Transplant-associated Thrombotic Microangiopathy Treated with Eculizumab and Romiplostim

Transplant-associated thrombotic microangiopathy (TA-TMA) can occur after solid organ transplantation. It results in thrombocytopenia, haemolytic anaemia and microvascular occlusion. TA-TMA is not fully understood and treatment has not been clearly established. However, there is increasing evidence to suggest an immune-complement mediated component to its development. Eculizumab is a monoclonal antibody that inhibits the cleavage of C5 into pro-inflammatory, prothrombotic terminal complement elements and has been utilized in the treatment of atypical haemolytic uremic syndrome. We report a case of TA-TMA successfully treated with eculizumab and romiplostim. This case adds to the evidence that TA-TMA is triggered by complement dysregulation and suggests possible interventions for refractory cases.

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Successful Management Of Calcineurin Induced Thrombotic Microangiopathy(TMA) With Eculizumab After Non- Renal Solid Organ Transplantation

Blood ◽

10.1182/blood.v122.21.1078.1078 ◽

2013 ◽

Vol 122 (21) ◽

pp. 1078-1078 ◽

Cited By ~ 5

Author(s):

Catherine Broome ◽

James K. McCloskey ◽

Raffaele Girlanda

Keyword(s):

Small Bowel ◽

Serum Creatinine ◽

Organ Transplantation ◽

Thrombotic Microangiopathy ◽

Graft Rejection ◽

Calcineurin Inhibitor ◽

Solid Organ Transplantation ◽

Solid Organ ◽

Post Transplant ◽

Complement Dysregulation

Abstract Thrombotic microangiopathy (TMA) is seen in up to 30% of patients receiving solid organ transplantation and almost always occurs in the setting of calcineurin inhibitor (CNI) therapy. The underlying pathophysiology of calcineurin induced TMA is poorly understood. Long term follow up in non renal transplant patients with TMA suggests that in spite of plasma exchange therapy the 1 year mortality following TMA is up to 70%. Between November 2010 and August 2012, 7 patients at our institution who underwent organ transplants ( 5 small bowel, 2 orthotopic liver) developed clinical and laboratory evidence of TMA while receiving CNI therapy. TMA was diagnosed from 3 to 13(median 11) months post transplant and none of the patients responded symptomatically or by laboratory parameters to a reduction in dose of CNI. Other unsuccessful therapies included substitution of other immunosuppressive agents (N=1) and 11 daily plasma exchanges (N=1). At the time of TMA diagnosis notable laboratory values included platelets 22-73 (median 46) K/UL, hemoglobin 4.5 to 8.1(median 6.9) GM/DL, serum creatinine 1.16-5.4 (median 2.66)MG/DL, LDH 262-2903(median 435) Units/L, and ADAMSTS13 37-137%. All patients had a negative DAT, schistocytes on peripheral smear and all but one had undetectable haptoglobin. ( Table 1 ) Clinical symptoms at diagnosis included nausea, vomiting, abdominal pain, fever, hypertension, cerebral vascular accident (N=1), acute coronary syndrome (N=1). None of the patients had evidence of graft rejection on biopsy of the transplanted organ at the time of TMA diagnosis however 2 patients with small bowel transplants had pathologic evidence of ischemic changes and vascular thrombi on biopsy of the small bowel graft.Table 1Comparison of Medians of TMA Laboratory ParametersMedian ValuesPreTransplantTMA Diagnosis4 weeks post eculizumabPlatelet count K/UL12046202Hemoglobin GM/DL11.06.99.0Serum Creatinine MG/DL0.832.661.7LDH Units/L174435322HaptoglobinNT<3190 Eculizumab is a monoclonal antibody which binds with high affinity to C5 and is highly effective in disorders associated with abnormalities in the regulation of complement such as paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome (aHUS) another TMA disease. Due to the clinical and laboratory similarities of post transplant CNI associated TMA and aHUS all patients in our series were treated with the standard induction dose of eculizumab 1200mg weekly for 4 weeks and 900mg every 2 weeks thereafter. Treatment duration ranges from 4 weeks to 107 weeks. All patients were successfully maintained on adequate immunosuppression with calcineurin inhibitor (tacrolimus in all cases) to inhibit graft rejection. All patients demonstrated a rapid and complete resolution of laboratory and clinical manifestations of TMA. After the fourth dose of eculizumab platelet counts ranged from 104-291(median 202), hemoglobin 8.1-10.9(median 9.0), serum creatinine 0.70-4.08(median 1.7), LDH 157-475(median 322) and haptoglobin 23-204(median 90). Only 1 of the 4 patients requiring dialysis at TMA diagnosis remained on dialysis at 4 weeks of therapy.( Table 1) No patients show evidence of recurrent TMA or increase in infectious complications on continued eculizumab plus calcineurin inhibitor therapy at greater than 2 years of eculizumab therapy. The excellent clinical and laboratory response of our patients to eculizumab strongly suggests a central role for complement dysregulation in the pathophysiology of calcineurin induced TMA. There are multiple theories regarding the mechanism by which CNIs induce complement dysregulation including: (1) an underlying genetic predisposition to complement dysregulation worsened or exacerbated by CNI therapy, (2) CNI therapy may induce widespread and significant endothelial damage which serves as a stimulus for chronic complement activation, or (3) chronic over stimulation of complement production secondary to CNI inhibition of T-cell function .While the mechanism remains to be elucidated the clinical implications seem clear: CNI induced TMA is mediated by complement and is treated very effectively with eculizumab allowing patients to continue on graft function preserving CNI therapy. Disclosures: Broome: Alexion Pharmaceuticals: Honoraria, Speakers Bureau. Off Label Use: Eculizumab for the treatment of calcineurin induced TMA.

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Successful Management of CNI-Induced Atypical Hemolytic Uremic Syndrome With Eculizumab After Non-Renal Solid Organ Transplantation.

Transplantation Journal ◽

10.1097/00007890-201407151-02955 ◽

2014 ◽

Vol 98 ◽

pp. 864

Author(s):

C. Broome ◽

R. Girlanda ◽

C. Matsumoto ◽

T. Fishbein

Keyword(s):

Hemolytic Uremic Syndrome ◽

Organ Transplantation ◽

Atypical Hemolytic Uremic Syndrome ◽

Solid Organ Transplantation ◽

Solid Organ ◽

Successful Management ◽

Uremic Syndrome

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Anti-CD20 Monoclonal Antibody (rituximab) for Refractory PTLD after Pediatric Solid Organ Transplantation: Multicenter Experience from a Registry and from a Prospective Clinical Trial.

Blood ◽

10.1182/blood.v104.11.746.746 ◽

2004 ◽

Vol 104 (11) ◽

pp. 746-746 ◽

Cited By ~ 15

Author(s):

Steven Webber ◽

William Harmon ◽

Albert Faro ◽

Michael Green ◽

Minnie Sarwal ◽

...

Keyword(s):

Clinical Trial ◽

Monoclonal Antibody ◽

B Cell ◽

Organ Transplantation ◽

Graft Loss ◽

Solid Organ Transplantation ◽

Solid Organ ◽

Refractory Disease ◽

First Line

Abstract Background: Anti B cell antibodies have been proposed as a treatment for post-transplant lymphoproliferative disorders (PTLD). Experience in children is limited. Methods and Results: We report experience (n=40) with use of the chimeric mouse/human antiCD20 monoclonal antibody (rituximab) in pediatric PTLD patients with refractory disease (no response to reduced immunosuppression, progressive or relapsed disease, or concomitant allograft rejection). Initial experience was through a voluntary registry (n=26), and most recent experience is from an onging prospective, non-randomized clinical trial (n=14). Use of chemotherapy or other experimental therapies were an exclusion criteria for both studies. All PTLD were of B cell origin and expressed CD20 and all but 2 (both in registry cohort) were EBV positive. The first cohort (registry) comprised 26 solid organ recipients from 12 centers (heart 11, kidney 6, lung 4, other 5) with mean age of 12.5 years, 29 months (range 2–132) from transplant. Histology revealed these lesions: polymorphic 17, monomorphic 7 (including 1 Burkitts-like), Hodgkins-like 1, unspecified 1. 21/26 received 375mg/m2 x 4 doses. There were no SAE’s. 18 pts (69%) showed CR, and 4 (16%) showed PR. The 4 non-responders comprised the 2 EBV negative cases, the Burkitts-like disease and the earliest onset case (fulminant disease at 2 months post-transplant). At latest follow-up (mean 41 months), 73% survive with one graft loss (kidney). In the prospective clinical trial, 14 patients (to date) with refractory disease were enrolled. The protocol comprises 4 doses of 375mg/m2 (weeks 1–4) with no further treatment for patients with CR or for those with no response. Patients with PR receive 4 further doses (weeks 5–8). The 14 patients were from 5 centers (lung 5, kidney 5, heart 4) with mean age of 6.5 years, 41 months (range 4–120) from transplant. Histology revealed the following: polymorphic 10, monomorphic 3, Hodgkin-like 1. There were no SAE’s. Two are still recieving therapy. Of the other 12, 9 (75%) acheived CR and 10 pts (83%) are alive with one graft loss (kidney) at mean follow-up of 1.5 years. The two deaths were due to fungal pneumonia and complications of elective surgery in a patient in CR (both lung recipients). Conclusions: These results suggest that rituximab may have an important role to play in management of refractory PTLD in solid organ recipients (CR rate approx. 70–75% with low incidence of graft loss). This group of patients traditionally has high mortality and has been treated with chemotherapy. Rituximab should be considered as first line treatment for refractory polymorphic PTLD in children after solid organ transplantation. Role in monomorphic disease requires further investigation. Use of rituximab as first line therapy is under investigation.

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