C5AR1 and acute respiratory distress syndrome: Experimental studies in the 1980s involving monkeys and employing a rabbit anti-human polyclonal antibody to C5a indicated that blockade of C5a by such antibodies could significantly attenuate live Escherichia coli-induced septic shock and accompanying acute respiratory distress syndrome (ARDS) [7] and that such antibodies could significantly lower the C5a levels in monkey blood [8].