Abstract
BACKGROUND The bacterial pathogen Helicobacter pylori (H. pylori) can cause chronic gastritis. CA54/61 is a serum tumor marker that has been shown to be positive in the several types of human malignancy. However, the association of between chronic gastritis due to H. pylori and elevated serum levels of CA54/61 has not been previously reported. This report is of three cases of increased serum levels of CA54/61 associated with H. pylori chronic gastritis. CASE REPORT Case 1 was a 44-year-old Japanese woman with a serum CA54/61 level of 138 U/ml (normal level: 12 U/ml). Following treatment and eradication of H. pylori the serum CA54/61 level decreased to 14 U/ml. Case 2 was a 73-year-old Japanese man with a serum level of less than 2 U/ml before completion of successful eradication therapy of H. pylori with a small peak of 30 U/ml after therapy. Case 3 was a 54-year-old Japanese man who maintained a serum CA54/61 level of approximately 20 U/ml before and until 603 days after eradication therapy. None of the three patients had malignancy, which is usually suggested by this serum marker. CONCLUSIONS These three case reports suggest the possibility of an association between chronic gastritis involving H. pylori infection and an elevated serum level of CA54/61. It is possible that the inflammatory gastric mucosal cells supply CA54/61 to the bloodstream. However, further studies are required to confirm the association between serum levels of CA54/61 and H. pylori chronic gastritis and the underlying mechanisms of this association.