Successful treatment of severe thrombotic thrombocytopenic purpura with the monoclonal antibody rituximab

The only established treatment for patients with thrombotic thrombocytopenic purpura (TTP) is plasma exchange against fresh frozen plasma. For cases refractory to plasma exchange, no generally treatment schedule exists. One option is immunosuppressive therapy with corticosteroids and vincristine. Rituximab is a chimeric monoclonal antibody directed against the CD20 antigen, and it has been successfully used in B-cell malignancies and is being investigated in autoimmune diseases. Its efficacy in TTP has not yet been determined. We report two female patients with severe TTP refractory to multiple courses of plasmapheresis, high-dose steroid treatment, and vincristine who responded after adding rituximab while continuing plasmapheresis.     

Excellent response of refractory life-threatening thrombotic thrombocytopenic purpura to cyclosporine treatment

The introduction of plasma exchange has significantly improved the outcome of thrombotic thrombocytopenic purpura (TTP), and survival has increased from 10 to 80-90%. TTP refractory to plasma exchange therapy, however, is still a therapeutic challenge. We describe here a patient who partially responded to plasma exchange therapy, but remained totally dependent on plasma infusions. Several attempts to discontinue plasma therapy repeatedly lead to relapses. TTP did not response to vincristine, either. After 3 months treatment with plasma therapy, cyclosporine was started. Plasma therapy could be discontinued after 3 weeks on cyclosporine, and serum LDH and blood platelet count were gradually normalized during 2 months. Cyclosporine was tapered off after 6 months treatment, and the patient has stayed in remission ever since. We conclude that cyclosporine is a worthwhile treatment option in patients with refractory TTP.     

Refractory thrombotic thrombocytopenic purpura successfully treated with a combination of rituximab and vincristine

A 26-year-old man was referred to our hospital with vomiting and high fever. He was disoriented and laboratory results showed microangiopathic hemolytic anemia (Hb 7.1 g/dl) and severe thrombocytopenia (15 x 10(3)/microl). The diagnosis of thrombotic thrombocytopenic purpura (TTP) was established. The activity of von Willebrand cleaving protease (ADAMTS13) was found to be remarkably low (<0.5%) and the high activity of the inhibitor (11.0 Bethesda U/ml) was detected, confirming the diagnosis of typical acquired TIP. Although he had been successfully treated with daily plasma exchange and methylprednisolone, he relapsed after a week. To this therapeutic strategy we added four weekly doses of rituximab (375 mg/m2) and two weekly doses of vincristine (1 mg/m2) simultaneously. The response was very rapid and complete, that is, the platelet count recovered to normal seven days after the first rituximab and vincristine treatment. The patient maintains complete remission nine months later under the administration of 17.5 mg prednisolone. Recovery of the plasma ADAMTS13 activity was clearly correlated with the decrease or disappearance of the inhibitor activity. Combination of rituximab and vincristine therapy would appear to be very effective against refractory TTP.     

A dramatic response to rituximab in a patient with resistant thrombotic thrombocytopenic purpura (TTP) who developed acute stroke

Background Refractory condition can occur in 10–30% of all cases of thrombotic thrombocytopenic purpura despite increased frequency of total plasma exchange. Rituximab can affect the clinical outcome of the refractory cases. However, little is known about usefulness of rituximab on central nervous system involvement mimicking acute ischemic stroke. Methods We report the case of a woman with refractory thrombotic thrombocytopenic purpura who developed an acute onset right sided paralysis, dysarthria, and central facial paralysis, suggestive of cerebrovascular accident while under plasma exchange, corticosteroid, and vincristine therapy. Results After initiation of rituximab (375 mg/m² weekly for 4 weeks), a dramatic response occurred and the patient’s neurologic function recovered fully within days. Sustained remission was achieved, and the patient was well 1 year after her admission, while she was on azathioprine treatment. Conclusion This report suggests that rituximab can provide a good outcome of the dramatic central nervous system involvement in patients with thrombotic thrombocytopenic purpura.     

A phase 2 study of the safety and efficacy of rituximab with plasma exchange in acute acquired thrombotic thrombocytopenic purpura

The safety and efficacy of weekly rituximab 375 mg/m(2) (×4), given within 3 days of acute TTP admission, with standard therapy (PEX and steroids) was evaluated. Clinical outcomes were compared to historical controls (n = 40) who had not received rituximab. Within the trial group, 15 of 40 required ICU admission and 15% of all cases with the highest troponin T levels on admission were ventilated. Before the second rituximab infusion, 68% of cases had a platelet count > 50 × 10(9)/L and 38% > 150 × 10(9)/L. Fewer PEX were required in whites compared to nonwhite in the rituximab group (mean 14 vs 21, P = .0095). Inpatient stay was reduced by 7 days in the non-ICU trial cases compared to historical controls (P = .04), especially in whites, with a mean reduction of 7 days (P = .05). Ten percent of trial cases relapsed, median, 27 months (17-31 months), compared to 57% in historical controls, median 18 months (3-60 months; P = .0011). There were no excess infections or serious adverse events with rituximab. In conclusion, rituximab appears a safe and effective therapy. Inpatient stay and relapse are significantly reduced in the rituximab cohort. Rituximab should be considered in conjunction with standard therapy on acute presentation of TTP. This study was registered at www.clinicaltrials.gov as NCT009-3713.     

High versus standard dose methylprednisolone in the acute phase of idiopathic thrombotic thrombocytopenic purpura: a randomized study

Therapeutic plasma exchange (PE) is the accepted therapy for thrombotic thrombocytopenic purpura (TTP). Because not all patients achieve remission, other treatment modalities have been used in addition to PE, but no randomized clinical trial evaluated their efficacy. The aim of this multicentric study was to compare the effectiveness of standard- versus high-dose methylprednisolone as an adjunctive treatment to PE in the acute phase of TTP. Sixty patients with idiopathic TTP were randomized to receive methylprednisolone 1 mg/kg/die intravenous or 10 mg/kg/die for 3 days, thereafter, 2.5 mg/kg/die in addition to PE. Both dosages of steroids were well tolerated. At the end of induction therapy (day 23), the percentage of patients failing to achieve complete remission was significantly higher in the standard dose (16 of 30) than in the high-dose group (seven of 30). Also, the number of cases without a good response at day 9 and the number of deaths were higher in the standard-dose arm, but the differences did not reach the statistical significance. Results of present study indicate that the association of PE with high-dose instead of standard-dose steroids reduces the percentage of TTP patients that fail to achieve complete remission.     

Efficiency of curative and prophylactic treatment with rituximab in ADAMTS13-deficient thrombotic thrombocytopenic purpura: a study of 11 cases

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease that occurs mainly in young adults. Acquired cases are usually a result of antibodies directed against ADAMTS13 (a disintegrin-like and metalloprotease [reprolysin type] with thrombospondin type 1 motif 13), a protease that cleaves the von Willebrand factor multimers. Prognosis has been improved by plasma therapy, but some acute severe forms are refractory to this treatment and achieving a sustained remission is still a challenge in chronic relapsing forms. We therefore conducted a multicentric open-label prospective trial to test the efficacy of rituximab, an anti-B-cell monoclonal antibody, as a curative and prophylactic treatment in patients with TTP as a result of anti-ADAMTS13 antibodies. Six patients were included during an acute refractory TTP episode. Five patients with severe relapsing TTP and persistent anti-ADAMTS13 antibodies were prophylactically treated during remission. All patients received 4 weekly infusions of rituximab. The target of treatment was to restore a significant ADAMTS13 plasma activity (> 10%). Treatment with rituximab led to clinical remission in all cases of acute refractory TTP. In all patients, anti-ADAMTS13 antibodies disappeared, and a significant (18%-75%) plasma ADAMTS13 activity was detected following treatment. Tolerance of rituximab was good. Rituximab is a promising first-line immunosuppressive treatment in patients with acute refractory and severe relapsing TTP related to anti-ADAMTS13 antibodies.     

Excellent response of refractory life‐threatening thrombotic thrombocytopenic purpura to cyclosporine treatment

The introduction of plasma exchange has significantly improved the outcome of thrombotic thrombocytopenic purpura (TTP), and survival has increased from 10 to 80–90%. TTP refractory to plasma exchange therapy, however, is still a therapeutic challenge. We describe here a patient who partially responded to plasma exchange therapy, but remained totally dependent on plasma infusions. Several attempts to discontinue plasma therapy repeatedly lead to relapses. TTP did not response to vincristine, either. After 3 months treatment with plasma therapy, cyclosporine was started. Plasma therapy could be discontinued after 3 weeks on cyclosporine, and serum LDH and blood platelet count were gradually normalized during 2 months. Cyclosporine was tapered off after 6 months treatment, and the patient has stayed in remission ever since. We conclude that cyclosporine is a worthwhile treatment option in patients with refractory TTP.     

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.     

Two cases of refractory thrombotic thrombocytopenic purpura associated with collagen vascular disease were significantly improved by rituximab treatment

Thrombotic thrombocytopenic purpura (TTP) is a rare disorder of small vessels. TTP is associated with deficiency of the von Willebrand factor-cleaving protease, ADAMTS13, and its inhibitor. Low ADAMTS13 activity is present in most of idiopathic TTP patients. The prognosis of TTP was improved by plasma exchange treatment, which replaces the ADAMTS13 and removes ADAMTS13 inhibitor. However, ADAMTS13 activity is normal in some TTP patients. These are found among the secondary TTP patients associated with collagen disease, hematopoietic stem cell transplantation, malignancy, or drugs. In addition, most of them do not respond to plasma exchange. On the other hand, several reports demonstrated that rituximab, which is an anti-CD20 monoclonal antibody, is effective for refractory TTP cases caused by ADAMTS13 deficiency. It is considered that the effect of rituximab is associated with disappearance of ADAMTS13 inhibitor. However, rituximab therapy was effective for the TTP patients with normal ADAMTS13 activity in our cases. We considered another mechanism of rituximab for TTP cases.     

Efficacy of rituximab in acute refractory or chronic relapsing non-familial idiopathic thrombotic thrombocytopenic purpura: a systematic review with pooled data analysis

Idiopathic thrombotic thrombocytopenic purpura (TTP) occurs primarily due to the formation of autoantibody against ADAMTS13, a specific von Willebrand factor-cleaving protease, resulting in low ADAMTS13 activity and subsequent accumulation of large vWF multimers, platelet aggregation and thrombus formation in the microvasculature of tissues. Limited clinical data suggest that the administration of anti-CD20 antibody (rituximab) may be useful in treating acute refractory or chronic relapsing idiopathic TTP. We carried out a systematic review with pooled data analysis using individual patient data to evaluate the efficacy of rituximab in these settings. Fifteen case series and 16 case reports comprising 100 patients were eligible for the study. Median age was 39?years. Male constituted 31?% and female 69?%. Complete remission was seen in 98?%, non-response in 2?% and relapse after complete remission in 9?%. For patients with complete remission, median follow-up was 13?months. Median platelet recovery from the first dose of rituximab was 14?days. ADAMTS13 inhibitor positivity and severe ADAMTS13 deficiency were highly predictive of the response to rituximab, implying that these can be useful markers in predicting response to rituximab in acute refractory or chronic relapsing idiopathic TTP.     

B cell depletion as a novel treatment for systemic lupus erythematosus: a phase I/II dose-escalation trial of rituximab

OBJECTIVE: Safer and more effective therapies are needed for the treatment of systemic lupus erythematosus (SLE). B lymphocytes have been shown to play fundamental pathogenic roles in SLE, and therefore, elimination of B cells with the use of rituximab may represent a new therapy for SLE. METHODS: A phase I/II dose-escalation trial of rituximab added to ongoing therapy in SLE was conducted. Rituximab was administered as a single infusion of 100 mg/m2 (low dose), a single infusion of 375 mg/m2 (intermediate dose), or as 4 infusions (1 week apart) of 375 mg/m2 (high dose). CD19+ lymphocytes were measured to determine the effectiveness of B cell depletion. The Systemic Lupus Activity Measure (SLAM) score was used as the primary outcome for clinical efficacy. RESULTS: Rituximab was well tolerated in this patient population, with most experiencing no significant adverse effects. Only 3 serious adverse events, which were thought to be unrelated to rituximab administration, were noted. A majority of patients (11 of 17) had profound B cell depletion (to <5 CD19+ B cells/microl). In these patients, the SLAM score was significantly improved at 2 and 3 months compared with baseline (P = 0.0016 and P = 0.0022, respectively, by paired t-test). This improvement persisted for 12 months, despite the absence of a significant change in anti-double-stranded DNA antibody and complement levels. Six patients developed human antichimeric antibodies (HACAs) at a level > or =100 ng/ml. These HACA titers were associated with African American ancestry, higher baseline SLAM scores, reduced B cell depletion, and lower levels of rituximab at 2 months after initial infusion. CONCLUSION: Rituximab therapy appears to be safe for the treatment of SLE and holds significant therapeutic promise, at least for the majority of patients experiencing profound B cell depletion. Based on these results, controlled trials of rituximab appear to be warranted.     

Sustained response with rituximab in patients with thrombotic thrombocytopenic purpura: A report of 13 cases and review of the literature

Idiopathic thrombotic thrombocytopenic purpura (TTP) is a life‐threatening disease mediated by autoantibodies directed against ADAMTS‐13. A number of small series and case reports have shown promising results with rituximab in refractory or relapsed TTP. In this report, we present 13 patients with TTP treated with rituximab. Twelve of the 13 patients (92%) achieved complete response; no subsequent relapses occurred with median follow‐up of 24 months (range, 13–84 months). The addition of rituximab to standard therapy appears to be effective in sustaining long‐term remission in TTP. However, the optimal dosing and timing of rituximab warrant further investigation. Am. J. Hematol., 2009. © 2009 Wiley‐Liss, Inc.     

Weekly rituximab followed by monthly rituximab treatment for steroid-refractory chronic graft-versus-host disease: results from a prospective, multicenter, phase II study

Background

Since it was suggested that B cells play a role in the pathogenesis of chronic graft-versus-host disease, rituximab, an anti-CD20 monoclonal antibody targeting B cells, has been shown to be effective in steroid-refractory, chronic graft-versus-host disease. However, most of the data were from small numbers of patients or retrospective analyses. We, therefore, conducted a multicenter phase II study to confirm the efficacy of this treatment strategy that targets B cells.

Design and Methods

We diagnosed and evaluated chronic graft-versus-host disease according to the National Institute of Health criteria for clinical trials on this condition. The treatment consisted of weekly intravenous infusions of rituximab for 4 weeks followed by monthly rituximab for 4 months. We evaluated the patients’ responses and monitored their disease activity until their final visit, which was on day 365. We also assessed the patients’ subsequent quality of life and serum levels of B-cell-activating factor of the tumor necrosis factor family.

Results

Among 37 patients enrolled (median age, 29 years; range 8–57 years), 32 patients responded to rituximab with 8 complete and 24 partial responses. Twenty-one patients maintained their response for 1 year, so their steroid treatment was discontinued or its dose reduced (21/37, or 56.8%), and their scores representing quality of life were improved although these changes were not statistically significant. The responses were better for clinical manifestations of the skin, oral cavity and musculoskeletal system (response rate, 71.4–100%) than for other organs. However, infectious complications and primary disease relapse accounted for the majority of treatment failure. The pre-treatment serum level of B cell-activating factor of the tumor necrosis factor family was not associated with better treatment outcome (P=0.147).

Conclusions

Rituximab could improve clinical responses and quality of life of patients with steroid-refractory chronic graft-versus-host disease, although such patients may need active prophylaxis against infection.     

Successful treatment with rituximab of refractory idiopathic thrombocytopenic purpura in a patient with Kabuki syndrome

Kabuki syndrome (KS) is often associated with autoimmune abnormalities, such as idiopathic thrombocytopenic purpura (ITP), autoimmune hemolytic anemia, leukoplakia and thyroiditis, as well as congenital anomalies. We herein present a KS patient with refractory ITP who achieved durable and complete remission in response to a total of four once-monthly infusions of rituximab. KS patients are often more susceptible to infection, so splenectomy should be avoided. Therefore, rituximab therapy is an alternative option for KS patients with ITP who fail to respond to first-line therapy.