Quantification of torque teno virus (TTV) DNA in saliva and plasma samples in patients at short time before and after kidney transplantation.

BACKGROUND: Several reports have proposed that the viral load of torque teno virus (TTV) in plasma is a biomarker of immune function in solid organ transplantation (SOT) and in allogeneic hematopoietic stem cell transplantation. Additionally, for the latter one, TTV-DNA quantification in saliva has also been suggested. AIM: to investigate the correlation between the TTV viral load and immune function in paired saliva and plasma samples in patients on kidney transplantation. MATERIALS AND METHODS: TTV-DNA viral load was quantified in paired samples of saliva and plasma from 71 patients before and a short-time after renal-transplantation by real-time PCR. RESULTS: The data obtained from 213 paired samples showed a slight consistency in the comparison between saliva and plasma, with prevalence of TTV-DNA being 58%, 52% and 60% in saliva samples and 60%, 73% and 90% in plasma samples before and at 15-20 and 45-60 days after transplantation, respectively. Additionally, a high TTV viral load was observed in plasma at 15-20 and 45-60 days after transplantation compared to that observed in saliva at the same time. CONCLUSIONS: Overall, monitoring TTV-DNA in saliva samples could be an additional fast non-invasive option to assess the immune functionality in SOT populations.

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

Torquetenovirus (TTV) is present in biological fluids from healthy individuals and measurement of its titer is used to assess immune status in individuals with chronic infections and after transplants. We assessed if the titer of TTV in saliva varied with the presence of SARS-CoV-2 in the nasopharynx and could be a marker of COVID-19 status. Saliva from 91 individuals positive for SARS-CoV-2 in nasal-oropharyngeal samples, and from 126 individuals who were SARS-CoV-2-negative, all with mild respiratory symptoms, were analyzed. Both groups were similar in age, gender, symptom duration and time after symptom initiation when saliva was collected. Titers of TTV and SARS-CoV-2 were assessed by gene amplification. Loss of smell (p = 0.0001) and fever (p = 0.0186) were more prevalent in SARS-CoV-2-positive individuals, while sore throat (p = 0.0001), fatigue (p = 0.0037) and diarrhea (p = 0.0475) were more frequent in the SARS-CoV-2 negative group. The saliva TTV and nasal-oropharyngeal SARS-CoV-2 titers were correlated (p = 0.0085). The TTV level decreased as symptoms resolved in the SARS-CoV-2 infected group (p = 0.0285) but remained unchanged in the SARS-CoV-2 negative controls. In SARS-CoV-2 positive subjects who provided 2-4 saliva samples and in which TTV was initially present, the TTV titer always decreased over time as symptoms resolved. We propose that sequential TTV measurement in saliva is potentially useful to assess the likelihood of symptom resolution in SARS-CoV-2-positive individuals and to predict prognosis.

Oral shedding of CMV and HSV-1 in hematopoietic stem cell transplantation patients.

OBJECTIVES: To evaluate the oral shedding of herpesviruses in patients undergoing hematopoietic stem cell transplantation (HSCT) and correlate it with oral mucositis (OM). METHODS: Saliva samples were collected before the HSCT and on day D + 8. Multiplex Polymerse Chain Reaction (PCR) was performed to detect herpes simplex virus (HSV)-1 and HSV-2, Epstein-Barr virus (EBV), Cytomegalovirus (CMV), Variella-zoster virus (VZV), and human herpesvirus (HHV)-6, HHV-7, and HHV-8. OM was assessed according to WHO criteria. RESULTS: Thirty one patients were enrolled, in which 20 of 31 (64.5%) were males; median age was 50 (21-70) years; 16 of 31 (51.6%) underwent allo-HSCT; and 15 of 31 (48.4%) underwent auto-HSCT. On D + 8, OM grades III and IV were observed in 8 of 31 (25.8%) patients. In the first salivary collection, EBV was found in 24 of 31 (77.4%), followed by HHV-6 (7/31, 22.6%) and HHV-7 (8/31 25.8%). In the second collection, EBV was found in 24 of 27(89%), followed by HSV-1 (8/27, 30%) and CMV, HHV-6, and HHV-7 (5/27, 18.5%, each one). On D + 8, OM grades II and IV were associated with the presence of HSV-1. HSV-1 was also associated with worsening degrees of OM on D + 15. CONCLUSION: The presence of HSV-1 and CMV in oral samples was more frequent on day D + 8 after HSCT. HSV-1 detection was associated with severity and worsening of OM. HSV-1 and CMV seem to be associated with oral dysbiosis due to HSCT.

Performance of at-home self-collected saliva and nasal-oropharyngeal swabs in the surveillance of COVID-19.

Background: SARS-CoV-2 quickly spreads in the worldwide population, imposing social restrictions to control the infection, being the massive testing another essential strategy to break the chain of transmission. Aim: To compare the performance of at-home self-collected samples - saliva and combined nasal-oropharyngeal swabs (NOP) - for SARS-CoV-2 detection in a telemedicine platform for COVID-19 surveillance. Material and methods: We analyzed 201 patients who met the criteria of suspected COVID-19. NOP sampling was combined (nostrils and oropharynx) and saliva collected using a cotton pad device. Detection of SARS-COV-2 was performed by using the Altona RealStar® SARS-CoV-2 RT-PCR Kit 1.0.  Results: There was an overall significant agreement (κ coefficient value of 0.58) between saliva and NOP. Considering results in either sample, 70 patients positive for SARS-CoV-2 were identified, with 52/70 being positive in NOP and 55/70 in saliva. This corresponds to sensitivities of 74.2% (95% CI; 63.7% to 83.1%) for NOP and 78.6% (95% CI; 67.6% to 86.6%) for saliva. Conclusion: Our data show the feasibility of using at-home self-collected samples (especially saliva), as an adequate alternative for SARS-CoV-2 detection. This new approach of testing can be useful to develop strategies for COVID-19 surveillance and for guiding public health decisions.