Evaluation of Pneumocystis pneumonia infection risk factors in patients with connective tissue disease

Abstract

We conducted a retrospective, clinical evaluation of connective tissue disease (CTD) patients who were tested for either sputum or bronchoalveolar lavage fluid Pneumocystis polymerase chain reaction (PC-PCR) and analyzed the risk factors that cause Pneumocystis pneumonia (PCP) susceptibility and fatality. PC-PCR was performed on 66 CTD patients who presented with symptoms, data, or radiological findings strongly suggesting respiratory infection. Patients with higher oral corticosteroid doses, use of oral methotrexate (MTX), bilateral lung findings, positive beta-D-glucan, and no prophylaxis use were more susceptible to PCP. They had significantly low immunoglobulin G and significantly high beta-D-glucan and lactate dehydrogenase. Survivors and nonsurvivors of PCP were also evaluated. Poor prognoses were observed with older age, elevated beta-D-glucan, rheumatoid arthritis (RA) patients using MTX, hypoxemia, bilateral lung findings, and mechanical ventilation use. Nonsurvivors had significantly lower lymphocytes, oxygen saturation, and significantly higher beta-D-glucan. In RA, poor prognoses were seen with those taking MTX. Disease duration, underlying pulmonary complications, and oral corticosteroid doses did not lead to poor prognoses in RA. Because PCP in CTD leads to abrupt onset of symptoms with poor survival rates, early diagnosis and initiation of treatment are critical, and it is essential for clinicians to recognize risk factors that predispose patients to PCP and its mortality.

Colonization by Pneumocystis jirovecii and Its Role in Disease

“…Several studies have examined the performance characteristics of commercial BG assays and found a sensitivity ranging from 90 to 100% and a specificity of 88 to 96% in non-HIV-infected immunosuppressed patients with pneumonia, with various cutoffs used depending on the BG kit and the population (58,64,315). In a study of 111 HIV-infected PCP patients, median serum BG levels were significantly higher in PCP patients than in controls, and a cutoff of 23.2 pg/ml had a 78 to 98% sensitivity and a specificity of 77 to 94% (113,128,315). Although one study has found that BG levels correlate with organism burden, most others do not find a relationship of BG levels to organism burden, PCP severity, or response to therapy (58,113,315).…”

Is There a Role for Consensus Guidelines forP. jiroveciPneumonia Prophylaxis in Immunosuppressed Patients with Rheumatic Diseases?

“…Although lymphopenia is present in almost all patients with connective tissue disease who develop PCP, exact levels are less definitive 10 . Lymphocyte and CD4+ counts in SLE patients 6-7 months before PCP onset were significantly lower than counts in age-and sex-matched SLE patients who did not develop PCP (CD4+ counts 156 vs 276/mm 3 ; p = 0.01) in one study 12 , while Iikuni, et al found that RA patients who died from PCP had significantly lower CD4+ counts than those who survived (198.4/mm 3 vs 593.0/mm 3 ; p < 0.05), with drops in both lymphocyte count and IgG seen over the 6 months prior to illness 13 .…”

Cavitary Pulmonary Disease

“…However, with the onset of the human immunodeficiency virus epidemic, P. jiroveci pneumonia incidence rose dramatically, and it continues to be one of the most common opportunistic illnesses in human immunodeficiency virus-infected persons (259). Other immunocompromised persons are also at risk for P. jiroveci pneumonia, including persons with the following risk factors: solid-organ or stem cell transplant; hematologic and solid malignancies; chronic, high-dose corticosteroid use; and use of immunomodulators such as methotrexate or tumor necrosis factor alpha antagonists (85,126,161,174,179,313,363,410). P. jiroveci pneumonia in individuals with no known immune compromise has been reported, but this is a very rare phenomenon (40).…”