Complex sentence: An increased incidence of asthma has not been reported for adrenalectomized patients; they are probably protected from airway hyper-reactivity from their corticosteroid replacement therapy.
Split into simpler sentences: An increased incidence of asthma has not been reported for adrenalectomized patients. Those with a predisposition to asthma will have some protection from airway hyper-reactivity from their corticosteroid replacement therapy.