Anti-CD20 antibody in thrombotic thrombocytopenic purpura refractory to plasma exchange

Thrombotic thrombocytopenic purpura is a rare condition characterized by microangiopathic haemolytic anaemia, thrombocytopenia, altered neurology, renal impairment and fever. While plasma exchange has reduced mortality from more than 90% to between 10 and 30%, a proportion of cases fail to respond. Rituximab may be efficacious in the management of refractory cases of thrombotic thrombocytopenic purpura. We present two cases in which rituximab was used with successful outcomes. Treatment resulted in resolution of severe clinical and haematological abnormalities in both patients. There has been no relapse after 16 months follow up. Our experience supports the use of rituximab in difficult cases of TTP. Ongoing evaluation of its use is in progress at our institution.     

Refractory thrombotic thrombocytopenic purpura in a 16‐year‐old girl: successful treatment with bortezomib

We present a case of a 16‐year‐old girl with autoimmune thrombotic thrombocytopenic purpura (TTP), refractory to plasma exchange and high‐dose prednisone. Despite the additional treatment with rituximab, she developed renal and neurological complications with ongoing hemolysis and thrombocytopenia. Bortezomib, a proteasome inhibitor and thereby blocking plasma cells, was added, and our patient recovered. We suggest that bortezomib can be of additional value in severe immunologically mediated TTP in adolescents. Its use may prevent the necessity of other invasive therapies, such as splenectomy, with significant side effects.     

Rituximab for refractory and or relapsing thrombotic thrombocytopenic purpura related to immune‐mediated severe ADAMTS13‐deficiency: a report of four cases and a systematic review of the literature

Thrombotic thrombocytopenic purpura (TTP) is a potentially life‐threatening disorder that in significant proportion of cases is related to the development of autoantibodies to, and resulting severe deficiency of, the ADAMTS13 protease. However, ADAMTS13 deficiency does not account for all cases. Response to plasma exchange (PE) is seen in TTP with and without ADAMTS13 deficiency and is therefore indicated for all with a clinical diagnosis of TTP, although the pathogenesis of the latter group remains to be defined. Although the majority of cases respond to PE, a significant percent are refractory or experience relapse. Rituximab is being increasingly used off‐label in this setting, but many reports do not define the pathogenesis of TTP so treated. We here report our experience with, and systematically review the published experience to date, of rituximab in management of refractory and or relapsing TTP specifically related to immune‐mediated severe ADAMTS13‐deficiency. In total, 73 patients met defined study inclusion criteria. The majority (～95%) achieved complete remission within weeks of the first application of rituximab. The reported relapse rate was low in this patient subgroup, which carry an anticipated relapse rate of up to 60%. However, caution in interpretation of this data is needed given the relatively short median duration of follow‐up of approximately 10 months. Rituximab was generally well tolerated, with few serious adverse events reported. However, three severe infectious complications were identified, including viral reactivation in keeping with black box warnings for this agent. Furthermore, reflecting the rarity of this disorder, only a relatively small number of patients have been treated and data with regards to long‐term follow‐up are largely based on individual case reports. Prospective studies are urgently needed to define the true efficacy and long‐term safety of rituximab.     

Role of ADAMTS13 in the management of thrombotic microangiopathies including thrombotic thrombocytopenic purpura (TTP)

The clinical presentation of thrombotic thrombocytopenia purpura (TTP) and other thrombotic microangiopathies (TMAs) can often be similar. The role of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) in diagnosing TTP is accepted by most researchers but continues to be debated in a few studies. We report the experience of our single‐centre academic institution, where ADAMTS13 is used to diagnose TTP and guide plasma exchange (PLEX). Patients presenting to our institution with thrombotic microangiopathy (60 patients) between January 2006 and December 2012 were divided into two groups based on ADAMTS13 activity and clinical history. Patients with ADAMTS13 activity <10% were included in the TTP (n = 30) cohort while patients with activity >11% were classified as ‘other microangiopathies’ (TMA, n = 30). PLEX was only initiated in patients with a high likelihood of TTP and discontinued when the baseline ADAMTS13 activity was >11%. Patients with severe ADAMTS13 deficiency (TTP group) showed significant presenting differences: lower platelet counts, less renal dysfunction, higher presence of neurological abnormalities, and greater haemolysis markers as compared to non‐deficient patients (TMA group). Most importantly, patients without severe ADAMTS13 deficiency were safely managed without increased mortality despite receiving no PLEX or discontinuing PLEX after a short course (upon availability of ADAMTS13 results). In conclusion, ADAMTS13 can be used to diagnose TTP and guide appropriate PLEX therapy.     

Acquired thrombotic thrombocytopenic purpura as the presenting symptom of systemic lupus erythematosus. Successful treatment with plasma exchange and immunosuppression--report of two cases

Thrombotic thrombocytopenic purpura (TTP) is a rare but life-threatening syndrome characterized by platelet aggregation causing occlusive microangiopathy. It has been described as a complication in systemic lupus erythematosus (SLE). Recent research indicated that genetic or autoantibody-induced deficiency of the metalloprotease ADAMTS13 plays a key role in the pathogenesis of TTP. Here we report two uncommon cases of TTP as the first presenting symptom of SLE. Both patients were treated with combined plasma exchange and immunosuppressive therapy, and recovered completely. Although TTP and SLE have several clinical findings in common, and both disorders may coexist more frequently than we currently assume, features of one disease should not mislead to reject the alternative disorder.     

Cryosupernatant as replacement fluid for plasma exchange in thrombotic thrombocytopenic purpura

The current established treatment of thrombotic thrombocytopenic purpura (TTP) is plasma exchange with fresh frozen plasma (FFP). With this treatment, there is a 49% response after seven exchanges and a 78% survival at 1 month. Although the exact cause of TTP is unknown, the presence of von Willebrand factor (VWF) multimers has been implicated in the disease. Accordingly, it has been suggested that cryosupernatant (plasma from which cryoprecipitate has been removed), which is relatively deficient in VWF multimers, might be an effective replacement fluid during plasma exchange.
Patients from six centres were treated by plasma exchange with cryosupernatant. 18 patients who had failed a first course (average 7.7 exchanges) of plasma exchange with FFP, received a further seven exchanges with cryosupernatant. Subsequently, 40 previously untreated patients were exchanged with cryosupernatant.
Of the 18 previously treated patients, 11 responded (defined as an increase in platelet count to >150 × 10⁹/l and no neurological events) after seven exchanges and 15 (83%) of the patients were alive at 1 month. The response rate in the 40 previously untreated patients was 75% at the end of seven exchanges and 95% of the patients were alive at 1 month. These values are significantly different ( P <0.05) from those reported in our earlier study and in other patients concurrently treated at the same centres with FFP when cryosupernatant was not available.
Some patients who have failed to respond to plasma exchange with FFP replacement will respond to further exchange with cryosupernatant. Cryosupernatant replacement may be more effective as first-line treatment of TTP than FFP.     

Methylene blue-photoinactivated plasma vs. fresh-frozen plasma as replacement fluid for plasma exchange in thrombotic thrombocytopenic purpura

BACKGROUND AND OBJECTIVES: Plasma exchange with fresh-frozen plasma (FFP) is the treatment of choice in thrombotic thrombocytopenic purpura (TTP). Methylene blue-photoinactivated plasma (MBPIP) has been proposed as a safer alternative to FFP, but its effectiveness in the treatment of TTP is not well established. The purpose of this study was to investigate whether MBPIP is as effective as FFP in the treatment of TTP by plasma exchange. MATERIALS AND METHODS: A retrospective analysis was carried out of 56 TTP episodes, occurring between 1990 and 2003, which had been treated by plasma exchange. MBPIP was used for fluid replacement in 27 episodes and FFP in 29. The effect of plasma (MBPIP or FFP) on treatment outcomes was analysed by multivariate logistic regression. RESULTS: Compared to patients treated with FFP, those receiving MBPIP had an increased risk of dying from progressive TTP [adjusted odds ratio (OR) = 31; 95% confidence interval (CI): 1.2 to > 100], a greater number of recurrences while on plasma exchange therapy (OR = 4.6; 95% CI: 1.2-17), and a lower probability of attaining a sustained remission within 9 days of starting plasma exchange (OR = 5.2; 95% CI: 1.3-20). CONCLUSIONS: MBPIP seems to be less effective than FFP in the treatment of TTP. It is therefore prudent to avoid MBPIP until therapeutic equivalency to FFP has been established by randomized, controlled trials.     

Methylene blue-photoinactivated plasma versus quarantine fresh frozen plasma in thrombotic thrombocytopenic purpura: a multicentric, prospective cohort study

Plasma exchange (PE) with plasma infusion is the treatment of choice for thrombotic thrombocytopenic purpura (TTP) but doubts remain as to whether all kinds of plasma are equally effective. A multicentric cohort study was conducted to compare methylene blue-photoinactivated plasma (MBPIP) with quarantine fresh frozen plasma (qFFP) in the treatment of TTP. One hundred and two episodes of idiopathic TTP were included; MBPIP was used in 63 and qFFP in 39. The treatment schedule consisted of daily PE and costicosteroids, and the main end-point was remission status on day 8. Patients treated with MBPIP required more PEs (median: 11 vs. 5, P = 0.002) and a larger volume of plasma (median: 485 ml/kg vs. 216 ml/kg, P = 0.007) to achieve a remission, and presented more recrudescences while on PE therapy (29 of 63 vs. 8 of 39, P = 0.02) than those receiving qFFP. After adjustment for possible confounding factors, the use of MBPIP was associated with a lower likelihood of remission on day 8 [Odds ratio (OR): 0.17; 95% confidence interval (CI): 0.06-0.47] and a higher risk of recrudescence while on treatment (OR: 4.2; 95% CI: 1.6-10.8). In conclusion, MBPIP is less effective than qFFP in the treatment of TTP.     

The treatment of thrombotic thrombocytopenic purpura: plasma infusion or exchange?

SUMMARY. Classic thrombotic thrombocytopenic purpura has substantial mortality and, because the pathogenesis is uncertain, multiple therapies are often used. These include corticosteroids and antiplatelet drugs, with plasma infusion or exchange most dramatically influencing outcome. To compare the relative efficacy of these latter two options, the records of 20 patients were retrospectively analysed. The groups were well matched for size and disease severity and received equivalent volumes of plasma. No significant difference in response rate or survival was demonstrated, although plasmapheresis may be preferable in the presence of impaired renal function with fluid overload.     

New mutation found to cause hereditary thrombotic thrombocytopenic purpura in a patient presenting with seizures in adulthood

Abstract

We present a case of hereditary thrombotic thrombocytopenic purpura (hTTP) caused by a previously undescribed mutation in a 36-year-old woman who presented with seizures in the context of a possible infection. Her hematologic manifestations were mild, despite undetectable ADAMTS13 (A Distintegrin and Metalloproteinase with Thrombospondin Motifs 13) activity. Genetic analysis showed a homozygous variant in ADAMTS13 gene which was not previously reported but predicted to be associated with disease. She responded to plasma therapy. Her diagnosis subsequently led to the diagnosis of hTTP in her younger sibling who presented with unexplained strokes a few years earlier.     

Treatment of thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP), characterized by thrombocytopenia and microangiopathic haemolytic anaemia, was almost universally fatal until the introduction of plasma exchange (PE) therapy in the 1970s. Based on clinical studies, daily PE has become the first-choice therapy since 1991. Recent findings may explain its effectiveness, which may include, in particular, the removal of anti-ADAMTS13 autoantibodies and unusually large von Willebrand factor multimers and/or supply of ADAMTS13 in acquired idiopathic or congenital TTP. Based on currently available data, the favoured PE regimen is daily PE [involving replacement of 1-1.5 times the patient's plasma volume with fresh-frozen plasma (FFP)] until remission. Adverse events of treatment are mainly related to central venous catheters. The potential reduction of plasma related side-effects, such as transfusion-related acute lung injury (TRALI) or febrile transfusion reactions by use of solvent-detergent treated (S/D) plasma instead of FFP is not established by controlled clinical studies. Uncontrolled clinical observations and the hypothesis of an autoimmune process in a significant part of the patients with acquired idiopathic TTP suggest a beneficial effect of adjunctive therapy with corticosteroids. Other immunosuppressive treatments are not tested in controlled trials and should be reserved for refractory or relapsing disease. There is no convincing evidence for the use of antiplatelet agents. Supportive treatment with transfusion of red blood cells or platelets has to be evaluated on a clinical basis, but the transfusion trigger for platelets should be very restrictive. Further controlled, prospective studies should consider the different pathophysiological features of thrombotic microangiopathies, address the prognostic significance of ADAMTS13 and explore alternative exchange fluids to FFP, the role of immunosuppressive therapies and of new plasma saving approaches as recombinant ADAMTS13 and protein A immunoadsorption.     

The course of ADAMTS-13 activity and inhibitor titre in the treatment of thrombotic thrombocytopenic purpura with plasma exchange and vincristine

The therapeutic efficacy of plasma exchange (PE) in thrombotic thrombocytopenic purpura (TTP) is attributed to the restoration in ADAMTS-13 (a disintegrin and metalloproteinase with thrombospondin motif-13) activity by substitution of the enzyme and removal of ADAMTS-13-neutralizing autoantibodies. We explored this rationale by analysing ADAMTS-13 activity and corresponding inhibitor levels during PE-treatment in 27 episodes from 23 adults with TTP. All patients with an initial episode of TTP (n = 14) and nine of 11 patients with a relapse showed severe ADAMTS-13 deficiency. ADAMTS-13 inhibitors were detected in 81% of these patients. Twenty-one patients responded to PE-therapy and two patients died. For patients with severe ADAMTS-13 deficiency, 15 patients (71%) showed a PE-induced recovery in ADAMTS-13 activity and six patients (29%) had persistent severe ADAMTS-13 deficiency despite clinical response. Three patients with recurrent TTP demonstrated a permanent increase in inhibitor titre during therapy. Six patients (43%) with an initial episode of TTP displayed a transient increase in inhibitor titre during PE-therapy, which was associated with deterioration in clinical and haematological symptoms of TTP. Treatment with vincristine induced an immediate increase in platelet count and ADAMTS-13 activity in seven of eight patients. We conclude that ADAMTS-13 activity and inhibitor levels, as measured using current methodology, do not solely determine the clinical course of TTP.     

Rituximab induces remission of cerebral ischemia caused by thrombotic thrombocytopenic purpura

OBJECTIVE: This report describes the experience of a case of atypical thrombotic thrombocytopenic purpura (TTP) whose diagnosis was based on severe deficiency of the von Willebrand factor (vWF) cleaving metalloprotease ADAMTS13. METHODS: The level of ADAMTS13 activity, the titer of the inhibitors of this protease and the size distribution of vWF multimers in plasma samples were analysed in a patient with recurrent episodes of dizziness and blurred vision. RESULTS: In the absence of thrombocytopenia or microangiopathic hemolysis, diagnosis of TTP was established by demonstration of very low ADAMTS13 activity levels and the presence of inhibitors of this protease. After rituximab therapy decreased the inhibitor titer and increased the ADAMTS13 level, the patient has had no relapse of ischemic symptoms in the following 16 months. CONCLUSIONS: Acute neurological deficits may occur in TTP without concurrent thrombocytopenia or microangiopathic hemolysis. The role of rituximab for patients with TTP deserves further exploration.     

Post-appendectomy thrombotic thrombocytopenic purpura: a case report and review of the literature

Thrombotic thrombocytopenic purpura (TTP) is a syndrome characterized by microangiopathic hemolytic anemia and thrombocytopenia with varying degrees of renal dysfunction, neurologic signs and symptoms, and fever. Evidence has supported that a large proportion of cases of acquired TTP are due to the accumulation of ultralarge von Willebrand factor (vWF) multimers due to an acquired deficiency in the vWF cleaving protease, ADAMTS-13. TTP is rare in the post-surgical setting but is best described after cardiothoracic and vascular surgeries. We present a case of postoperative TTP first presenting with microangiopathic hemolytic anemia and thrombocytopenia 9 days after emergent appendectomy for a ruptured appendix. ADAMTS-13 and factor H levels returned normal and an ADAMTS-13 inhibitor was not identified. To our knowledge, this is the first case report of postoperative TTP after an appendectomy and the first report with correlative ADAMTS-13 data. Plasma exchange with fresh frozen plasma followed by cryopoor plasma, along with steroids resulted in eventual remission of TTP in our patient. Early postoperative diagnosis and aggressive management with consideration of initiation of plasma exchange is imperative to decrease the morbidity and morality associated with TTP.     

Development and validation of a predictive model for death in acquired severe ADAMTS13 deficiency-associated idiopathic thrombotic thrombocytopenic purpura: the French TMA Reference Center experience

Background

Acquired thrombotic thrombocytopenic purpura is still associated with a 10–20% death rate. It has still not been possible to clearly identify early prognostic factors of death. This study involved thrombotic thrombocytopenic purpura patients with acquired severe (<10% of normal activity) ADAMTS13 deficiency and aimed to identify prognostic factors associated with 30-day death.

Design and Methods

The study involved a prospective cohort of patients and was carried out between October 2000 and August 2010. A validation cohort of patients was set up from September 2010 to August 2011. Altogether, 281 (analysis cohort) and 66 (validation cohort) consecutive adult thrombotic thrombocytopenic purpura patients with acquired severe ADAMTS13 deficiency were enrolled. The study evaluated 30-day mortality after treatment initiation according to characteristics at inclusion.

Results

Non-survivors (11%) were older (P=10⁻⁶) and more frequently presented arterial hypertension (P=5.10⁻⁴) and ischemic heart disease (P=0.013). Prognosis was increasingly poor with age (P=0.004). On presentation, cerebral manifestations were more frequent in non-survivors (P=0.018) and serum creatinine level was higher (P=0.008). The most significant independent variables determining death were age, severe cerebral involvement and LDH level 10 N or over. A 3-level risk score for early death was defined and confirmed in the validation cohort using these variables, with higher values corresponding to increased risk of early death.

Conclusions

A risk score for early death was defined in patients with thrombotic thrombocytopenic purpura and validated on an independent cohort. This score should help to stratify early treatment and identify patients with a worse prognosis.