We agree with the recommendations made in the review by Petrescu and colleagues that outlines important issues surrounding vaccination and discusses the risks of overwhelming postsplenectomy infection in patients who are or will be asplenic following splenectomy.1 Surgical or traumatic removal of the spleen is an important and easily recognizable medical event that should prompt a discussion between physician and patient regarding the risk of overwhelming postsplenectomy infection.
Equally important, but not mentioned in the review, is the hyposplenic state associated with a number of common medical conditions. In addition to congenital hyposplenism (which is rare), splenic atrophy with functional asplenia is frequently present in sickle cell disease, celiac disease, advanced HIV infection, and in patients with chronic graft-versus-host disease following hematopoietic stem cell transplantation. A complete list of medical conditions has been published elsewhere.2
Medically hyposplenic patients are at a similar risk of overwhelming postsplenectomy infection as those with surgical asplenism, and all such patients should be counselled about the risk and offered the appropriate vaccinations as outlined by Petrescu and colleagues.1 Medical hyposplenism must be suspected by history of a relevant medical condition, and can be confirmed by the presence of characteristic findings on the peripheral blood smear, such as Howell–Jolly bodies, acanthocytes or nucleated red blood cells. Functional radionuclide (technetium-based) scans can provide quantification of splenic function, but are expensive and generally unnecessary. We urge clinicians to consider medically hyposplenic patients for vaccination and counselling regarding the risk of overwhelming postsplenectomy infection.