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The presence of various numbers of EPIYA tyrosine phosphorylation motifs in the CagA protein of Helicobacter pylori has been suggested to contribute to pathogenesis in adults. In this prospective study, we characterized H. pylori isolates from symptomatic children, with reference to the diversity of functional EPIYA motifs in the CagA protein and vacA isotypes, and assessed the potential correlation with the histopathological manifestations of the infection. We analyzed 105 H. pylori isolates from 98 children and determined the diversity of EPIYA motifs in CagA by amplification and sequencing of the 3' variable region of the cagA gene as well as vacA isotypes for the signal, middle, and intermediate regions. CagA phosphorylation and levels of secreted IL-8 were determined following in vitro infection of AGS gastric epithelial cells. Histopathological evaluation of H. pylori colonization, activity, and severity of the associated gastritis was performed according to the updated Sydney criteria. EPIYA A (GLKN[ST]EPIYAKVNKKK), EPIYA B (Q[V/A]ASPEPIY[A/T]QVAKKVNAKI), and EPIYA C (RS[V/A]SPEPIYATIDDLG) motifs were detected in the ABC (46.6%) and ABCC (17.1%) combinations. No isolates harboring more than two EPIYA C motifs in CagA were found. The presence of isogenic strains with variable numbers of CagA EPIYA C motifs within the same patient was detected in seven cases. Occurrence of increasing numbers of EPIYA C motifs correlated strongly with presence of a high-vacuolation (s1 or s2/i1/m1) phenotype and age. A weak positive correlation was observed between vacuolating vacA genotypes and presence of nodular gastritis. However, CagA- and VacA-dependent pathogenicities were not found to contribute to severity of histopathology manifestations in H. pylori-infected children.

We report a Sertoli-Leydig cell (SLC) tumor of the right ovary in a 10-year-old girl, which was dealt with surgical removal. Three months after resection, she presented with a new episode of acute abdomen because of an abdominal mass, which histologically was compatible with an undifferentiated embryonal rhabdomyosarcoma. Chemotherapy, according to SIOP-??? 89 protocol, was administered additionally to radiotherapy (3,960 cGy). Three years after completing treatment, the patient developed a painful swelling at her left upper arm. The diagnosis was Ewing sarcoma of the humerus, which was confirmed by identification of the typical 11; 22 translocation on cytogenetic and molecular analysis of the tumor tissue. The patient died 14 months from Ewing diagnosis due to progressive disease.