CNS malignancy patients have higher risk of PJP

This patient is presenting with acute respiratory failure caused by Pneumocystis jirovecii pneumonia. Patients with malignancies of the CNS are at higher risk for developing Pneumocystis pneumonia than patients with other solid tumors, and patients with CNS malignancy receiving glucocorticoids and receiving cranial irradiation are at particularly high risk. In some case series, Pneumocystis pneumonia in patients with CNS malignancies has been specifically associated with the time period of glucocorticoid tapering. Temozolomide, an oral alkylating agent that is typically used as a first-line agent for patients with glioblastoma, has also been associated with an increased risk of Pneumocystis pneumonia. Among patients with primary CNS malignancies and acute infectious pneumonias causing acute respiratory failure, the causative pathogen is found to be Pneumocystis in up to 20% of cases.

This patient has already been treated with broad-spectrum antibiotics for a bacterial, hospital-acquired pneumonia for 48 h but has had progressive worsening of his respiratory status. Given the severity of his respiratory failure and the clear risk factors for Pneumocystis pneumonia in this patient, empiric therapy should be initiated prior to definitive diagnosis. If Pneumocystis is the causative agent, a definitive diagnosis in the next 1 to 3 days should be possible based on the results of BAL using microscopy with direct fluorescent antibody staining and/or polymerase chain reaction (PCR) assay. PCR testing of either BAL fluid or high-quality sputum samples is more sensitive than microscopy with staining in HIV-uninfected patients who are immunocompromised and should be strongly considered even in the case of negative staining. Elevated serum lactate dehydrogenase and β-D-glucan levels should also be considered as adjunctive information that supports a diagnosis of Pneumocystis pneumonia.

Other fungal pneumonia pathogens such as aspergillus, Candida species, or endemic mycoses are less common in the solid tumor population compared with those patients with hematologic malignancies. Ganciclovir is an antiviral medication typically used to treat cytomegalovirus (CMV) infections, including CMV pneumonitis. CMV pneumonitis is uncommon in patients with solid tumors and is more likely to be seen in patients who have received T-cell–directed therapies to facilitate solid organ transplantation or stem cell transplantation.123456

A 39-year-old man with a relapsed glioblastoma multiforme is an inpatient on the oncology service, being treated with reirradiation and bevacizumab. He is also receiving a tapering dose of dexamethasone for seizures and headaches. Five days into his hospital stay, he develops a new fever and dyspnea. His vital signs at that time reveal a temperature of 38.4°C; BP, 118/79 mm Hg; and respirations, 28/min with SpO2 of 94% on a nonrebreather mask. He is transferred to the ICU and is initiated on high-flow nasal cannula and started on piperacillin/tazobactam, azithromycin, and vancomycin for presumed hospital-acquired pneumonia. A chest radiograph shows the new development of diffuse, bilateral, interstitial opacities; 48 h later, he has progressive worsening of hypoxemia and tachypnea and is subsequently intubated. A bronchoscopy and BAL is performed.

While awaiting the results of the BAL, which of the following should be done in the management of the patient’s antimicrobial therapy?

Footnotes

  1. SEEK Questionnaires ↩

  2. Azoulay É, Bergeron A, Chevret S, et al. Polymerase chain reaction for diagnosing Pneumocystis pneumonia in non-HIV immunocompromised patients with pulmonary infiltrates. Chest. 2009;135(3):655-661. PubMed ↩

  3. Decavèle M, Rivals I, Marois C, et al. Etiology and prognosis of acute respiratory failure in patients with primary malignant brain tumors admitted to the intensive care unit. J Neurooncol. 2019;142(1):139-148. PubMed ↩

  4. Karageorgopoulos DE, Qu JM, Korbila IP, et al. Accuracy of β-D-glucan for the diagnosis of Pneumocystis jirovecii pneumonia: a meta-analysis. Clin Microbiol Infect. 2013;19(1):39-49. PubMed ↩

  5. Sepkowitz KA, Brown AE, Telzak EE, et al. Pneumocystis carinii pneumonia among patients without AIDS at a cancer hospital. JAMA. 1992;267(6):832-837. PubMed ↩

  6. Slivka A, Wen PY, Shea WM, et al. Pneumocystis carinii pneumonia during steroid taper in patients with primary brain tumors. Am J Med. 1993;94(2):216-219. PubMed ↩