Anti-TNF Anti-drug antibodies CD4+ T lymphocyte Crohn disease Inflammatory bowel disease Methotrexate Review Thiopurines adalimumab azathioprine biosimilar agent cell proliferation certolizumab pegol clinical assessment coronavirus disease 2019 drug antibody drug efficacy drug safety erythrocyte count golimumab human immunogenicity immunomodulating agent inflammatory bowel disease infliximab lymphoma memory B lymphocyte mercaptopurine methotrexate multicenter study (topic)