Page 91 - Haematologica May 2022
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Complement dysregulation & COVID-19
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Figure 3. C5 and factor D inhibition block complement activation induced by COVID-19 patient serum. Flow cytometry demonstrat- ed increased C5b-9 (A) and C3c (B) deposition in two representative COVID-19 patients. C5b-9 deposi- tion was completely blocked in the presence of 50 μg anti-C5 antibody. 1 μM factor D inhibitor (ACH145951) partially reduced the C5b-9 deposition in patient 2 and achieved complete inhibition in patient 1 (A). Factor D inhibitor also effectively decreased C3c accumu- lation induced by both patients’ sera, whereas anti-C5 antibody did not appreciably prevent C3c deposi- tion (B). SSCH: side scatter; ACH145951: factor D inhibitor; Anti- C5 Ab: anti-C5 monoclonal anti- body. NHS: normal human serum; EDTA: ethylenediaminetetraacetic.
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