Warm Antibody Autoimmune Haemolytic Anaemia Associated with Ovarian Teratoma

The ovarian cystic teratoma is a rare cause of autoimmune haemolytic anaemia by warm antibodies, resistant to corticotherapy, with few case reports published in the medical literature. We present a case of a 45-year-old woman admitted to hospital due to general weakness. Laboratory studies revealed macrocytic anaemia, biochemical parameters of haemolysis and peripheral spherocytosis. The direct Coombs test was positive. Viral serologies, anti-nuclear antibodies, anti-double-stranded DNA antibodies and β2-microglobulin were negative. CT scan of the thorax, abdomen and pelvis showed a heterogeneous right anexial lesion. The patient was treated with corticotherapy without improvement of anaemia. Regression of extra-vascular haemolysis and normalisation of haemoglobin was obtained only after laparoscopic splenectomy and right ooforectomy, and the histopathology of the right anexial mass revealed a cystic teratoma. Previously published cases controlled the haemolysis by surgically removing the lesion associated with splenectomy.

Gain-of-Function Mutations in IFIH1 Cause a Spectrum of Human Disease Phenotypes Associated with Upregulated Type I Interferon Signaling

The type I interferon system is integral to human antiviral immunity. However, inappropriate stimulation or defective negative regulation of this system can lead to inflammatory disease. We sought to determine the molecular basis of genetically uncharacterized cases of the type I interferonopathy Aicardi-Goutières syndrome, and of other patients with undefined neurological and immunological phenotypes also demonstrating an upregulated type I interferon response. We found that heterozygous mutations in the cytosolic double-stranded RNA receptor gene IFIH1 (MDA5) cause a spectrum of neuro-immunological features consistently associated with an enhanced interferon state. Cellular and biochemical assays indicate that these mutations confer a gain-of-function - so that mutant IFIH1 binds RNA more avidly, leading to increased baseline and ligand-induced interferon signaling. Our results demonstrate that aberrant sensing of nucleic acids can cause immune upregulation.