Kinetics of torque teno virus DNA load in saliva and plasma following allogeneic hematopoietic stem cell transplantation

Abstract

Plasma torque teno virus (TTV) DNA load directly correlates with the degree of T-cell immune reconstitution early after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Here, the kinetics of oral TTV DNA shedding was examined to assess whether quantitation of TTV DNA load in saliva may either replace or complement that in plasma for predicting lymphocyte (ALC) reconstitution after engraftment. This prospective observational study enrolled 38 nonconsecutive allo-HSCT recipients. Saliva and plasma specimens were collected at baseline (pretransplant) and at around days +30, +50, and +90 after allo-HSCT. TTV DNA was quantitated in both specimen types by real-time PCR. ALCs were measured by cytometry. A total of 104 paired saliva and plasma specimens were available for TTV PCR analyses. TTV DNA was detected more frequently in saliva than in plasma specimens at all time points (overall, 94.2% vs 86.5%). Increasing levels of TTV DNA were seen in both specimen types from day +30 to day +90 after transplantation. Overall, TTV DNA loads were significantly higher in saliva than in plasma specimens (P = .0002) and correlated significantly (P ≤ .0001). A direct correlation between TTV DNA loads in saliva and plasma and ALCs was observed after engraftment (P = .034 and P = .002, respectively). Future studies should be aimed at determining whether monitoring of oral TTV DNA shedding may be of any utility for inference of immune reconstitution after allo-HSCT.

Torquetenovirus in saliva: A potential biomarker for SARS-CoV-2 infection?

“…TTV has been shown to be present in human saliva [8,9]. In a patient who underwent an allogeneic hematopoietic stem cell transplant, detection of TTV was more frequent and the TTV titer was higher in saliva as opposed to plasma [9].…”

“…In a patient who underwent an allogeneic hematopoietic stem cell transplant, detection of TTV was more frequent and the TTV titer was higher in saliva as opposed to plasma [9]. This led the authors to suggest that quantitation of TTV in saliva may be of value in predicting immunocompetence after engraftment [8].…”

Better detection of Torque teno virus in children with leukemia by metagenomic sequencing than by quantitative PCR

“…11 As TTV is ubiquitous, and viral replication correlates with immune status, TTV has been studied as a promising marker to assess global functional immune competence in, for example, transplant recipients. [12][13][14][15][16][17][18][19][20] TTV has not been demonstrated to cause any disease in humans.…”

Kinetics of Torque Teno virus DNA in stools may predict occurrence of acute intestinal graft versus host disease early after allogeneic hematopoietic stem cell transplantation

“…[7][8][9][10][11][12][13] We previously reported that although overall TTV DNA levels in saliva and plasma tended to correlate, they may follow different kinetics in allo-HSCT recipients, thereby suggesting that the level of TTV replication could be compartment dependent. 16 In addition, TTV DNA can be detected in stools from healthy people and patients with enteritis. 17 On the basis of this evidence, 16,17 we hypothesized that the kinetics of TTV DNA load in the gastrointestinal tract early after allo-HSCT may allow us to anticipate aIGvHD occurrence.…”

“…16 In addition, TTV DNA can be detected in stools from healthy people and patients with enteritis. 17 On the basis of this evidence, 16,17 we hypothesized that the kinetics of TTV DNA load in the gastrointestinal tract early after allo-HSCT may allow us to anticipate aIGvHD occurrence.…”