S100A8 and Iron deficiency anemia: Long-term infections—especially with H. pylori CagA+ strains producing CagA (cytotoxin associated gene A) protein—in conjunction with excessive local inflammatory response in the gastric tissue may also contribute to the development of systemic inflammation and extragastric diseases such as immune thrombocytopenic purpura, iron deficiency anemia, and vitamin B12 deficiency [7,8,9,10].