Eculizumab in severe Shiga toxin-mediated haemolytic uraemic syndrome.

Shiga toxin (Stx)-producing Escherichia coli-mediated haemolytic uraemic syndrome is a primary thrombotic microangiopathy, typified by the development of microangiopathic haemolytic anaemia, thrombocytopaenia and acute renal failure. It is a leading cause of acute renal failure in paediatrics, with a second peak in prevalence in adults over the age of 60. Presentations of Stx-producing E. coli-mediated haemolytic uraemic syndrome in young adults are rare. We present the case of a previously well female in her early 30s presenting with Stx-producing E. coli-mediated haemolytic uraemic syndrome with severe renal and neurological manifestations. Eculizumab was administered due to the severity of presentation and disease trajectory refractory to initial supportive therapy. A significant clinical and biochemical improvement was observed following eculizumab.

Systemic sclerosis following COVID-19 infection with recurrent corticosteroid-induced scleroderma renal crisis.

Systemic sclerosis is a complex multisystem connective tissue disease resulting in fibrosis of the skin and internal organs. Exposure to corticosteroids can trigger scleroderma renal crisis, a life-threatening complication of the disease. Autoimmune disease following infection with COVID-19 is being increasingly recognised. The mechanisms of post-COVID-19 autoimmunity are likely multifactorial, involving immune dysregulation, molecular mimicry and the development of cross-reactive antibodies. There are currently only two reported cases of systemic sclerosis occurring post-COVID-19 infection.We present the case of a female patient who developed systemic sclerosis post-COVID-19 infection. Following exposure to corticosteroids, the patient developed scleroderma renal crisis complicated by thrombotic microangiopathy, seizures and acute renal failure. Despite an antibody profile not typically associated with renal crisis (anti-topoisomerase positive, anti-RNA-polymerase III negative), the patient developed recurrent renal crisis with repeated exposure to corticosteroid therapy, highlighting the risk of steroid use in all patients with systemic sclerosis.

Investigation of magnetic field effects on the dose-response of 3D dosimeters for magnetic resonance - image guided radiation therapy applications.

BACKGROUND AND PURPOSE: The strong magnetic field of integrated magnetic resonance imaging (MRI) and radiation treatment systems influences secondary electrons resulting in changes in dose deposition in three dimensions. To fill the need for volumetric dose quality assurance, we investigated the effects of strong magnetic fields on 3D dosimeters for MR-image-guided radiation therapy (MR-IGRT) applications. MATERIAL AND METHODS: There are currently three main categories of 3D dosimeters, and the following were used in this study: radiochromic plastic (PRESAGE®), radiochromic gel (FOX), and polymer gel (BANG™). For the purposes of batch consistency, an electromagnet was used for same-day irradiations with and without a strong magnetic field (B0, 1.5T for PRESAGE® and FOX and 1.0T for BANG™). RESULTS: For PRESAGE®, the percent difference in optical signal with and without B0 was 1.5% at the spectral peak of 632nm. For FOX, the optical signal percent difference was 1.6% at 440nm and 0.5% at 585nm. For BANG™, the percent difference in R2 MR signal was 0.7%. CONCLUSIONS: The percent differences in responses with and without strong magnetic fields were minimal for all three 3D dosimeter systems. These 3D dosimeters therefore can be applied to MR-IGRT without requiring a correction factor.