PIGA and meningococcemia: Eculizumab OR Complement inhibitor AND Meningococcemia OR Neisseria Meningitidis AND Paroxysmal Nocturnal Hemoglobinuria OR PIGA gene defect AND Atypical Hemolytic Uremic Syndrome AND (( "Complement Inactivating Agents/adverse effects"[Majr] OR  "Complement Inactivating Agents/immunology"[Majr] AND (( "Neisseria meningitidis/drug effects"[Majr] OR  "Neisseria meningitidis/genetics"[Majr] AND (( "Hemoglobinuria, Paroxysmal/blood"[Majr] OR  "Hemoglobinuria, Paroxysmal/drug therapy"[Majr]