Posterior reversible encephalopathy syndrome presenting with thrombotic microangiopathy triggered by malignant hypertension: a case report and literature review.

Background: Posterior reversible encephalopathy syndrome (PRES) is a disease characterised by reversible subcortical vasogenic oedema, neurological symptoms and abnormal findings on head imaging. It is recognised as one of the most prominent organ disorders in hypertensive emergencies but is rarely associated with thrombotic microangiopathy (TMA). Case presentation: A woman in her 40s with untreated hypertension had occasional headaches in the past 4 months. The headaches worsened during the 3 weeks prior to admission. On the day of admission, the patient presented with severe headache accompanied by frequent vomiting. MRI of the head revealed oedematous changes in the brainstem, including the subcortical, cerebellum and pons. Fundus examination revealed hypertensive retinopathy with papilloedema. Blood tests indicated thrombocytopenia, renal dysfunction and haemolytic anaemia, and a blood smear confirmed fragmented erythrocytes. Coombs' test, and tests for ADAMTS13 activity and infectious and autoimmune diseases were negative. The patient was diagnosed with PRES, secondary to malignant hypertension (MH) and associated with TMA. Antihypertensive therapy promptly improved the clinical symptoms, blood pressure, and the abnormal MRI and blood test findings. The patient was discharged from the hospital 20 days after admission. Conclusions: We report a rare case of PRES that was associated with TMA and triggered by MH. Antihypertensive therapy was effective in alleviating the associated adverse clinical symptoms. Differentiation of underlying diseases is essential for early intervention, since treatment depends on factors causing TMA.

A Case of Effective Mepolizumab Induction Therapy for Severe Eosinophilic Granulomatosis with Polyangiitis Diagnosed by Eosinophilic Cholecystitis and Interstitial Nephritis.

A 66-year-old man with a history of bronchial asthma and sinusitis was admitted with cholecystitis and peripheral neuropathy. The histopathological findings of the gallbladder revealed necrotic vasculitis and granulomatous inflammation with marked eosinophilic infiltration. Kidney biopsy also showed marked eosinophilic infiltration in the tubulointerstitial area and eosinophilic tubulitis. He was diagnosed with eosinophilic granulomatosis with polyangiitis (EGPA) and treated with corticosteroids. However, he showed no response. Therefore, he was administered mepolizumab 300 mg, which resulted in clinical improvement, including normalization of the eosinophil and CRP levels. We herein describe the first case of successful induction therapy of EGPA using mepolizumab.