Quantification of CD8⁺CD38⁺ T lymphocytes by flow cytometry does not represent a good biomarker to monitor the reactivation of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation

Abstract

BackgroundInfection/reactivation of cytomegalovirus is a major cause of morbidity and mortality in immunocompromised transplant patients. It has already been observed in kidney and liver transplantation patients that cytomegalovirus disease is accompanied by significant increases in circulating CD8+CD38+ T lymphocytes. There are no reports that study CD8+CD38+ T lymphocytes to monitor/diagnose cytomegalovirus disease in hematopoietic stem cell transplantation patients.ObjectiveThe aim of this study was to evaluate some cellular activation markers on circulating mononuclear cells (CD38 and HLA-DR) in patients submitted to hematopoietic stem cell transplantation and to establish any correlation with cytomegalovirus disease as diagnosed by antigenemia.MethodsBlood samples of 15 transplant patients were analyzed by flow cytometry using anti-CD3, anti-CD4, anti-CD8, anti-CD38, CD16, CD56 and anti-HLA-DR monoclonal antibodies and the results were evaluated in respect to cytomegalovirus antigenemia measured by indirect immunofluorescence. Minitab for Windows was used for statistical analysis and a p-value < 0.05 was considered significant.ResultsPatients with positive antigenemia did not show any significant increase in the percentages of cells expressing the CD38 or HLADR activation markers when compared to patients with negative antigenemia. On the contrary, all patients showed high percentages of these cells independent of the presence of cytomegalovirus disease.ConclusionsThis study suggests that the investigation of these lymphocyte sub-populations in patients submitted to hematopoietic stem cell transplantation does not seem to contribute to the early identification of cytomegalovirus disease.

Identification of lymphocyte subgroups with flow cytometry in COVID-19 patients

“…When the patients were divided into early and advanced stages, the CD38 on T cells was found to be significantly lower in an advanced stage. CD38 is expressed at a low rate in mature naive T lymphocytes, but CD38 expression in T lymphocytes is upregulated with mitogenic activation (14). This finding may suggest that T lymphocytes may lose their active state as the COVID-19 infection progresses.…”

Special features of quantification of CD8⁺CD38⁺T-cells by flow cytometry does not represent a good biomarker to monitor the reactivation of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation

“…One important matter to be clarified is whether the overexpression of the CD38 molecule by circulating T cells may represent a universal biomarker for CMV infection after all modalities of organ transplantation. In order to address this issue, Lino et al (7) performed a prospective investigation to clarify the applicability of flow cytometric enumeration of CD8 + CD38 + T-cells in peripheral blood as a laboratorial indicator of CVM infection/reactivation in allogeneic hematopoietic stem cell (HSCT) recipients.…”