Pneumocystis carinii pneumonia in patients with connective tissue diseases: The role of hospital experience in diagnosis and mortality

Abstract

Objective. Pneumonia due to Pneumocystis carinii has been increasingly reported in patients with connective tissue diseases, but the frequency of this complication is not known. We sought to determine the frequency of P carinii pneumonia (PCP) in patients with connective tissue diseases, and to determine the role that a hospital's acquired immunodeficiency syndrome (AIDS)-related experience may have in the diagnosis of PCP in these patients.Methods. We used a state hospitalization registry to identify all patients with PCP and either rheumatoid arthritis, systemic lupus erythematosus, Wegener's granulomatosis, polymyositis, dermatomyositis, polyarteritis nodosa, or scleroderma who had an emergent or urgent hospitalization in California from 1983 to 1994. We compared patient and hospital characteristics between these patients and patients with connective tissue diseases hospitalized with other types of pneumonia.Results. Two hundred twenty-three patients with connective tissue diseases were diagnosed with PCP in the 12-year study period. The frequency of PCP ranged from 89 cases/10,000 hospitalizations/year in patients with Wegener's granulomatosis to 2 cases/10,000 hospitalizations/year in patients with rheumatoid arthritis. Compared with 5,457 patients with connective tissue diseases and pneumonia due to other organisms, patients with PCP were more likely to be younger, to be male, to have private medical insurance, and to have systemic lupus erythematosus, Wegener's granulomatosis, inflammatory myopathy, or polyarteritis nodosa rather than rheumatoid arthritis, and were less likely to be African American. Hospital size, teaching status, urban/rural location, proportion of admissions due to AIDS or PCP, and proportion of patients with pneumonia undergoing bronchoscopy were each associated with the likelihood of diagnosis of PCP in univariate analyses, but only the number of patients with PCP being treated at a hospital (odds ratio [OR] 1.03 for each additional 10 cases/year, 95% confidence interval [95% CI] 1.01-1.05) was associated with the likelihood of diagnosis of PCP in multivariate analyses. Patients were also somewhat more likely to be diagnosed with PCP if there had previously been a case of PCP in a patient with a connective tissue disease at the same hospital (OR 1.35, 95% CI 0.98-1.85). In-hospital mortality was 45.7%, and was unrelated to hospital characteristics.Conclusion. PCP is an uncommon, but often fatal, occurrence in patients with connective tissue disease. A hospital's prior experience with patients with PCP is associated with the likelihood that this condition is diagnosed in patients with connective tissue diseases who present with pneumonia, suggesting that diagnostic suspicion is an important factor in the correct identification of affected patients.

Audit of pneumocystis pneumonia in patients seen by the Christchurch Hospital rheumatology service over a 5‐year period

“…The estimated mortality from PCP in patients with underlying connective tissue disease varies according to the underlying disorder; 63% in WG, 58% in inflammatory myopathy, 48% in Polyarteritis Nodosa, 31% in RA and 17% in systemic sclerosis. 7 The overall mortality from PCP in HIV-negative patients is reported to be 30-60%, significantly higher than the reported 10-20% mortality rate in HIV-positive patients. 1,26 Given the higher mortality in HIV-negative patients it has been suggested that the threshold for commencing PCP chemoprophylaxis should be lower in this group of patients.…”

“…Whereas there are several reports of PCP occurring in patients with rheumatic diseases, the absolute incidence has not been well defined. [5][6][7] In general the risk of PCP appears to be higher in patients with WG as compared with other rheumatic disorders. In a large hospital-based study in California, which examined the incidence of PCP in rheumatology patients over a 12-year period, there were 223 cases of PCP in patients with connective tissue disorders.…”

“…The frequency of PCP was reported to range between 89 cases/10 000 hospitalizations/year in patients with WG and 2 cases/ 10 000 hospitalizations/year in patients with RA. 7 Several immunosuppressive therapies have been associated with PCP infection, including MTX, AZA, cyclosporin, CYC and more recently tumour necrosis factor inhibitors. 6,[8][9][10][11] All four cases described in this report developed PCP infection within 6 months of commencing treatment with MTX or CYC.…”

“…In addition, the underlying disease process may have a role with a higher incidence of PCP in patients with WG. 7 The retrospective nature of our study following the diagnosis of PCP in a patient presents a selection bias. Given that PCP infection in rheumatology patients is a relatively uncommon event the inclusion of the index case in the data may increase the incidence rate.…”

Outcome of Pneumocystis jirovecii pneumonia diagnosed by polymerase chain reaction in patients without human immunodeficiency virus infection

“…1 A number of studies have described the risk factors, clinical manifestations and outcomes of PCP in patients without HIV infection. [2][3][4][5][6][7][8][9][10][11][12][13] In HIV-negative patients, PCP tends to follow a more acute course, and the mortality rate for patients with PCP has been reported to be 19.6-52.9%, 2,5,7,8, [10][11][12][13] which is considerably higher than the reported mortality among HIV-infected patients with PCP. 14 Most previous studies have used a variety of staining techniques for the diagnosis of PCP.…”