Induction of prolonged survival of CD4⁺ T lymphocytes by intermittent IL-2 therapy in HIV-infected patients
J. Clin. Invest. Joseph A. Kovacs, et al. 115:2139 doi:10.1172/JCI23196 [Go to this article.]

Figure 4
BrdU labeling kinetics in 4 patients receiving a BrdU infusion immediately after the last IL-2 dose. (A) Experimental data for CD4 cells, represented by blue squares, and for CD8 cells, represented by red triangles. For patient 3 (top panels), data following labeling before any IL-2 was received are shown by green squares (CD4) and black triangles (CD8). The solid lines represent the fitting by the model equations. (B) The probability density function of the normal distribution of log d multiplied by the total source of labeled cells (S) for the same patients. The last 2 patients were long-term responders (patients 1 and 19 from Figure 1). Mean log decay m_d values for these data are (CD4/CD8): pt. 3, 0.10/–0.07 (for labeling with no IL-2), 0.14/0.88 (cycle 1); pt. 8, 1.38/0.85; pt. 1, –1.34/0.11; pt. 19, –1.28/0.35. Consistent with the deuterium-labeling studies, the 2 long-term responders had a smaller m_d for labeled CD4 but not CD8 cells, indicating longer survival of the proliferating cells. (C) BrdU labeling kinetics in naive (CD27⁺CD45RO^–), central memory (CD27⁺CD45RO⁺), and effector memory (CD27^–CD45RO⁺ and CD27^–CD45RO^–) CD4 (top) and CD8 (bottom) subpopulations for patient 19. Presentation of data is as in A and B. For both CD4 and CD8 cells, m_d is substantially smaller (indicating a slower decay) for the 2 CD27⁺ populations. Mean log decay m_d values for these data are (CD45RO^–/CD45RO⁺): CD4/CD27⁺, –1.58/–1.10; CD8/CD27⁺, –1.02/–1.32; CD4/CD27^–, 0.69/2.32; CD8/CD27^–, 0.07/1.92.