Atypical presentation of Pneumocystis jirovecii pneumonia in a patient with rheumatoid arthritis treated with tofacitinib: a case presentation

Background We report the case of a patient with rheumatoid arthritis (RA) treated with tofacitinib who developed severe Pneumocystis jirovecii pneumonia (PJP) with an atypical clinical presentation.Case presentation A 78-year old male patient with RA treated with tofacitinib, methotrexate (MTX) and low dose corticosteroids was admitted to the hospital with arthralgia and nausea. Laboratory findings revealed hypercalcemia with normal levels of parathyroid hormone (PTH) and elevated 1,25-(OH)2 vitamin D levels. A lung CT scan showed bilateral interstitial pneumonic infiltrates. PCR from bronchoalveloar lavage was positive for Pneumocystis jirovecii. Hypercalcemia resolved under PJP treatment and was - after exclusion of other possible causes - probably fungal associated.Conclusion Due to the increased risk of opportunistic infections in immunocompromised patients, the finding of hypercalcemia in conjunction with a pulmonary infection should raise high clinical suspicion of PJP.