The estimated mean increase in CD4+ T-cell counts between weeks 0 and 24 was more than 78 cells/μl per month [95% confidence interval (CI) +66 to 90] in the IL-2 group, whereas it was stable (more than 2 cells/μl per month, 95% CI −11 to +15) in the control group. When adjusting for other factors (Table 1), the cumulative duration of exposure to ART before inclusion and the level of HIV-1 DNA were associated with the CD4 T-cell counts dynamics before antiretroviral interruption. Indeed, the increase of CD4 T-cell counts was blunted for longer exposure to antiretrovirals (four cells per month less per year of exposure, P = 0.04) and for higher levels of HIV-1 DNA (28 cells/month less per log10 copies/million of peripheral blood mononuclear cells, P = 0.02). None of these factors modified the effect of IL-2 on CD4+ T-cell counts change.
After week 24, we identified a biphasic decline of CD4 with a first slope before week 32 and a weaker decline between week 32 and week 168. These slopes (in cells/μl per month) were significantly different (all P ≤ 0.0001) between the two groups being more pronounced in the IL-2 group (−234 and −17) than in the control group (−106 and −7).
Figure 3b shows actual median plasma HIV-RNA over time. All patients had viral loads less than 50 copies/ml at week 24. Following ART cessation, plasma HIV RNA rebounded up to 4.33 log10 copies/ml (3.86; 4.79) in the IL-2 group and 4.39 log10 copies/ml (3.92; 4.76) in the control group (P = 0.71) and did not change throughout the follow-up period.
Thirty patients from each group participated in an immunologic substudy. Baseline characteristics of these patients were globally similar to the study population with the exception of sex (Table 2 in SDC 1, http://links.lww.com/QAD/A204). In this substudy, at week 24, median CD4+ T cells/μl were 1143 and 653 in IL-2 and control groups, respectively (P < 0.001). These values were 811 and 645 at week 48 (P = 0.01) and 594 and 541 at week 96 (P = 0.57). Analyses of CD4+ T-cell subpopulations in the IL-2 group show that naive, central memory, effector memory cells increased from 356, 284, 57 to 461, 458 and 144 cells/μl (P < 0.006 for all comparisons) at week 24, whereas no changes in terminally differentiated effector memory cells were noted (47 and 42). As expected [2,7], IL-2-expanded-CD4+ T cells expressed CD25 (41% of all CD4 T cells at week 24; Fig. 4a). The proportion of CD4+ T cells expressing CD38 or human leucocyte antigen (HLA-DR) decreased significantly between baseline and week 24 (P < 0.001 and P = 0.041) in the IL-2 group. No significant changes for any of the above markers were noted in the control group (Fig. 4b). Following interruption of ART, between weeks 24 and 48, the median decline of naive, central memory, effector memory and terminally differentiated effector memory populations at week 48 was −96, −119, −40 and −20 cells/μl in the IL-2 group. These values were similar in the control group (P > 0.07 for all comparisons): −61, −35, −12 and −5 cells/μl, so that differences observed at week 24 persisted at week 48. The proportion of CD4+ T cells expressing activation markers (CD38 or HLA-DR) tended to remain lower in IL-2 recipients as compared to controls at weeks 24 and 48 (P = 0.023 and P = 0.081, respectively). IL-2-expanded CD4+CD25+ T cells decreased to 26% at week 96 but remained higher than in the control group (26 vs. 16%, P = 0.006). Conversely, the number of CD4+CD25− T cells decreased after week 24 but did not differ between the two groups (P > 0.07 for all comparisons). The differential expression of the activation markers CD38 and HLA-DR on CD4+CD25+ T cells between IL-2 recipients and controls was even more pronounced than in the total CD4+ T-cell population (Fig. 4b). The pattern of the dynamics of the markers seemed remarkably defined very early after viral rebound as seen in the three patients with highly repeated measurements after treatment interruption (Table 3 in SDC 1, http://links.lww.com/QAD/A204).
Safety and tolerability
A high number of adverse events related to IL-2 administration were reported during the first 24 weeks of the trial. The vast majority of these events were mild (grades 1 to 2). Constitutional symptoms (such as asthenia, fever, nausea…) were the most frequent complaints and accounted for 50% of all adverse events. Among the 17 patients who decided to stop IL-2, adverse effects of IL-2 were involved as the main reason in 11 of them. The number of severe adverse events was low (n = 10 patients; seven in IL-2 group and three in control group). Also, 11 patients (14%) in the IL-2 group and 16 (24%) in the control group experienced grade 3 or 4 laboratory abnormalities (P = 0.11), with a similar number of events in each group. One patient from the IL-2 group (esophageal candidasis) at week 196 and three patients from the control group (ocular B-cell lymphoma, B-cell lymphoma, esophageal candidasis at week 43, 104 and 82, respectively) experienced an AIDS-defining event. Six cardiovascular events occurred in four patients after week 24 (antiretroviral interruption): one myocardial infarction with coronary bypass in a patient presenting an abdominal aneurysm, two strokes (same patient), one pulmonary embolism, one arterial thrombosis. Only one occurred in the IL-2 group (i.e. pulmonary embolism).
The ANRS-National Institute of Health (NIH) ILIADE trial showed that administration of three cycles of IL-2 in HIV-infected patients with high CD4+ T-cell counts and controlled viral load while on ART may significantly delay indication of ART resumption following ART interruption. Longitudinal phenotypic analyses showed a unique behavior and phenotype of IL-2-expanded CD4+ T cells. Despite viral replication, IL-2-expanded CD4+ T cells remained significantly higher than in the control group up to 72 weeks. This effect was related to a significant increase of CD4+ T cells harboring CD25 and expressing a low level of activation markers.
The ANRS/NIH ILIADE trial was designed at a period in which several clinical studies evaluating the potential interest of structured treatment interruption (STI) [22,23] were initiated. The major safety problem for patients enrolled in a study with STI of a short-term duration (less than 6 months) is related to CD4+ T-cell counts drop below 350 cells/μl. Recent studies from our group and others have shown that patients’ survival might be affected if they are exposed to CD4+ T-cell counts less than 500 cells/μl [24,25]. Although the value of CD4+ T-cell counts as a surrogate marker for disease progression in IL-2 therapy setting is highly challenged, the rationale of the use of IL-2 before treatment interruption was to limit CD4+ T-cell decline. Moreover, our study differed in several aspects to the large majority of ART interruption studies [26,27]. First, the population of patients eligible to participate was expected to have a high CD4+ T-cell counts at inclusion (higher than 500) and most patients had still high CD4+ T-cell counts at week 48. Second, the decrease of CD4+ T cells following ART interruption was steeper in the present study and even more pronounced in IL-2-treated patients. The same magnitude of CD4 steep decrease and viral load plateau was reported by the ACTG A5132 among IL-2-treated patients after ART interruption included . This observation may be seen as unexpected in regard of previous studies demonstrating clearly that IL-2-expanded CD4+ T cells exhibit a longer half-life as compared to ‘conventional’ CD4+ T cells . However, one mechanistic explanation is that the drop of CD4+ T cells at a given time is proportional to the number of cells in addition to the death rate. Therefore, for a given death rate, the decline of CD4+ T-cell counts will be steeper for a patient with a higher number of CD4+ T cells at the time of antiretroviral treatment interruption. This could also be the explanation of observed differences in CD4+ T-cell drop in the control group (with a median of 703 cells/μl at week 24) compared to the previously published studies (with a median around 350 cells/μl before interruption). As previously reported, we also found that the frequency of CD4+ T cells expressing activation markers, even following treatment interruption, was lower in IL-2-treated patients as compared to those treated with ART only. Altogether, these data suggest at least two phases in the homeostasis of T-cell pool in IL-2-treated patients following viral rebound. The initial phase is marked by drop of CD4+ T cells highly correlated with the CD4+ T-cell gain at the end of IL-2 cycling (week 24). In contrast, the second phase is characterized by a slow decline of long-living CD4+CD25+ T cells that were not activated, quiescent, and therefore prone to resist HIV infection.
A key challenge in developing disease-modifying interventions is showing that a biomarker or combination of biomarkers is a surrogate for disease progression. Results from SILCAAT and ESPRIT studies have shown that CD4+ T-cell counts under IL-2 therapy cannot be considered as a valuable surrogate marker of disease progression. Our results suggest that in addition to total CD4 cell counts, markers such as T-cell immunophenotypic analyses (e.g., activated and regulatory T cells), and possibly functional assays or other markers of inflammation and activation, should be considered. We show that IL-2 administration before ART interruption tips the balance in favor of CD4+CD25+ as compared to ‘conventional’ CD4+CD25−. Long-term clinical consequences of this new equilibrium are not obvious. In one hand, the recent observation in ART-treated patients that these cells may suppress effector T cells responses, suggest a potential harmful effect . On the other hand, a limited expansion and persistence of these cells might help to contain immune activation and to prevent the development of opportunistic infections as recently suggested in more advanced patients with a benefit of IL-2 restricted to a narrow range of CD4+ T-cell counts . More recently, further analyses of SILCAAT and ESPRIT studies have also shown that the effect of IL-2 on all causes of death may vary by baseline D-dimer levels . These results underscore the need to pursue researches aiming at identifying a target population who might benefit from disease-modifying interventions and specifically from gamma chain-utilizing cytokines such as IL-7 and IL-15.
In conclusion, this study shows that the administration of IL-2 before antiretroviral treatment interruption in individuals with nonadvanced HIV disease led to a longer period before antiretroviral resumption that might be explained by the expansion of CD4+ T cells with a unique phenotype [29,32] and a long survival despite the presence of replicating virus.
Presented in part at the 16th Conference on Retroviruses and Opportunistic Infections, Montreal, February 2009, ML, USA (abstract H-110).
We thank Chiron laboratories for graciously providing Interleukin 2 for this trial. We are grateful to Jean-Pierre Aboulker, Pablo Tebas, Claude Bazin and Dominique Emilie, members of the Data and Safety Monitoring Board of the study.
We acknowledge the excellent work performed by the events validation committee: Geneviève Beck-Wirth, Véronique Joly, A.S.L., Corinne Rancinan and I.S.
We thank Cecile François and Daniel Commenges for their contribution to the modeling analysis.
ILIADE ANRS 118 study team: The following institutions and investigators participated in the ILIADE trial. CH Annecy: C Michon, JP Bru, J Gaillat; CH Belfort: JP Faller; Hôpital Jean Verdier, Bondy: V Jeantils, M Thomas; CHU Bordeaux, Hôpital Saint-André: J Beylot, P.M., Hôpital Pellegrin: JM Ragnaud; CHU Clermont-Ferrand: J Beytout, C Jacomet; Hospices Civils de Lyon, Hôtel Dieu: L Cotte, C Trepo; Hôpital Edouard Herriot: JL Touraine, F Jeanblanc; CHU Montpellier: J Reynes; CH Mulhouse: G Beck-Wirth; CHU Nantes, Hôtel Dieu: F Raffi; Assistance Publique-Hôpitaux de Marseille, Hôpital Sainte Marguerite: JA Gastaud, I Poizot-Martin; Assistance Publique-Hôpitaux de Paris, Hôpital Avicenne, Bobigny: M Bentata; Hôpital de Bicêtre, Le Kremlin Bicêtre: J.F.D., C Goujard; Hôpital Antoine Béclère, Clamart: F Boué, P Galanaud; Hôpital Henri Mondor, Créteil: Y.L., A Sobel; Hôpital Bichat Claude-Bernard: E Bouvet, P Yéni; Hôpital Européen Georges Pompidou: M Kazatchkine, L.W.; Hôpital Lariboisière: JF Bergmann, P Sellier; Hôpital Necker: B Dupont, J.P.V.; Hôpital Saint-Antoine: P.M.G.; Hôpital Saint-Louis: C Lascoux-Combe, J.M.M., E Oksenhendler, D Séréni; National Institutes of Health Clinical Center, Bethesda (USA): C.L., T Miller, I.S.
Steering Committee: G.C., JF Delfraissy, M.L.G., C Goujard, Y.L., J.M.M., C Rancinan, C.R., AM Taburet, A.V., J.P.V., L.W., S Couffin-Cadiergues (representing ANRS), M Beumont (representing Chiron), and invited experts: V Avettand-Fenoel, M Bocquentin, C Jung, C Lacabaratz, A.S.L., B.P., L Rogge, R.T.
Funding: This study was supported by the French National Agency for Research on AIDS and Viral Hepatitis (ANRS, Trial No. 118) and the Intramural Research Program of NIAID/NIH (NIH 04-I-0018 trial).
Clinical Trials Unit/INSERM U897, Bordeaux School of Public Health (ISPED), University Victor Segalen Bordeaux 2: M Badets, M Bonarek, C.B., G.C., S Desjardins, C Fagard, M François, A Frosch, L Lallemand, G Poizat, C Rancinan, R Winum.
Sponsor: ANRS (French National Agency for Research on AIDS and Viral Hepatitis): M.J. Commoy, S. Couffin-Cadiergues, A. Metro.
Conflicts of interest
None of the authors declare conflict of interest.
1. Levy Y, Capitant C, Houhou S, Carriere I, Viard JP, Goujard C, et al. Comparison of subcutaneous and intravenous interleukin-2 in asymptomatic HIV-1 infection: a randomised controlled trial. ANRS 048 study group
2. Sereti I, Anthony KB, Martinez Wilson H, Lempicki R, Adelsberger J, Metcalf JA, et al. IL-2-induced CD4(+) T-cell expansion in HIV-infected patients is associated with long-term decreases in T-cell proliferation
3. Levy Y, Durier C, Krzysiek R, Rabian C, Capitant C, Lascaux AS, et al. Effects of interleukin-2 therapy combined with highly active antiretroviral therapy on immune restoration in HIV-1 infection: a randomized controlled trial
4. Farel CE, Chaitt DG, Hahn BK, Tavel JA, Kovacs JA, Polis MA, et al. Induction and maintenance therapy with intermittent interleukin-2 in HIV-1 infection
5. Durier C, Capitant C, Lascaux AS, Goujard C, Oksenhendler E, Poizot-Martin I, et al. Long-term effects of intermittent interleukin-2 therapy in chronic HIV-infected patients (ANRS 048-079 Trials)
6. Abrams D, Levy Y, Losso MH, Babiker A, Collins G, Cooper DA, et al. Interleukin-2 therapy in patients with HIV infection
. N Engl J Med
7. Weiss L, Letimier FA, Carriere M, Maiella S, Donkova-Petrini V, Targat B, et al. In vivo expansion of naive and activated CD4+CD25+FOXP3+ regulatory T cell populations in interleukin-2-treated HIV patients
. Proc Nat Acad Sci USA
8. Molina JM, Levy Y, Fournier I, Hamonic S, Bentata M, Beck-Wirth G, et al. Interleukin-2 before Antiretroviral Therapy in Patients with HIV Infection: A Randomized Trial (ANRS 119)
. J Infect Dis
9. Tavel JA, Babiker A, Fox L, Gey D, Lopardo G, Markowitz N, et al. Effects of intermittent IL-2 alone or with peri-cycle antiretroviral therapy in early HIV infection: the STALWART study
. PLoS One
10. Levy Y, Lacabaratz C, Weiss L, Viard JP, Goujard C, Lelievre JD, et al. Enhanced T cell recovery in HIV-1-infected adults through IL-7 treatment
. J Clin Invest
11. Angel JB, High K, Rhame F, Brand D, Whitmore JB, Agosti JM, et al. Phase III study of granulocyte-macrophage colony-stimulating factor in advanced HIV disease: effect on infections, CD4 cell counts and HIV suppression. Leukine/HIV Study Group
12. Napolitano LA, Schmidt D, Gotway MB, Ameli N, Filbert EL, Ng MM, et al. Growth hormone enhances thymic function in HIV-1-infected adults
. J Clin Invest
13. Hansen BR, Kolte L, Haugaard SB, Dirksen C, Jensen FK, Ryder LP, et al. Improved thymic index, density and output in HIV-infected patients following low-dose growth hormone therapy: a placebo controlled study
14. Kilby JM, Bucy RP, Mildvan D, Fischl M, Santana-Bagur J, Lennox J, et al. A randomized, partially blinded phase 2 trial of antiretroviral therapy, HIV-specific immunizations, and interleukin-2 cycles to promote efficient control of viral replication (ACTG A5024)
. J Infect Dis
15. Keh CE, Shen JM, Hahn B, Hallahan CW, Rehm CA, Thaker V, et al. Interruption of antiretroviral therapy blunts but does not abrogate CD4 T-cell responses to interleukin-2 administration in HIV infected patients
16. Henry K, Katzenstein D, Cherng DW, Valdez H, Powderly W, Vargas MB, et al. A pilot study evaluating time to CD4 T-cell count < 350 cells/mm(3) after treatment interruption following antiretroviral therapy +/- interleukin 2: Results of ACTG A5102
. J Acquir Immune Defic Syndr
17. Porter BO, Anthony KB, Shen J, Hahn B, Keh CE, Maidarelli F, et al. Inferiority of IL-2 alone versus IL-2 with HAART in maintaining CD4 T cell counts during HAART interruption: a randomized controlled trial
18. Hunt PW, Martin JN, Sinclair E, Bredt B, Hagos E, Lampiris H, Deeks SG. T cell activation is associated with lower CD4+ T cell gains in human immunodeficiency virus-infected patients with sustained viral suppression during antiretroviral therapy
. J Infect Dis
19. Hunt PW, Brenchley J, Sinclair E, McCune JM, Roland M, Page-Shafer K, et al. Relationship between T cell activation and CD4+ T cell count in HIV-seropositive individuals with undetectable plasma HIV RNA levels in the absence of therapy
. J Infect Dis
21. Centers for Disease Control. 1993 revised classification system for HIV
infection and expanded surveillance case definition for AIDS among adolescents and adults. Morb Mortal Wkly Rep
22. Marchou B, Tangre P, Charreau I, Izopet J, Girard PM, May T, et al. Intermittent antiretroviral therapy in patients with controlled HIV infection
23. El Sadr WM, Lundgren JD, Neaton JD, Gordin F, Abrams D, Arduino RC, et al. CD4+count-guided interruption of antiretroviral treatment
. N Engl J Med
24. Lewden C, Chene G, Morlat P, Raffi F, Dupon M, Dellamonica P, et al. HIV-infected adults with a CD4 cell count greater than 500 cells/mm3 on long-term combination antiretroviral therapy reach same mortality rates as the general population
. J Acquir Immune Defic Syndr
25. Zwahlen M, Harris R, May M, Hogg R, Costagliola D, de Wolf F, et al. Mortality of HIV-infected patients starting potent antiretroviral therapy: comparison with the general population in nine industrialized countries
. Int J Epidemiol
26. Skiest DJ, Su Z, Havlir DV, Robertson KR, Coombs RW, Cain P, et al. Interruption of antiretroviral treatment in HIV-infected patients with preserved immune function is associated with a low rate of clinical progression: a prospective study by AIDS Clinical Trials Group 5170
. J Infect Dis
27. Thiébaut R, Pellegrin I, Chêne G, Viallard JF, Fleury H, Moreau JF, et al. Immunological markers after long-term treatment interruption in chronically HIV-1 infected patients with CD4 cell count above 400x10(6) cells/I
28. Bosch RJ, Pollard RB, Landay A, Aga E, Fox L. Mitsuyasu For The Aids Clinical Trials Group ATRA randomized trial of interleukin-2 during withdrawal of antiretroviral treatment
. J Interferon Cytokine Res
29. Kovacs JA, Lempicki RA, Sidorov IA, Adelsberger JW, Sereti I, Sachau W, et al. Induction of prolonged survival of CD4(+) T lymphocytes by intermittent IL-2 therapy in HIV-infected patients
. J Clin Invest
30. Fontas E, Kousignian I, Pradier C, Poizot-Martin I, Durier C, Weiss L, et al. IL-2 therapy: potential impact of the CD4 cell count at initiation on clinical efficacy – results from the ANRS CO4 cohort
. J Antimicrob Chemother
31. Lane C. Baseline D-dimer Levels Identify a Subset of Patients at Higher Risk of Death following IL-2 Administration (abstract)
. 18th Conference on Retroviruses and Opportunistic Infections
. Boston 2011. http://www.retroconference.org
32. Sereti I, Imamichi H, Natarajan V, Imamichi T, Ramchandani MS, Badralmaa Y, et al. In vivo expansion of CD4(+)CD45RO-CD25(+) T cells expressing foxP3 in IL-2-treated HIV-infected patients
. J Clin Invest
Keywords:© 2012 Lippincott Williams & Wilkins, Inc.
antiretroviral therapy interruption; HIV; interleukin-2