Biological agents should generally only be used if methotrexate and other conventional agents are not effective after a trial of three months. They are associated with a higher rate of serious infections as compared to other DMARDs. Biological DMARD agents used to treat rheumatoid arthritis include: tumor necrosis factor alpha (TNFα) blockers such as infliximab; interleukin 1 blockers such as anakinra, monoclonal antibodies against B cells such as rituximab, and tocilizumab T cell co-stimulation blocker such as abatacept. They are often used in combination with either methotrexate or leflunomide. Biologic monotherapy or tofacitinib with methotrexate may improve ACR50, RA remission rates and function. Abatacept should not be used at the same time as other biologics. In those who are well controlled (low disease activity) on TNF blockers, decreasing the dose does not appear to affect overall function. Discontinuation of TNF blockers (as opposed to gradually lowering the dose) by people with low disease activity may lead to increased disease activity and may affect remission, damage that is visible on an x-ray, and a person's function. People should be screened for latent tuberculosis before starting any TNF blockers therapy to avoid reactivation of tuberculosis.