Invasive fungal infection in ANCA-associated vasculitis: Between the Devil and Deep blue sea. Case series and review of the literature.

INTRODUCTION:Patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV) are susceptible to opportunistic infections, including invasive fungal infections (IFI). This is due to many factors, including prolonged immunosuppressive therapy. The treatment of AAV with such IFIs is challenging. METHODS:A descriptive analysis of 5 patients with AAV complicated by concomitant invasive fungal infections was performed. We also have done a comprehensive literature review of IFIs in AAV using PubMed and Google Scholar databases. RESULTS:All 5 patients initially received immunosuppressive medication but subsequently acquired IFI. One patient had sphenoid sinus involvement, and four had lung parenchymal involvement. Aspergillus infection was diagnosed in three patients, Cryptococcus infection in one patient and mixed infection with Aspergillus and Mucor infection in one patient. All our patients were on low doses of corticosteroids for several months to years or had received high-dose pulse steroids with cyclophosphamide in the last few weeks before being diagnosed with IFI. It was difficult to distinguish disease activity from IFI in all the cases. Two of the five patients died despite antifungal therapy. The literature review revealed a prevalence of IFIs ranging from 1 to 9.6% (excluding pneumocystis pneumonia). Aspergillosis was the predominant type of IFI, affecting 46 of 86 patients. Most of these patients (40/46) had pulmonary involvement. The prognosis for patients with IFI was consistently poor, as evidenced by 19 deaths out of 29 reported outcomes. CONCLUSION:Overall, IFIs have a poor prognosis in patients with AAV. Differentiating disease activity from IFI is difficult because of similar organ distribution, imaging lesions, and histopathological characteristics. A high suspicion index and good-quality microbiology are needed for early treatment and prevention of mortality.