B cells
Group of human B-cells which play a large role in the immune response system.

The T- and B-cell compartments are normally reconstituted following allogeneic hematopoietic stem cell transplantation in patients with sickle cell disease, according to a new study published in the journal Clinical and Translational Immunology. Moreover, the increase after the transplantation of B-regulatory cells that produce IL-10 could contribute to immune regulation and homeostasis.

Allogeneic hematopoietic stem cell transplantation is the only curative treatment for patients with sickle cell disease. 

Read more about stem cell transplantation and other therapies for sickle cell disease.

In order to understand the quality of the immune reconstitution in patients with sickle cell disease who are chronically inflamed and how this correlates with clinical outcomes after allogeneic hematopoietic stem cell transplantation, a team of researchers from Brazil comprehensively analyzed the reconstitution of T- and B-cell compartments in 29 patients with sickle cell disease after the transplantation. The researchers also evaluated how this correlated with the development of acute graft-versus-host disease.

The results showed that, following the transplantation, T-cell neogenesis, which had been comparable to healthy people, initially declined. However, it went up to the level seen in healthy people 1 year after the transplantation. The peripheral T-cell subset took 2 years to be restored.

B-cell neogenesis, on the other hand, remained high following allogeneic hematopoietic stem cell transplantation, as it was before the transplantation, compared to healthy people. Importantly, patients had increased frequencies of B-regulatory cells producing IL-10  and memory B-cells that were IgM+, compared to before the transplant and to healthy controls. This, the authors said, suggests that the procedure may benefit patients beyond its original aim.

“Occurrence of acute graft-versus-host disease transiently affected T- and B-cell neogenesis and overall reconstitution of T- and B-cell peripheral subsets,” the researchers also reported. 

They concluded that these findings can help improve allogeneic hematopoietic stem cell transplantation protocols for sickle cell disease patients in the future.

Reference

Jarduli-Maciel LR, de Azevedo JTC, Clave E, de Mello Costa TC, et al. Allogeneic haematopoietic stem cell transplantation resets T- and B-cell compartments in sickle cell disease patients. Clin Transl Immunol. Published online April 23, 2022. doi:10.1002/cti2.1389