Antithymocyte Globulin Therapy Research Articles

Diagnosis and therapy of neutropenia in large granular lymphocyte leukemia

T-cell large granular lymphocyte leukemia is a chronic clonal lymphoproliferation of cytotoxic T cells often associated with immune-mediated cytopenias. The pathophysiology of cytopenias includes cytokine effects and direct antigen-specific cytotoxicity to hematopoietic precursors. This review will address the diagnostic challenges of and therapeutic options for T-cell large granular lymphocyte leukemia. Immunosuppressive therapy, with cyclosporine, methotrexate, and oral cyclophosphamide, is often used, but formal trials have not been performed and response rates are poorly established. In refractory cases, alternative regimens such as antithymocyte globulin or monoclonal antibody therapy have exhibited hematologic response. T-cell large granular lymphocyte leukemia may assume an indolent course but sometimes manifests with significant cytopenias. A majority of patients will ultimately require immunosuppressive therapy due to symptomatic neutropenia or anemia. In these cases, a variety of agents maybe used successfully though chronic therapy is often necessary.

Acute Lung Injury during Antithymocyte Globulin Therapy for Aplastic Anemia

The case of a 33-year-old man with aplastic anemia who experienced recurrent episodes of hypoxemia and pulmonary infiltrates during infusions of antithymocyte globulin (ATG) is described. With the use of high-dose corticosteroids, the patient's original episodes resolved, and were subsequently prevented before additional administrations of ATG. Rare reports of an association between ATG and acute lung injury are found in the literature, but this is the first report of successful steroid-supported re-exposure. Although the mechanism of ATG-related acute lung injury remains uncertain, it may be parallel to the mechanism of transfusion-related acute lung injury because the pathogenesis of the latter relies, in part, on antileukocyte antibodies. ATG-related toxicity should be included in the differential diagnosis of new, infusion-associated pulmonary infiltrates, and corticosteroids may be a useful therapeutic consideration in the management.

Efficacy of a Negative Conversion Trial and Subsequent Living Donor Kidney Transplant Outcome in Recipients with a Positive Lymphocyte Crossmatch

Background: Patients with a positive lymphocyte crossmatch (LCX) do not undergo kidney transplantation. In such patients, a negative conversion protocol consisting of intravenous immunoglobulin (IVIG), plasmapheresis, and potent immunosuppressant is one of the options for transplantation. Methods: 14 patients who showed a positive LCX with living donors underwent a trial of negative conversion between January 2002 and July 2007. Plasmapheresis was performed every other day, up to 6 times maximum. IVIG was infused after plasmapheresis, with a total dose of 500 mg/kg divided over 6 days. Kidney transplantation was performed immediately after negative conversion. Anti-thymocyte globulin (ATG) or OKT3 induction therapy was used with the combination of tacrolimus, mycophenolate mofetil, and prednisone in the perioperative period. Results: Negative conversion of LCX was achieved in 13 of 14 patients (92.9%). Transplantations were performed successfully in these 13 patients without hyperacute rejection. Four recipients developed acute rejection, which was well controlled by steroid pulse therapy. During the follow-up periods of 45.4 ± 22.0 months, all recipients except 1 showed excellent graft function. Conclusion: Selected patients with a positive LCX can undergo successful transplantation using plasmapheresis, IVIG, and potent immunosuppressants. Recipients with negative conversion of LCX showed acceptable posttransplant results.

Autoantibodies Specific to hnRNP K: A New Diagnostic Marker for Immune Pathophysiology in Bone Marrow Failure Syndromes.

The pathophysiology of bone marrow failure syndromes (BMS) such as aplastic anemia (AA) and refractory anemia (RA) of myelodysplastic syndromes defined by the FAB classification involves immune mediated bone marrow injury and intrinsic defects of hematopoietic stem cells. The diagnosis of the immune pathophysiology is essential in providing the optimal treatment to patients with BMS. In order to identify a new diagnostic marker for the immune pathophysiology of BMS, the sera of AA patients characterized by the presence of small populations of paroxysmal nocturnal hemoglobinuria-type (PNH) cells were screened for the presence of antibodies (Abs) recognizing proteins derived from a megakaryocytic leukemia cell line, UT-7. Two-dimensional electrophoresis of UT-7 lysates followed by immunoblotting revealed a distinct spot of 65 kDa. Peptide mass fingerprinting identified this protein as a heterogeneous nuclear ribonucleoprotein (hnRNP) K. Although hnRNP K is known to be ubiquitously expressed, the expression levels based on a Western blotting analysis were greater in several leukemia cell lines such as UT-7, K562 and OUN-1 in comparison to peripheral blood mononuclear cells. When the sera of newly diagnosed 87 BMS patients (62 with AA and 25 with RA) were examined for the presence of anti-hnRNP K Abs using an enzyme-linked immunosorbent assay (ELISA) with recombinant hnRNP K protein, significantly higher titers of anti-hnRNP K Abs were detected in 13 (34%, 10 with AA and 3 with RA) of 38 patients with BMS displaying increased PNH-type cells (PNH+) and in 15 (31%, 8 with AA and 7 with RA) of 49 patients without increased PNH-type cells. The presence of hnRNP K Abs was significantly correlated with the presence of anti-diazepam-binding inhibitor-related protein-1 (DRS-1) Abs (r=0.7206) and anti-moesin Abs (r=0.8318). Of the 87 patients, 49 patients (39 with AA and 10 with RA) received antithymocyte globulin plus cyclosporine therapy after the Ab screening. All of the 22 patients with high anti-hnRNP K Ab titers responded to therapy while 10 (37%) of 27 patients without the high titer Abs responded (P < 0.005). When the three Ab titers were assessed, the response rate to immunosuppressive therapy in patients showing high titers in at least one Ab was 96%, while the response rate in patients not showing high titers in any of the auto-Abs was 39% (P < 0.005). These findings suggest that in patients with immune mediated BMS, a breakdown of immune tolerance to multiple self antigens including hnRNP K may take place and that the detection of these auto-Abs may help diagnose the immune pathophysiology of BMS.

Prolonged Insulin Independence After Islet Allotransplants in Recipients with Type 1 Diabetes

We sought to determine the long-term outcomes in type 1 diabetic recipients of intraportal alloislet transplants on a modified immunosuppressive protocol. Six recipients with hypoglycemia unawareness received one to two islet infusions. Induction therapy was with antithymocyte globulin (ATG) plus etanercept for tumor necrosis factor-alpha blockade. Recipients received cyclosporine and everolimus for maintenance immunosuppression for the first year posttransplant, with mycophenolic acid or mycophenolate mofetil subsequently substituted for everolimus. Recipients have been followed for 1173 +/- 270 days since their last infusion for islet graft function (insulin independence, hemoglobin A(1c) levels and C-peptide production) and for adverse events associated with the study protocol. Of the six recipients, five were insulin-independent at 1 year, and four continue to be insulin-independent at a mean of 3.4 +/- 0.4 years posttransplant. None of the six recipients experienced recurrence of severe hypoglycemia. Measured glomerular filtration rate decreased from 110.5 +/- 21.2 mL/min/1.73 m(2) pretransplant to 82.6 +/-19.1 mL/min/1.73 m(2) at 1 year posttransplant. In conclusion, islet transplants restored insulin independence for a mean of >3 years in four of six recipients treated with ATG and etanercept induction therapy and with cyclosporine and, initially, everolimus for maintenance. Our results suggest this immunosuppressive protocol may allow long-term graft survival.

Antithymocyte globulin therapy for steroid‐resistant acute graft versus host disease

Antithymocyte globulin therapy for steroid‐resistant acute graft versus host disease

Intragraft Coagulation Events and Delayed Graft Function in Clinical Renal Transplantation

Cold preservation, reperfusion damage, immunosuppressive drugs, and uremia-induced acquired thrombophilias increase the risk of thrombotic complications in renal transplantation. Intragraft fibrin deposition may be associated with delayed graft function. We studied coagulation and fibrinolysis in 45 patients of a larger trial in renal transplantation: perioperative antithymocyte globulin (group A, n=15), perioperative basiliximab (group B, n=16), and conventional triple therapy (group C, n=14). Blood samples for prothrombin fragment F1+2, plasminogen activator inhibitor (PAI)-1, d-dimer, tPA antigen, tPA activity, and platelet counts were obtained simultaneously at 1 and 5 min after reperfusion from iliac artery and graft vein for calculation of transrenal changes. Because antithymocyte globulin activates coagulation and fibrinolysis, group A was analyzed separately. Groups B and C were pooled (group BC). In group BC, transrenal D-dimer release occurred at 1 min, tPA-antigen release at 1 and 5 min, and transrenal PAI-1 uptake at 5 min postreperfusion. tPA activity increased marginally only at 1 min. High graft tPA-antigen release at 5 min and D-dimer release at 1 min were associated with delayed graft function. In group A, transrenal tPA-antigen release occurred at 1 and 5 min and D-dimer release at 1 min. There were no transrenal F1+2 changes in either group. Although graft PAI-1 uptake inhibits tPA activity, graft releases D-dimer at early reperfusion without concomitant F1+2 release. Data suggest thrombin and fibrin formation already before cold preservation during donor care and organ retrieval. This fibrin deposition increases risk of delayed graft function.

The status of antithymocyte globulin therapy for adult patients in Japan: retrospective analysis of a nationwide survey

We conducted a nationwide survey on antithymocyte globulin (ATG) therapy for adult patients in Japan. We mailed questionnaires to 454 hospitals with hematology divisions, of which 181 (40%) responded, and the records of 448 patients were collected. Patient characteristics, hematological responses, and adverse effects were evaluated in 421 patients with sufficient data. A total of 366 patients had idiopathic aplastic anemia (AA), 29 had other types of AA, and 25 had other diseases. The response rate (RR) at 6 months was 54% for all patients, and 53% for those with idiopathic AA. Ten patients (2%) died within 30 days, and 11 (3%) died between 31 and 100 days after ATG therapy. In 346 patients with moderate to very severe AA, who received their first ATG therapy, factors that influence the outcomes of ATG therapy were extracted. Among 11 pre-treatment and therapy-related variables, three were found to be correlated with a higher RR: shorter duration of AA, no history of specific therapy for AA, and the use of CsA. Most notably, the RR of patients treated within 3 months of diagnosis, those between 3 months and 2 years, and those later than 2 years were 68% (130/190), 48% (54/113), and 13% (5/38), respectively.

Murine Antithymocyte Globulin Therapy Alters Disease Progression in NOD Mice by a Time-Dependent Induction of Immunoregulation

Antilymphocyte serum can reverse overt type 1 diabetes in NOD mice; yet, the therapeutic parameters and immunological mechanisms underlying the ability for this agent to modulate autoimmune responses against beta-cells are unclear, forming the rationale for this investigation. A form of antilymphocyte serum, rabbit anti-mouse thymocyte globulin (mATG), was utilized in a variety of in vivo and in vitro settings, each for the purpose of defining the physiological, immunological, and metabolic activities of this agent, with particular focus on actions influencing development of type 1 diabetes. We observed that mATG attenuates type 1 diabetes development in an age-dependent fashion, only proving efficacious at disease onset or in the late pre-diabetic phase (12 weeks of age). When provided at 12 weeks of age, mATG reversed pancreatic insulitis, improved metabolic responses to glucose challenge, and rapidly increased frequency of antigen-presenting cells in spleen and pancreatic lymph nodes. Surprisingly, mATG therapy dramatically increased, in an age-dependent fashion, the frequency and the functional activity of CD4(+)CD25(+) regulatory T-cells. Adoptive transfer/cotransfer studies of type 1 diabetes also support the concept that mATG treatment induces a stable and transferable immunomodulatory repertoire in vivo. These findings indicate that an induction of immunoregulation, rather than simple lymphocyte depletion, contributes to the therapeutic efficacy of antithymocyte globulin and suggest that time-dependent windows for the ability to delay or reverse type 1 diabetes exist based on the capacity to enhance the functional activity of regulatory T-cells.

Polyclonal Antibody-Induced Serum Sickness Presenting as Rapidly Progressive Descending Paralysis

Polyclonal antibody-induced serum sickness is an immune-complex mediated illness that is commonly manifested as fever, arthralgias, arthritis, lymphadenopathy, with or without renal failure. To our knowledge, an associated rapidly progressive descending paralysis has never been documented. We report a case of a living related renal transplant recipient who presented with serum sickness 1 week after the completion of a 7-day course of rabbit antithymocyte globulin (thymoglobulin at a dose of 1.5 mg/kg/day) for presumed severe acute cellular rejection due to inadvertent discontinuation of tacrolimus immunosuppression. As the patient was taking daily aspirin at the time, a biopsy was not performed. On exam, she was found to have a swollen and tender graft. Her serum creatinine peaked at 2.9 mg/dl and returned to her baseline at 1.3 mg/dl after thymoglobulin therapy. At one week after discharge, however, the patient presented with polyarticular arthralgias, myalgias, back pain, trismus, severe muscle weakness and descending paralysis that progressed within a matter of hours. She also developed a generalized pruritic skin rash that resolved with self-medicated diphenhydramine. On exam, she was noted to have severe joint tenderness at the knees, ankles, shoulders, wrists, and mandible. Neurological assessment revealed bilateral proximal greater than distal weakness, hyperreflexia, and ankle clonus. A clinical diagnosis of thymoglobulin-induced serum sickness was entertained although the neurological findings also raised the possibility of central nervous system pathology, and/or inflammatory myopathies. Chemistry panel revealed a slight increase in serum creatinine to 1.5 mg/dl. Due to her debilitating symptoms, therapeutic plasmapheresis (TPE) was initiated the day of admission pending further evaluation with brain magnetic resonance imaging, cervical spine, and appropriate serologic testing. The patient had immediate relief of her joint pain during plasmapheresis, and more interestingly, drastic improvement of her extremity weakness by the end of the session. She received a second course of plasmapheresis on hospital day 2 due to residual extremity “discomfort” and had complete resolution of her symptoms. Her serum creatinine decreased to 1.1 mg/dl. At 1 week follow-up, the patient reported doing well and had returned to her routine daily activities. The use of TPE in the treatment of serum sickness after antithymocyte globulin therapy has been well reported (1–3). Compared to pulse steroid or analgesics, TPE accelerates the time to recovery (10–14 days vs. 24–48 hr, respectively) (1–3). To our knowledge, this is the first case report of thymoglobulin-induced serum sickness presenting as descending paralysis. Phuong-Thu T. Pham Division of Nephrology, Kidney, and Pancreas Transplantation David Geffen School of Medicine at UCLA Los Angeles, CA Phuong-Mai Pham Department of Medicine Central Maine Medical Center Lewiston, ME Jeffrey M. Miller Division of Hematology/Oncology Olive View UCLA Medical Center Sylmar, CA Phuong-Chi T. Pham Division of Nephrology, Olive View UCLA Medical Center Sylmar, CA

Effect of Induction Therapy on Kinetic of Procalcitonin Following Uncomplicated Heart Transplantation

The aim of the study was to determine the early postoperative kinetics of serum procalcitonin (PCT) levels in uncomplicated heart transplant patients under induction therapy using antithymocyte globulin (ATG). PCT serum concentrations were measured for 7 days in 30 adult patients (26 males, 4 females, mean age 54.5 +/- 7.7 years) undergoing uncomplicated orthotopic heart transplantation. Of the 30 patients, 28 received ATG and 2 with the same immunosuppression regimen had no induction therapy. The induction therapy consisted of 100 mg/day ATG and was started 6 hours postoperatively. Mean PCT levels immediately before HTX were <0.3 ng/mL in both groups. After the first ATG infusion patients developed a significant (p < 0.05) elevation in PCT plasma levels without any incidence of infectious disease with peak levels up to 11.7 +/- 19.7 ng/mL on postoperative day (POD) 1. Thereafter values continuously decreased independently of further ATG administration in all patients (6.7 +/- 10.5 ng/mL on POD 3, 3.2 +/- 7.4 ng/mL on POD 5 and 1.2 +/- 3.0 ng/mL on POD 7). In the non-ATG group a mild postoperative rise in the serum PCT was observed. The values peaked on POD 2 with 2.0 +/- 1.6 ng/mL and normalized within four days. Perioperative administration of ATG is associated with significantly increased PCT levels even in uncomplicated heart transplant recipients. This phenomenon should not be misinterpreted as systemic infection, as systemic inflammatory reaction that seems to be induced by ATG therapy is responsible for increased PCT production.

Urgent liver transplantation for acute liver failure due to parvovirus B19 infection complicated by primary Epstein–Barr virus and cytomegalovirus infections and aplastic anaemia

An 11-year-old boy presented with hepatic failure secondary to parvovirus B19 infection, requiring urgent liver transplantation. His recovery was complicated by primary Epstein-Barr virus and cytomegalovirus infections. He subsequently developed aplastic anaemia that has been refractory to antithymocyte globulin and cyclosporine therapy and may now require bone marrow transplantation. We present this case to emphasize parvovirus as a rare cause of hepatic failure and of aplastic anaemia as a complication of the virus.

Immunosuppressive treatment strategies in low-risk MDS

<h2>Summary</h2> Ineffective haematopoiesis with peripheral cytopenias despite normo- or hypercellular bone marrow is the hallmark of the myelodysplastic syndromes especially in the low-risk subgroups. It is caused by increased secretion of inhibitory cytokines in the marrow through a yet unresolved pathophysiological mechanism. Immunoinhibitory or modulatory therapy aims at restoring haematopoiesis by reversing these inhibitory processes and includes antithymocyte globulin (ATG), ciclosporin A (CSA), direct TNF-inhibitors and lenalidomide. Although not yet approved for clinical use, ATG therapy improves mono-, bi- and trilineage cytopenias in around 35–40% of low-risk MDS patients usually after a single treatment course. Highest response rates are seen in younger patients, those with a shorter duration of the disease and low transfusion requirement, with hypocellular bone marrow or with thrombocytopenia. The presence of the HLA-DR15 (DR2) genotype is an additional parameter predicting a response. In contrast, differentiation defects with an increased blast cell percentage or sideroachrestic changes characterize the poor responders. A simple scoring system, using age, duration of transfusion dependency, and HLA-DR15 status, has been developed and allows identifying patients with a high, intermediate, or low probability of response to treatment with ATG. Other immunosuppressive agents which can also induce responses, e.g. CSA, have been combined with ATG, but have not yet been fully evaluated for their potential role in the treatment of MDS. Lenalidomide has a superior efficacy in the 5q-syndrome, but also some efficacy in the other low-risk MDS patients. Further clinical trials are needed to define the potential of immunosuppressive/modulatory treatment in MDS.

Roles of DRB1 ∗1501 and DRB1 ∗1502 in the pathogenesis of aplastic anemia

Although a number of reports have documented a significantly increased incidence of HLA-DR15 in aplastic anemia (AA), the exact role of HLA-DR15 in the immune mechanisms of AA remains unclear. We herein clarify the difference between DRB1( *)1501 and DRB1( *)1502, the two DRB1 alleles that determine the presentation of HLA-DR15, in the pathophysiology of AA. We investigated the relationships of the patients( *) HLA-DRB1 allele with both the presence of a small population of CD55(-)CD59(-) (PNH-type) blood cells and the response to antithymocyte globulin (ATG) plus cyclosporin (CsA) therapy in 140 Japanese AA patients. Of the 30 different DRB1 alleles, only DRB1( *)1501 (33.6% vs 12.8%, p(c) < 0.01) and DRB1( *)1502 (43.6% vs 24.4%, p(c) < 0.01) displayed significantly higher frequencies among the AA patients than among a control. AA patients possessing HLA-DR15 tended to be old, and especially, the frequency of DRB1( *)1502 in patients 40 years of age and older (52.4%) was markedly higher than that in those younger than 40 years old (16.2%, p(c) < 0.01). Only DRB1( *)1501 was significantly associated with the presence of a small population of PNH-type cells and it also showed a good response to ATG plus CsA therapy in a univariate analysis. A multivariate analysis showed only the presence of a small population of PNH-type cells to be a significant factor associated with a good response to the immunosuppressive therapy (p < 0.01). Although both DRB1( *)1501 and DRB1( *)1502 contribute to the development of AA, the methods of contribution differ between the two alleles.

Roles of HLA-DR15 Alleles in the Pathogenesis of Acquired Aplastic Anemia (AA): DRB1*1502 Is in Linkages Disequilibrium with Unique Genes Which Determine Susceptibility to AA.

It is well known that HLA-DRB1 alleles corresponding to HLA-DR15 such as DRB1*1501 and DRB1*1502 are associated with susceptibility to acquired aplastic anemia (AA) and paroxysmal nocturnal hemoglobinuria (PNH). However, little is known about how these DRB1 alleles contribute to the development of AA. We previously reported that DRB1*1501 is significantly associated with both an increase in the proportion of PNH-type cells and good response to a immunosuppressive therapy (IST) including antithymocyte globulin (ATG) plus cyslosporine (CsA) or CsA alone, while DRB1*1502, whose DR molecules differ from those derived from DRB1*1501 in only one amino acid, is not associated with either of the two factors. To gain insight into the reason for different contributions to the development of AA by the two DRB1 alleles, we determined DRB1 alleles and the proportion of PNH-type cells of 77 patients with recently diagnosed AA and analyzed the relationship of DRB1 alleles and the presence of increased PNH-type cells with response to ATG plus CsA therapy. Fifty-five of 77 patients (71%) improved with ATG plus CsA therapy. When the factors favorably affecting the response to IST in the AA patients were examined under a multivariate analysis, only the presence of PNH-type cells was significantly associated with the response to IST. Kaplan-Meier curves showed that there were significant differences in the probability of the response to IST between the DRB1*1501 + 1502 − patients and either the DRB1*1501 − 1502 + patients (P <0.01) or the DR15- patients (P =0.01). However, these differences in the probability of response to IST were no longer observed when the probability of response was compared in either the PNH + patients or the PNH − patients (Figure). Although DRB1*1502 was not associated with a good response to IST, the markedly high frequency of the allele in patients aged over 40 (52%) prompted us to study genes in linkage disequilibrium with DRB1*1502 which may determine susceptibility to AA. We compared the frequencies of 30 microsatellite marker alleles on chromosome 6 among three different groups of individuals possessing DRB1*1502 which include 18 PNH + AA patients, 13 PNH − AA patients, and 29 healthy individuals. There were no significant differences in the frequency of any of the polymorphic makers between PNH + AA patients and healthy individuals. On the other hand, one of the microsatellite maker alleles (C1-3-1) in close proximity to HLA-C locus was found at a significantly higher (Pc =0.01) frequency in PNH − AA patients than in PNH + AA patients and healthy individuals. These data suggest that DRB1*1501 contributes to development of AA via immune mechanisms leading to an increase in the proportion of PNH-type cells while DRB1*1502 is involved in the pathogenesis of AA by way of other genes in linkage disequilibrium with this DRB1 allele. [Display omitted]

The Incidence of Acute Cellular Rejection After Lung Transplantation: A Comparative Study of Anti-thymocyte Globulin and Daclizumab

This study examined the effects of anti-thymocyte globulin (ATG) and daclizumab immunosuppressive induction therapy on the frequency and severity of acute cellular rejection in lung transplantation patients. A retrospective analysis was conducted of 335 lung transplantation patients from a single center in the period 1992 to 2003. Patients completed standard ATG (Merieux, 2.5 mg/kg/day, or ATGAM, 12.5 mg/kg/day, for 3 consecutive days) (n = 151) or daclizumab (5 fortnightly treatments at a dose of 1 mg/kg) (n = 151) induction therapy. End points included acute cellular rejection requiring treatment (> or = A2), and moderate/severe acute cellular rejection (A3/A4). The percentage of patients free of rejection requiring treatment (< A2) was 32% at 3 months and 26% at 2 years after transplantation in the ATG group and 9% and 0%, respectively, in the daclizumab group (p < 0.0001). Compared with the ATG group, a significantly higher proportion of patients in the daclizumab group experienced 3 or more episodes of acute cellular rejection > or = A2 during the first 3 months (p < 0.0001) and the entire 2-year follow-up (p < 0.0001). The daclizumab group also experienced more moderate/severe acute cellular rejection episodes compared with the ATG group during the first 3 months (p = 0.005). Cox regression analysis demonstrated ATG induction therapy was independently associated with a significantly longer duration of freedom from acute cellular rejection requiring treatment (> or = A2) (p < 0.001). After lung transplantation, ATG induction appears to be superior to daclizumab induction in the reduction in the incidence and severity of acute cellular rejection.

Choice of Antibody Immunotherapy Influences Cytomegalovirus Viremia in Simultaneous Pancreas-Kidney Transplant Recipients

Simultaneous pancreas-kidney (SPK) transplantation in type 1 diabetic patients requires immunotherapy against allo- and autoreactive T-cells. Cytomegalovirus (CMV) infection is a major cause for morbidity after transplantation and is possibly related to recurrent autoimmunity. In this study, we assessed the pattern of CMV viremia in SPK transplant recipients receiving either antithymocyte globulin (ATG) or anti-CD25 (daclizumab) immunosuppressive induction therapy. We evaluated 36 SPK transplant recipients from a randomized cohort that received either ATG or daclizumab as induction therapy. Patients at risk for CMV infection received oral prophylactic ganciclovir therapy. The CMV DNA level in plasma was measured for at least 180 days using a quantitative real-time PCR. Recipient peripheral blood mononuclear cells were cross-sectionally HLA tetramer-stained for CMV-specific CD8(+) T-cells. Positive CMV serostatus in donors was correlated with a higher incidence of CMV viremia than negative serostatus. In patients at risk, daclizumab induction therapy significantly prolonged CMV-free survival. CMV viremia occurred earlier and was more severe in patients with rejection episodes than in patients without rejection episodes. CMV-specific CD8(+) T-cell counts were significantly lower in patients developing CMV viremia than in those who did not. Despite their comparable immunosuppressive potential, daclizumab is safer than ATG regarding CMV infection risk in SPK transplantation. ATG-treated rejection episodes are associated with earlier and more severe infection. Furthermore, high CMV-specific tetramer counts reflect antiviral immunity rather than concurrent viremia because they imply low viremic activity. These findings may prove valuable in the discussion on both safety of induction therapy and recurrent autoimmunity in SPK and islet transplantation.

Resistant pure red cell aplasia after allogeneic bone marrow transplantation with major ABO mismatch treated by purified CD34+ cell infusion

We report a case of pure red cell aplasia (PRCA) subsequent to an allogeneic bone marrow transplantation with a major ABO mismatch, which was resistant to the standard treatment options such as plasma exchange, erythropoietin and changes in the immunosuppressive treatment. Accordingly, two cycles of Rituximab therapy were administered without success. The patient had a chronic graft-vs.-host disease of the liver, which meant that an additional donor leukocyte infusion could not be introduced. Instead, purified CD34(+) cells were administered after fludarabine and antithymocyte globulin therapy. As a result, the PRCA was resolved and the antidonor isohemagglutinin titer became undetectable.

Bone Marrow Transplantation in Thalassemia Major Patients Using “Short” Anti-Thymocyte Globulin Therapy in Shiraz, Southern Iran

Allogeneic bone marrow transplantation (BMT) was performed on 113 Iranian transfusion-dependent thalassemia major patients from May 1993 through September 2003. To have at least 2 years follow-up, we report BMT on 90 patients transplanted up to December 2001. The donors were human leukocyte antigen (HLA)-identical, mixed lymphocyte culture (MLC)-nonreactive siblings ( n = 74) on parents ( n = 6); HLA-identical MLC-reactive siblings ( n = 5) or parents ( n = 1); and one HLA antigen-mismatched sibling ( n = 4). The induction regimen in 11 patients was oral busulfan (BU) (14 mg/kg) and IV cyclophosphamide (CY; 200 mg/kg); in fifteen patients it was BU (15 mg/kg) and cyclophosphamide (CY; 200 mg/kg); in 47 patients, BU (15 mg/kg), CY (200 mg/kg), and short course of anti-thymocyte globulin (ATG, horse; 40 mg/kg including 10 mg/kg on days −2, −1, +1, +2); and in 15 patients, BU (15 mg/kg) CY (200 mg/kg), and ATG (60 to 100 mg/kg; 10 mg/kg at 3 to 5 days before and after BMT). Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and prednisolone. The group who received BU (14 mg/kg) and CY (200 mg/kg), as compared to the group receiving BU (15 mg/kg) and CY (200 mg/kg), was of younger age and lower risk; median age 7 versus 10 years, and 46% versus 7% in Lucarelli’s risk group class I (the best prognostic group), respectively. These patients showed a lower disease-free survival (DFS), namely 64% versus 73%, with a follow up of 2 to 10.5 years. Thus from 9.5 years ago, our standard protocol for BU has been 15 mg/kg. The group who received “short” ATG (40 mg/kg), BU (15 mg/kg), and CY (200 mg/kg) showed almost the same outcome as the group who received a higher dose of ATG (60 to 100 mg/kg), namely DFS 72% versus 73%, respectively, despite the fact that half of both groups were included in the Lucarelli’s risk group class III (the worst prognostic group) 49% versus 53%. We showed the same DFS for the patients who received BU (15 mg/kg), CY (200 mg/kg), and no ATG compared with the ATG group (73% vs 72%), but 27% of the group without ATG developed grade IV acute GVHD and 54% developed chronic GVHD. In the group with short ATG, 15% and 17% of patients developed grade IV acute and chronic GVHD, respectively. There was no significant difference for falls in platelets and white blood cell or engraftment days and the number of packed red blood cell transfusions among the groups. The median hospital stay was longer for the group with BU (15 mg/kg), CY (200 mg/kg) namely 81 versus 61 to 65 days. Second bone marrow infusions were needed in 6% and 20% of patients who received ATG doses of (40 versus 60 to 100 mg/kg; respectively (1 to 2 month post-BMT). BU at a dose of 15 mg/kg was more effective than 14 mg/kg BU for its myeloablative properties. By adding “short” ATG course to the conditioning regimen, the incidence of grade IV acute and chronic GVHD was reduced in thalassemic patients, especially when an HLA disparity was present.

Activated Protein C Reduces Graft Neutrophil Activation in Clinical Renal Transplantation

We studied the role of endogenous activated protein C (APC), the major physiological anti-coagulant with concomitant anti-inflammatory properties, on ischemia/reperfusion (I/R) in 45 patients participating in a larger trial comparing three immunosuppressive protocols in cadaveric renal transplantation: perioperative anti-thymocyte globulin (ATG, Fresenius AG, Bad Homburg, Germany), perioperative basiliximab and conventional triple therapy. Blood samples for assessing plasma APC, protein C, and lactoferrin concentrations, neutrophil CD11b and L-selectin expressions and blood leukocyte differential counts were obtained preoperatively and before reperfusion from central venous cannula, complemented with simultaneous samples from iliac artery and graft vein for calculation of transrenal differences (Delta) of study parameters at 1 and 5 min after reperfusion. Unlike basiliximab or conventional therapy groups, ATG infusion induced a substantial increase in plasma APC concentration (119 [88-144]% before infusion vs. 232 [85-1246]% after infusion, p<0.001), resulting in renal graft sequestration of APC at 1 min after reperfusion (Delta=-72 [-567 to 12]%, p<0.001). Graft APC consumption was associated with transrenal reduction of neutrophil activation markers (L-selectin r=0.7, p=0.01; lactoferrin r=-0.6, p=0.02; CD11b r=-0.8, p=0.001), and with both warm (r=0.6, p=0.01) and cold ischemia time (r=0.6, p=0.02) and donor age (r=0.6, p=0.01). These findings suggest that APC has an anti-inflammatory role in I/R injury in clinical renal transplantation.