An X-linked agammaglobulinemia (XLA) patient with fever and disturbance of consciousness: infection with Torque teno virus?

A children patient with intracranial infection after brain surgery associated with elevated Torque Teno Virus

Introduction

Intracranial infections are challenging to diagnose, especially in immunocompromised patients. Next-generation sequencing (NGS) has emerged as a powerful tool for broad pathogen detection, including Torque Teno Virus (TTV). Elevated TTV loads have been associated with immune dysfunction, potentially serving as a biomarker for opportunistic infections. However, the clinical significance of TTV in intracranial infections remains unclear.

Case presentation

An 8-year-old boy developed a complex intracranial infection following craniotomy, characterized by elevated TTV levels in cerebrospinal fluid (CSF) and subsequent fungal co-infection. Initial empirical antibiotics failed to fully control the infection. NGS identified TTV in the CSF, prompting the addition of intravenous immunoglobulin. Recurrent infection led to the suspicion of a fungal infection, confirmed by positive G/GM tests and successful treatment with fluconazole.

Conclusion

Elevated TTV levels in CSF may indicate underlying immunodeficiency and predispose patients to opportunistic fungal infections. Prompt fungal testing including qPCR is recommended when TTV is detected in CSF. Further research is needed to elucidate the role of TTV in clinical infections and optimize management strategies.

The mysterious anelloviruses: investigating its role in human diseases

Anelloviruses (AVs) that infect the human population are members of the Anelloviridae family. They are widely distributed in human populations worldwide. Torque teno virus (TTV) was the first virus of this family to be identified and is estimated to be found in the serum of 80-90% of the human population. Sometime after the identification of TTV, Torque teno mini virus (TTMV) and Torque teno midi virus (TTMDV) were also identified and classified in this family. Since identifying these viruses, have been detected in various types of biological fluids of the human body, including blood and urine, as well as vital organs such as the liver and kidney. They can be transmitted from person to person through blood transfusions, fecal-oral contact, and possibly sexual intercourse. Recent studies on these newly introduced viruses show that although they are not directly related to human disease, they may be indirectly involved in initiating or exacerbating some human population-related diseases and viral infections. Among these diseases, we can mention various types of cancers, immune system diseases, viral infections, hepatitis, and AIDS. Also, they likely use the microRNAs (miRNAs) they encode to fulfill this cooperative role. Also, in recent years, the role of proliferation and their viral load, especially TTV, has been highlighted to indicate the immune system status of immunocompromised people or people who undergo organ transplants. Here, we review the possible role of these viruses in diseases that target humans and highlight them as important viruses that require further study. This review can provide new insights to researchers.

Torque teno virus and cancers: current knowledge

Aim: The aim of this systematic review is to assess the current knowledge about the relationship between Torque teno virus (TTV) and cancer in different settings. Methods: A systematic search was conducted in Medline via PubMed, Embase and Cochrane Library from the inception to the end of January 2023. Results: 34 articles were included in the qualitative synthesis of this review and 2145 patients with solid tumors have been analyzed. The most prevalent cancer types were hepatocellular carcinoma (HCC) and lung cancer. Conclusion: TTV has proven its role as a marker of functional immune competence in the setting of hematopoietic stem cell transplantation (HSCT), but in the oncological field is yet to be defined.