Association of Crohn's disease, thiopurines, and primary epstein-barr virus infection with hemophagocytic lymphohistiocytosis.

OBJECTIVE: To assess the incidence of hemophagocytic lymphohistiocytosis (HLH) in a well-defined population of children with inflammatory bowel disease (IBD) and evaluate the common clinical and laboratory characteristics of individuals with IBD who developed HLH. STUDY DESIGN: We conducted a retrospective study of all children who developed HLH over an 8-year period. The incidence of HLH in patients with IBD was calculated using US census data and a statewide project examining the epidemiology of pediatric IBD. RESULTS: Among children in Wisconsin, 20 cases of HLH occurred during the study period; 5 cases occurred in children with IBD. Common characteristics include: Crohn's disease (CD), thiopurine administration, fever lasting more than 5 days, lymphadenopathy, splenomegaly, anemia, lymphopenia, and elevated serum triglycerides and ferritin. Of the patients, 4 had primary Epstein-Barr virus infections. The incidence of HLH among all children in Wisconsin was 1.5 per 100 000 per year. The risk was more than 100-fold greater for children with CD (P < .00001). CONCLUSIONS: Pediatric patients with CD are at increased risk for developing HLH; primary Epstein-Barr virus infection and thiopurine administration may be risk factors.

Capsule endoscopy performed across the pediatric age range: indications, incomplete studies, and utility in management of inflammatory bowel disease.

BACKGROUND: Capsule endoscopy (CE) is used increasingly to evaluate the small bowel in children. An upper GI series is recommended before CE to evaluate the risk of obstruction. Despite normal findings on an upper GI series, CE may still be incomplete. Although large adult studies have demonstrated the safety and diagnostic yield of CE, similar pediatric studies have not been available. OBJECTIVE: To identify factors associated with incomplete studies and the diagnostic yield in pediatric patients. DESIGN: Retrospective review of consecutive CE studies from February 2005 through June 2008. SETTING: Large tertiary children's hospital. PATIENTS: A total of 123 CE studies in 117 patients; median age 12.9 years (range 0.8-22.4 years). MAIN OUTCOME MEASUREMENTS: Demographic information, indication, placement technique, pre-CE imaging results, and cecal completion status were recorded. Risk factors were analyzed with bivariate and multivariate regression analysis. RESULTS: There were 27 (22%) incomplete studies; of these, there were normal pre-CE radiologic study findings in 12 (44%), and findings requiring medical, endoscopic, or operative intervention in 6. Of the 117 patients, CE produced a new diagnosis in 21 (18%). Abnormal findings on previous imaging (odds ratio [OR] 3.0; 95% CI, 1.2-8.0), endoscopic placement (OR 3.1; 95% CI, 1.1-8.4), and female sex (OR 3.3; 95% CI, 1.2-9.4) were associated with incomplete studies. LIMITATIONS: Retrospective, incomplete follow-up. CONCLUSIONS: CE may be performed in children as small as 11.5 kg, with 18% yield in all studies, and 28% in pediatric known inflammatory bowel disease. Capsule retention requiring retrieval did not pose life-threatening risk in our series, and CE may be used to identify disease-associated small-bowel stenosis.