Neutropenia-related aspergillosis in non-transplant haematological patients hospitalised under ambient air versus purified air conditions.

Abstract

To reduce the risk of invasive aspergillosis (IA), air purification by high-efficiency particulate air filtration and laminar air flow (HEPA/LAF) is standard of care in allogeneic blood stem cell transplantation. Its use in non-transplant haematological patients is inconsistent. We sought to assess the incidence and outcome of pulmonary IA in non-transplant patients with life-threatening neutropenia by comparing an ambient air hospitalisation period (2008-2011) with a subsequent HEPA/LAF hospitalisation period (2012-2014). We compared 204 consecutive patients with acute myeloid leukaemia, acute lymphoblastic leukaemia or aplastic anaemia completing 534 neutropenia-related hospitalisations under ambient air conditions with 126 such patients completing 437 neutropenia-related hospitalisations under HEPA/LAF conditions. IA was defined using the 2008 EORTC/MSG criteria. Within a 7-year study period, we observed one 'proven', three 'probable' and 73 'possible' IAs, most often during acute leukaemia remission induction. Their frequency rose with increasing duration of life-threatening neutropenia (1-10 days, 1.8%; >40 days, 35.2%) and concomitant severe anaemia (0 days, 3.2%; >20 days, 31.0%). Multiple logistic regression revealed a strong correlation between IA incidence and hospitalisation under HEPA/LAF conditions (odds ratio [OR], 0.368 [95% confidence interval, 0.207-0.654]; p< .001) and duration of neutropenia (OR, 1.043 [1.023-1.062] per day; p< .001) and anaemia (OR, 1.044 [1.008-1.081] per day; p= .016). IA-associated fatal outcomes were non-significantly reduced under HEPA/LAF (OR, 0.077 [0.005-1.151]; p= .063). The protective effect of HEPA/LAF was not seen under posaconazole prophylaxis (OR, 0.856 [0.376-1.950]; p= .711). Implementation of HEPA/LAF was associated with a significant reduction in neutropenia-related IA in non-transplant haematological patients.