Siblings with coronavirus disease 2019 infection and opposite outcome-the hemodialysis's better outcome paradox: Two case reports.

Background: Coronavirus disease 2019 (COVID-19) is a highly contagious infection caused by the severe acute respiratory syndrome coronavirus 2 virus and has a unique underlying pathogenesis. Hemodialysis (HD) patients experience high risk of contamination with COVID-19 and are considered to have higher mortality rates than the general population by most but not all clinical series. We aim to highlight the peculiarities in the immune state of HD patients, who seem to have both immune-activation and immune-depression affecting their outcome in COVID-19 infection.

Case summary: We report the opposite clinical outcomes (nearly asymptomatic course vs death) of two diabetic elderly patients infected simultaneously by COVID-19, one being on chronic HD and the other with normal renal function. They were both admitted in our hospital with COVID-19 symptoms and received the same treatment by protocol. The non-HD sibling deteriorated rapidly and was intubated and transferred to the Intensive Care Unit, where he died despite all supportive care. The HD sibling, although considered more "high-risk" for adverse outcome, followed a benign course and left the hospital alive and well.

Conclusion: These cases may shed light on aspects of the immune responses to COVID-19 between HD and non-HD patients and stimulate further research in pathophysiology and treatment of this dreadful disease.