Glycosaminoglycans (GAGs) are accumulated in various organs in both mucopolysaccharidoses (MPS) and mucolipidoses II and III (ML II and III). MPS and ML II and III patients can not properly degrade ...dermatan sulfate (DS) and/or heparan sulfate (HS). HS storage occurs in the brain leading to neurological signs while DS storage involves mainly visceral and skeletal manifestations. Excessive DS and HS released into circulation and thus blood levels of both are elevated, therefore, DS and HS in blood could be critical biomarkers for MPS and ML. Such measurement can provide a potential early screening, assessment of the clinical course and efficacy of therapies. We here assay DS and HS levels in MPS and ML patients using liquid chromatography tandem mass spectrometry (LC/MS/MS).
Plasma samples were digested by heparitinase and chondroitinase B to obtain disaccharides of DS and HS, followed by LC/MS/MS analysis. One hundred-twenty samples from patients and 112 control samples were analyzed. We found that all MPS I, II, III and VI patients had a significant elevation of all DS
+
HS compositions analyzed in plasma, compared with the controls (
P
<
0.0001). Specificity and sensitivity was 100% if the cut off value is 800
ng/ml between control and these types of MPS group. All MPS I, II and III patients also had a significant elevation of plasma HS, compared with the controls (
P
<
0.0001). All MPS VI patients had a significant elevation of plasma DS, compared with the controls (
P
<
0.0001).
These findings suggest measurement of DS and/or HS levels by LC/MS/MS is applicable to the screening for MPS I, II, III and VI patients.
In this single-center retrospective observational study, we report that the incidence of seizures in febrile children with COVID-19 was significantly higher in the Omicron era than in the pre-Omicron ...era (14.6% vs 1.7%, P < .001). One-third of the cases in the Omicron era were older than 5 years.
Antiviral therapy against cytomegalovirus (CMV) infection is indicated for symptomatic infection in the fetus and premature neonates. In mature neonates, the benefit of antiviral therapy for severe ...CMV infection remains controversial. Additionally, when diagnosing symptomatic CMV disease occurring during the early neonatal period, it is difficult to differentiate between congenital and acquired infections. We herein report a neonatal case of CMV infection complicated with severe thrombocytopenia that was successfully managed with antiviral treatment. A 21-day-old male infant presented with low-grade fever and erythema on his extremities. During outpatient follow-up, he developed petechiae and thrombocytopenia (platelet count 17,000/μL). Subsequent serological examination and molecular detection of CMV confirmed the diagnosis of CMV infection. In consideration of the severe thrombocytopenia, antiviral therapy with valganciclovir 32 mg/kg/day was initiated. The platelet counts increased with decreasing CMV loads. After excluding congenital CMV infection, we discontinued antiviral therapy without relapse of the disease. The present case suggests that neonatal cases of severe symptomatic CMV infection may require antiviral therapy while excluding the possibility of congenital infection.
Mucopolysaccharidosis I (MPS I) is an autosomal recessive disorder caused by deficiency of α-L-iduronidase leading to accumulation of its catabolic substrates, dermatan sulfate (DS) and heparan ...sulfate (HS), in lysosomes. This results in progressive multiorgan dysfunction and death in early childhood. The recent success of enzyme replacement therapy (ERT) for MPS I highlights the need for biomarkers that reflect response to such therapy. To determine which biochemical markers are better, we determined serum and urine DS and HS levels by liquid chromatography tandem mass spectrometry in ERT-treated MPS I patients. The group included one Hurler, 11 Hurler/Scheie, and two Scheie patients. Seven patients were treated from week 1, whereas the other seven were treated from week 26. Serum and urine DS (ΔDi-4S/6S) and HS (ΔDiHS-0S, ΔDiHS-NS) were measured at baseline, week 26, and week 72. Serum ΔDi-4S/6S, ΔDiHS-0S, and ΔDiHS-NS levels decreased by 72%, 56%, and 56%, respectively, from baseline at week 72. Urinary glycosaminoglycan level decreased by 61.2%, whereas urine ΔDi-4S/6S, ΔDiHS-0S, and ΔDiHS-NS decreased by 66.8%, 71.8%, and 71%, respectively. Regardless of age and clinical severity, all patients showed marked decrease of DS and HS in blood and urine samples. We also evaluated serum DS and HS from dried blood-spot samples of three MPS I newborn patients, showing marked elevation of DS and HS levels compared with those in control newborns. In conclusion, blood and urine levels of DS and HS provide an intrinsic monitoring and screening tool for MPS I patients.
Pulmonary arterial hypertension (PAH) is a rare complication of glycogen storage disease (GSD), and several cases with a poor outcome have been reported. A 17-year-old boy, who was diagnosed with GSD ...at 1 year of age, complained of shortness of breath on exertion, and was diagnosed with PAH based on the echocardiographic findings. Beraprost sodium (BPS) was started, and his symptoms improved after 3 months of treatment. Eighteen months later, he experienced frequent episodes of syncope. Because increasing the dose of BPS was ineffective, he was admitted to hospital. The echocardiogram showed marked elevation of the right ventricular pressure and low cardiac output, and his symptoms deteriorated despite continuous infusion of olprinone hydrochloride. Because a single dose of sildenafil increased his cardiac output, treatment with 25 mg sildenafil twice daily was started. His symptoms gradually ameliorated, and 3 weeks later he left the hospital. Two months after starting sildenafil, the cardiac index and the serous B-type natriuretic peptide concentration had become normal. Sildenafil may be effective in patients with secondary PAH and in patients who have developed tolerance to BPS. (Circ J 2009; 73: 1965-1968)
Diagnosis of mitochondrial respiratory chain disorder (MRCD) is often difficult. Its pathogenesis is still unclear. We diagnosed MRCD by measuring the activity of the mitochondrial respiratory chain ...enzyme, and the patient also had hemophagocytic lymphohistiocytosis (HLH). A preterm female infant was born at 34 weeks of gestation. On day 6, HLH was revealed by bone marrow aspiration. She died on day 10 due to uncontrollable HLH. An autopsy was performed, and we measured the activity of the mitochondrial respiratory chain enzyme in the liver, muscle, and heart. The activity of complex I was decreased in all tissues. As we could not prove another origin of the HLH, she was diagnosed as having HLH caused by MRCD. It is useful to measure the activity of the mitochondrial respiratory chain enzyme for diagnosing MRCD. MRCD, which has a severe clinical course, may be related to HLH.
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