Table 1. Diagnostic methods for PCM and evaluation of value and drawbacks.
| Diagnostic methods | Sensitivity | Specificity | Pros | Cons |
|---|---|---|---|---|
| Serology (DID, CIE, IIF) | 69%–100% | 80%–100% | • Correlates with the severity of disease • Monitor therapeutic response • Inexpensive |
• No commercial kits available • No standardization, impairing reproducibility and repetitiveness No validated serological techniques for P. lutzii • May be negative in immunosuppressive conditions • Cross-reaction with histoplasmosis and aspergillosis |
| Specific antigen detection gp43kDa and gp70kDa |
100% | 96% | • Provides diagnosis in immunocompromised patients with negative production of specific antibodies • Provides diagnosis in biological materials with low burden of infection by detecting specific fungal antigens (serum, BAL, CSF) |
• Expensive when compared with conventional methods • Not available for routine diagnosis of PCM |
| Fresh examination/ direct microscopy | 48%–75%, worst in sputum | HIGH | • Immediate results • Samples are easy to obtain • Inexpensive |
• Requires skilled professionals to read the exam Micromorphology of P. brasiliensis/P. lutzii pathogens are not distinguished |
| Culture | 25%–44% | 100% | • Provides material for further evaluation of species, antifungal susceptibility, and virulence | • 2–6 weeks of incubation • Biohazard concerns |
| Histopathology | 65%–97% | HIGH | • May help to define the severity of disease (compact granuloma versus loose granuloma) • Requires skilled professionals |
• Invasive procedure is required for biopsy Small forms of Paracoccidioides spp. might be confounded with Histoplasma capsulatum or Cryptococcus neoformans |
| Molecular methods (PCR) | HIGH | HIGH | • Provides species identification • Provides diagnosis in biological materials with low burden of infection |
• Expensive when compared with conventional methods • Not available for routine diagnosis of PCM |
Abbreviations: BAL, bronchoalveolar lavage; CIE, counterimmune electrophoresis; CSF, cerebrospinal fluid; DID, double immunodiffusion; gp43kDa, gp43kDa gene of P. brasiliensis; gp70kDa, gp70kDa gene of P. brasiliensis; IIF, indirect immunofluorescence test; PCM, paracoccidioidomycosis.