The 5th European Conference on Infections in Leukaemia (ECIL-5) meeting aimed to establish evidence-based recommendations for the prophylaxis of Pneumocystis jirovecii pneumonia (PCP) in non-HIV-infected patients with an underlying haematological condition, including allogeneic HSCT recipients. Recommendations were based on the grading system of the IDSA. Trimethoprim/sulfamethoxazole given 2–3 times weekly is the drug of choice for the primary prophylaxis of PCP in adults (A-II) and children (A-I) and should be given during the entire period at risk. Recent data indicate that children may benefit equally from a once-weekly regimen (B-II). All other drugs, including pentamidine, atovaquone and dapsone, are considered second-line alternatives when trimethoprim/sulfamethoxazole is poorly tolerated or contraindicated. The main indications of PCP prophylaxis are ALL, allogeneic HSCT, treatment with alemtuzumab, fludarabine/cyclophosphamide/rituximab combinations, >4 weeks of treatment with corticosteroids and well-defined primary immune deficiencies in children. Additional indications are proposed depending on the treatment regimen.

The Fifth European Conference on Infections in Leukaemia (ECIL-5) convened a meeting to establish evidence-based recommendations for using tests to diagnose Pneumocystis jirovecii pneumonia (PCP) in adult patients with haematological malignancies. Immunofluorescence assays are recommended as the most sensitive microscopic method (recommendation A-II). Real-time PCR is recommended for the routine diagnosis of PCP (A-II). Bronchoalveolar lavage (BAL) fluid is recommended as the best specimen as it yields good negative predictive value (A-II). Non-invasive specimens can be suitable alternatives (B-II), acknowledging that PCP cannot be ruled out in case of a negative PCR result (A-II). Detecting β-d-glucan in serum can contribute to the diagnosis but not the follow-up of PCP (A-II). A negative serum β-d-glucan result can exclude PCP in a patient at risk (A-II), whereas a positive test result may indicate other fungal infections. Genotyping using multilocus sequence markers can be used to investigate suspected outbreaks (A-II). The routine detection of dihydropteroate synthase mutations in cases of treatment failure is not recommended (B-II) since these mutations do not affect response to high-dose co-trimoxazole. The clinical utility of these diagnostic tests for the early management of PCP should be further assessed in prospective, randomized interventional studies.

The initiation of systemic antimicrobial treatment of Pneumocystis jirovecii pneumonia (PCP) is triggered by clinical signs and symptoms, typical radiological and occasionally laboratory findings in patients at risk of this infection. Diagnostic proof by bronchoalveolar lavage should not delay the start of treatment. Most patients with haematological malignancies present with a severe PCP; therefore, antimicrobial therapy should be started intravenously. High-dose trimethoprim/sulfamethoxazole is the treatment of choice. In patients with documented intolerance to this regimen, the preferred alternative is the combination of primaquine plus clindamycin. Treatment success should be first evaluated after 1 week, and in case of clinical non-response, pulmonary CT scan and bronchoalveolar lavage should be repeated to look for secondary or co-infections. Treatment duration typically is 3 weeks and secondary anti-PCP prophylaxis is indicated in all patients thereafter. In patients with critical respiratory failure, non-invasive ventilation is not significantly superior to intubation and mechanical ventilation. The administration of glucocorticoids must be decided on a case-by-case basis.

Pneumocystis jirovecii can cause life-threatening pneumonia following treatment for haematological malignancies or after HSCT. The mortality rate of P. jirovecii pneumonia (PCP) in these patients is 30%–60%, especially after HSCT. The clinical presentation of PCP in haematology differs from that associated with HIV infection, with the disease being acute and more often severe, having a lower fungal burden and being more frequently linked to treatment with corticosteroids. Most cases occur in patients not receiving adequate prophylaxis. The development of new therapies, including targeted treatments and monoclonal antibodies in various haematological diseases, justifies constant vigilance in order to identify new at-risk populations and give prophylaxis accordingly. The fifth and sixth European Conferences on Infections in Leukaemia (ECIL-5 and ECIL-6) aimed to review risk factors for PCP in haematology patients and to establish evidence-based recommendations for PCP diagnosis, prophylaxis and treatment. This article focuses on the magnitude of the problem, the main differences in clinical presentation between haematology patients and other immunocompromised populations, especially HIV-infected patients, and the main risk factors.