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Monitoring of CD3+ T-Cell Count in Patients Receiving Antithymocyte Globulin Induction After Cadaveric Renal Transplantation
Monitoring of CD3ⴙ T-Cell Count in Patients Receiving Antithymocyte Globulin Induction After Cadaveric Renal Transplantation P. Ata, M. Kara, E. Özdemir, M. Canbakan, A.M. Gökçe, F.A. Bayraktar, G. S¸ahin, L. Özel, and M.I. Titiz ABSTRACT Aim. Although antithymocyte globulin (ATG) has been used for years, its ideal dose and administration period is obscure. Herein, we sought to use the CD3⫹ cell count to detect the optimal ATG dosage. Material and Methods. Twenty-one patients who underwent cadaveric donor renal transplantation from January 2009 to January 2012 received a 1 mg/kg ATG initial dose at the time of the operation. Patients were randomized into 2 cohorts. Group 1 (n ⫽ 11) received ATG according to the clinical and total lymphocyte count and group 2 (n ⫽ 10), the dose was tailored according to the CD3⫹ cell count. We compared the total and daily ATG dosages, ATG administration period, side effects of ATG, the number of days to a serum creatinine level ⬍2 mg/dL, graft function at 3 months, acute rejection episodes, infection rates, costs of CD3⫹ analysis, and ATG amounts. Results. Both groups showed similar gender, age, and human leukocyte antigen matching data. There was no difference in presensitizing events or panel-reactive antibody class 1 and 2 levels. The number of days to a serum creatinine level of ⬍2 mg/dL was 11 ⫾ 1.5 for group 1 versus 10.4 ⫾ 0.8 for group 2 (P ⫽ .45). Between groups 1 and 2, there was a significant difference between the mean total (P ⫽ .031) and mean daily ATG dosages (P ⫽ .006). We used a total dose of 3800 mg ATG for group 1 and 2200 mg for group 2 and for the group 2 who underwent 43 CD3⫹ cell counts. The expenditure per patient was 20% higher among group 1 than group 2. Conclusion. Determination of appropriate ATG dosages by CD3⫹ cell counts was useful, reliable, and cost effective. NDUCTION immunosuppression denotes intense prophylactic therapy use at the time of transplantation to prevent an early acute rejection.1 The principle of antithymo is to decrease the T cells that meet graft antigens. Antithymocyte globulins are solutions of purified immunoglobulins obtained by hyperimmunization of rabbits with human thymocytes, lymphoblasts, or lymphocytes.1,2 They display polyclonal activity against CD45RA (naïve T-cell), CD3, CD4, CD8, ␣/-TCR (T-cell activation/first signal); CD7, CD28, CD80, CD86, CD152 (co-stimulator molecules); CD5, CD38, CD45 (signal transduction); CD2, CD6, CD11a, CD54, CD56, CD58 (adhesion molecules); CD95 (apoptosis); CD21 (EBV receptor), and CD25, CD71 (proliferation markers). These polyclonal antibodies have a powerful immunosuppressive effects that are mediated through lymphocyte depletion, modulation, or coating.2 ATG became part of many sequential protocols, where the
I
© 2013 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710 Transplantation Proceedings, 45, 929 –931 (2013)
introduction of calcineurin inhibitors was delayed to avoid drug nephrotoxicity post-transplantation. Although important benefits were achieved, the use of antibody therapies in renal transplantation was often associated with increased treatment costs and excessive immunosuppression, resulting in hematologic, infectious, and neoplastic complications.3 Polyclonal antibodies display a long half-life inducing long-term depletion of lymphocytes. Therefore, they are used at low or variable doses according to their biologic
From the Department of Transplantation and 1st General Surgery, Haydarpasa Numune Hospital, Istanbul, Turkey. Address reprint requests to P. Ata, Department of 1st Surgery, Haydarpasa Numune Hospital, Istanbul, Turkey. E-mail: pinaren@ gmail.com 0041-1345/–see front matter http://dx.doi.org/10.1016/j.transproceed.2013.02.092 929
930
ATA, KARA, ÖZDEMIR ET AL Table 1. Demographic Data
Age (yrs) Gender, F/M HLA match with donor for 6 HLA loci PRA levels (no. of patients having PRA ⬎ 20%) Class 1 Class 2 Sensitizing events (patient number with sensitizing event) Prior transplantation Blood transfusion Pregnancy
Group 1 (n ⫽ 11)
Group 2 (n ⫽ 10)
P
43.6 ⫾ 4 3/8 2.67 ⫾ 1.2
37 ⫾ 3.8 4/6 2.4 ⫾ 1.4
.265 .231 .983
4 2
2 4
.167 .289
3 3 1
2 4 2
.654 .378 .496
Abbreviations: HLA, human leukocyte antigen; PRA, panel-reactive antibody.
effects on T cells.3,4 Herein we sought to examine whether ATG could be monitored according to CD3-positive T versus total lymphocyte counts and what the effects of the modality were on costs and clinical outcomes of renal transplant patients. MATERIALS AND METHODS Twenty-one first cadaveric donor transplant recipients between January 2009 and January 2012 received an 1 mg/kg ATG initial dose at the time of their operation. Patients were randomized as group 1 (n ⫽ 11) where subsequent ATG doses were administered according to clinical criteria and total lymphocyte counts, whereas group 2 (n ⫽ 10) had ATG doses tailored according to the CD3⫹ cell count. For group 1, if the lymphocyte count was ⬍300/mL, the ATG dose was skipped for that day. For group 2, if the CD3⫹ cell count was between 150 and 50/mL, half of the calculated dose was administered, and if ⬍50/mL, it was not prescribed on that day. When group 1 subjects showed lymphocyte counts ⬍300 cells/L, the ATG was stopped for 9 times. Whereas in group 2 only one patient had ATG therapy cessation twice during her treatment schedule. When the serum creatinine level has returned to baseline, a standard immunosuppressive regime was started with cessation of ATG. We compared the total and daily ATG dosages, administration period, side effects, number of days to a serum creatinine ⬍2 mg/dL, graft function at 3 months, acute rejection episodes and infection rates, costs of CD3⫹ analysis and amounts of ATG.
RESULTS
The groups showed similar gender, age, and human leukocyte antigen (HLA) matching data. There was no significant difference with in presensitizing events or panel-reactive antibody (PRA) class 1 and 2 levels (Table 1). The number of days for the serum creatinine to decrease ⬍2 mg/dL was 11 ⫾ 1.5 days for group 1 and 10.4 ⫾ 0.8 for group 2 (P ⫽ .45). Multivariate analysis showed no impact of PRA positivity (⬎20%) or presensitization events on graft survival or ATG dosage. ATG was administered for 10.4 ⫾ 0.8 versus
8.6 ⫾ 1.14 days for groups 1 and 2, respectively (P ⫽ .365). There was a significant difference between mean total ATG dosages between group 1 (620 ⫾ 114 mg) and group 2 (445 ⫾ 112 mg; P ⫽ .031). The difference of mean daily ATG dosages was significant (0.93 ⫾ 0.13 vs 0.69 ⫾ 0.07 mg/kg per day; P ⫽ .006; Table 2). There was no acute rejection episode during the first 3 post-transplant months. One patient in group 1 displayed a urinary infection. Figure 1 shows a labile total lymphocyte count in group 1 compared with group 2, indicating that ATG doses were changed more often among group 1. Group 2 showed less manipulation of the administered ATG dose; there was a stable cell count response (Fig 1). We used as a total of 3800 mg ATG for group 1 and 2200 mg for group 2. Group 2 have 43 CD3 cell count analyses. The expenditure per patient was 20% higher among group 1 versus group 2. Wide use of ATG during the post-transplant period can result in overimmunosuppression and costly therapy. Studies by Cosimi et al and by Thomas et al sought the number of lymphocytes to be ⬍10% of the pretreatment value; other studies have set the T-cell counts at 100/mL, 50/mL, or 10/mL.5– 8 These differences may be owing to unique study designs or type of globulin, as stated by Djamali et al. In our study, we considered a reliable T-cell threshold to skip an ATG dose as 150 –50/mL and total lymphocyte count as 300/mL.9 Neither of our groups displayed a viral infections or an acute rejection episode in the early post-transplant period. The cutoff levels of cell counts to assessing ATG effectiveness cannot be evaluated. The lymphocte count group had intermittent higher ATG doses compared with the CD3⫹ cell count group. The trends did not correlated between total lymphocyte and CD3⫹ counts. We were not able to finely tune the accurate ATG dose by the lymphocyte count. Also, there were more dose interventions and manipulations of ATG dose among the lymphocyte count group. Although it did not achieve significance, group 2 patients started graft function earlier. In conclusion, our study demonstrated that peripheral CD3 monitoring of ATG therapy was useful and cost effective in renal transplant patients. CD3 monitoring resulted in the administration of 45% less ATG and overall a 20% cost
Table 2. Comparison of ATG Daily and Cumulative Doses
Cumulative ATG dose (mg) Daily ATG dose (mg/kg per day) No. of days ATG administered
Group 1: Lymphocyte Count
Group 2: CD3-Positive Cell Count
P
620 ⫾ 114
445 ⫾ 112
.003
0.93 ⫾ 0.13
0.69 ⫾ 0.07
.006
10.4 ⫾ 0.8
8.6 ⫾ 1.14
.365
Abbreviation: ATG, antithymocyte globulin.
ATG INDUCTION AND CD3⫹ T-CELL COUNT
Fig 1.
931
Total lymphocyte (left) and CD3-positive T-cell (right) counts of groups 1 and 2.
savings. CD3-positive T-cell counts were suitable, reliable, and cost-effective to monitor administered ATG dose.
REFERENCES 1. Kirk AD. Induction immunosuppression. Transplantation. 2006;82:593– 602. 2. Mueller TF. Mechanisms of action of thymoglobulin. Transplantation. 2007;84:S5–S10. 3. Djamali A, Turc-Baron C, Portales P, et al. Low dose antithymocyte globulins in renal transplantation: daily versus intermittent administration based on T cell monitoring. Transplantation. 2000;69:799 – 805. 4. Haudebourg T, Pirier N, Vanhove B. Depleting T-cell subpopulations in organ transplantation. Transplant International. 2009;22:509 –518.
5. Krasinskas AM, Kreisel D, Acker MA, et al. CD3 monitoring of antithymocyte globulin theraphy in thoracic organ transplantation. Transplantation. 2002;73:1339 –1341. 6. Abouna GM, Al-Abdullah IH, Kelly-Sullivan D, et al. Randomized clinical trial of antithymocyte globulin induction in renal transplantation comparing a fixed daily dose with dose adjustment according to T cell monitoring. Transplantation. 1995;59:1564 –1568. 7. Thomas FT, Griesedieck C, Thomas J, et al. Differential effects of horse ATG and rabbit ATG on T cell and T cell subset levels measured by monoclonal antibodies. Transplant Proc. 1984; 16:1561–1563. 8. Clark KR, Forsythe JL, Shenton BK, et al. Administration of ATG according to the absolute T lymphocyte count during therapy for steroid-resistant rejection. Transpl Int. 1993;6:18 –21. 9. Kuo HT, Huang E, Emami S, et al. Effects of antibody induction on transplant outcomes in human leukocyte antigen zero-mismatch deceased donor kidney recipients. Transplantation. 2012;93:493–502.
I
© 2013 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710 Transplantation Proceedings, 45, 929 –931 (2013)
introduction of calcineurin inhibitors was delayed to avoid drug nephrotoxicity post-transplantation. Although important benefits were achieved, the use of antibody therapies in renal transplantation was often associated with increased treatment costs and excessive immunosuppression, resulting in hematologic, infectious, and neoplastic complications.3 Polyclonal antibodies display a long half-life inducing long-term depletion of lymphocytes. Therefore, they are used at low or variable doses according to their biologic
From the Department of Transplantation and 1st General Surgery, Haydarpasa Numune Hospital, Istanbul, Turkey. Address reprint requests to P. Ata, Department of 1st Surgery, Haydarpasa Numune Hospital, Istanbul, Turkey. E-mail: pinaren@ gmail.com 0041-1345/–see front matter http://dx.doi.org/10.1016/j.transproceed.2013.02.092 929
930
ATA, KARA, ÖZDEMIR ET AL Table 1. Demographic Data
Age (yrs) Gender, F/M HLA match with donor for 6 HLA loci PRA levels (no. of patients having PRA ⬎ 20%) Class 1 Class 2 Sensitizing events (patient number with sensitizing event) Prior transplantation Blood transfusion Pregnancy
Group 1 (n ⫽ 11)
Group 2 (n ⫽ 10)
P
43.6 ⫾ 4 3/8 2.67 ⫾ 1.2
37 ⫾ 3.8 4/6 2.4 ⫾ 1.4
.265 .231 .983
4 2
2 4
.167 .289
3 3 1
2 4 2
.654 .378 .496
Abbreviations: HLA, human leukocyte antigen; PRA, panel-reactive antibody.
effects on T cells.3,4 Herein we sought to examine whether ATG could be monitored according to CD3-positive T versus total lymphocyte counts and what the effects of the modality were on costs and clinical outcomes of renal transplant patients. MATERIALS AND METHODS Twenty-one first cadaveric donor transplant recipients between January 2009 and January 2012 received an 1 mg/kg ATG initial dose at the time of their operation. Patients were randomized as group 1 (n ⫽ 11) where subsequent ATG doses were administered according to clinical criteria and total lymphocyte counts, whereas group 2 (n ⫽ 10) had ATG doses tailored according to the CD3⫹ cell count. For group 1, if the lymphocyte count was ⬍300/mL, the ATG dose was skipped for that day. For group 2, if the CD3⫹ cell count was between 150 and 50/mL, half of the calculated dose was administered, and if ⬍50/mL, it was not prescribed on that day. When group 1 subjects showed lymphocyte counts ⬍300 cells/L, the ATG was stopped for 9 times. Whereas in group 2 only one patient had ATG therapy cessation twice during her treatment schedule. When the serum creatinine level has returned to baseline, a standard immunosuppressive regime was started with cessation of ATG. We compared the total and daily ATG dosages, administration period, side effects, number of days to a serum creatinine ⬍2 mg/dL, graft function at 3 months, acute rejection episodes and infection rates, costs of CD3⫹ analysis and amounts of ATG.
RESULTS
The groups showed similar gender, age, and human leukocyte antigen (HLA) matching data. There was no significant difference with in presensitizing events or panel-reactive antibody (PRA) class 1 and 2 levels (Table 1). The number of days for the serum creatinine to decrease ⬍2 mg/dL was 11 ⫾ 1.5 days for group 1 and 10.4 ⫾ 0.8 for group 2 (P ⫽ .45). Multivariate analysis showed no impact of PRA positivity (⬎20%) or presensitization events on graft survival or ATG dosage. ATG was administered for 10.4 ⫾ 0.8 versus
8.6 ⫾ 1.14 days for groups 1 and 2, respectively (P ⫽ .365). There was a significant difference between mean total ATG dosages between group 1 (620 ⫾ 114 mg) and group 2 (445 ⫾ 112 mg; P ⫽ .031). The difference of mean daily ATG dosages was significant (0.93 ⫾ 0.13 vs 0.69 ⫾ 0.07 mg/kg per day; P ⫽ .006; Table 2). There was no acute rejection episode during the first 3 post-transplant months. One patient in group 1 displayed a urinary infection. Figure 1 shows a labile total lymphocyte count in group 1 compared with group 2, indicating that ATG doses were changed more often among group 1. Group 2 showed less manipulation of the administered ATG dose; there was a stable cell count response (Fig 1). We used as a total of 3800 mg ATG for group 1 and 2200 mg for group 2. Group 2 have 43 CD3 cell count analyses. The expenditure per patient was 20% higher among group 1 versus group 2. Wide use of ATG during the post-transplant period can result in overimmunosuppression and costly therapy. Studies by Cosimi et al and by Thomas et al sought the number of lymphocytes to be ⬍10% of the pretreatment value; other studies have set the T-cell counts at 100/mL, 50/mL, or 10/mL.5– 8 These differences may be owing to unique study designs or type of globulin, as stated by Djamali et al. In our study, we considered a reliable T-cell threshold to skip an ATG dose as 150 –50/mL and total lymphocyte count as 300/mL.9 Neither of our groups displayed a viral infections or an acute rejection episode in the early post-transplant period. The cutoff levels of cell counts to assessing ATG effectiveness cannot be evaluated. The lymphocte count group had intermittent higher ATG doses compared with the CD3⫹ cell count group. The trends did not correlated between total lymphocyte and CD3⫹ counts. We were not able to finely tune the accurate ATG dose by the lymphocyte count. Also, there were more dose interventions and manipulations of ATG dose among the lymphocyte count group. Although it did not achieve significance, group 2 patients started graft function earlier. In conclusion, our study demonstrated that peripheral CD3 monitoring of ATG therapy was useful and cost effective in renal transplant patients. CD3 monitoring resulted in the administration of 45% less ATG and overall a 20% cost
Table 2. Comparison of ATG Daily and Cumulative Doses
Cumulative ATG dose (mg) Daily ATG dose (mg/kg per day) No. of days ATG administered
Group 1: Lymphocyte Count
Group 2: CD3-Positive Cell Count
P
620 ⫾ 114
445 ⫾ 112
.003
0.93 ⫾ 0.13
0.69 ⫾ 0.07
.006
10.4 ⫾ 0.8
8.6 ⫾ 1.14
.365
Abbreviation: ATG, antithymocyte globulin.
ATG INDUCTION AND CD3⫹ T-CELL COUNT
Fig 1.
931
Total lymphocyte (left) and CD3-positive T-cell (right) counts of groups 1 and 2.
savings. CD3-positive T-cell counts were suitable, reliable, and cost-effective to monitor administered ATG dose.
REFERENCES 1. Kirk AD. Induction immunosuppression. Transplantation. 2006;82:593– 602. 2. Mueller TF. Mechanisms of action of thymoglobulin. Transplantation. 2007;84:S5–S10. 3. Djamali A, Turc-Baron C, Portales P, et al. Low dose antithymocyte globulins in renal transplantation: daily versus intermittent administration based on T cell monitoring. Transplantation. 2000;69:799 – 805. 4. Haudebourg T, Pirier N, Vanhove B. Depleting T-cell subpopulations in organ transplantation. Transplant International. 2009;22:509 –518.
5. Krasinskas AM, Kreisel D, Acker MA, et al. CD3 monitoring of antithymocyte globulin theraphy in thoracic organ transplantation. Transplantation. 2002;73:1339 –1341. 6. Abouna GM, Al-Abdullah IH, Kelly-Sullivan D, et al. Randomized clinical trial of antithymocyte globulin induction in renal transplantation comparing a fixed daily dose with dose adjustment according to T cell monitoring. Transplantation. 1995;59:1564 –1568. 7. Thomas FT, Griesedieck C, Thomas J, et al. Differential effects of horse ATG and rabbit ATG on T cell and T cell subset levels measured by monoclonal antibodies. Transplant Proc. 1984; 16:1561–1563. 8. Clark KR, Forsythe JL, Shenton BK, et al. Administration of ATG according to the absolute T lymphocyte count during therapy for steroid-resistant rejection. Transpl Int. 1993;6:18 –21. 9. Kuo HT, Huang E, Emami S, et al. Effects of antibody induction on transplant outcomes in human leukocyte antigen zero-mismatch deceased donor kidney recipients. Transplantation. 2012;93:493–502.