Solid organ transplant: medication management issues

Solid organ transplant patients are surviving longer today with a better quality of life. Although the incidence of acute rejection has decreased sharply in the past decade, chronic rejection remains an important problem. Goals for immunosuppression should focus equally on prevention of rejection and post-transplant complications. Newer and more specific immunosuppressive agents are available that can improve patient outcomes with fewer adverse effects. Pharmacists can help to prevent post-transplant complications and improve outcomes with immunosuppressive therapy.

Pilot study of immunotherapy with interleukin-2 after autologous stem cell transplantation in advanced breast cancers

Median survival for advanced breast cancer does not exceed 2 years. Immunotherapy following Hihg Dose Chemotherapy (HDC) and autologous stem cell transplantation (ASCT) is a procedure that could hypothetically decrease relapse rate. The mechanism implicated is induction of immune modulation and a possible Graft Versus Tumor effect (GVHT). Tolerance and feasibility of rIL-2 administered after HDC with ASCT was analyzed in twenty one advanced breast cancer patients. The patients were treated either with intra-venous high-dose rIL-2 (9 patients) or subcutaneous low dose (12 patients). With intra-venous high-dose rIL-2, 50% of the scheduled dose was administered and 100% of the scheduled dose was administered at a lower dose in the subcutaneous route. rIL-2 was administered safely after HDC and ASCT, particularly in the subcutaneous low dose arm. However no clinical beneficial effect was documented for these advanced heavily pretreated breast cancers. Immune modulation with rIL-2 earlier requires further investigation.

Passenger lymphocyte syndrome with severe hemolytic anemia due to an anti-Jk(a) after allogeneic PBPC transplantation

BACKGROUND

After allogeneic peripheral blood progenitor cell (PBPC) transplantation, a patient developed a severe hemolytic transfusion reaction due to passenger lymphocyte syndrome.

CASE REPORT

A 50-year-old woman with secondary acute myeloid leukemia transforming from a myelodysplastic syndrome received an ABO-compatible PBPC graft from her HLA-identical sister. For prophylaxis of GVHD, the patient was treated with cyclosporine and methotrexate. Eighteen days after the transplant, the patient experienced a severe hemolytic transfusion reaction due to an alloantibody (anti-Jk(a)) produced by donor lymphocytes.

RESULTS

The patient was typed as group A, Jk(a+) before transplantation; the donor was typed as group A, Jk(a-). On Day 18 after transplantation, the immunohematologic screening revealed a positive DAT (C3d 3+) and an alloanti-Jk(a). Hemolysis in the patient at that time was indicated by a drop in the Hb and an increase in the LDH level (maximum, 592 IU/L on Day 23).

CONCLUSION

The course of hemolysis and the time of appearance of an alloantibody in this patient meet the criteria for passenger lymphocyte syndrome. In most cases, this syndrome is triggered by ABO system antibodies. This is the first reported case of passenger lymphocyte syndrome after PBPC transplantation that was due to an alloantibody that did not belong to the ABO system.

Resistance of mice exposed to whole-body irradiation to transplanted hemopoietic cells modified with RNA preparations

The resistance of irradiated mice to bone marrow grafts treated with RNA from the liver of syngenic, allogenic, or xenogenic (rat) species was studied. Syngenic recipients developed resistance to grafts treated with allogenic RNA. The resistance to allografts increased after treatment with xenogenic RNA, whereas treatment of allo- and xenografts with syngenic RNA facilitated their take.

Local hypertrophic/hyperplastic changes of keratinizing squamous epithelium of pinna induced by concanavalin A and other immunomodulators in mice

Intradermal administration of concanavalin A, a potent T-cell mitogen, into an ear lap resulted in activation of chondrogenesis and stimulation of epidermis proliferation. This proliferation is sometimes invasive in character (pearls and epidermal nests form in the underlying connective tissue) but never turns into true cancerous lesions. This reaction can be delayed, but not prevented, by the prostaglandin inhibitor indomethacin. Stimulation of epidermis proliferation was also caused by administration of other immunomodulators, such as carrageenan type IV, Moloney sarcoma development, and rarely in the course of GvHr, but to much lesser degree than with concanavalin A. It is suggested that the same growth factors, which are mediators of local chondrocyte stimulation, are also mediators of keratinocyte activation.

Nitric oxide increases the amount of murine cytomegalovirus-DNA in mice latently infected with the virus

At 5 wk after the intraperitoneal infection of murine cytomegalovirus (MCMV) in adult (C3H/He x BALB/c) F1 (CBF1) mice, MCMV-DNA was noted mainly in the salivary glands (SG). Since graft-versus-host reaction (GVHR) is well known as a major risk factor for CMV reactivation, parental BALB/c spleen cells were then intravenously transferred to these mice to induce GVHR. A high copy number of full-length MCMV-DNA was thus observed in the lungs as well as the hearts and livers at 4 to 6 wk after the cell transfer, whereas the copy numbers in SG after the cell transfer were comparable to those before the transfer. It was therefore suggested that the amount of MCMV-DNA noted in these organs had been increased by GVHR. However, no transcripts of MCMV-DNA could be detected. Since a marked expression of mRNA of inducible nitric oxide synthetase (iNOS) was noted in the lungs and the hearts during the course of GVHR, the role of NO in the increase of MCMV-DNA after the cell transfer was next examined. The administration of L-arginine, a substrate for NO, increased the amount of MCMV-DNA in the lungs and the hearts after the induction of GVHR. In contrast, the material which suppressed iNOS induction inhibited the emergence of MCMV-DNA. Therefore, the NO generated during the course of GVHR increased the amount of the viral DNA in the lungs and the hearts of the mice latently infected with MCMV. If the increase in the amount of viral genome is the initial step of viral reactivation from the latent state, then NO would thus trigger the initial step of the reactivation of the DNA virus. As the lungs are the major organ to produce NO after systemic stimulation, the observations of this study may explain why the lungs are the major site of CMV latency and why GVHR triggers CMV reactivation. These findings are thus considered to demonstrate that NO plays a novel role in viral infection.

Induction of remission after donor leucocyte infusion for the treatment of relapsed chronic idiopathic myelofibrosis following allogeneic transplantation: evidence for a 'graft vs. myelofibrosis' effect

A 54-year-old man showed evidence of disease progression and a reduction in donor chimaerism by molecular microsatellite analysis 6 months after an allogeneic peripheral blood stem cell transplant for chronic idiopathic myelofibrosis. He was treated with a single infusion of donor leucocyte infusions (DLI), which led to the development of mild acute graft versus host disease (GVHD) and the rapid restoration of full donor haemopoiesis. This subsequently led to a progressive reduction in marrow fibrosis from grade IV to grade I over the following 6 months. We believe that this is the first report to provide clear evidence for the efficacy of DLI in this setting, which also provides evidence for the existence of a T-cell-mediated 'graft vs. myelofibrosis' effect similar to that seen against other haematological malignancies.

Vaginal outflow tract obstruction by graft-versus-host reaction

We describe a 25-year-old patient suffering from vaginal outflow obstruction which presented as secondary amenorrhea during hormone replacement therapy. The patient had undergone bone marrow transplantation for acute myelocytic leukemia, which caused ovarian failure. Oral mucositis associated with a chronic GVH reaction also occurred. For 3 years she was treated with HRT and had regular menses which gradually ceased and were associated with dyspareunia and abdominal cramps. Abdominal US examination demonstrated hematocolpus. Sonography guided adhesiolysis of a dense vaginal obstruction allowed free drainage with histologic confirmation of a graft-versus-host reaction. The possibility of vaginal stricture or obstruction should be considered in all patients after BMT who suffer from graft-versus-host disease.

Cutaneous graft-versus-host-like reaction in systemic T-cell lymphoma

We report a case of systemic T-cell lymphoma with cutaneous lesions showing histological features of a cutaneous graft-versus-host-like-reaction. Histology from liver, lymph node and bone marrow showed a malignant T-cell infiltrate. T-cell receptor gene rearrangement studies confirmed the diagnosis. A cutaneous graft-versus-host-like reaction has been reported with disseminated malignancy and one case has been reported with systemic lymphoma. Graft-versus-host disease normally occurs when lymphocytes from an immunocompetent donor are introduced into a histo-incompatible recipient who is incapable of rejecting them. In our patient a similar reaction may have occurred if the lymphoma was composed of cytotoxic cells or if a cell-mediated immune response against the malignant T-cells cross-reacted with epidermal keratinocytes. Alternatively the malignant T-cells could have been functionally active and induced a lichenoid reaction in the skin.

The addition of allogeneic peripheral blood-derived progenitor cells to bone marrow for transplantation: results of a randomised clinical trial

BACKGROUND

The use of cytokine-mobilised peripheral-blood-derived progenitor cells (PBPC) has resulted in a significant improvement in the safety of autologous transplantation. Collections of PBPC contain large numbers of haemopoietic progenitors and T-lymphocytes when compared with bone marrow (BM).

AIMS

To assess the clinical effects and safety of filgrastim-mobilised allogeneic PBPC, in particular whether PBPC would alter the kinetics of engraftment or the incidence and severity of graft-versus-host disease (GVHD).

METHODS

Twenty-seven patients undergoing allogeneic transplantation were randomised to receive BM or BM supplemented by PBPC. Patients were conditioned with busulphan 16 mg/kg and cyclophosphamide 120 mg/kg. GVHD prophylaxis was with methotrexate and cyclosporin. Ganciclovir prophylaxis was administered to all cytomegalovirus seropositive patients. No haemopoietic growth factor was used after BMT. Donors of PBPC underwent a single, seven litre apheresis after four days of filgrastim, 10 microg/kg/day by subcutaneous injection.

RESULTS

Donor toxicity was mild, with the most frequently reported being bone pain in the cytokine-treated donors. The patients transplanted with BM+PBPC received an eight-fold increase in CD3+ T-lymphocytes (1.65X 10(8)kg vs 0.22 x 10(8)/kg, p=0.04) and the cytokine product contained a median of 5 x 10(6) CD34+ cells/kg. BM+PBPC patients had more rapid engraftment of neutrophils to 0.5x 10(9)/L (17 days vs 19 days, p=0.02) and platelets to 50X 10(9)/L (22 days vs 35 days, p=0.04). BM megakaryocyte numbers were significantly enhanced at days 14 and 28 after BMT (both p=0.04), however platelet transfusions were not significantly different. The incidence, organ distribution, severity and time to onset of acute and chronic GVHD were not different between the treatment groups and there was no difference in overall survival or event-free survival.

CONCLUSIONS

Allogeneic PBPC from HLA-identical siblings may speed engraftment of neutrophils and platelets without detrimental effects on GVHD or survival.

Hematopoietic stem cell transplantation in malignant lymphoproliferative diseases. A single center, retrospective study

During the 1982-1997 period, out of the 133 hematopoietic stem cell (HSC) transplantations performed at Mont Godinne for malignant hemopathies, 85 were done in lymphoproliferative diseases: 27 in aggressive non-Hodgkin's lymphomas (ANHL), 21 in multiple myeloma (MM) patients, 17 in low-grade non-Hodgkin's lymphomas (LNHL), 9 in Hodgkin's disease (HD) cases, 9 in acute lymphoblastic leukemia (ALL) and 2 in chronic lymphocytic leukemia (CLL) patients. According to the HSC source, there were 19 allogeneic bone marrow grafts and 66 autologous HSC grafts (14 bone marrow and 52 peripheral stem cell grafts). In 40 cases the procedure was done after achieving partial or complete remission through conventional chemotherapy and in 45 patients in case of relapse or progressive disease. The conditioning regimens consisted of high-dose chemotherapy, associated with total body irradiation in case of allografts and in autografts for ALL. Engraftment was obtained in all autografted patients, transplant related mortality (TRM) occurring in 2 patients (3%). In the allogeneic transplantation group, 1 patient did not engraft and TRM was much higher, occurring in 10 cases (52%). Hematologic recovery occurred significantly faster in the autograft group than in the allograft group. The overall costs of an autograft were much lower than those of an allograft. Out of the 59 patients followed 4 years or longer, 23 (39%) are alive, free of disease, the proportion varying from 57% in the HD cases to 16% in the MM cases. The overall survival at 4 years was 49%. Negative prognostic factors for disease free survival at 4 years included male sex, lack of complete remission status at transplantation and MM diagnosis, whereas male sex and allografting were the negative prognostic factors for the 4-year overall survival.

Evaluation of graft-host response for various tissue sources and animal models

The efficacy of pancreatic islet transplants in correcting hyperglycemia and slowing the progression of complications in diabetics has been confirmed by many experimental and clinical studies. Unfortunately, the availability of human islets is extremely limited and, therefore, treatment of large numbers of human diabetic patients will almost certainly require either the use of islets harvested from animals (xenografts) or the use of insulin-secreting genetically modified cells of either human or animal origin. There is currently no effective regimen which will allow long-term survival of xenogeneic islets from widely unrelated donor-recipient combinations, such as pig-to-rodent, pig-to-dog, or pig-to-primate. There is considerable interest in the development of immunoisolation techniques for protection of donor islets. However, most materials used in immunoisolation devices are relatively bio-incompatible. Poly-L-lysine-alginate microcapsules are biocompatible and provide an optimal geometry for transmembrane diffusion of insulin and nutrients. Microcapsules allow long-term survival of xenogeneic islets in diabetic rodents or dogs with induced diabetes. However, mice and rats with spontaneous diabetes destroy encapsulated islet grafts within 2 to 3 weeks. Biopsies reveal large numbers of macrophages, immunoglobulins and limited numbers of helper and cytotoxic T-cells in the peri-microcapsule environment of the peritoneal cavity. Cytokines have been identified in peritoneal fluid from mice with islet grafts and may play a role in encapsulated islet destruction. Targeted immunomodulation by treatment of recipients with either anti-helper T-cell antibodies, or fusion proteins which block costimulatory interactions between antigen presenting cells and host T-cells have demonstrated synergy in significant prolongation of encapsulated islet xenograft survival in NOD mice with spontaneous diabetes. Technical improvements in microcapsule design also have contributed to prolonged graft survival. "Double-wall" microencapsulation provides a more durable microcapsule and islet pretreatment prior to encapsulation reduces the frequency of defective capsules with islets entrapped in the membrane. Long-term durability of encapsulated islet grafts remains a concern and further improvements in microcapsule design are a prerequisite to clinical trials.

Reinventing bone marrow transplantation. Nonmyeloablative preparative regimens and induction of graft-vs-malignancy effect

The therapeutic benefit of allogeneic hematopoietic transplantation is due largely to an immune graft-vs-malignancy effect. Most of the evidence for such an effect has come from studies of allogeneic transplantation in leukemia. In patients with susceptible malignancies who relapse following an allogeneic transplant, infusion of donor lymphocytes can induce durable remissions. Use of less toxic, nonmyeloablative preparative regimens permits engraftment and generation of graft-vs-malignancy effects. This strategy permits allogeneic transplantation to be used in older patients and those with comorbidities who cannot tolerate conventional high-dose preparative regimens. The long-term efficacy of nonmyeloablative preparative regimens and induction of graft-vs-malignancy effects remains to be determined. Also, further clinical trials are required to address various unresolved issues and to compare this strategy with standard, myeloablative transplantation regimens.

Progress in experimental intestinal transplantation in small animal models

The unique immune response after small bowel transplantation (SBT) has been the subject of extensive research using small animal models in rats and mice. These animals are inexpensive, for most societies ethically acceptable and the existence of inbred strains allows for reproducibility and defined immunobiological conditions. The basic immunological reactions, such as graft-versus-host-reactions (GVHR), host-versus-graft-reactions (HVGR), a combination of both reactions, chronic rejection and tolerance have been described. Almost all immunosuppressive agents of proven or potential clinical relevance have been tested for their efficacy in small bowel transplantation. All techniques which are applied to intestinal transplantation in humans including multiorgan transplantation, can also be performed in rats. Intestinal transplantation in mice is methodically restricted to heterotopic transplantation. The mouse however, offers several advantages compared to the rat model. A large number of congenic and knockout strains is available as well as many analytical tools. In the future, intriguing new insights into the unique immunological mechanisms of allograft rejection will be discovered using murine models.

[Experimental study on mice scheduled-bone marrow transplantation]

OBJECTIVE

To enhance the grafting efficiency of bone marrow transplantation.

METHODS

Lethally irradiated recipient Kunming mice were transplanted with bone marrow cells from normal Kunming mice either in one large (10(7)) number (BMT group) or in four separate small (10(5)-10(6)) numbers (scheduled BMT group) and the survival rate, hematopoiesis reconstitution and acute graft versus host disease (aGVHD) were compared between the two groups.

RESULTS

Both BMT and SBMT (10(5) x 4) groups obtained the same survival rate of 30%. In SBMT (10(6) x 4) group, the peripheral WBC count, bone marrow nucleated cells and CFU-E, CFU-GM, CFU-S and CFU-F yields all returned to normal 17 days after irradiation. The degree of GVHD in SBMT group was less severe than that in BMT group, and the survival rate (60%) was significantly higher than that in BMT group (30%).

CONCLUSION

SBMT can significantly enhance the grafting efficiency.

Update on leucocyte depletion of blood components by filtration

It has long been recognized that allogenic leucocytes from donor blood are responsible for serious untoward effects in some transfused patients such as alloimmunization, febrile reactions, platelet refractoriness, transfusion associated acute lung injury, immunosuppression as well as transmission or reactivation of viruses such as CMV, HTLV or EBV. Leucocytes are also known to accelerate the rate of storage lesion. The optimal method to remove leucocytes from blood components has been shown to be filtration. However, many variables exist in the properties of leuco-depletion filters (material, composition, surface charge, mechanisms of leucocyte entrapment), the blood components to be filtered (composition, age), and the filtration method (pre- or post-storage, priming and rinsing, temperature, flow rate). In this paper principles of filtration and subsequent logistic consequences will be discussed. It is recommended to carefully select a filter for a specific blood component and to perform leuco-depletion procedures under controlled conditions according to validated methods meeting Good Manufacturing Practice (GMP) and Good Laboratory Practice (GLP).

Transosseous transposition of a pedicled rectus abdominis flap to cover hip wounds

Bone-marrow transplantation may be complicated by aseptic necrosis of the femoral head. Prolonged immunosuppression places the patient at increased risk of infection and is of particular concern if replacement arthroplasty is contemplated. Infection of a prosthesis usually requires thorough debridement and removal of the device. However, attention must also be paid to the resultant cavity and soft-tissue cover. Several flaps have been reported for this problem, though limitations of flap size may make it difficult to achieve both objectives. This report describes the use a pedicled rectus abdominis flap that was tunnelled through the acetabulum in order to gain direct access to the hip and allow adequate length both to fill the dead-space and to provide cover.