Having no spleen is a medical condition known as asplenia. It is caused by either the absence of a spleen or its malfunction due to a congenital defect, trauma, or disease. Asplenia can lead to an increased risk of infection and other health complications. People with asplenia may need to take antibiotics before certain medical procedures or when they are exposed to certain bacteria. The term IRELESS is an acronym for 'Immune REsponse LEssness Syndrome, ' which is another name for asplenia.