Pneumocystis jiroveci pneumonia (PJP) in non-HIV immunocompromised individuals

PJP is a major cause of morbidity and mortality in immunocompromised individuals. Diagnosing PJP is often difficult because respiratory signs might be minimal or absent and the sensitivity of a chest X-ray (CXR) is low. We studied the clinical risk factors in order to increase awareness and facilitate the diagnosis.

We studied a prospective case series over a one year period (from 1 January 2015 to 1 January 2016) and did a retrospective analysis (from 2013 to 2016) of all PJP positive bronchoalveolar lavage (BAL) analysis.

Seven patients with metastatic solid tumors were diagnosed with symptomatic PJP (based on positive polymerase chain reaction) over a one year period. The median age was 61 years. Three patients had brain metastasis. Four of them were on steroids, the median dose was 16 mg methylprednisolone with three of them at a tapered dose. Respiratory failure developed in four cases and prompted intensive care monitoring. Two patients needed non-invasive ventilation and the third patient was intubated and mechanically ventilated. No patient died of PJP. A retrospective analysis on microbiological results obtained from BAL in our hospital from 2013 to 2016 shows a striking high percentage PJP positivity in cancer patients (including hematologic cancers) of nearly 22% (15/69) as opposed to the overall number of PJP-positives 7.3% (59/803).

The incidence of clinical PJP in patients treated for metastatic cancer is substantial. A high index of suspicion, especially in cases with unexplained respiratory symptoms, concurrent or recent use of steroids, a normal CXR and otherwise unexplained increased lactate dehydrogenase levels, is critical. The threshold for performing a CT-scan must be low and the diagnosis needs to be confirmed microbiologically.