Human T-cell responses to the glucosyltransferases of Streptococcus mutans.

We previously reported differential humoral responses to glucosyltransferases (GTFs), with significantly higher saliva and serum antibody levels to GtfD than to GtfB or GtfC. To test the hypothesis that cellular immune responses to these molecules also may differ, peripheral blood mononuclear cell (PBMC) and T-cell proliferative responses in young adults and children with distinct genetic backgrounds were determined using purified recombinant GtfC and GtfD. PBMCs from all of the volunteers responded to GtfC and -D, but responses were directed predominantly towards GtfD and were major histocompatibility class II antigen dependent. A predominant T-cell response to GtfD, over GtfC, was detectable at various antigen concentrations ranging from 1 to 20 microg/ml and correlated with the differential serum immunoglobulin G (IgG) and salivary IgA antibody responses to the GTFs. Therefore, in naturally sensitized humans, Streptococcus mutans GTFs stimulate differential humoral and cellular immune responses, with the secreted form of GtfD eliciting a stronger response than the cell wall-associated form of GtfC.

Congenital hepatic arterioportal fistula complicated with gastrointestinal bleeding treated with transcatheter embolization: case report.

Congenital hepatic arterioportal fistula (HAVF) is extremely rare in children. We present a patient with congenital hepaticoportal arteriovenous fistula complicated with gastrointestinal bleeding treated using transcatheter arterial embolization. Our patient was the youngest (2 days old) case ever reported with congenital HAVF and the first one to receive arterial embolization for HAVF during childhood. The 3-year-old girl was suggested of having congenital HAVF using Doppler ultrasonography. However, her family refused further investigation, and she was lost to follow-up. Three years later, she was sent to our hospital due to melaena. Repeated ultrasonography revealed dilated intrahepatic portal vein with arterial flow demonstrated using Doppler imaging. No esophageal varices or gastric or duodenal ulcer was seen during endoscopy. Angiography showed a HAVF and transcatheter embolization was done simultaneously. Follow-up at one and two weeks post-embolization revealed no more shunt flow within the portal vein, though cystic like dilatation of the portal vein persisted, and no thrombosis was observed. This case emphasizes that transcatheter arterial embolization can be easily and successfully used for treating childhood congenital HAVF. Abnormal dilatation of the portal vein in children needs doppler evaluation and possibly angiography.