Extremely Early Onset Transthyretin Familial Amyloid Polyneuropathy with a Leu55Pro Mutation: A Pediatric Case Report and Literature Review.

Transthyretin familial amyloid polyneuropathy (TTR-FAP) is a life-threatening autosomal dominant disease caused by the deposition of amyloid fibrils composed of TTR proteins. Symptoms of this disease include progressive sensorimotor neuropathy, cardiomyopathy, and involvement of other organs. We described a pediatric case of extremely early onset TTR-FAP with a TTR Leu55Pro mutation. A 17-year-old boy began to suffer from lower limb weakness, gait disturbance, and decreased sensation from 14 years of age onward. He presented with hypertrophic cardiomyopathy, periorbital and scleral ecchymosis, anhidrosis, orthostatic intolerance, and gastrointestinal autonomic dysfunction including nausea, vomiting, and diarrhea alternating with constipation. The patient's older sister had developed similar gastrointestinal symptoms from 20 years of age onward and was diagnosed as having hypertrophic cardiomyopathy. The boy's biopsy results showed infiltrated amyloid deposition on subcutaneous fat tissue and endocardium. Genetic analysis of the TTR gene demonstrated that both the patient and his sister had a pathogenic mutation, c.224T > C (Leu55Pro). Both patients were prescribed tafamidis, a TTR stabilizing agent. Although a majority of TTR-FAPs occur during adulthood, it should be suspected, even in pediatric populations, when symmetric length dependent neuropathy occurs in conjunction with a family history of neuropathy, autonomic neuropathy, and/or cardiomyopathy.

Central nervous system vasculitis from Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disorder in children: A case report.

BACKGROUND: Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disorders (EBV-T/NK-LPD) is a group of rare disorders resulting from EBV-infected T/NK-cells. It manifests as a broad spectrum of clinical symptoms according to immunologic status and viral load of an infected patient. Here, we report a boy who developed central nervous system (CNS) vasculitis and myelopathy as possible neurologic manifestations of EBV-T/NK-LPD. CASE REPORT: A 16-year-old boy came to our hospital with a necrotic skin lesion on his right shoulder. He suffered from local skin reactions with high fevers after mosquito bites since he was 10 years old. During the evaluation of his skin lesion, he suddenly developed left facial palsy. Brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) showed acute infarctions of the pons and middle cerebellar peduncle and irregularities of both anterior inferior cerebellar arteries. Serologic testing showed an elevation of total Ig E levels, anti-VCA IgG levels, and anti-EA IgG titers. EBV DNA copy numbers of the whole blood and cerebrospinal fluid (CSF) were elevated. Biopsy of the right shoulder skin showed extranodal NK/T-cell lymphoma. According to clinical features and laboratory findings, he was diagnosed with EBV-T/NK-LPD. He was treated with chemotherapy and hematopoietic stem cell transplantation but developed recurrent infarctions during treatment. CONCLUSION: This case showed the diagnostic challenge of neurologic manifestations of EBV-T/NK-LPD. EBV-T/NK-LPD-associated CNS vasculitis needs to be considered as a differential diagnosis of CNS vasculitis, when it is accompanied by the typical clinical spectrum of EBV-T/NK-LPD such as severe mosquito bite allergy, extranodal NK/T-cell lymphoma.

Vitamin C Improves Therapeutic Effects of Adipose-derived Stem Cell Transplantation in Mouse Tendonitis Model.

BACKGROUND/AIM: We hypothesized that combined therapy using adipose-derived stem cells (ASCs) and vitamin C might improve tendon regeneration in tendonitis. To determine combined effects of ASC transplantation with vitamin C, we used senescence marker protein 30 (SMP30)-knockout (KO) mice that cannot biosynthesize vitamin C by themselves. MATERIALS AND METHODS: SMP30-KO were divided into four groups: Control, vitamin C, ASCs, and vitamin C plus ASCs. Tendonitis was induced in the achilles tendons via injection of collagenase type I. After 1 week, ASCs were injected into the intratendonal region. After 30 days, all mice were sacrificed and Achilles tendons were isolated. RESULTS: Gross and microscopic findings showed mice treated with combination of ASC transplantation and vitamin C showed better tendon regeneration than those in other groups. This combination led to higher serum vitamin C levels than use of vitamin C alone. This indicates that the vitamin C-treated group used more vitamin C as a precursor to collagen synthesis, whereas vitamin C was in excess in the combination group because of the added effect of ASCs on tendon healing. CONCLUSION: This study showed that vitamin C improved the effect of ASC transplantation on tendonitis by inducing a better stem cell niche.