# The plasma viral communities associate with clinical profiles in a large-scale haematological patients cohort

## TL;DR

This study explores how the presence of viruses in the blood plasma of haematological patients is linked to their clinical conditions and symptoms.

## Contribution

The study identifies specific viral associations with clinical features in haematological patients, offering insights for improved diagnosis and treatment.

## Key findings

- Haematological patients show higher diversity and prevalence of viral pathogens compared to non-haematological patients.
- TTV detection increases after transplantation and during lung infections, with specific associations to neutrophil counts and inflammatory markers.
- Certain viruses like TTV, B19V, and HPgV-C show preferences for age and seasonal infections, while others are linked to specific clinical stages.

## Abstract

Haematological patients exhibit immune system abnormalities that make them susceptible to viral infections. Understanding the relationship between the virome in the blood plasma of haematological patients and their clinical characteristic is crucial for disease management. We aimed to explore the presence of viral pathogens and identify close associations between viral infections and various clinical features.

A total of 21 DNA viruses and 6 RNA viruses from 12 virus families were identified from 1383 patients. Patients with haematological diseases exhibited significantly higher diversity, prevalence, and co-detection rates of viral pathogens. During fever episodes, pathogen detection was notably higher, with Epstein-Barr virus (EBV) and Mucorales infections being the most probable culprits for fever symptoms in non-haematological patients. The detection rate of torque teno virus (TTV) significantly increases in haematological patients after transplantation and during primary lung infections. Additionally, TTV-positive patients demonstrate significantly higher absolute neutrophil counts, while C-reactive protein and procalcitonin levels are notably lower. Furthermore, TTV, cytomegalovirus, and parvovirus B19 (B19V) were found to be more prevalent in non-neutropenic patients, while non-viral pathogenic infections, such as Gram-negative bacteria and Mucorales, were more common in neutropenic patients. Pegivirus C (HPgV-C) infection often occurred post-transplantation, regardless of neutropenia. Additionally, some viruses such as TTV, B19V, EBV, and HPgV-C showed preferences for age and seasonal infections.

Analysis of the plasma virome revealed the susceptibility of haematological patients to plasma viral infections at specific disease stages, along with the occurrence of mixed infections with non-viral pathogens. Close associations were observed between the plasma virome and various clinical characteristics, as well as clinical detection parameters. Understanding plasma virome aids in auxiliary clinical diagnosis and treatment, enabling early prevention to reduce infection rates in patients and improve their quality of life.

Video Abstract

Video Abstract

The online version contains supplementary material available at 10.1186/s40168-024-01855-4.