Atrophy of the spleen or "splenic atrophy" refers to the wasting of the spleen, an organ whose importance to proper functioning of the immune system is becoming increasingly recognised, in part due to the consequences of splenectomy. Splenic atrophy appears in association with a number of diseases. Atrophy of the spleen may cause "hyposplenism" and sometimes "asplenia," which can have serious consequences.
The immune system function of the spleen is to filter the blood, detecting and defending against harmful foreign materials. Cells called macrophages and dendritic cells capture antigens in the blood passing through the spleen and also bring antigens to the spleen, where an immune response is launched, with B cells producing bacteria-and-virus-fighting antibodies.
"Atrophy" means "wasting," as in wasting away. When the spleen atrophies, it becomes smaller in size and it can no longer function properly. Reduced splenic function is referred to as "hyposplenism." If splenic atrophy continues, hyposplenism may become asplenia, meaning that it is as though the person has no spleen. The association of splenic atrophy with sickle cell disease and Celiac disease is well-recognised, but it is also associated with other conditions.
Because of the role the spleen plays in the immune system, people with hyposplenism or asplenism are at greater risk for bacterial infection and may experience more severe forms of viral infections and other infections such as malaria. As with the consequences of splenectomy, this risk includes sepsis, a serious and potentially fatal condition.
According to Dr. Mazen Sabah, Dr. Rosemary Phillips and Dr. Jeffrey Phillips in a March 2008 article in the international journal Medicine On-line, "Streptococcus pneumoniae is the commonest cause of sepsis in asplenic individuals accounting for up to 90 per cent of such episodes." Streptoccocus pneumoniae is a bacteria that causes pneumonia and other infections, including meningitis.
Vaccination is a possible preventive measure against the deadly possibility of sepsis. Sabah, Phillips and Phillips, of the Department of Critical Care, Princess Alexandra Hospital, Harlow, UK, recommend that patients with asplenia or splenic dysfunction should be vaccinated against pneumococcal, H. influenzae type B, meningoccoccal group C and influenza, while recognising that different countries may have slight variations in recommendation.
The person with splenic atrophy needs to be aware that he or she may be at greater risk for serious bacterial or other infection and consult a physician about preventive and emergency measures.