From the Guidelines
Diagnosing fungal pneumonia requires a combination of clinical evaluation, imaging, and laboratory testing, with high-resolution CT scans being the most sensitive method for detecting pulmonary infiltrates, as shown in a study published in the Annals of Oncology 1. The initial assessment should include chest imaging (X-ray or CT scan) to identify infiltrates, nodules, or cavitary lesions characteristic of fungal infection.
- CT findings such as consolidation, ‘halo sign’ and ‘air-crescent sign’ may be important signs of filamentous fungal disease 1.
- A ‘reversed halo sign’ has been reported as relatively specific for fungal pneumonia due to zygomycetes/mucorales 1. Definitive diagnosis requires identification of the causative fungal organism through microbiological testing.
- Specimens should be collected via sputum samples, bronchoalveolar lavage (BAL), or lung biopsy depending on the clinical situation and patient stability 1.
- These samples should undergo fungal culture, direct microscopy with special stains (KOH prep, calcofluor white), and in some cases, histopathological examination. Serological testing for fungal antigens (such as galactomannan for Aspergillus or beta-D-glucan for various fungi) and antibodies can provide supportive evidence.
- The use of mannan antigen and anti-mannan antibodies in the diagnosis of invasive candidiasis has been recommended by the European Conference on Infections in Leukemia 1. Molecular diagnostic techniques like PCR may offer more rapid results.
- The clinical context is crucial for interpretation, as certain fungi are endemic to specific geographic regions (Histoplasma in the Mississippi Valley, Coccidioides in the southwestern US) 1. Immunocompromised status significantly increases risk and should lower the threshold for fungal pneumonia suspicion.
- Pre-emptive treatment with mold-active systemic antifungal agents improves clinical outcome, while other microorganisms are preferably treated only when microbiologically documented 1. Once diagnosed, treatment should be tailored to the specific fungal pathogen identified, with antifungal agents such as amphotericin B, azoles (fluconazole, voriconazole), or echinocandins depending on the organism and severity of infection.
- High-dose TMP/SMX is first choice for treatment of Pneumocystis pneumonia, while cytomegalovirus pneumonia is treated primarily with ganciclovir or foscarnet in most patients 1.
From the Research
Fungal Pneumonia Diagnosis
- Fungal pneumonia, particularly invasive aspergillosis, can be diagnosed using various methods, including bronchoalveolar lavage, with the help of galactomannan (GM) and lateral flow assay (LFA) 2.
- The European Organization for Research and Treatment of Cancer Mycoses (EORT/MSG criteria) can be used for diagnosis, but it has limitations for broncho-pulmonary forms of aspergillosis 2.
Treatment Options
- Voriconazole and isavuconazole are considered first-line treatment options for fungal pneumonia, including invasive aspergillosis 3, 4, 2.
- Other treatment options include posaconazole, liposomal amphotericin B, and anidulafungin, which can be used as alternative or salvage therapy 3, 5, 6.
- The choice of treatment depends on various factors, including the patient's underlying condition, drug interactions, and toxicity profiles 5, 2.
Efficacy and Safety
- Voriconazole has been shown to be effective in treating invasive aspergillosis, with a response rate of 52.8% compared to 31.6% for amphotericin B 4.
- Posaconazole has been found to be non-inferior to voriconazole in terms of all-cause mortality, and it may have a better safety profile 5.
- Isavuconazole may also have a better safety profile compared to voriconazole, with fewer treatment-related adverse events 3.