Immune reconstitution inflammatory syndrome in neutropenic patients with invasive pulmonary aspergillosis

Summary Objectives Clinical and radiologic deterioration is sometimes observed during neutrophil recovery in patients with invasive pulmonary aspergillosis (IPA). This deterioration can be caused by immune reconstitution inflammatory syndrome (IRIS) as well as by progression of the IPA. However, there is limited data on IRIS in neutropenic patients. Methods Over a 6-year period, adult patients with neutropenia who met the criteria for probable or proven IPA by the revised EORTC/MSG definition were retrospectively enrolled. IRIS was defined as de novo appearance or worsening of radiologic pulmonary findings temporally related to neutrophil recovery, with evidence of a decrease of 50% in serum galactomannan level. Results Of 153 patients, 36 (24%, 95% CI 18%–31%) developed IRIS during neutrophil recovery. More of these patients received voriconazole than did those with non-IRIS (42% vs. 25%, P = 0.05). Thirty- and ninety-day mortalities were lower in the patients with IRIS than in those with non-IRIS (11% vs. 33%, P = 0.01, and 33% vs. 58%, P = 0.01, respectively). Conclusion IRIS is relatively common among neutropenic patients with IPA, occurring in about one quarter of such patients. It is associated with voriconazole use and has a good prognosis.