Thrombotic thrombocytopenic purpura: recovery after plasmapheresis, corticosteroids, splenectomy, and antiplatelet agents

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.

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.

Improved survival in thrombotic thrombocytopenic purpura-hemolytic uremic syndrome. Clinical experience in 108 patients

BACKGROUND AND METHODS

Thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) is characterized by microangiopathic hemolytic anemia, thrombocytopenia, fever, central nervous system abnormalities, and renal dysfunction. In early reports the mortality approached 100 percent. A treatment protocol was introduced in 1979 for patients admitted to Johns Hopkins Hospital with the diagnosis of TTP-HUS. Treatment regimens included 200 mg of prednisone a day, for patients with minimal symptoms and no central nervous system symptoms, and prednisone plus plasma exchange, for patients with rapid clinical deterioration who did not improve after 48 hours of prednisone alone and for patients presenting with central nervous system symptoms and rapidly declining hematocrit values and platelet counts.

RESULTS

A total of 108 patients were treated, and 91 percent survived. Prednisone alone was judged to be effective in 30 patients with mild TTP-HUS (two relapses and two deaths). Plasma exchange plus prednisone was given to 78 patients with complicated TTP-HUS, resulting in 67 relapses and 8 deaths. Relapses occurred in 22 of 36 patients given maintenance plasma infusions. Neither splenectomy nor treatment with aspirin and dipyridamole was effective in those with a poor response to plasma exchange. None of the 71 patients tested had positive cultures for O157:H7 Escherichia coli. Nine percent of the patients were pregnant, and none gave birth to infants with TTP-HUS.

CONCLUSIONS

Effective treatment with 91 percent survival is available for patients with TTP-HUS.

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.

Apheresis in hematologic and oncologic disease

Therapeutic bloodletting dates back to ancient times. With the development of sophisticated in vivo cell separators, it has become an established and effective modality in the treatment of a number of hematologic-oncologic diseases. Apheresis must, however, be used with discrimination--only when more conservative measures have proved inadequate.

Thrombotic thrombocytopenic purpura: report of fourteen cases--occurrence during pregnancy and response to plasma exchange

Thrombotic thrombocytopenic purpura (TTP), a syndrome of diverse etiology probably related to factors regulating platelet-vessel wall interaction, is predominantly a disorder of women. We report our experience with 14 patients in an 11-year period. Thirteen were female and aged between 25-69 years. Four were postmenopausal, and of the nine premenopausal women three were pregnant, one was immediately postpartum, and three were taking estrogen-containing oral contraceptives. A review of the literature confirms the two to one female/male preponderance and that TTP is reported in 56 women who are pregnant or recently postpartum. While this association with possible hormonal events has been noted, it has previously received little comment. We stress the similarity between TTP and some occurrences of preeclamptic toxemia, and that this may suggest not only a common etiology but that therapeutic attempts should be similar. While no single therapeutic modality is universally successful, our experience is that plasma exchange is the most effective, with five of seven patients so-treated obtaining prolonged remission; four of five patients responded to splenectomy and corticosteroids, but one died of infection postoperatively. Five patients, including two treated exclusively with antiplatelet aggregating agents, died without achieving remission. The frequency of successful therapy is not changed by the concurrent pregnancy, but the fetal loss is high. There does seem to be an increased risk of recurrence of TTP in a subsequent pregnancy, and this might be considered when counseling premenopausal patients who have achieved remission of TTP.