Pneumocystis carinii pneumonia in patients with connective tissue disease

Although the association of Pneumocystis carinii pneumonia (PCP) with connective tissue disease (CTD) has been noted for a long time, there are few series reported.

The objective of this study was to describe clinical features and prognosis of PCP infections in patients with CTD in China.

We retrospectively reviewed the characteristics, clinical features, and prognosis of PCP in patients with CTD in a single hospital.

A total of 7 cases were reviewed (systemic lupus erythematosus n = 2, microscopic polyangiitis n = 2, dermatomyositis n = 2, polymyositis n = 1). Eighty-six percent of patients developed PCP within 3 months of the diagnosis of CTD. All patients were receiving daily glucocorticoid therapy and cytotoxic drugs before the diagnosis of PCP. Most patients had fever, progressive dyspnea, and dry cough at onset of PCP. The mean duration of symptoms before PCP diagnosis was 7 days. Absolute lymphocyte counts ranged from 126 to 528/microL. The CD4 lymphocyte counts of all patients were 87 +/- 78/microL. One patient was diagnosed by induced sputum; 6 patients were diagnosed by bronchoalveolar lavage fluid. Complicating fungal infection was found in 4 of 7 patients at the time of diagnosis of PCP. All patients were treated by trimethoprim-sulfamethoxazole and corticosteroids. Six (86%) patients died. The mean duration of the time from diagnosis to death was 14 +/- 4 days.

Our results suggest that PCP is an uncommon and fatal opportunistic infection in patients with CTD. When patients with CTD who are receiving immunosuppressive therapy have low lymphocyte counts and/or CD4 lymphocyte counts less than 250/microL develop fever, dry cough, dyspnea, and chest radiography shows diffuse interstitial infiltrate, the diagnosis of PCP should be highly suspected. Induced sputum or BAL must be quickly performed to confirm diagnosis. Further study is needed as to whether earlier treatment will improve prognoses or whether patients with CTD with low CD4 counts should receive PCP prophylaxis.