Epidemiology of Visceral Mycoses in Patients with Acute Leukemia and Myelodysplastic Syndrome: Analyzing the National Autopsy Database in Japan

【Introduction】 Visceral mycoses (VM) are deadly infection and commonly occur in the severely immunocompromised hosts such as in patients with acute leukemia and myelodysplastic syndrome (MDS). To investigate the prevalence of visceral mycoses, we retrospectively analyze the data reported to the “Annual Report of Autopsy Cases in Japan” that includes nationwide autopsy cases published yearly by the Japanese Society of Pathology. 【Method】 We analyzed all the autopsy data from patients with acute leukemia and MDS included adult T-cell leukemia (ATL) reported in the “Annual Report of Autopsy Cases in Japan” between 1989 to 2015. These data also include patients received hematopoietic stem cell transplantation (SCT). Cases involved stillborn babies or inconclusive in diagnoses are excluded in current analysis. Severe cases were defined as follows: (1) direct cause of death, (2) severe pulmonary infection involving both lobes of the lung, (3) severe visceral infections of 2 or more organ systems, including those involving the central nervous system, (4) multiorgan systemic infection of 3 or more, or (5) a case described as fungemia. 【Result】 There are total of 175,615 autopsy cases in the data bank and about 7183 cases (4.1%) are acute leukemia and MDS patients. While visceral mycoses were only found in 7756 cases (4.4%) in total cases, there are 1,562 cases (21.7 %) in acute leukemia and MDS, nearly 6-fold higher in prevalence compared with none acute leukemia and MDS cases. Among cases confirmed by single infected pathogen, Aspergillus spp. is the most predominant causative agent (45.0%), while Candida spp. is the second (22.7%). The prevalence of Aspergillus spp. was increased and peaked around 54.0% between 2001 and 2005, then gradually decreased since with more significantly in recent years. Candida spp. was also steadily decreased yearly and bottomed out in 2013. Overall, prevalence is half in Candida spp. and doubled in Mucor spp. compare with 30years ago. Complicated infections cases were founded in 6.5% of patients with acute leukemia and MDS. The most frequent combination is Candida spp. plus Aspergillus spp. (59.8%), while next Mucor spp. plus another spp. (27.0%) and such combination has a trend of gradually increasing since 1997. Most of the severe cases are patients with acute leukemia and MDS presented as visceral mycoses (62.2%). Among them the frequency was 55-67% in Aspergillus spp., Candida spp. and Cryptococcus spp. in severe cases. Otherwise