Apheresis in grade 4 bone marrow transplant associated thrombotic microangiopathy: a case series

Treatment of thrombotic microangiopathy after hematopoietic stem cell transplantation with recombinant human soluble thrombomodulin

BACKGROUND

Transplant-associated thrombotic microangiopathy (TA-TMA) after hematopoietic stem cell transplantation (HSCT) remains a severe complication associated with underlying endothelial damage. TMA has a high mortality rate with no definite treatments and effective treatments are needed.

STUDY DESIGN AND METHODS

The study objective was to retrospectively analyze the outcome of patients receiving recombinant human soluble thrombomodulin (rTM), which has cytoprotective effects against calcineurin inhibitor-induced endothelial cell damage, or other therapeutics for TA-TMA from 254 consecutive HSCT recipients between 2009 to 2014 at a single institution. We hypothesized that patients receiving rTM as a first-line treatment would receive a benefit.

RESULTS

Sixteen patients were diagnosed as TA-TMA. Of these 16 patients, nine were treated with rTM (rTM group), and seven received treatment other than rTM (control group) as a first-line therapy. Seven of the nine patients in the rTM group recovered from TA-TMA without complications, but none in the control group recovered. The rTM group showed a significantly better overall survival after TA-TMA onset than did the control group (median, 123.0 days vs. 45.5 days, respectively; p = 0.045). The cumulative incidence of acute graft-versus-host disease was the same in both groups (56% vs. 57%, respectively; p = 0.52) on Day 100 after TA-TMA onset.

CONCLUSION

This is the first report evaluating rTM administration for TA-TMA compared with previous treatments. Our data suggests that rTM might offer a better clinical outcome in patients with TA-TMA.

Toxic epidermal necrolysis and hemolytic uremic syndrome after allogeneic stem-cell transplantation

TEN and HUS are challenging complications with excessive mortality after HSCT. We report the development of these two conditions in combination in a nine-yr-old boy after HSCT from an unrelated donor. TEN with skin detachment of more than 90% of body surface area developed after initial treatment for GvHD. Within a few days of admission to the burns unit, the patient developed severe hemolysis, hypertension, thrombocytopenia, and acute renal failure consistent with HUS, apparently caused by CSA. The management included intensive care in a burns unit, accelerated drug removal using plasmapheresis, and a dedicated multi-disciplinary team approach to balance immunosuppression and infections management in a situation with extensive skin detachment. The patient survived and recovered renal function but requires continued treatment for severe GvHD. Suspecting and identifying causative drugs together with meticulous supportive care in the burns unit is essential in the management of these patients and long-term survival is possible.

Diagnosis and treatment of transplantation-associated thrombotic microangiopathy: real progress or are we still waiting?

Transplantation-associated thrombotic microangiopathy (TA-TMA) is an infrequent but devastating syndrome that occurs in allogeneic hematopoietic stem cell transplant recipients, and is associated with a variety of transplantation-related factors, including conditioning regimens, immunosuppressive agents, GVHD and opportunistic infections. Progress in managing this condition has been hampered by lack of a consensus definition and poor understanding of the pathophysiology of the disorder. Two different groups recently have proposed consensus definitions, yet they fail to distinguish the primary syndrome from the secondary causes, such as a variety of infections, medication exposure or other conditions. Increasing evidence suggests that TA-TMA is a multifactorial disorder that is distinct from thrombotic thrombocytopenic purpura (TTP), and likely represents the final common pathway of a number of endothelial cell insults. TA-TMA responds poorly to conventional treatment for TTP, including plasma exchange, but newer agents, including daclizumab and defibrotide show promise. In addition, other agents known to modify endothelial responses to injury, including statins, prostacyclin analogues, endothelin-receptor antagonists and free radical scavengers, may lead to improved outcomes for patients affected by this disorder.

Blood and marrow transplant clinical trials network toxicity committee consensus summary: thrombotic microangiopathy after hematopoietic stem cell transplantation

The syndrome of microangiopathic hemolysis associated with renal failure, neurologic impairment, or both is a recognized complication of hematopoietic stem cell transplantation. This entity is often called hemolytic uremic syndrome (HUS) or thrombotic thrombocytopenic purpura (TTP), yet it is clear that the pathophysiology of transplant-associated HUS/TTP is different from that of classic HUS or TTP. Furthermore, the incidence of this syndrome varies from 0.5% to 76% in different transplant series, primarily because of the lack of a uniform definition. The toxicity committee of the Blood and Marrow Transplant Clinical Trials Network has reviewed the current literature on transplant-related HUS/TTP and recommends that it be henceforth renamed posttransplantation thrombotic microangiopathy (TMA). An operational definition for TMA based on the presence of microangiopathic hemolysis and renal and/or neurologic dysfunction is proposed. The primary intervention after diagnosis of TMA should be withdrawal of calcineurin inhibitors. Plasma exchange, although frequently used in this condition, has not been proven to be effective. In the absence of definitive trials, plasma exchange cannot be considered a standard of care for TMA. It is hoped that these positions will improve the identification and reporting of this devastating complication after hematopoietic stem cell transplantation and facilitate future clinical studies for its prevention and treatment.

Thrombotic thrombocytopenic purpura-hemolytic uremic syndrome following allogeneic HPC transplantation: a diagnostic dilemma

BACKGROUND

Thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) has been described as a specific sequela of allogeneic HPC transplantation (HPCT). Nevertheless, because multiple transplant-related sequela can cause the characteristic clinical features of TTP-HUS, the diagnosis is difficult.

STUDY DESIGN AND METHODS

All English-language articles describing patients with TTP-HUS following HPCT were identified. Articles reporting five or more total patients, including at least one patient diagnosed with TTP-HUS following allogeneic HPCT, were reviewed. All articles describing autopsies of patients diagnosed with TTP-HUS following allogeneic HPCT were also reviewed.

RESULTS

Thirty-five articles reporting 5 or more total patients described 447 patients diagnosed with TTP-HUS following allogeneic HPCT. The frequency of diagnosis of TTP-HUS following allogeneic HPCT varied by 125-fold (0.5%-63.6%). Twenty-eight different sets of diagnostic criteria were described in the 35 articles; 25 articles included both RBC fragmentation and increased serum LDH. Many risk factors described as correlating with the diagnosis of TTP-HUS also predict greater risk for multiple transplant-related complications. Benefit of plasma exchange treatment could not be documented. Survival information was reported for 379 patients, 232 (61%) died, and reported mortality rates varied from 0 to 100 percent. Autopsies have been reported for 35 patients who were diagnosed with TTP-HUS following allogeneic HPCT; none had systemic thrombotic microangiopathy, the diagnostic abnormality of TTP-HUS; and infection (19 patients) was the most commonly reported cause of death.

CONCLUSIONS

The clinical features of TTP-HUS following allogeneic HPCT may be caused by common transplant-related complications; the benefit from plasma exchange treatment is uncertain.

Therapeutic plasma exchange in patients with grade 2-3 hematopoietic stem cell transplantation-associated thrombotic thrombocytopenic purpura: a ten-year experience

In the present retrospective study we report our 10-year experience with therapeutic plasma exchange (TPE) in 18 patients with grade 2-3 hematopoietic stem cell transplantation (HSCT)-associated thrombotic thrombocytopenic purpura (TTP). During TPE a mean total quantity of 26.5 +/- 15.1 L of plasma was exchanged. Five patients (27.7%) had a complete response eight patients (44.4%) had a partial response while five patients (27.7%) died during TPE treatment. Among the survivors, relapse of TTP occured in three patients (23%) and although these patients were treated again with TPE, all died. First-year survival rate was 41.2%. Our results indicate that TPE may be effective in the treatment of some patients with grade 2-3 HSCT-associated TTP.

Posttransplantation thrombotic thrombocytopenic purpura: a single-center experience and a contemporary review

OBJECTIVE

To assess the activity of von Willebrand factor-cleaving protease (vWF-CP) in patients with thrombotic thrombocytopenic purpura (TTP) complicating bone marrow transplantation (BMT) and peripheral blood stem cell transplantation (PBSCT).

PATIENTS AND METHODS

From March 1, 1999, to June 30, 2001, allogeneic and autologous hematopoietic stem cell transplantation was performed in 118 and 400 patients, respectively. We reviewed risk factors for development of posttransplantation TTP and measured vWF-CP activity during active TTP in 10 recipients.

RESULTS

The incidence of TTP after allogeneic and autologous transplantation was 6.8% (8/118) and 0.25% (1/400), respectively. Among the allogeneic transplant recipients, the incidence of TTP after nonmyeloablative (NMA) PBSCT, matched unrelated donor BMT, and sibling BMT or PBSCT was 15.4% (2/13), 11.8% (2/17), and 4.5% (4/88), respectively. Of the 10 patients with TTP, 9 (90%) had received extensive prior therapy, including autologous transplantation in both NMA recipients. Acute graft-vs-host disease (GVHD) prophylaxis consisted of cyclosporine and methotrexate in most affected patients. The vWF antigen level was elevated in all patients, and no patients showed evidence of vWF-CP deficiency. During active TTP, 6 patients had grade II-IV acute GVHD, 1 had extensive chronic GVHD, and 4 had cytomegalovirus viremia. Risk factor analysis for development of TTP showed that transplant type (NMA and matched unrelated donor) and source of stem cells (bone marrow vs peripheral blood stem cell) were significant.

CONCLUSIONS

Posttransplantation TTP was not found to be associated with severe vWF-CP deficiency. The elevated levels of vWF antigen are consistent with diffuse endothelial injury likely because of multiple interacting factors such as extensive prior therapy, GVHD, cyclosporine, and reactivation of cytomegalovirus. The disorder appears to be more frequent among patients with, or at risk for, acute GVHD, suggesting a possible role in the pathogenesis. Nonmyeloablative transplantation does not appear to confer a lesser risk, possibly for these reasons.

Transplantation-associated thrombotic microangiopathy: twenty-two years later

A syndrome of microangiopathic hemolytic anemia, renal dysfunction and neurological abnormalities was first noted in bone marrow transplant recipients 22 years ago. Now known as transplantation-associated thrombotic microangiopathy (TA-TMA) to distinguish it from other thrombotic microangiopathies, this disorder responds poorly to conventional treatments for thrombotic thrombocytopenic purpura. In this review, we discuss the incidence and risk factors for TA-TMA and describe a pathophysiologic model of the disorder based on results obtained from laboratory models of the thrombotic microangiopathies. We conclude by suggesting possible approaches to the early diagnosis and treatment of TA-TMA based on this model that may warrant testing in future clinical trials.

Plasmapheresis in thrombotic microangiopathy-associated syndromes: review of outcome data derived from clinical trials and open studies

Current reimbursement policy of health insurance for therapeutic plasmapheresis requires proof of efficacy using the concept of evidence-based medicine. The aim of this paper is to review the outcome of plasmapheresis used to treat thrombotic microangiopathy (TMA)-associated syndromes in the last decade to provide scientific evidence to back up reimbursement applications. The strength of evidence of each reviewed study was assessed using the five levels of evidence criteria as defined by the American Society of Hematology in 1996 for assessment of the treatment of immune thrombocytopenia. The level Experimental indication was added for situations where only case reports or small series supported by pathophysiological reasoning are available. The definitions of evidence used in this paper are as follows: Level I, randomized clinical trial with low rates of error (p < 0.01); Level II, randomized clinical trial with high rates of error (p < 0.05); Level III, nonrandomized studies with concurrent control group; Level IV, nonrandomized studies with historical control group; Level V, case series without a control group or expert opinion; and Experimental, case reports and pathophysiological reasoning. The results of this analysis based on the published data is summarized as follows: The indication of plasmapheresis is assigned to Level IV evidence for thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS); cancer/chemotherapy-associated TTP/HUS is assigned to Level V evidence; and TTP/HUS refractory to standard plasma exchange and post-bone marrow transplantation TTP/HUS are assigned to Experimental indication. For both subsets, protein A immunoadsorption is reportedly successful. The other TMA-associated syndromes, hemolysis elevated liver enzymes low platelets and HUS in early childhood, are no indication of plasmapheresis. Two randomized clinical trials were performed in order to demonstrate the superiority of plasma exchange/fresh frozen plasma (PEX/FFP) over plasma transfusion in the management of TTP/HUS. The results prove the greater clinical success of the latter type of plasma administration. Standard PEX/FFP has reduced the mortality of TTP/HUS from 94.5% to 13%.

Transplantation-associated thrombotic microangiopathy is associated with transplantation from unrelated donors, acute graft-versus-host disease and venoocclusive disease of the liver

Transplantation-associated thrombotic microangiopathy (TA-TMA) has been associated with significantly reduced survival following allogeneic bone marrow transplantation. In this study we describe the course and response to plasma exchange therapy of TA-TMA as well as risk factors for its' development. Twenty-five patients who underwent plasma exchange therapy were matched to fifty control patients selected for transplant indication and stage of disease at the time of transplant. Transplant indications were acute myeloid leukemia, acute lymphoblastic leukemia, chronic myeloid leukemia, aplastic anemia, myelodysplastic syndrome and multiple myeloma. Groups were well balanced with respect to disease status, age at time of transplant and use of radiation-based conditioning. TA-TMA was diagnosed a median of 27 days after transplantation and neurological abnormalities were present in ten cases. Patients received a median of 10 (range 2-43) plasma exchange treatments. Hematological responses were recorded in eight cases. Risk factors for the development of TA-TMA included transplantation from unrelated donors (p = 0.002), hepatic venoocclusive disease (VOD) (p = 0.034), grade 2-4 acute graft-versus-host disease (GVHD) (p = 0.042) and bacteremia with diphtheroid organisms (p = 0.009). Only hepatic VOD (p = 0.0026) and grade 2-4 acute GVHD (p = 0.0436) remained significant risk factors for later development of TA-TMA in a multivariate logistic regression model. The median survival of patients with TA-TMA was 66 (range 32-733) days while that of unaffected patients was 742 (range 15-2392) days after transplantation. Only one patient with TA-TMA remains alive 733 days after transplantation.

BMT: Bone Marrow Transplant Associated Thrombotic Microangiopathy

Thrombotic microangiopathy is a severe microvascular disorder which may occur in up to 70% of patients undergoing bone marrow transplant. Clinically the term thrombotic microangiopathy encompasses a wide spectrum of syndromes, most importantly the thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS). Thrombotic microangiopathy is characterized by the presence of thrombocytopenia, microangiopathic hemolytic anemia, renal impairment, neurological disturbances and multiorgan failure. Several causative agents have been advocated as triggering factors for bone marrow transplant associated thrombotic microangiopathy, including cyclosporine, FK506, the use of total body irradiation, infections and the presence of severe graft-versus-host disease. Plasma exchange represents the standard treatment for patients who develop TTP/HUS after bone marrow transplant, however, the mortality rate still remains high despite aggressive therapy.

Impact of thrombotic thrombocytopenic purpura on leukemic children undergoing bone marrow transplantation

Thrombotic thrombocytopenic purpura (TTP) has emerged as one of the main transplant-related complications over the last 15 years. The current study defines the incidence and the risk factors for the occurrence of TTP in 131 consecutive leukemic children who were transplanted between January 1994 and December 1997 at four Italian pediatric centers. Patients with ALL (101), AML (21), MDS (9), underwent an HLA-identical sibling BMT (82) or an HLA-identical unrelated BMT (49), receiving a conditioning regimen consisting of high-dose chemotherapy in 24 patients and of F-TBI combined with high-dose chemotherapy in 107 patients. The diagnosis of TTP was retrospectively evaluated on the basis of parallel criteria. TTP treatment varied according to the protocol of each treatment center. Twenty-eight of 131 patients (21.4%) developed TTP at a median of 46 days (range 21-80) after BMT. Multivariate analysis demonstrated that the risk of TTP was higher in patients who underwent unrelated BMT (P value = 0.02). Acute GVHD, stage of disease at BMT, conditioning with TBI, gender, age, did not appear to be associated with the occurrence of TTP. As to the outcome, TTP resolved in 19 patients while in nine it was the principal cause of death (32.1%). In patients with TTP, LDH peak value was the only statistically significant factor (P = 0.001) related to severe TTP. In conclusion, our experience demonstrates that leukemic children undergoing BMT, especially from an unrelated donor, should be carefully assessed for TTP which appears to be a severe and relatively common transplant-related complication when strict diagnostic criteria are applied.

Immunoadsorption, current status and future developments

The association of abnormalities in the cellular and humoral immune system with various autoimmune diseases provides the rationale for apheresis technologies. While plasmapheresis or plasma exchange is limited by its non-selective removal of all plasma components, modern apheresis techniques aim to provide more specific elimination according to clinical needs and avoid plasma product replacement. However, the commercialisation has not met the expectations in the early 80's and the number of patients treated by extracorporeal immunoadsorption remains small due to a lack of well-defined controlled trials and limited reimbursement. This review highlights the immunological and technical basis for extracorporeal immunoadsorption, as well as its current status in the treatment of immunologically-mediated diseases.