Comment on "Persistent long-term changes in lymphocyte subsets induced by polyclonal antibodies" by Müller et al.

Abstract

The interesting study of Müller et al. (1) suggests that polyclonal antithymocyte antibodies are responsible for persistent long-term changes in T-cell lymphocyte subsets. The most significant change they found was an expansion of the CD8+bright CD57+ subpopulation. A few years ago, we reported similar abnormalities in the peripheral blood lymphocyte subsets of long-term stable renal transplant recipients with a mean follow-up of 78 months after transplantation (2). The subset of CD57+ cells was significantly expanded. The majority of these cells expressed CD8, but a significant proportion expressed CD4. These CD4+ CD57+ cells were large granular lymphocytes, did not exhibit natural killer activity, and were not able to produce significant level of interleukin-2 upon stimulation with phytohemagglutinin or allogeneic cells (3). Their function has never been precisely determined. Interestingly, the patients we studied received conventional immunosuppression, i.e., high-dose steroids and azathioprine, but never received either cyclosporine or polyclonal antithymocyte antibodies. We agree with Müller et al. that awareness of long-term consequences of any kind of immunosuppression on lymphocyte subsets is necessary. Christophe Legendre Service de Néphrologie; Hôpital Saint-Louis; 75010 Paris, France