While
tumor necrosis factor (
TNF) inhibitors have dramatically improved the clinical outcomes of
rheumatoid arthritis (RA) in recent years, infectious complications are a serious concern.
Adalimumab (ADA) is a newly-developed human
monoclonal antibody against
TNF-alpha. Here we report 2 cases of
pneumocystis pneumonia (PCP) which developed in RA patients during ADA
therapy. One patient is a 66-year-old woman who had a history of RA for 6 months. The patient was given ADA at 40 mg biweekly for her active
arthritis which had been refractory to 6 mg/week of
methotrexate (MTX), and 5 mg/day of
prednisolone (PSL). One hundred and six days later, she was admitted to our hospital because of
fever,
cough, and
dyspnea. Another patient is a 62-year-old man who had a history of RA for 3 years. Since his
arthritis was so active even under the treatment with MTX (8 mg/week) and PSL (15 mg/day), the patient started to be given ADA at 40 mg biweekly. After 28 days, the patient was admitted to the hospital because of
dyspnea. Chest roentgenogram and computed tomography revealed
interstitial pneumonia in both patients. Beta-
D-glucan levels were so high in their serum suggesting the diagnosis of PCP, which was confirmed by the detection of Pneumocystis jirovecii
DNA in the sputa by polymerase chain reaction. The patients were immediately treated with
sulfamethoxazole/
trimethoprim and high-dose
prednisolone, which successfully improved
pneumonia, and they were discharged from the hospital on the 8(th) and 16(th) day, respectively. PCR and β-
D-glucan were useful for the early diagnosis of PCP and lead to the timely induction of adequate treatment and the rescue of these patients.