and reduces the incidence of coronary artery aneurysms if given before 7 days. However, in some, these lesions persist and require ongoing management during follow-up during childhood and into adult life. Evidence for further investigations in order to minimize complications is presented in order to minimize the myofibroblast proliferation and stenosis in the long term.

Use of anti-inflammatory analgesics in sickle-cell disease

WHAT IS KNOWN AND OBJECTIVE

Non-steroidal anti-inflammatory drugs (NSAIDs) have been commonly used to treat pain in sickle-cell disease (SCD), but NSAID use is associated with renal, gastrointestinal and cardiovascular toxicities. Our objective was to evaluate the use of aspirin and non-aspirin NSAIDs in SCD.

COMMENT

Despite analgesic and anti-inflammatory benefits in SCD, non-aspirin NSAIDs are associated with renal, cardiovascular and gastrointestinal toxicities in this patient population. Aspirin may have less renal and cardiovascular toxicities. The different side effect profile of NSAIDs is related to the COX-1/COX-2 selectivity at their therapeutic doses. Individual risk factors and genetic biomarkers should be considered when selecting appropriate NSAIDs and their dose.

WHAT IS NEW AND CONCLUSION

NSAIDs have the potential to be an important component of pain regimens in SCD, but the use of NSAIDs should be individualized based on potential side effects and patient risk factors and the lowest effective dose should be prescribed with proper monitoring in patients with SCD.

Prevention of Influenza in Children

Influenza infects 5% to 20% of school-age children annually. Although universal influenza vaccine is recommended for children and adults 6 months of age and older, uptake is below national targets. Influenza immunization of the child and the family is the key to decreasing annual disease burden. Antiviral therapy is an important treatment strategy for children and adults, especially those who are at high risk of complications from influenza, irrespective of immunization status or whether illness onset is greater than 48 hours. Although antiviral therapy may also be used for pre-exposure and postexposure prophylaxis, it should not replace immunization as a preventive strategy when immunization is feasible.

Nonsteroidal Anti-Inflammatory Drug and Aspirin Use, and Mortality among Critically Ill Pandemic H1N1 Influenza Patients: an Exploratory Analysis

We explored nonsteroidal anti-inflammatory drug (NSAID) and aspirin (ASA) use and mortality in the U.S. Department of Health and Human Services' registry of 683 adult and 838 pediatric critically ill pandemic 2009 H1N1 influenza (pH1N1) patients. Among adults, 88 (12.9%) and 101 (14.8%) reported pre-admission use of an NSAID and ASA, respectively; mortality was similar (23-24%) regardless of NSAID or ASA use. Mortality among 89 pediatric NSAID users and 749 nonusers did not differ significantly (10.1% and 8.8%, respectively). One of 16 pediatric ASA users died. Among pediatric patients, the adjusted relative risk estimate for NSAID use and 90-day mortality was higher when influenza vaccination was included in the model (risk ratio [RR] = 1.5; 95% confidence interval, 0.7-3.2), although not statistically significant. Among adults, RR estimates did not change appreciably after adjusting for age, sex, health status, or vaccine status. We found no compelling evidence that NSAID or ASA use influenced mortality in severe pH1N1.

Varicella zoster virus infection

Infection with varicella zoster virus (VZV) causes varicella (chickenpox), which can be severe in immunocompromised individuals, infants and adults. Primary infection is followed by latency in ganglionic neurons. During this period, no virus particles are produced and no obvious neuronal damage occurs. Reactivation of the virus leads to virus replication, which causes zoster (shingles) in tissues innervated by the involved neurons, inflammation and cell death - a process that can lead to persistent radicular pain (postherpetic neuralgia). The pathogenesis of postherpetic neuralgia is unknown and it is difficult to treat. Furthermore, other zoster complications can develop, including myelitis, cranial nerve palsies, meningitis, stroke (vasculopathy), retinitis, and gastroenterological infections such as ulcers, pancreatitis and hepatitis. VZV is the only human herpesvirus for which highly effective vaccines are available. After varicella or vaccination, both wild-type and vaccine-type VZV establish latency, and long-term immunity to varicella develops. However, immunity does not protect against reactivation. Thus, two vaccines are used: one to prevent varicella and one to prevent zoster. In this Primer we discuss the pathogenesis, diagnosis, treatment, and prevention of VZV infections, with an emphasis on the molecular events that regulate these diseases. For an illustrated summary of this Primer, visit: http://go.nature.com/14xVI1.

Post-pericardiotomy syndrome in pediatric patients following surgical closure of secundum atrial septal defects: incidence and risk factors

Surgical repair for atrial septal defects (ASD) generally occurs during childhood. Post-pericardiotomy syndrome (PPS) after cardiac surgery has a reported incidence of 1-40 %. We focused exclusively on secundum ASD repair to evaluate the incidence of PPS. The purpose of this study is to determine the incidence of PPS after surgical repair of secundum ASD and investigate what risk factors may be predictive of its development. A retrospective study was performed, and 97 patients who underwent surgical closure of a secundum ASD were identified. 27 (28 %) were diagnosed with PPS within the first postoperative year. Diagnosis was made if they had evidence of new or worsening pericardial effusion and the presence of ≥2 of the following criteria: fever >72 h postoperatively, irritability, pleuritic chest pain, or pericardial friction rub. Closure of secundum ASDs was performed at a median age of 3.8 years (Interquartile Range (IQR): 2.2-6.0 years) and a median weight of 14.3 kilograms (IQR: 10.9-19.3 kilograms). The median time for development of PPS was 8 days post-op (IQR: 5-14). Significantly, 19 (27 %) of 70 patients in the non-PPS group had a small pericardial effusion on their discharge echocardiogram, while of the 27 patients who developed PPS, 17 (63 %) had a small pericardial effusion on their discharge echocardiogram (p = 0.001). PPS is relatively common following surgical closure of secundum ASDs. A small pericardial effusion on discharge echocardiogram is predictive of development of PPS postoperatively. In patients who develop PPS, there is a good response to therapy with a benign course.

The association between acetaminophen and asthma: is there anything to learn from the upper airways?

PURPOSE OF REVIEW

To examine the literature evidence for the association between acetaminophen (paracetamol) use and development of rhinitis.

RECENT FINDINGS

Increased use of acetaminophen (paracetamol) as the favored antipyretic during pregnancy and infancy has been hypothesized to be a risk factor for the development of asthma. There is a paucity of well designed birth cohort studies to examine paracetamol as a risk factor in the development of rhinitis. Confounding by antibiotic use, viral infections, and recall bias are problematic for many of the studies that are published.

SUMMARY

Prospective birth cohorts need to dedicate sufficient time and research personnel to adequately assess paracetamol exposure as a primary variable of interest rather than as an incidental exposure variable collected during routine questionnaire administration.

Abnormal hepatocellular mitochondria in methylmalonic acidemia

Methylmalonic acidemia (MMA) is one of the most frequently encountered forms of branched-chain organic acidemias. Biochemical abnormalities seen in some MMA patients, such as lactic acidemia and increased tricarboxylic acid cycle intermediate excretion, suggest mitochondrial dysfunction. In order to investigate the possibility of mitochondrial involvement in MMA, we examined liver tissue for evidence of mitochondrial ultrastructural abnormalities. Five explanted livers obtained from MMA mut(0) patients undergoing liver transplantation were biopsied. All patients had previous episodes of metabolic acidosis, lactic acidemia, ketonuria, and hyperammonemia. All biopsies revealed a striking mitochondriopathy by electron microscopy. Mitochondria were markedly variable in size, shape, and conformation of cristae. The inner matrix appeared to be greatly expanded and the cristae were diminutive and disconnected. No crystalloid inclusions were noted. This series clearly documents extensive mitochondrial ultrastructure abnormalities in liver samples from MMA patients undergoing transplantation, providing pathological evidence for mitochondrial dysfunction in the pathophysiology of MMA mut(0). Considering the trend to abnormally large mitochondria, the metabolic effects of MMA may restrict mitochondrial fission or promote fusion. The correlation between mitochondrial dysfunction and morphological abnormalities in MMA may provide insights for better understanding and monitoring of optimized or novel therapeutic strategies.

Neurologic manifestations of acute liver failure

Fulminant hepatic failure presents with a hepatic encephalopathy and may progress to coma and often brain death from cerebral edema. This natural progression in severe cases contributes to early mortality, but outcome can be good if liver transplantation is appropriately timed and increased intracranial pressure (ICP) is managed. Neurologists and neurosurgeons have become more involved in these very challenging patients and are often asked to rapidly identify patients who are at risk of cerebral edema, to carefully select the patient population who will benefit from invasive ICP monitoring, to judge the correct time to start monitoring, to participate in treatment of cerebral edema, and to manage complications such as intracranial hemorrhage or seizures. This chapter summarizes the current multidisciplinary approach to fulminant hepatic failure and how to best bridge patients to emergency liver transplantation.