Inflammatory bowel disease associated with immune thrombocytopenic purpura in children

OBJECTIVE

Previous reports suggest an association between inflammatory bowel disease (IBD) and immune thrombocytopenic purpura (ITP) in adults. To date, only five children with both diseases have been described. The aim of the study was to describe the characteristics of children with IBD and ITP.

METHODS

Cases were obtained from the pediatric gastroenterology community by means of the pediatric gastroenterology internet bulletin board in June 1999. Eight cases were submitted from seven medical centers. Medical records were reviewed by two pediatric gastroenterologists and a pediatric hematologist.

RESULTS

The age range of the patients was 2.1 to 16.5 years, with a mean age of 9.6 +/- 5.2 years. Four children had ulcerative colitis, three had Crohn disease, and one had indeterminate colitis. All had colonic involvement of IBD. Of eight patients, three had IBD first, three had ITP first, and two had both simultaneously. At ITP diagnosis, platelet count was less than 10,000/mL in five children, 17,000/mL in one child, and 50,000 to 60,000/mL in two children. Of the three children diagnosed with ITP first, two initially had rectal bleeding at the time of ITP diagnosis. Bone marrow evaluations, performed in six of eight children, were consistent with ITP. Six of the eight children had chronic ITP, including three children who were 5 years of age or younger. Therapy for ITP included steroids (n = 6), intravenous immunoglobulin (n = 6), Rh o (D) intravenous immunoglobulin (n = 2), and splenectomy (n = 1).

CONCLUSIONS

The authors describe the largest pediatric case series of children with IBD and ITP. More than 50% of the children had the chronic form of ITP. Most patients responded to conventional therapy for ITP and IBD.

Evidence for non-transferrin-mediated uptake and release of iron and manganese in glial cell cultures from hypotransferrinemic mice

Transferrin (Tf) is accepted as the iron mobilization protein, but its role in transport of other metals is controversial. In this study, we used mixed glial cultures from hypotransferrinemic (Hp) mice to determine the dependence of these cells on transferrin for iron and manganese delivery and release. Hp mice have a splicing defect in the transferrin (Tf) gene, resulting in < 1% of the normal plasma levels of Tf. Cellular iron and manganese uptake increases over 24 hr in cultures of normal and Hp glial cells in the presence of standard concentrations of Tf in the media; although total 59iron uptake in the Hp mouse cultures was 2X greater than normal, 54Mn uptake was similar between the two groups. The absence of Tf in the media resulted in a significant increase in 59iron uptake in both normal and Hp glial but did not affect Mn uptake. Elevated Tf (10X normal) in the media reduced both 59iron and 54Mn uptake. Efflux of 59Iron and 54Mn occurred in normal and Hp cultures, indicating the existence of a dynamic exchange of metals, and that intracellular Tf is not necessary for metal release. However, in the absence of Tf in the media, significantly more iron was retained in the cells than if Tf were present in both normal and Hp glial cultures. 54Mn release was minimally affected by extracellular Tf. The data demonstrate that Tf is not required for iron and Mn uptake into glial cells. These data further demonstrate a dynamic metal exchange system for glial cells which is not dependent on intracellular Tf.