Thrombotic thrombocytopenic purpura (TTP) and splenectomy: a current appraisal

[Treatment of thrombotic thrombocytopenic purpura]

The review discusses approaches to treatment of acquired thrombotic thrombocytopenic purpuгa (aTTP). In patients with aTTP plasma exchanges, glucocorticosteroids allow to stop an acute attack of TTP, and use of rituximab allows to achieve remission. In recent years, caplacizumab has been used. Treatment options such as cyclosporin A, bortezomib, splenectomy, N-acetylcysteine, recombinant ADAMTS13 are also described. Separately discussed issues of management of patients with TTP during pregnancy, and pediatric patients with TTP.

Thrombotic Thrombocytopenic Purpura

Thrombotic thrombocytopenic purpura (TTP) is classically highlighted by a pentad of features: fever, hemolytic anemia, thrombocytopenia purpura, transient or permanent central nervous system signs, and renal disease. The antemortem diagnosis is reliant upon the multisystem clinical signs and symptoms in conjunction with severe hemolytic anemia and thrombocytopenia. Relapse is common within the first six months after initial presentation. Laboratory findings have been generally nonspecific per se, and antemortem tissue biopsy findings are frequently unrewarding. Recently, however, unusually large multimers of the Factor VIII:Ag molecule (von Willebrand protein) have been identified in the plasma of patients with TTP who have recovered from an acute attack. This observation is very important because it may lead to essential information on the nature of the inciting event in this devastating illness. The differential diagnosis includes several multisystem disease processes such as the hemolytic uremic syndrome, toxemia of pregnancy, systemic lupus erythematosus, subacute bacterial endocarditis, nonbacterial thrombotic endocarditis, immune thrombocytopenic purpura, and the postpartum renal failure syndrome. The hemolytic uremic syndrome, toxemia of pregnancy, and TTP may resemble each other, exhibit many overlapping features, and are probably related. The cause of TTP remains unknown; the overwhelming majority of cases occur in otherwise healthy people without any recognizable underlying illness. Since 1965 45 to 70% of patients survive, a significant improvement in contrast to the early 1900s when the mortality rate was greater than 90%. The most dramatic advance has been observed in therapeutics, namely the utilization of some mode of plasma therapy (either infusion alone or plasmapheresis followed by plasma infusion). Corticosteroids remain very important in the management of patients with TTP. Vincristine may be very helpful, but additional studies are needed. The efficacy of vinca alkaloids, chronic immunosuppressive therapy, and sple. nectomy remains undefined. At present there is very little, if any, evidence that antiplatelet agents, aspirin, and prostacyclin are beneficial to patients with TTP. Prompt diagnosis and vigorous aggressive therapy is critical for successful management of TTP patients.

Case series: splenectomy: does it still play a role in the management of thrombotic thrombocytopenic purpura?

BACKGROUND

Plasma exchange is first-line therapy for patients with thrombotic thrombocytopenic purpura (TTP). Splenectomy is often indicated for patients with relapsing or refractory disease. Concerns exist about its efficacy and safety in these patients. We describe a series of patients whose TTP was treated with laparoscopic splenectomy. We also reviewed the literature in order to describe the use and safety of splenectomy for refractory or relapsing TTP.

METHODS

We reviewed the charts of consecutive patients with TTP referred for splenectomy and searched MEDLINE for studies describing outcomes following splenectomy for relapsing or refractory TTP.

RESULTS

In all, 5 patients were referred for relapsing TTP and underwent uneventful laparoscopic splenectomy. All 5 were in remission after more than 40 months of follow-up. We found 18 studies (87 patients) reporting the results of splenectomy for relapsing TTP and 15 studies (74 patients) involving patients who underwent splenectomy for refractory TTP. The aggregate complication (6% v. 10%) and mortality rates (1.2% v. 5%) were lower for patients who received treatment for relapsing versus refractory TTP. The rate of postsplenectomy relapse among patients with relapsing disease was 17%, whereas the nonresponse rate was 8% for patients with refractory TTP. There were no complications among the 22 laparoscopic cases reported.

CONCLUSION

Although the data supporting splenectomy for treatment of TTP are limited to case series with no control groups, they suggest that splenectomy is an option for patients with refractory or relapsing disease. When performed laparoscopically in patients with relapsing disease, splenectomy is associated with minimal morbidity and mortality.

Clinical outcomes after platelet transfusions in patients with thrombotic thrombocytopenic purpura

BACKGROUND

Reports of deterioration and death after platelet (PLT) transfusions in patients with thrombotic thrombocytopenic purpura (TTP) have led to recommendations that they should not be given except for life-threatening hemorrhage.

STUDY DESIGN AND METHODS

Published reports of PLT transfusions in patients with TTP were systematically reviewed and data from the Oklahoma TTP-HUS Registry, an inception cohort of 382 consecutive patients, 1989 through 2007, were analyzed.

RESULTS

A systematic review identified 34 publications describing outcomes of patients with TTP after PLT transfusions: 9 articles attributed complications to PLT transfusions, 4 suggested that they may be safe, and 21 articles did not comment about a relation between PLT transfusions and outcomes. Fifty-four consecutive patients from the Oklahoma TTP-HUS Registry were prospectively analyzed. ADAMTS13 activity was less than 10 percent in 47 patients; also included were 7 patients whose activity was not measured but who may have been deficient. Thirty-three (61%) patients received PLT transfusions. The frequency of death was not different between the two groups (p = 0.971): 8 (24%) patients who received PLT transfusions died (thrombosis, 5; hemorrhage, 1; sepsis, 2) and 5 (24%) patients who did not receive PLT transfusions died (thrombosis, 4; hemorrhage, 1). The frequency of severe neurologic events was also not different (p = 0.190): 17 (52%) patients who received PLT transfusions (in 5 of these 17 patients, neurologic events only occurred before PLT transfusions) and 7 (33%) patients who did not receive PLT transfusions.

CONCLUSION

Evidence for harm from PLT transfusions in patients with TTP is uncertain.

Outcomes in the treatment of thrombotic thrombocytopenic purpura with splenectomy: a retrospective cohort study

The mainstay of treatment for thrombotic thrombocytopenic purpura (TTP) is plasma exchange (PE), but the role of splenectomy is still undefined. The records of all patients with TTP at a single center over a 20-year period were retrospectively reviewed. Response to plasma exchange was determined. The outcome of patients treated with splenectomy in the setting of TTP was evaluated. Sixty-one patients had been treated for TTP. Thirty-nine patients (64%) achieved complete remission (CR) with PE, nineteen (31%) of these achieving sustained CR and seventeen (28%) with relapsed TTP. Twenty patients (33%) had PE refractory TTP and two patients (3%) had PE dependent TTP. During this time period, 10 patients (16%) underwent splenectomy, four patients (7%) for PE dependent TTP, three (5%) for relapsed TTP, and three (5%) for refractory TTP. All of the patients achieved CR after splenectomy. Two patients who had undergone splenectomy had subsequent relapses, both with previously relapsed TTP. In relapsed patients the relapse rate after splenectomy was 0.27 events per patient year compared to 0.6 events per patient year before splenectomy. Median follow-up after splenectomy was 19 months (range 0.13-90 months). In conclusion, relapses in TTP can be managed successfully with additional PE or with splenectomy. PE dependent or refractory TTP can be successfully treated with splenectomy.

Splenectomy for the treatment of thrombotic thrombocytopenic purpura

Plasma exchange is the treatment of choice for patients with thrombotic thrombocytopenic purpura (TTP) and results in remission in >80% of the cases. Treatment of patients who are refractory to plasma therapy or have relapsing disease is difficult. Splenectomy has been a therapeutic option in these conditions but its value remains controversial. We report on a series of 33 patients with TTP who were splenectomised because they were plasma refractory (n = 9) or for relapsed disease (n = 24). Splenectomy generated prompt and unmaintained remissions in all except five patients, in whom remission was delayed (n = 4) or who died with progressive disease (n = 1). Four postoperative complications occurred: one pulmonary embolism and three surgical complications. Median follow-up after splenectomy was 109 months (range 28-230 months). The overall postsplenectomy relapse rate was 0.09 relapses/patient-year and the 10-year relapse-free survival (RFS) was 70% (95% CI 50-83%). In the patients with relapsing TTP, relapse rate fell from 0.74 relapses/patient-year before splenectomy to 0.10 after splenectomy (P < 0.00001). Two patients died from first postsplenectomy relapse. Although these results are based on retrospective data and that the relapse rate may spontaneously decrease with time, we conclude that splenectomy, when performed during stable disease, has an acceptable safety profile and should be considered in cases of plasma refractoriness or relapsing TTP to reach durable remissions and to reduce or prevent future relapses.

Thrombotic thrombocytopenic purpura: indications for and results of splenectomy

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP) is a rare, life-threatening disorder of unknown pathophysiology. The role of splenectomy in the multimodality therapy of TTP is controversial.

MATERIALS AND METHODS

All charts of patients with TTP at the University of Utah between 1984 and 1994 were reviewed to evaluate various treatment regimens, and specifically, the impact of splenectomy on morbidity and survival.

RESULTS

Of the 15 patients identified, 14 underwent initial treatment with plasmapheresis and steroids. Nine patients were treated with medical therapy only, 6 of whom completely recovered, while 3 patients died. Six patients failed plasmapheresis and underwent splenectomy. There were no operative complications or postoperative deaths. All surgical patients had no active disease at last follow-up.

CONCLUSION

Plasmapheresis and steroid administration remain the first-line therapy for TTP. This series documents that splenectomy offers excellent results with minimal morbidity and mortality in patients who do not respond to or who relapse after plasmapheresis.

The role of splenectomy in the treatment of relapsing thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a serious disorder of unknown etiology. Clinical findings are the result of vascular occlusions by platelet aggregates. Treatment with plasma exchange, often used in combination with corticosteroids, vincristine, aspirin, and dipyridamole, has reduced mortality to 20%. Relapses may occur even after long disease-free intervals. In this report we describe our experience with splenectomy in patients with relapsing TTP. Between July 1978 and March 1994, 16 patients with TTP were treated in our hospital. Five of the 13 patients surviving the first episode of TTP had relapses. Most relapses were treated as the first episode of TTP with plasma exchange with fresh-frozen plasma, followed by plasma infusions, corticosteroids, and vincristine. Sometimes aspirin and dipyridamole were added. Splenectomy was performed after five relapses in the first two patients and after two and three relapses in the other patients. Before splenectomy the disease-free interval varied from 3 weeks to 27 months and the incidence rate of relapses was 1.5 relapse/patient/year. None of the patients had relapses after splenectomy. The mean follow-up after splenectomy is 39 months with a range of 9-62 months. We conclude that patients with relapsing TTP can benefit from splenectomy, since it seems to increase disease-free intervals. Further investigation is necessary to understand the role of the spleen in the pathogenesis of TTP.

The gingival biopsy in the diagnosis of thrombotic thrombocytopenic purpura

Gingival biopsy specimens from five patients with a clinical diagnosis of thrombotic thrombocytopenic purpura (TTP) were reviewed. All biopsy specimens demonstrated the characteristic histologic lesion associated with TTP. Review of the literature showed an average diagnostic yield of 37% (30/81) for this procedure. The increase in diagnostic correlation in this study may be explained in part by the marked degree of disease expression in the patients who underwent gingival biopsy. Three of the five patients who underwent gingival biopsies ultimately died of their disease. In addition, a persistent search through multiple serial sections for the characteristic lesion, beyond the usual three levels, was performed. Despite the disparity in diagnostic yield, we consider the gingival biopsy to be a safe diagnostic correlate of TTP because of easy access, rich vascularity, and low surgical morbidity. Furthermore, we recommend biopsy, as Goodman and colleagues have, only in areas of the gingiva that appear clinically normal and free of inflammation in order to reduce misinterpretation as a consequence of false-positive intraluminal fibrin thrombi that may occur with inflammation.

Management of treatment failures in thrombotic thrombocytopenic purpura

The prognosis and optimal management of patients with thrombotic thrombocytopenic purpura (TTP) who fail initial therapy with plasmapheresis or splenectomy are unclear. We report our experience with eight patients with TTP who did not respond to initial therapy. Seven patients achieved complete remission when alternate therapy was started soon after the recognition of initial treatment failure. One patient who received no alternative therapy died of progressive TTP. Our cases combined with those in the literature indicate a 74% salvage rate for patients who fail initial treatment for TTP. The combination of splenectomy, dextran, and steroids appears to be an effective treatment for patients with TTP who fail to respond adequately to plasmapheresis.

Thrombotic thrombocytopenic purpura: recovery after splenectomy associated with persistence of abnormally large von Willebrand factor multimers

A patient with thrombotic thrombocytopenic purpura (TTP) responded transiently to four courses of plasma exchange therapy, then subsequently had a sustained completed remission following splenectomy. The von Willebrand factor multimeric pattern during remission following each plasma exchange and during the entire postsplenectomy period showed abnormally large forms that were not present on presentation and with each clinical relapse. These findings support prior observations regarding the presence of abnormal von Willebrand factor multimers in relapsing TTP and suggest that the multimers contribute to platelet aggregation and the thrombotic lesions. The association of sustained remission and persistence of the abnormally large plasma multimers after splenectomy suggests that this response was not coincidental. This supports the concept that a subgroup of patients with TTP may exist in which the pathophysiology of disease is significantly modulated by the spleen and in which splenectomy may induce long-lasting remission.

The role of splenectomy in multimodality treatment of thrombotic thrombocytopenic purpura

Current treatment modalities for thrombotic thrombocytopenic purpura (TTP) include plasmapheresis (PP), splenectomy, steroids, dextran, other antiplatelet agents, and vinca alkaloids. Prior to the development of PP and use of multimodality treatment for TTP, mortality rates exceeded 50%. This report reviews 11 patients treated for TTP, demonstrates the successful use of splenectomy as salvage therapy, and defines our indications for splenectomy in the treatment of this disorder. Ten of 11 patients were initially treated with PP; three responded completely and one died of fulminant disease. Six patients had a transient partial response to plasmapheresis and were subsequently treated with splenectomy, steroids, and dextran-70. Initial plasmapheresis resulted in improvement in laboratory values and clinical status in those patients requiring splenectomy. Durable remission (6-48 months) was achieved in 91% of patients with minimal morbidity.