A search for ways to overcome the secondary inefficiency of anti-cytokine therapy (ACT) with infliximab (IFX) in patients with inflammatory bowel diseases (IBD) remains relevant and determines the need for new approaches to solving this problem. The secondary inefficiency of ACT has been found to depend on the level of antibodies to IFX (anti-IFX Ab). The Department of Intestinal Pathology, Central Research Institute of Gastroenterology, is investigating the mechanisms for the occurrence of primary and secondary inefficiency of ACT, as well as ways to overcome them by cultured allogenic bone marrow mesenchymal stromal cells (MSC). In the framework of the searching investigation evaluating the efficiency and safety of MSC in patients with IBD, the investigators revealed that was a phenomenon of a decrease in anti-IFX Ab and came to the conclusion that the secondary inefficiency of ACT should be overcome in a patient with ulcerative colitis (UC). The elevated anti-IFX Ab levels were directly associated with the worsening clinical and endoscopic picture of UC and with the enhanced activity of an inflammatory process. The administration of cultures MSC contributed to lower anti-IFX Ab levels, overcome secondary inefficiency (an escape phenomenon) during ACT, and enhanced IFX sensitivity. The clinical observation indicated that MSC administration reduced anti-IFX concentrations and promoted UC remission during IFX therapy. Thus, MSC transplantation can be considered as a promising method for overcoming the secondary inefficiency of ACT, which aids in increasing the previously lost response to anti-inflammatory therapy.