A case of antisynthetase syndrome presenting solely with life-threatening interstitial lung disease.

A previously fit and well 38-year-old man presented during the COVID-19 pandemic with dyspnoea, cough and palpitations. C-reactive protein was elevated and chest X-ray demonstrated bilateral lower zone consolidation. SARS CoV-2 swab was negative. He was diagnosed with community-acquired pneumonia and treated with oral antibiotics. He developed severe type 1 respiratory failure and was admitted to the high-dependency unit for non-invasive ventilation. CTPA was negative for pulmonary embolism, instead demonstrating bilateral organising pneumonia. Empirical treatment for swab-negative COVID-19 pneumonitis was started; however, further deterioration ensued and prompted intubation and ventilation. Microbiological testing did not yield any positive results, thereby raising suspicion for the presence of an autoimmune disease. Pulsed intravenous methylprednisolone was administered with good effect. ENA screen was positive for anti-Jo1 and myositis-specific autoantibodies were positive for Ro-52, Ku and PL-12. The patient was extubated and did not exhibit any muscle weakness on clinical examination. Creatine kinase was only mildly elevated. He was diagnosed with amyopathic antisynthetase syndrome - frequently considered as a form of idiopathic inflammatory myopathy (IIM) - and treated with further intravenous methylprednisolone and cyclophosphamide. Oxygen therapy was gradually weaned and the patient discharged on mycophenolate mofetil and a weaning course of oral steroids.

Pathogenesis of hepatic encephalopathy: role of ammonia and systemic inflammation.

The syndrome we refer to as Hepatic Encephalopathy (HE) was first characterized by a team of Nobel Prize winning physiologists led by Pavlov and Nencki at the Imperial Institute of Experimental Medicine in Russia in the 1890's. This focused upon the key observation that performing a portocaval shunt, which bypassed nitrogen-rich blood away from the liver, induced elevated blood and brain ammonia concentrations in association with profound neurobehavioral changes. There exists however a spectrum of metabolic encephalopathies attributable to a variety (or even absence) of liver hepatocellular dysfunctions and it is this spectrum rather than a single disease entity that has come to be defined as HE. Differences in the underlying pathophysiology, treatment responses and outcomes can therefore be highly variable between acute and chronic HE. The term also fails to articulate quite how systemic the syndrome of HE can be and how it can be influenced by the gastrointestinal, renal, nervous, or immune systems without any change in background liver function. The pathogenesis of HE therefore encapsulates a complex network of interdependent organ systems which as yet remain poorly characterized. There is nonetheless a growing recognition that there is a complex but influential synergistic relationship between ammonia, inflammation (sterile and non-sterile) and oxidative stress in the pathogenesis HE which develops in an environment of functional immunoparesis in patients with liver dysfunction. Therapeutic strategies are thus moving further away from the traditional specialty of hepatology and more towards novel immune and inflammatory targets which will be discussed in this review.