Intentional ABO-incompatible heart transplantation: a case report of 2 adult patients.

BACKGROUND: In 2009, we started to screen all patients on the heart transplant waiting list for the presence of blood group anti-A or anti-B antibodies. From our experience with ABO-incompatible kidney transplantation, we know that transplantation can safely be performed if the antibody level is reduced to a titer of immunoglobulin G (IgG) 1:8. METHODS: We decided to accept all patients with anti-A or anti-B antibody titer ≤1:8 for ABO-incompatible heart transplantation without any special pre-treatment and patients with antibody titers of IgG 1:16 and 1:32, provided 1 apheresis session could be performed immediately before transplantation. RESULTS: We found 6 of 13 patients were suitable for this program, and 2 ABO incompatible patients underwent successful transplantation with a follow-up of 1 year. CONCLUSION: In heart transplant candidates where there are problems obtaining a compatible heart and who are not suitable for ventricular assist device support, ABO-incompatible heart transplantations can be considered using our protocol, provided that the levels of anti-A or anti-B antibodies are low.

ABO-incompatible kidney transplantation in children.

We designed a new protocol to enable safe ABO-incompatible kidney transplantation. The new protocol utilizes antigen-specific immunoadsorption rather than unspecific plasma exchange to remove existing anti A/B antibodies and rituximab rather than splenectomy to prevent rebound of antibodies. Sixty patients have so far been successfully transplanted with this protocol and 10 of those have been children. When compared with ABO-compatible transplantations, we could not find any differences in success rate, renal function, or adverse events.

Immune modulation to prevent antibody-mediated rejection after allogeneic hematopoietic stem cell transplantation.

It has been shown that antibodies to donor CD34+/VEGFR-2+ stem cells or antibodies against mismatched HLA are associated with graft rejection after hematopoietic stem cell transplantation (HSCT). CD34/VEGFR-2 positive stem cells have been implicated to play a major role in engraftment after HSCT. In this study we treated four patients with an imminent risk of antibody-mediated rejection with immune modulation, i.e. plasma exchange, intravenous immunoglobulin (IVIG), and rituximab before HSCT. Three of the patients had been previously transplanted and rejected their initial grafts after 12 months, 1 month, and less than 1 month, respectively. The fourth patient was not transplanted previously but had HLA directed antibodies present against the graft. During the immune modulatory treatment we followed the pattern of antibodies in sera using FACS and microcytotoxicity assay. We could show that two patients had antibodies against donor CD34+/VEGFR-2+ cells while the other two had antibodies directed against HLA. All four patients tolerated the immune modulatory regimen without any side effects. In this preliminary study we show that immune modulatory treatment may be used to reduce antibody levels and to prevent rejection after HSCT. In two of the three patients which experienced previous rejections and had detectable anti-HLA or anti-CD34+/VEGFR-2+ antibodies, immune modulation resulted in engraftment. In the fourth patient with known anti-HLA-class I antibodies, the treatment also resulted in engraftment. Our results encourage further studies regarding this treatment regimen.

Improved survival after allogeneic hematopoietic stem cell transplantation in recent years. A single-center study.

We analyzed the outcome of allogeneic hematopoietic stem cell transplantation (HSCT) over the past 2 decades. Between 1992 and 2009, 953 patients were treated with HSCT, mainly for a hematologic malignancy. They were divided according to 4 different time periods of treatment: 1992 to 1995, 1996 to 2000, 2001 to 2005, and 2006 to 2009. Over the years, many factors have changed considerably regarding patient age, diagnosis, disease stage, type of donor, stem cell source, genomic HLA typing, cell dose, type of conditioning, treatment of infections, use of granulocyte-colony stimulating factor (G-CSF), use of mesenchymal stem cells, use of cytotoxic T cells, and home care. When we compared the last period (2006-2009) with earlier periods, we found slower neutrophil engraftment, a higher incidence of acute graft-versus-host disease (aGVHD) of grades II-IV, and less chronic GVHD (cGHVD). The incidence of relapse was unchanged over the 4 periods (22%-25%). Overall survival (OS) and transplant-related mortality (TRM) improved significantly in the more recent periods, with the best results during the last period (2006-2009) and a 100-day TRM of 5.5%. This improvement was also apparent in a multivariate analysis. When correcting for differences between the 4 groups, the hazard ratio for mortality in the last period was 0.59 (95% confidence interval [CI]: 0.44-0.79; P < .001) and for TRM it was 0.63 (CI: 0.43-0.92; P = .02). This study shows that the combined efforts to improve outcome after HSCT have been very effective. Even though we now treat older patients with more advanced disease and use more alternative HLA nonidentical donors, OS and TRM have improved. The problem of relapse still has to be remedied. Thus, several different developments together have resulted in significantly lower TRM and improved survival after HSCT over the last few years.

The efficacy of antigen-specific immunoadsorption and rebound of anti-A/B antibodies in ABO-incompatible kidney transplantation.

BACKGROUND: As antigen-specific immunoadsorption (IA) using the Glycosorb®-ABO columns is becoming increasingly popular in ABO-incompatible (ABOi) transplantation, in this study, we retrospectively investigated the efficacy of Glycosorb®-ABO IA in vivo and ex vivo. We also assessed the risk of anti-A/B antibody (ABab) rebound before and after ABOi kidney transplantation. METHODS: A protocol for ABOi living donor kidney transplantation was used, combining four preoperative and three preemptive postoperative Glycosorb®-ABO IAs with rituximab and maintenance immunosuppression. ABabs were determined by a haemagglutination titration technique. RESULTS: ABOi kidney transplantation was attempted 45 times and 43 transplantations were performed. Overall patient survival was 93% and graft survival was 91%. Mean follow-up was 4.5 years. Glycosorb®-ABO IA significantly reduced the ABabs in the majority of patients (P < 0.0001). However, in three patients (6.8%), the antibody elimination was incomplete. Inadequate adsorption of core-chain-dependent ABabs may explain this finding, but further studies are needed. In five patients, the preconditioning was interrupted before transplantation, resulting in ABab rebound. Yet, when preconditioning was restarted, the antibodies could be removed as planned. After ABOi transplantation, rebound of ABabs was seen in two patients (5%). CONCLUSIONS: Glycosorb®-ABO IA in combination with rituximab effectively depletes ABabs in most patients, but owing to core-chain-dependent ABabs, Glycosorb®-ABO IA may be less effective than nonspecific techniques for antibody removal in some patients. Rebound before transplantation subsequent to interrupted preconditioning does not hamper a successful ABOi transplantation. Postoperatively, when this protocol for ABOi transplantation is followed, the risk of ABab rebound is small.

Isoagglutinin adsorption in ABO-incompatible transplantation.

As the demand for kidney transplantation is constantly growing methods to expand the donor pool have become increasingly important. ABO-incompatibility has hitherto been regarded as an absolute contraindication to living donor donation. However, as ABO-incompatibility has accounted for the majority of living donor exclusions, efforts have been made to overcome this immunologic barrier. Successful desensitization protocols thus far, have combined plasmapheresis for antibody removal with splenectomy to reduce the antibody producing B-cell pool, in addition to quadruple immunosuppression. Although good graft function has been achieved, the high risks involved have been deterrent. We have developed a protocol for ABO-incompatible kidney transplantation based on antigen-specific immunoadsorption and rituximab, in combination with standard maintenance immunosuppression (tacrolimus, mycophenolate mofetil and corticosteroids). We hypothesized that the anti-A/B antibodies could be effectively eliminated and good graft function achieved, without the complications of coagulopathy and transfusion reactions associated with plasmapheresis. Furthermore, we hypothesized that the substitution of splenectomy with a single dose of the anti-CD20 antibody rituximab would further reduce surgical risk as well as the risk of infectious complications. In 2001 the program for ABO-incompatible kidney transplantation was started at our center. To date 50 ABO-incompatible kidney transplantations have been performed according to the protocol based on antigen-specific immunoadsorption and rituximab. Safety and efficacy of the protocol has been evaluated in several studies, all showing that the antigen-specific immunoadsorption is well tolerated and without any serious side effects. Patient and graft survival as well as kidney function have been comparable to that of ABO-compatible living donor kidney transplantation and the incidence of antibody-mediated rejection 0%. We conclude that AB0-incompatible kidney transplantation using a protocol based on antigen-specific immunoadsorption and rituximab, in combination with triple immunosuppressive therapy is safe and effective. ABO-incompatibility following this protocol does not have a negative impact on graft function. ABO-incompatible kidney transplantation is equivalent to standard ABO-compatible living donor kidney transplantation.

ABO-incompatible kidney transplantation using antigen-specific immunoadsorption and rituximab: a 3-year follow-up.

BACKGROUND: In 2001 a protocol for ABO-incompatible (ABOi) kidney transplantation based on antigen-specific immunoadsorption and rituximab was introduced at our center, short-term results being comparable with those of ABO-compatible (ABOc) living donor kidney transplantation. Of greater importance, however, is long-term graft function, thus far not evaluated. The aim of this study was therefore to assess long-term results of this protocol. METHODS: Twenty ABOi kidney recipients with more than 12-month follow-up were included in the study: all adult crossmatch negative ABOi kidney recipients (n=15) were compared with an adult ABOc living donor recipient control group (n=30), and all pediatric ABOi kidney recipients (<16 years of age) (n=5) were compared with a group of pediatric ABOc kidney recipients (n=18). RESULTS: Mean follow-up was three years. There was no significant difference in patient survival, nor in graft survival or in the incidence of acute rejection in any of the groups. In the adult kidney recipients mean glomerular filtration rate was equivalent at all time points (79-83 mL/min), as was Deltas-creatinine. In the pediatric groups, Deltas-creatinine was similar but glomerular filtration rate lower among the ABOi kidney recipients. There was a significant reduction (P<0.0001) without rebound in A/B antibody titers after transplantation (median IgG 1:2 and median IgM 1:1>1 year posttransplant) compared with pretransplant levels (median IgG 1:32 and IgM 1:16). CONCLUSION: We conclude that ABOi kidney transplantation using antigen-specific immunoadsorption and rituximab is equivalent to ABOc living donor kidney transplantation. ABOi transplantation after this protocol does not have a negative impact on long-term graft function.

Implementation of a Protocol for ABO-incompatible kidney transplantation--a three-center experience with 60 consecutive transplantations.

BACKGROUND: A new protocol for ABO-incompatible kidney transplantation has recently been introduced. We report here on the joint experience of the implementation in Stockholm and Uppsala, Sweden and Freiburg, Germany. METHODS: The new protocol utilizes antigen-specific immunoadsorption to remove existing ABO-antibodies, rituximab, and intravenous immunoglobulin to prevent the rebound of antibodies, and conventional tacrolimus, mycophenolate-mofetil, and prednisolone immunosuppression. Sixty consecutive ABO-incompatible kidney transplantations were included in the study. The outcome is compared with the results of 274 ABO-compatible live donor transplantations performed during the same period. RESULTS: Two of the ABO-incompatible grafts have been lost (non-compliance and death with functioning graft). All the remaining 58 grafts had good renal function at a follow-up of up to 61 months. We did not observe any late rebound of antibodies and there were no humoral rejections. Graft survival was 97% for the ABO-incompatible compared with 95% for the ABO-compatible. Patient survival was 98% in both groups. There was a significant variation in preoperative A/B-antibody titer between the centers, with a median 1:8 in Uppsala, median 1:32 in Stockholm and median 1:128 in Freiburg. More preoperative antibody adsorptions were therefore needed in Freiburg than in Stockholm and Uppsala. CONCLUSIONS: The new protocol was easily implemented and there were no graft losses that could be related to ABO-incompatibility. A significant inter-institutional variation in the measurement of anti-AB-antibodies was found, having a substantial impact on the number of immunoadsorptions and consequently on the total cost for the procedure. A standardized fluorescence-activated cell sorting technique for antibody quantification is much needed.

Comparing the tube and gel techniques for ABO antibody titration, as performed in three European centers.

Data from 60 consecutive ABO-incompatible kidney transplantations performed in Stockholm, Sweden; Freiburg, Germany; and Uppsala, Sweden, revealed significant variation in preoperative A/B antibody levels, with median titers of 1:32, 1:128, and 1:8, respectively. We wanted to investigate whether these differences were method-related. The same samples from 21 healthy blood donors were analyzed in the three centers using current local methods. Results confirmed method-related differences, with higher A/B titers in Freiburg and lower titers in Uppsala compared with Stockholm. Results for the same sample differed by a median of three (range 0 to 6) titer steps. When the same number of samples were analyzed in the three centers using the same gel method and the same test erythrocytes, results differed by a median of one titer step (range 0 to 4) for the same sample. In conclusion, gel hemagglutination technique significantly decreases intercenter variation compared with tube technique.

Present techniques for antibody removal.

Renal transplantation into a patient with a positive cytotoxic cross-match or with an incompatible blood group inevitably results in acute humoral rejection, unless the HLA or anti-A/B antibodies have been removed before transplantation. Although there are several procedures to remove HLA and anti-A/B antibodies, plasmapheresis and immunoadsorption are the most commonly used. In this report, presently available techniques for antibody removal are briefly reviewed.

Long-term results of ABO-incompatible kidney transplantation with antigen-specific immunoadsorption and rituximab.

ABO-incompatible (ABOi) kidney transplantation has gained a renewed interest during the past years. In 2001, a protocol for ABOi kidney transplantation based on antigen-specific immunoadsorption and rituximab was introduced at our center. In this study long-term graft function using this protocol was assessed. All ABOi kidney recipients with >1-year follow-up (n=15) were compared with all ABO-compatible (ABOc) living donor kidney recipients maintained on the same basic immunosuppression (n=27). Patient and graft survival as well as rejections and calculated glomerular filtration rate were analyzed. Mean follow-up was 3 years. There was no significant difference in patient and graft survival nor in rejection episodes. Mean glomerular filtration rate (79-83 ml/min) was equivalent at 1, 2, and 3 years in both groups. We conclude that ABOi kidney transplantation using antigen-specific immunoadsorption and rituximab is equivalent to standard ABOc living donor kidney transplantation. ABOi transplantation following this protocol does not have a negative impact on graft function long-term.

Clinical experience with a new apheresis filter that specifically depletes ABO blood group antibodies.

BACKGROUND: Although living kidney donors are increasingly being used, in most centers, 30 to 40 percent of potential donors are being turned down due to ABO mismatch. A protocol for ABO-mismatched kidney transplantation without splenectomy and with antigen-specific adsorption of ABO antibodies instead of nonspecific plasmapheresis was therefore designed. STUDY DESIGN AND METHODS: The immunosuppressive protocol used at the Department of Transplantation Surgery, Karolinska University Hospital, Stockholm, Sweden, together with relevant clinical data for 11 of the studied patients, have been described previously. The protocol called for immunoadsorption of ABO antibodies on Days -6, -5, -2, and -1 and on Days +2, +5, and +8. Patient plasma was recirculated through a new apheresis filter, the Glycosorb ABO column (Glycorex Transplantation AB), containing synthetic terminal trisaccharide A or B blood group antigen linked to a Sepharose matrix. RESULTS: Since 2001, 15 patients, including 2 infants, have been successfully transplanted with ABO-mismatched kidneys from living donors. The donor-recipient blood groups were A1-O (n = 5), A2-O (n = 2), B-O (n = 4), B-A (n = 2), and A1B-B (n = 2). ABO antibody titers at transplantation did not exceed immunoglobulin G 4 or immunoglobulin M 4 levels. No humoral rejections and no late rebound of ABO antibodies were observed. No adverse effects related to immunoadsorption treatment have been recorded. CONCLUSION: It is concluded that ABO-mismatched kidney transplantations can be successfully performed without splenectomy and that ABO antibodies can be effectively and safely depleted with the Glycosorb ABO column.

The Stockholm experience with ABO-incompatible kidney transplantations without splenectomy.

BACKGROUND: ABO-incompatible kidney transplantations have previously only been performed after several pre-operative sessions of plasmapheresis followed by splenectomy, and with the conventional triple-drug immunosuppressive protocol being reinforced with anti-lymphocyte globulin and B-cell-specific drugs. We have designed a protocol without splenectomy, based on antigen-specific immunoadsorption, rituximab and a conventional triple-drug immunosuppressive protocol. METHODS: The protocol called for a 1-month pre-transplantation conditioning period, starting with one dosage of rituximab and followed by full-dose tacrolimus, mycophenolate mofetil and prednisolone. Antigen-specific immunoadsorption was performed on pre-transplantation days -6, -5, -2 and -1. After the last session, 0.5 g/kg of intravenous immunoglobulin (IVIG) was administered. Postoperatively, three more apheresis sessions were given every third day. RESULTS: Twenty-one patients have received transplants with this protocol. The ABO-antibodies (Abs) were readily removed by the antigen-specific immunoadsorption and were kept at a low level post-transplantation by further adsorptions. There were no side effects, and all but one patient have normal renal transplant function. CONCLUSIONS: We conclude that after one infusion each of rituximab and IVIG, and antigen-specific immunoadsorption, blood-group incompatible renal transplantations can be performed with standard immunosuppression and without splenectomy, and with excellent short- and long-term results.

Photopheresis for the treatment of refractory renal graft rejection.

Acute rejection episodes still occur after kidney transplantation in spite of modern immunosuppressive protocols including combined tacrolimus, mycophenolate mofetil, and prednisolone. The authors present seven cases of biopsy-proven acute rejection after kidney transplantation refractory to conventional rejection therapy with repeated pulses of high-dose steroids followed by polyclonal or monoclonal antibodies that responded well to photopheresis treatment. Photopheresis is an atoxic immunomodulatory apheresis-based treatment with no generalized immunosuppressive action; rather, it is directed at suppressing donor-specific T-cell clones. At the last follow-up, 9 to 43 months after transplantation, all patients had functioning grafts, with serum creatinine levels ranging from 105 to 312 microM. The authors conclude that photopheresis treatment contributed to the favorable outcome. Therefore, the authors are presently designing a prospective, randomized trial to evaluate the effect of photopheresis as an adjuvant prophylactic treatment after renal transplantation.

ABO incompatible kidney transplantations without splenectomy, using antigen-specific immunoadsorption and rituximab.

ABO incompatible kidney transplantations have previously only been performed after several preoperative sessions of plasmapheresis and splenectomy, with the conventional triple-drug immunosuppressive protocol being reinforced with antilymphocyte globulin and B-cell-specific drugs, such as cyclophosphamide or deoxyspergualine. We have designed a protocol without splenectomy, based on antigen-specific immunoadsorption, rituximab and a conventional triple-drug immunosuppressive protocol. The protocol calls for a 10-day pretransplantation conditioning period, starting with one dosage of rituximab and followed by full dose tacrolimus, mycophenolate mofetil and prednisolone. Antigen-specific immunoadsorption was performed on pretransplantation days -6, -5, -2 and -1. After the last session, 0.5 g/kg of intravenous immunoglobulin (IVIG) was administered. Postoperatively, three more apheresis sessions were given every third day. Furthermore, if there was a significant increase in the antibody titers, extra sessions were considered. Eleven patients have received transplants with this protocol. The ABO antibodies were readily removed by the antigen-specific immunoadsorption and were kept at a low level post-transplantation by further adsorptions. There were no side effects and all patients have normal renal transplant function. We conclude that after an infusion each of rituximab and IVIG, and antigen-specific immunoadsorption; blood group-incompatible renal transplantations can be performed with excellent results using standard immunosuppression and no splenectomy.

Successful ABO-incompatible kidney transplantations without splenectomy using antigen-specific immunoadsorption and rituximab.

BACKGROUND: Historically, ABO-incompatible kidney transplantations have only been undertaken after splenectomy and unspecific plasmapheresis and with quadruple drug immunosuppression plus B-cell specific drugs. We have evaluated a protocol for ABO-incompatible kidney transplantation without splenectomy using antigen-specific immunoadsorption, rituximab, and a conventional triple-drug immunosuppressive regimen. METHODS: The protocol called for a 10-day pretransplant conditioning period starting with one dosage of rituximab and followed by full dose tacrolimus, mycophenolate mofetil, and prednisolone. Antigen-specific immunoadsorption was performed on pretransplant days -6, -5, -4, and -1. After the last session, 0.5 g/kg of intravenous immunoglobulin was administered. Postoperatively, three more apheresis sessions were given every third day. Furthermore, if there was a significant increase in the antibody titers, extra sessions were considered. RESULTS: Four patients have received transplants with this protocol. The donor-recipient blood groups were A2/O, B/O, B/A, and A1/O. The ABO-antibodies were readily removed by the antigen-specific immunoadsorption and were kept at a low level posttransplantation by further adsorptions. There were no side effects, and all patients have normal renal-transplant function. CONCLUSIONS: We conclude that after one infusion each of rituximab and intravenous immunoglobulin and antigen-specific immunoadsorption, blood-group-incompatible renal transplantations can be performed with standard immunosuppression and without splenectomy.

Leukocyte depleted, unscreened blood products give a low risk for CMV infection and disease in CMV seronegative allogeneic stem cell transplant recipients with seronegative stem cell donors.

Leukocyte depletion (LD) by blood product filtration has been shown to be similarly effective to the use of screened, CMV seronegative blood products to prevent CMV disease in CMV seronegative allogeneic stem cell transplant (SCT) patients with CMV seronegative donors. The aim of this retrospective study was to determine the risk for development of CMV infection requiring preemptive therapy and for CMV disease if unscreened products treated by prestorage LD is used. Forty-nine consecutive patients transplanted after June 1995 were included. As a control group, 33 patients transplanted from January 1992 to June 1995 in whom a combination of CMV seronegative and LD blood products were given. All patients were monitored weekly by a leukocyte-based PCR for CMV DNA detection. Preemptive therapy was initiated after two consecutively positive tests. No patient developed CMV disease in either group. CMV DNA was detected in 6/49 (p = NS) in the study group and in 3/33 patients in the historical control group. Two patients in the study group were given preemptive therapy compared to one patient in the control group. This study suggests that the risk for CMV disease and the need for preemptive therapy against CMV is low in CMV seronegative allogeneic SCT patients receiving grafts from CMV seronegative stem cell donors receiving LD blood products. Thus, this strategy can be safely used together with PCR monitoring and preemptive therapy.

Risk factors for moderate-to-severe chronic graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

Among 810 consecutive hematopoietic stem cell transplantation (HSCT) patients, 679 survived more than 3 months and were evaluated for chronic GVHD. The aim of this study was to find predisposing factors increasing the risk of development of moderate-to-severe chronic GVHD. Many of the donors were HLA-identical siblings or related (n = 435), 185 were HLA-matched unrelated, and 59 were mismatched related or unrelated donors. Most of the patients had a hematological malignancy (n = 568), but 111 patients with a nonmalignant disease were included. Two hundred twenty-three patients (33%) developed mild, 41 (6%) moderate, and 15 (2.2%) severe chronic GVHD. The 5-year probability of development of moderate-to-severe chronic GVHD was 10%. We analyzed 30 potential risk factors for chronic GVHD. In the multivariate analysis, acute GVHD) grades II to IV (relative hazard [RH], 2.30; 95% CI, 1.29-4.10; P = .005), CML diagnosis (RH, 2.37; CI, 1.38-4.08; P = .002) and transplantation from an immunized female donor to a male recipient (RH, 2.16; CI, 1.14-4.11; P = .02) were independent risk factors for moderate-to-severe chronic GVHD. Recipient age also was significant (RH, 2.42; CI, 1.23-4.77; P = .01) if CML was not included in the analysis. In patients with no risk factors, the 5-year probability of development of moderate-to-severe chronic GVHD was 5%. In patients with 1 risk factor, the probability was 13%; 2 risk factors, 23%; and 3 risk factors, 45%. Among patients who developed chronic GVHD (n = 279), acute GVHD grades II to IV (RH, 2.18; CI, 1.23-3.86; P < .01) was the only predictive factor for moderate-to-severe chronic GVHD versus mild disease. Patients with previous acute GVHD grades II to IV may benefit from more aggressive initial treatment. This possibility would have to be examined in clinical trials.