Pneumocystis Jirovecii Pneumonia after Initiation of Tofacitinib Therapy in Rheumatoid Arthritis: Case-Based Review

The use of biologic and targeted synthetic disease-modifying anti-rheumatic drugs (tsDMARDs) in rheumatic diseases is constantly increasing during the last decade. Tofacitinib is a new oral Janus Kinase (JAK) inhibitor, approved for rheumatoid arthritis (RA), psoriatic arthritis and ulcerative colitis. Safety data of tofacitinib derived from randomized controlled trials and long-term extension studies has demonstrated a moderate increase in the risk for common serious infections. We describe a case of Pneumocystis jirovecii pneumonia (PJP) in a woman on tofacitinib therapy for RA. Although tofacitinib use has been associated with the development of opportunistic infections, PJP has been rarely reported. PJP should be included in the differential diagnosis of patients with autoimmune disorders under newer oral JAK inhibitors therapy who present with fever, hypoxia and pulmonary infiltrates.