Hyposplenism
Since splenic macrophages have a major role in phagocytosing bacteria and the spleen is the principal producer of antibodies, hyposplenic (functional or anatomic) patients have an increased susceptibility to serious infections caused by encapsulated bacteria and other pathogens such as pneumococcal septicemia.[133,134] Hyposplenism, which may be a complication of chronic folate deficiency, the result of excessive loss of lymphocytes through the damaged GI tract or related to the mucosal lesion,[135] is a well-documented complication of celiac disease in historical case series.[136–147] Hyposplenism appears to be much less common in children with celiac disease,[137,142,143,146] with duration of exposure to gluten as a significant factor for the prevalence and severity of the hyposplenism.[138] Adherence to a gluten-free diet was associated with a decrease in pitted red blood cells, suggesting hyposplenism may be reversible,[136] but this observation is not supported by other investigators.[147] Higher pitted red blood cell counts were also observed in those with more severe duodenal histology[143] or with complicated celiac disease such as jejunoileitis.[140]
Risk of Infection in Celiac Disease
Using the Swedish In-Patient Registry linked to death registration data, a population-based cohort study observed that people with celiac disease (n = 10,032) had a sevenfold increased risk of death from septicemia (SMR: 7.1 [95% CI: 1.9–18.2]), and threefold increased risk of death from infection (SMR: 2.9 [95% CI: 1.5–3.0] and pneumonia (SMR: 2.9 [95% CI: 2.1–3.8]) in comparison with general population controls.[51] Using the same In-Patient Registry, a recent population-based cohort study observed that people with celiac disease (n = 15,325) had a twofold increased risk of infection (HR: 1.6 [95% CI: 1.2–1.9]) and a fourfold increased risk of pneumococcal infection (HR: 2.5 [95% CI: 1.2–5.1]).[148] However, no increased risk of infection from meningococcus was observed. There was no difference in risk estimates for sepsis between celiacs diagnosed in childhood as opposed to in adulthood.[148]
Although studies link overwhelming infection with hyposplenism in the general population[133,134] and large population-based studies describe increased risk of mortality and morbidity from infection in people with celiac disease, the risk of infection in people with celiac disease and hyposplenism is not known, nor is the prevalence of hyposplenism in contemporary celiac disease. Since 1992, a 23-valent pneumococcal polysaccharide vaccination has been recommended in the UK by the Department of Health as part of the national immunization program for individuals at risk in the general population, including those with hyposplenia and celiac disease.[149] Despite the recommendation to vaccinate celiacs against Pneumococcus being reinforced by primary-care groups, recent primary-care data suggest only a minority of British celiacs have received pneumococcal vaccination.[150] Annual influenza vaccination is also appropriate as this reduces the frequency of secondary bacterial infection.
Expert Rev Gastroenterol Hepatol. 2010;4(6):767-780. © 2010 Expert Reviews Ltd.
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