Common variable immunodeficiency disorders (CVID) is a heterogeneous group of disorders characterized by recurrent infections, hypogammaglobulinaemia and poor response to vaccination. Splenomegaly is a common feature in CVID, but neither its causes nor its consequences are well understood . This clinical observation is associated closely with certain clinical presentations such as lymphadenopathy, granulomatous inflammation and autoimmune cytopenia [1, 2], and is more prevalent among those with reduced class-switched memory B cells (CD19+CD27+IgD–IgM–) and increased CD21lo B cells [3-5].
The spleen is the largest secondary lymphoid organ and plays vital roles in the immune response. Due to its unique structure and vascularization, the spleen is essential in the removal of various blood-borne pathogens . The innate and adaptive immune systems co-operate closely in the marginal zone of the spleen where the highly specialized monocyte–macrophage system captures pathogens by a set of unique surface receptors [7, 8]. In humans, the severe reduction of marginal zone-like B cells in the peripheral blood following splenectomy indicates an important role for the spleen in the development or maintenance of this B cell population . These B cells are thought to be crucial for the immune response to polysaccharides of encapsulated bacteria; therefore, CVID patients with decreased numbers of CD27+IgM+IgD+ marginal zone-like B cells may have an increased burden of infections . Thus the spleen, via several complementary mechanisms, supports defence especially against encapsulated bacteria. These unique functions of the spleen are illustrated clearly by the increased life-long risk of severe infections such as meningitis and septicaemia after splenectomy .
Despite the potential of compounding an existing immunodeficiency, splenectomy has been used in CVID patients mainly in the context of refractory autoimmune cytopenia and suspected lymphoma. There are understandable concerns about this approach, but unfortunately there are limited published data to guide these clinical decisions. Resnick and colleagues have reported recently that splenectomy was not associated with reduction in survival in CVID patients , but significant post-operative complications and infections have been shown in earlier reports [1, 13]. With the increasing use of rituximab as an alternative treatment for refractory autoimmune cytopenia in immunocompetent individuals [14, 15], the role of splenectomy needs to be re-examined in immune-incompetent patients.
Therefore, on behalf of the European Society for Immunodeficiencies (ESID) Clinical working party and EUROpean-Primary Antibody Deficiency network (EUROPADnet), a multi-centre retrospective clinical survey was set up to investigate the prevalence, indications for and outcomes of splenectomy in patients with CVID.