[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.

[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.

[Combined effect of gestational age and birth weight on metabolites related to inherited metabolic diseases in neonates]

OBJECTIVE

To study the combined effect of gestational age and birth weight on metabolites related to inherited metabolic diseases (IMD).

METHODS

A total of 3 381 samples ruled out of IMD by follow-up were randomly selected from 38 931 newborns who participated in the neonatal IMD screening during 2014-2016. The 3 381 neonates were categorized into seven groups according to their gestational age and birth weight: extremely preterm appropriate-for-gestational age (AGA) group (n=12), preterm small-for-gestational age (SGA) group (n=18), preterm AGA group (n=219), preterm large-for-gestational age (LGA) group (n=18), full-term SGA group (n=206), full-term AGA group (n=2 677), and full-term LGA group (n=231). Heel blood samples were collected from each group on postnatal days 3-7 after adequate breastfeeding. Levels of 17 key IMD-related metabolic indices in dried blood spots were measured using tandem mass spectrometry. Spearman′s correlation analysis was used to investigate the relationships between 17 IMD-related metabolic indices and their influencing factors, while covariance analysis was used to compare the metabolic indices between these groups.

RESULTS

After adjusting the influencing factors such as physiological and pathological status, compared with the full-term AGA group, the extremely preterm AGA, preterm SGA, and preterm AGA groups had significantly reduced levels of leucine\isoleucine\hydroxyproline and valine (P<0.05); the preterm AGA group had a significantly decreased ornithine level (P<0.05); the extremely preterm AGA and preterm AGA groups had a significantly reduced proline level (P<0.05). Besides, the phenylalanine level in the extremely preterm AGA and preterm AGA groups, the methionine level in the preterm SGA group, and the tyrosine level in the preterm AGA group all significantly increased (P<0.05). The increased levels of free carnitine, acetylcarnitine, and propionylcarnitine were found in the preterm SGA and preterm AGA groups. The oleylcarnitine level also significantly increased in the preterm SGA group (P<0.05). Most carnitine indices showed significant differences between the SGA group and the AGA/LGA group in both preterm and full-term infants (P<0.05).

CONCLUSIONS

Low gestational age and low birth weight may result in abnormal results in IMD screening. Therefore, gestational age and birth weight should be considered to comprehensively judge the abnormal results in IMD screening.

[Combined effect of gestational age and birth weight on metabolites related to inherited metabolic diseases in neonates]

OBJECTIVE

To study the combined effect of gestational age and birth weight on metabolites related to inherited metabolic diseases (IMD).

METHODS

A total of 3 381 samples ruled out of IMD by follow-up were randomly selected from 38 931 newborns who participated in the neonatal IMD screening during 2014-2016. The 3 381 neonates were categorized into seven groups according to their gestational age and birth weight: extremely preterm appropriate-for-gestational age (AGA) group (n=12), preterm small-for-gestational age (SGA) group (n=18), preterm AGA group (n=219), preterm large-for-gestational age (LGA) group (n=18), full-term SGA group (n=206), full-term AGA group (n=2 677), and full-term LGA group (n=231). Heel blood samples were collected from each group on postnatal days 3-7 after adequate breastfeeding. Levels of 17 key IMD-related metabolic indices in dried blood spots were measured using tandem mass spectrometry. Spearman&prime;s correlation analysis was used to investigate the relationships between 17 IMD-related metabolic indices and their influencing factors, while covariance analysis was used to compare the metabolic indices between these groups.

RESULTS

After adjusting the influencing factors such as physiological and pathological status, compared with the full-term AGA group, the extremely preterm AGA, preterm SGA, and preterm AGA groups had significantly reduced levels of leucine\isoleucine\hydroxyproline and valine (P&lt;0.05); the preterm AGA group had a significantly decreased ornithine level (P&lt;0.05); the extremely preterm AGA and preterm AGA groups had a significantly reduced proline level (P&lt;0.05). Besides, the phenylalanine level in the extremely preterm AGA and preterm AGA groups, the methionine level in the preterm SGA group, and the tyrosine level in the preterm AGA group all significantly increased (P&lt;0.05). The increased levels of free carnitine, acetylcarnitine, and propionylcarnitine were found in the preterm SGA and preterm AGA groups. The oleylcarnitine level also significantly increased in the preterm SGA group (P&lt;0.05). Most carnitine indices showed significant differences between the SGA group and the AGA/LGA group in both preterm and full-term infants (P&lt;0.05).

CONCLUSIONS

Low gestational age and low birth weight may result in abnormal results in IMD screening. Therefore, gestational age and birth weight should be considered to comprehensively judge the abnormal results in IMD screening.

[Clinical analysis of 15 851 children at risk of inherited metabolic diseases]

OBJECTIVE

To explore the value of urine gas chromatography-mass spectrometry (GC-MS) in the screening of children at risk of inherited metabolic diseases (IMD), and to identify the disease spectrum of IMD and the clinical characteristics of children with IMD.

METHODS

The clinical data of 15 851 children at risk of IMD who underwent urine GC-MS in the Tianjin Children's Hospital between February 2012 and December 2016 were retrospectively analyzed.

RESULTS

In the 15 851 children, 5 793 (36.55%) were detected to have metabolic disorders. A total of 117 (0.74%) children were confirmed to have IMD, including 77 cases of methylmalonic acidemia (65.8%). The clinical manifestations of confirmed cases in the neonatal period mainly included jaundice, metabolic acidosis, abnormal muscular tension, feeding difficulty, poor response, and lethargy or coma. The clinical manifestations of confirmed cases in the non-neonatal period mainly included delayed mental and motor development, metabolic acidosis, convulsion, recurrent vomiting, and anemia.

CONCLUSIONS

GC-MS is an effective method for the screening for IMD in children at risk. Methylmalonic acidemia is the most common IMD. The clinical manifestations of IMD are different between the confirmed cases in the neonatal and non-neonatal periods.

[Clinical analysis of 15 851 children at risk of inherited metabolic diseases]

OBJECTIVE

To explore the value of urine gas chromatography-mass spectrometry (GC-MS) in the screening of children at risk of inherited metabolic diseases (IMD), and to identify the disease spectrum of IMD and the clinical characteristics of children with IMD.

METHODS

The clinical data of 15 851 children at risk of IMD who underwent urine GC-MS in the Tianjin Children's Hospital between February 2012 and December 2016 were retrospectively analyzed.

RESULTS

In the 15 851 children, 5 793 (36.55%) were detected to have metabolic disorders. A total of 117 (0.74%) children were confirmed to have IMD, including 77 cases of methylmalonic acidemia (65.8%). The clinical manifestations of confirmed cases in the neonatal period mainly included jaundice, metabolic acidosis, abnormal muscular tension, feeding difficulty, poor response, and lethargy or coma. The clinical manifestations of confirmed cases in the non-neonatal period mainly included delayed mental and motor development, metabolic acidosis, convulsion, recurrent vomiting, and anemia.

CONCLUSIONS

GC-MS is an effective method for the screening for IMD in children at risk. Methylmalonic acidemia is the most common IMD. The clinical manifestations of IMD are different between the confirmed cases in the neonatal and non-neonatal periods.

[Pancytopenia and metabolic decompensation in a neonate]

A 9-day-old male patient was admitted to the hospital because of cough, anhelation, feeding difficulty and lethargy. The diagnostic examinations indicated pulmonary infection, severe metabolic acidosis, hyperglycemia, hyperammonemia and pancytopenia in the patient. Blood and urine screening and isovaleryl-CoA dehydrogenase (IVD) gene detection for inherited metabolic diseases were performed to clarify the etiology. Tandem mass spectrometric screening for blood showed an elevated isovalerylcarnitine (C5) level. The organic acid analysis of urine by gas chromatography-mass spectrometry showed significantly increased levels in isovaleryl glycine and 3-hydroxyisovaleric acid. Homozygous mutations (c.1208A>G, p.Tyr403Cys) in the IVD gene were identified in the patient. His parents were heterozygous carriers. After the treatment with low-leucine diets and L-carnitine for 3 days, the patient showed a significant improvement in symptoms, but he died one week later. It is concluded that the neonates with pneumonia and metabolic decompensation of unknown etiology should be screened for genetic metabolic disease.