Vascular pythiosis caused by Pythium aphanidermatum: the first case report in Asia

Background Pythium, soil-borne plant pathogens, are in the class Oomycetes. They are not true fungi, but are related to diatom and algae. There are two human pathogens including P. insidiosum and P. aphanidermatum. To date, only one case of pythiosis caused by P. aphanidermatum has been reported. We present herein the first case of P. aphanidermatum vascular pythiosis in Asia. Case presentation A 47-year-old Thai woman, living in North Thailand, with ß thalassemia/hemoglobin E presented with acute recurrent arterial insufficiency of both legs. Emergent embolectomy with clot removal was performed. The pathology of the clot exhibited noncaseous granulomatous inflammation with many fungal hyphal elements. PCR identified P. aphanidermatum with 100% identity. Final diagnosis is vascular pythiosis. Unfortunately, the patient eventually expired after treatment with itraconazole, terbinafine, azithromycin, and doxycycline. Conclusions To date, only one case of pythiosis caused by P. aphanidermatum has been reported. We present herein the first case of P. aphanidermatum vascular pythiosis in Asia.

Leg Ulcers: A Report in Patients with Hemoglobin E Beta Thalassemia and Review of the Literature in Severe Beta Thalassemia

Background: Leg ulcers are a frequent complication in patients with the inherited hemoglobin disorders. In thalassemia, the literature is limited, and factors associated with the development of leg ulcers in HbE beta thalassemia, the most common form of severe beta thalassemia worldwide, have not previously been reported. Methods: We reviewed all available medical records of patients with HbE beta thalassemia to document the onset of leg ulcers at the two largest treatment centres in Sri Lanka. We reviewed the literature to identify studies reporting outcomes of interventions for ulcers in severe thalassemia. Results : Of a total of 255 actively registered patients with HbE thalassemia in the two centres, 196 patient charts were evaluable. A leg ulcer with a documented date of onset was recorded in 45 (22%) of 196 evaluable patients, aged (mean ± SEM) 22.2 ± 1.4 years. Most had been irregularly transfused; steady state hemoglobin was 6.4 ± 0.2 g/dL. Treatment achieving healing in 17 patients included transfusions, antibiotics, oral zinc, wound toileting and skin grafting. Discussion/Conclusion: Leg ulcers may be more common in HbE beta thalassemia than in other forms of thalassemia. A systematic approach to treatment will be needed to document the prevalence and factors placing such patients at risk for leg ulcers. Controlled trials to evaluate the optimal treatment of this common complication are indicated.

Magnetic Resonance Imaging Reveals Significantly Increased Cerebral Blood Flow in the Hemoglobin E Mouse Model

Hemoglobin E (HbE) is the most common hemoglobin mutation world-wide. EE individuals exhibit a mild anemia as do those with β-thalassemia trait. A paradox arises with the combination of two relatively benign genes in HbE/β-thalassemia (HbE/β-thal) giving rise to highly morbid symptoms, anemia, growth retardation, developmental retardation, thalassemic bone type development, chronic leg ulcers (for a review, S Fucharoen and DJ Weatherall 2012) and often early mortality arising from cardiac failure (N Olivieri, Z Pakbaz et al. 2011). One approach to understanding the characteristics of HbE and this paradox was to generate a transgenic mouse model, expressing solely human HbE. This HbE mouse model exhibits a mild oxidative stress that parallels that observed in human EE individuals (QY Chen, EE Bouhassira et al. 2004, QY Chen, ME Fabry et al. 2012). These transgenic mice also exhibit mild cardiac dysfunction with depressed left ventricular contraction. We present here the first evidence of a significant increase in cerebral blood flow in the full knockout HbE (HbEKO) transgenic mouse model expressing solely human HbE compared to both the HbE+HbF (γ, gamma)-globin transgenic mouse, and the normal background C57 mouse. Cerebral blood flow is assessed non-invasively by MRI imaging. All protocols were approved by the Albert Einstein Institutional Animal Care and Use Committee. Comparing the HbEKO mouse (without human γ globin) to the C57 normal background mouse, a significant increase of over 20% in thalamus cerebral blood flow at baseline is observed (p=0.008). There is also an approximate 18% reduction in thalamus cerebral blood flow comparing HbE low γ mice to the full HbEKO (no γ) (p=0.011). Concomitant with these observations, no significant difference is observed comparing these low gamma HbE mice to the normal C57 background mouse (p=0.384). The goodness of the data is also seen in the relatively small variation in cerebral blood flow amongst the individual mice in each subset. These findings are of particular relevance to reports of neurologic symptoms, intracerebral hemorrhage, and brain infarct in HbE/β-thal patients (V Wong, YL Yu et al. 1990, S Das, S Dubey et al. 2019). In conclusion, these results suggest a direct role of HbE RBC initiating altered cerebral blood flow that when further complexed with β-thal could lead to intracerebral hemorrhage and other cerebral pathophysiology. The finding that the HbEKO mice with high HbF are not significantly different in cerebral blood flow from C57 mice may lend further support to therapeutic approaches enhancing the production of HbF in severe hemoglobinopathies, such as in sickle cell anemia, HbE/β-thal, and β-thal individuals. Disclosures No relevant conflicts of interest to declare.

Genetic Mutation of Hb E/beta Thalassemia Patient in Bangladesh and Its Relation With Clinical Severity

Background: Hemoglobin E/β-thalassemia is a common inherited hemoglobin disorder among South Asian countries. The phenotypically diverse presentation of the disease is often attributed to coinheritance of β-globin (HBB) gene mutations. The current study described the phenotype and genetic basis of Hb E/β-thalassemia patients and assessed its relation with clinical severity.Methods: A total of 32 patients were included in this cross-sectional study. Cases were confirmed by using capillary hemoglobin electrophoresis or high-performance liquid chromatography. Those with positive findings were further analyzed with clinical information and ancestral data either from the interview or medical records. Data collection was confined to May 2019 and July 2020. Gene sequencing was performed using Sanger’s sequencing method for mutational analysis, and Mahidol scoring was used to grade clinical severity.Result: A total of 13 heterozygous mutations were identified in the HBB gene. Of all, IVS-1-5 (G>C) (n=17, 53.1%) was the most common, and codon 30 (G>C) (n=4, 12.5%) was the second most common mutations. According to the Mahidol scoring system, 37.5% (n=12) were classified as phenotypically mild, 43.8% (n=14) as moderate and 18.8% (n=6) as severe. The IVS-1-5(G>C) mutation was found to be frequently associated with severe disease and showed no mild form.Conclusion: The present study described the clinical severity and its association with genetic mutations in hemoglobin E/β-thalassemia patients. This finding could guide individually tailored management strategies for this particular group of patients.

Association of the Degree of Erythroid Expansion and Maturation Arrest with the Clinical Severity of β0-Thalassemia/Hemoglobin E Patients

<b><i>Introduction:</i></b> β-Thalassemia/hemoglobin E represents one-half of all the clinically severe β-thalassemias worldwide. Despite similar genetic backgrounds, patients show clinical heterogeneity ranging from nearly asymptomatic to transfusion-dependent thalassemia. The underlying disease modifying factors remain largely obscure. <b><i>Methods:</i></b> To elucidate the correlation between ineffective erythropoiesis and β⁰-thalassemia/hemoglobin E (HbE) disease severity, in vitro culture of erythroid cells derived from patients with different clinical symptoms was established. Cell proliferation, viability, and differentiation were investigated. To identify potential molecular mechanisms leading to the arrested erythroid maturation, the expression levels of erythropoiesis modifying factors were measured. <b><i>Results:</i></b> The β⁰-thalassemia/HbE cells exhibited enhanced proliferation, limited differentiation, and impaired erythroid terminal maturation but did not show accelerated erythroblast differentiation and increased cell death. Erythroblasts derived from mild patients showed the highest proliferation rate with a faster cell division time, while erythroblasts derived from severe patients displayed extremely delayed erythroid maturation. Downregulation of growth differentiation factor 11 and FOXO3a was observed in mild β⁰-thalassemia/HbE erythroblasts, while upregulation of heat shock protein 70 and activin receptor 2A was revealed in severe erythroblasts. <b><i>Discussion/Conclusion:</i></b> The degree of erythroid expansion and maturation arrest contributes to the severity of β⁰-thalassemia/HbE patients, accounting for the disease heterogeneity. The findings suggest a restoration of erythroid maturation as a promising targeted therapy for severe patients.

“Efficacy and Safety of Deferasirox in Pediatric Thalassemia Patients: Experience from a Tertiary Care Children Hospital of Bangladesh”

Background: Thalassemia is an inherited hemoglobin disorder; mostly require life-long blood transfusions, leading to chronic iron overload which causes growth failure, delayed sexual development in adolescents and vital organ dysfunctions. So, children with thalassemia need lifelong iron chelation therapy. Hence, this study conducted with the aim of to evaluate efficacy and safety of Deferasirox in pediatric thalassemia patients. Materials and methods: This is an observational, prospective, single-centered hospital-based study conducted in a tertiary care teaching hospital from June 2018 to December 2019. Total sixty children (age 2-18 years) with beta thalassemia major and hemoglobin E beta thalassemia with iron overload were enrolled to commence deferasirox. Efficacy and safety we observed by measuring serum ferritin three monthly and SGPT, SGOT & serum creatinine monthly. Results: The serum ferritin level of 72% patients reduced significantly after 12 months in comparison to baseline level. There was no serious adverse effect except mild abdominal pain, nausea & vomiting and transaminitis. Conclusion: Deferasirox is efficacious in reducing iron overload of the body when administer at optimum dose over at least one year and presenting a safe as well as convenient alternative for most of the transfusion dependent pediatric thalassemia patients.

Extended Phenotyping and Functional Validation Facilitate Diagnosis of a Complex Patient Harboring Genetic Variants in MCCC1 and GNB5 Causing Overlapping Phenotypes

Identifying multiple ultra-rare genetic syndromes with overlapping phenotypes is a diagnostic conundrum in clinical genetics. This study investigated the pathogenicity of a homozygous missense variant in GNB5 (GNB5L; NM_016194.4: c.920T > G (p. Leu307Arg); GNB5S; NM_006578.4: c.794T > G (p. Leu265Arg)) identified through exome sequencing in a female child who also had 3-methylcrotonyl-CoA carboxylase (3-MCC) deficiency (newborn screening positive) and hemoglobin E trait. The proband presented with early-onset intellectual disability, the severity of which was more in keeping with GNB5-related disorder than 3-MCC deficiency. She later developed bradycardia and cardiac arrest, and upon re-phenotyping showed cone photo-transduction recovery deficit, all known only to GNB5-related disorders. Patient-derived fibroblast assays showed preserved GNB5S expression, but bioluminescence resonance energy transfer assay showed abolished function of the variant reconstituted Gβ5S containing RGS complexes for deactivation of D2 dopamine receptor activity, confirming variant pathogenicity. This study highlights the need for precise phenotyping and functional assays to facilitate variant classification and clinical diagnosis in patients with complex medical conditions.