Viral metagenomics reveals diverse anelloviruses in bone marrow specimens from hematologic patients

An infectious etiology has been proposed for many human cancers, but rarely have specific agents been identified. Viral metagenomic technique is useful for identification of viral pathogens potentially existing in bone marrow specimens from hematologic patients.

A total of 24 patients were included in this study, including 14 female (58.3 %) and 10 male patients (41.7 %) with a mean age of 55.20 ± 18.02 years (16-89 years).Twenty-four bone marrow specimens were collected from 24 hematologic patients (diagnosed with hypoferric anemia, diffuse large B cell lymphoma, myelodysplastic syndrome, acute myelo-monocytic leukemia, acute myelocytic leukemia with maturation, multiple myeloma, lymphoma angioimmunoblastic T cell, acute myeloid leukemia-M1, polycythemia vera/hypoferric anemia, leukocythemia, or megaloblastic anemia). Viral nucleic acid from marrow samples of hematologic patients were subjected to viral metagenomic analysis. PCR method was used to investigate the prevalence of these new viruses in this cohort of hematologic patients. Phylogenetic tree was established to elucidate the relationship of anelloviruses found here and the previously define ones.

Anelloviridae family are the main group of viruses detected in all the 4 libraries. Forty-six different species of Anelloviruses belonging to genera Alphatorquevirus, Betatorquevirus and Gammatorquevirus and unclassified anellovirus were recovered. Fifteen novel strains with complete ORF1 coding sequence were acquired and phylogenetically analyzed, indicating 8 of the 15 strains are proposed novel species belonging to genus Gammatorquevirus. Nested-PCR were then performed for these15 novel anellovirus strains in the 24 individual bone marrow samples, which showed 13 of them were present in more than one bone marrow samples.

Diverse types of anellovirus were present in bone marrow samples of hematologic patients. Whether these novel anelloviruses have association with certain hematonosis needs further investigation.