Non-splenectomized Patients Research Articles

Increased platelet adhesion under flow conditions is induced by both thalassemic platelets and red blood cells

Thromboembolic complications are not uncommon in thalassemia. Previous studies suggest increased platelet aggregation and a potential role of pathological changes in the red blood cell (RBC) lipid membrane, induced by oxidative stress. In the present study, platelet adhesion and the effect of thalassemic RBC on platelet adhesion under flow conditions were evaluated, using the Cone and Plate (let) Analyzer(CPA). Twenty-two beta-thalassemia patients and 22 blood type-matched healthy controls were studied. An increased platelet adhesion (% surface coverage, SC), was observed in patients as compared to controls (p < 0.05). When platelet count and haematocrit were normalized by autologous reconstitution, a significant increase in platelet aggregation (average size, AS) was observed (p < 0.05). Increased platelet adhesion (SC and AS), was demonstrated in six patients with a history of thrombosis as compared to 16 patients without any history of thrombosis (p < or = 0.007) and in 17 splenectomized patients as compared to five non-splenectomized patients (p = 0.003). In reconstitution studies, thalassemic RBC mixed with normal platelet-rich plasma significantly increased platelet adhesion compared to normal RBC (SC p < 0.03, AS p < 0.02). Thalassemic platelets reconstituted with normal RBC, had increased aggregation (AS, p < 0.004) in comparison with normal platelets. The results indicate that increased platelet adhesion in beta-thalassemia is induced by both platelets and RBC. Increased platelet adhesion correlated with clinical thrombotic events and thus may suggest a mechanism of thrombosis in thalassemic patients. The potential application of the CPA in identifying thalassemic patients with high risk for thrombosis should be studied prospectively in a larger cohort of patients.

Increased procoagulant cell-derived microparticles (C-MP) in splenectomized patients with ITP

Background: Splenectomy is frequently employed for therapeutic and diagnostic purposes in various clinical disorders. However its long-term safety is not well elucidated. Although risk of infection by encapsulated organisms is widely recognized, less well-known are risks of thrombosis and cardiovascular disease. Methods: We investigated levels of cell-derived microparticles (C-MP) in 23 splenectomized ITP (ITP-S) and 53 unsplenectomized ITP patients (ITP-nS). Assay of C-MP derived from platelets (PMP), leukocytes (LMP), red cells (RMP) and endothelial cells (EMP) were performed by flow cytometry. Coagulation parameters included PT, aPTT and activities of FVIII, IX and XI. Results of all measures were compared between the two groups, ITP-S vs ITP-nS. Results: Levels of all C-MP were higher in ITP-S than ITP-nS but only RMP and LMP reached statistical significance ( p = 0.0035 and p < 0.0001, respectively). The aPTT was significantly shorter in ITP-S ( p = 0.029). Interestingly, correlation analysis revealed that RMP, but not other C-MP, were associated with shortening of aPTT ( p = 0.024) as well as with increased activities of factors VIII ( p = 0.023), IX ( p = 0.021) and XI ( p = 0.0089). Conclusions: RMP and LMP were significantly elevated in splenectomized compared to non-splenectomized ITP patients. This suggests that the spleen functions to clear procoagulant C-MP, and that elevation of C-MP might contribute to increased risk of thrombosis, progression of atherosclerosis and cardiovascular disease following splenectomy.

Reduction in Immunoglobulin (IVIG or Anti D) Use in Patients with Chronic Immune Thrombocytopenic Purpura (ITP) Receiving AMG 531: Results from Two Phase 3 Randomized Placebo-Controlled Trials.

AMG 531 is a novel thrombopoiesis-stimulating peptibody that is being studied for its ability to increase platelet production by stimulating the thrombopoietin receptor. We report pooled data on acute use of immunoglobulin (IVIG or Anti D) in both splenectomized and nonsplenectomized patients from 2 randomized, double blind, placebo-controlled Phase 3 studies designed to evaluate the efficacy and safety of AMG 531 in adult patients with chronic ITP. Patients were randomized to receive either AMG 531 or placebo at a 2:1 ratio, and concomitant medications were continued. Of the 125 patients enrolled, 63 were splenectomized (placebo, 21; AMG 531, 42), and 62 were nonsplenectomized (placebo, 21; AMG 531, 41) with a median age of 52 years (range 21 to 88) and a mean baseline platelet count of 16.5x109/L. Immunoglobulin was allowed as rescue medication when medically necessary at the discretion of the physician. For both trial arms, we calculated the percentage of patients requiring immunoglobulin intervention in each month of treatment, and the age and sex-adjusted 24-week cumulative probability of immunoglobulin use. No difference was observed between splenectomized and nonsplenectomized patients; therefore pooled results are shown. Fisher's exact tests and Log-Rank tests were used to compare the between-arm differences. We also performed subgroup analyses of immunoglobulin use in overall responders (defined as either platelet count ≥50x109/L for ≥6 weeks during the last 8 weeks of the 24-week treatment period in the absence of rescue medications at any point in the study, or ≥4 weekly platelet counts ≥50x109/L in the absence of rescue medications in the previous 8 weeks), and placebo patients. In the 24-week study period, there were 19 immunoglobulin administrations among 83 AMG 531 patients, and 68 immunoglobulin administrations among 42 placebo patients. The cumulative probability of incurring immunoglobulin use in 24 weeks was 0.51 (SE: 0.08) for the placebo arm and 0.13 (SE: 0.04) for the AMG 531 arm (see Figure), with a hazard ratio of 5.31 (95% CI: 2.55–11.06, p<0.001). Per-cycle immunoglobulin use ranged from 19% to 29% in the placebo arm, and from 0% to 6% in the AMG 531 arm (p≤0.01 in all cycles). Subgroup analysis showed that compared to placebo patients, overall responders of AMG 531 had even greater reduction in immunoglobulin use in each cycle (0 to 4%, p<0.006). AMG 531 treatment was associated with significantly reduced immunoglobulin use in both splenectomized and nonsplenectomized patients with chronic ITP. Moreover, placebo patients were 5 times more likely to receive immunoglobulin therapy compared to AMG 531-treated patients. [Display omitted]

Evaluation of AMG 531 Efficacy in Nonsplenectomized Patients with Chronic Immune Thrombocytopenic Purpura (ITP) in a Randomized Placebo-Controlled Phase 3 Study.

AMG 531 is a novel platelet-stimulating peptibody that stimulates the thrombopoietin (TPO) receptor, and is being studied for its ability to increase production of platelets. Here we report efficacy data in nonsplenectomized patients from a randomized, double blind, placebo-controlled Phase 3 study designed to evaluate the efficacy and safety of AMG 531 in patients with chronic ITP. Sixty-two nonsplenectomized patients were enrolled (placebo, 21; AMG 531, 41) with a median age of 52 years (range 21 to 88) and a mean baseline platelet count of 18.3x109/L. Subcutaneous AMG 531 or placebo was administered weekly for 24 weeks at a starting dose of 1μg/kg, and adjusted to maintain a target platelet count of 50-200x109/L. One patient randomized to placebo received 3 doses of AMG 531 in error and was included in the efficacy analysis as a placebo. The primary study endpoint was the incidence of a durable platelet response, defined as a platelet count ≥50x109/L for ≥6 weeks during the last 8 weeks of the 24-week treatment period in the absence of rescue medications. Starting at a low dose of AMG 531 and gradually increasing it, as well as reducing the dose of steroids in certain patients, contributed to lower platelet counts early in the study. Twenty-five of the 41 patients (61.0%) receiving AMG 531 achieved a durable platelet response compared to 1/21 (4.8%) receiving placebo (p<0.0001). Overall response, defined as either durable or transient platelet response (≥4 weekly platelet responses), was observed in 36/41 (87.8%) patients receiving AMG 531, but was observed in only 3/21 (14.3%) placebo patients. The mean number of weekly platelet responses (platelet count ≥50x109/L) was significantly greater in patients receiving AMG 531 (15.2/24 weeks, 63%) compared to placebo (1.3/24 weeks, 5%) (p<0.0001). AMG 531 reduced the proportion of patients requiring ITP rescue medications, defined as either increase from baseline in dose of concurrent ITP medication or use of new medication to increase platelet counts. Thirteen of 21 (61.9%) placebo-treated patients received rescue medications compared to just 7/41 (17.1%) AMG 531-treated patients (p=0.0004). There were no treatment-related serious adverse events and no patients tested positive for neutralizing antibodies against either AMG 531 or endogenous TPO. In summary, as in previous studies, AMG 531 was well-tolerated while effectively increasing and sustaining platelet counts in nonsplenectomized patients with ITP. When compared to placebo, AMG 531 administration resulted in a higher mean platelet count, and was associated with less frequent use of rescue medications.

Spleen Related Complications and Implications of Splenectomy in Patients with Hemoglobin SC Disease.

The spleen is one of the earliest organs to undergo sickling-related damage with functional asplenia at a very early age followed by fibrosis and scarring with the absence of a palpable splenomegaly in patients with homozygous hemoglobin (Hb) SS. In contrast to Hb SS, 50% of Hb SC patients are reported to have persistent splenomegaly into adulthood. As a consequence, complications like splenic sequestration, infarction, and cytopenias are relatively common in adults with Hb SC. These symptoms might be severe enough to require splenectomy. Although there are several published reports on splenectomy in the pediatric population with Hb SC, little is known in adults in this regard. We therefore conducted a retrospective analysis of spleen related complications and splenectomy in adults with Hb SC. One hundred and twenty four adult Hb SC patients have been followed at the Sickle Cell Center, Medical College of Georgia. There were 60 males and 64 females. The median age was 27 (range 15–74 years old). Out of these 124 patients, 26 (21%) had palpable splenomegaly. Twelve (9.6%) patients underwent splenectomy. The reason for splenectomy was as follows: splenic infarction in 3/12 (25%), hypersplenism and sequestration in 5/12 (41.6%), subcapsular bleeding in 1/12 (8%), and information not available in 3/12 patients (25%). There was a significant difference between splenectomized and non-splenectomized patients in terms of Hb level (median 7.2 g/dL in the splenectomized vs. 12.5 g/dL in the non-splenectomized, p<0.0001), platelet counts (median of 146 x 106/L vs. 275 x 106/L, p=0.031), palpable spleen (66% vs. 16%, p=0.00004), acute chest syndrome frequency (75% vs. 12%, p=0.0001), and cholecystectomy rate (66% vs. 13%, p=0.000006). None of these patients had a cholecystectomy at the same time as splenectomy. There was a trend towards higher incidence of stroke as well in these patients (8% vs. 0.8%, p=0.053). In addition, SC patients who underwent splenectomy were more likely to be on hydroxyurea therapy (4/12 vs. 6/112, p=0.001). Following splenectomy, the median Hb level increased from 7.2 g/dl to 11.4 g/dl (p=0.007) and the median platelet count increased from 146 x 106/L to 416 x 106/L (p=0.007). There was no difference in terms of Hb S, C, and F levels between the splenectomized and non-splenectomized groups. None of the patients in the splenectomized group had any significant morbidity or mortality from undergoing splenectomy. There seems to be a subgroup of patients with Hb SC who require splenectomy due to splenic complications who also have other organ related complications. Hb SC is generally considered to be a relatively mild form of sickle cell disease, especially in adults. However spleen related complications can occur and as evidenced by statistically significant rates of ACS, cholecystectomy, stroke, and more severe anemia and thrombocytopenia may represent a marker of a more severe phenotype. Splenectomy in these patients appears to be very effective and safe.

Evaluation of AMG 531 Safety in Splenectomized (S) and Nonsplenectomized (NS) Patients with Chronic Immune Thrombocytopenic Purpura (ITP) in Two Randomized Placebo-Controlled Phase 3 Studies

AMG 531 is a novel platelet-stimulating peptibody that stimulates the thrombopoietin (TPO) receptor, and is being studied for its ability to increase production of platelets. We report safety data in both S and NS patients (pts) from 2 randomized, double blind, placebo-controlled Phase 3 studies designed to evaluate the efficacy and safety of AMG 531 in adult pts with chronic ITP. All pts that received at least 1 dose of AMG 531 were counted as AMG 531-treated pts in this safety analysis. Of the 125 pts enrolled, 63 were S (placebo, 21; AMG 531, 42), and 62 were NS (placebo, 21; AMG 531, 41) with a median age of 52 years (range 21 to 88) and a mean baseline platelet count of 16.5x109/L. Subcutaneous AMG 531 or placebo was administered weekly for 24 weeks at a starting dose of 1μg/kg, and adjusted to maintain a target platelet count of 50–200x109/L. Among AMG 531 pts, the mean weekly dose was 3.3±2.7 μg/kg, with most pts (54/84, 64%) receiving a dose between 1 and 4μg/kg. There was no difference in the safety profile between S and NS pts treated with AMG 531; therefore safety data were pooled. Adverse events were reported in 39/41 (95%) placebo and in all (100%) AMG 531 pts. The most frequently reported adverse events (AEs) were: headache (placebo vs AMG 531; 32% vs 35%), fatigue (29% vs 33%), epistaxis (24% vs 32%), arthralgia (20% vs 26%), and contusion (24% vs 25%). There were 2 AMG 531-related serious AEs, both in S pts; 1 pt with elevated bone marrow reticulin after 4 weeks of receiving AMG 531 that returned to baseline 3 months after drug withdrawal, and 1 pt experienced thrombosis (right transfemoral popliteal embolectomy) that was successfully treated allowing study continuation. One (2.4%) placebo and 3 (3.6%) AMG 531 pts withdrew from the study due to AEs. Three placebo pts died of cerebral hemorrhage, atypical pneumonia, and pulmonary embolism. One AMG 531 pt died of intracranial hemorrhage 2 weeks after discontinuation of AMG 531. The total number of bleeding events in the 42 placebo pts and 83 AMG 531 pts were 76 and 152, respectively, corresponding to an exposure-adjusted incidence of 7.9 and 7.8 per 100 Patient-Weeks, reduced to 5.2 per 100 Patient-Weeks in AMG 531-treated pts when their platelet counts were ≥50x109/L (platelet response). Clinically significant bleeding events (MedDRA 9.0 defined severity grade ≥3) did not occur in responding pts, and were reported only when platelet counts were <20x109/L. Among non-responders, there were 5 significant bleeding events in placebo pts and 10 in AMG 531 pts, corresponding to an exposure-adjusted incidence of 0.5 per 100 Patient-Weeks in each group. Blood chemistry and complete blood counts remained stable, with no clinically significant changes occurring except for platelet counts. No pts tested positive for neutralizing antibodies against either AMG 531 or endogenous TPO. In summary, AMG 531 appeared to be well-tolerated in ITP pts and reduced the incidence of bleeding events among pts exhibiting a platelet response.

Splenectomy in Patients with Chronic Myeloid Leukemia or Myeloproliferative Diseases: Outcomes, Complications and Prognostic Implications.

The results of splenectomy in 110 patients with myeloproliferative disorders (MPD) were analyzed to determine short-term outcome and complications, and long-term impact on AML transformation and survival. Thirty-one patients had CML in chronic(CP; n=10), accelerated(AP, n=10) or blast phase(BP, n=11); 60 myelofibrosis in CP(n=59) or BP(n=1); 8 CMML; and 11 other MPDs. Median characteristics (range): age 58 yrs (16–85), male 60%, time from diagnosis 6 months (0–187), 2 prior therapies (0–7), performance status 1 (0–3), B-symptoms 70%, transfusion-dependent 50%, spleen 15cm (0–30) below LCM. The number of indications for splenectomy was 1 in 44%, 2 in 40%, and ≥3 in 16%, with the most common indications being pain/ local symptoms (54%), anemia/ transfusion dependency (59%) and thrombocytopenia (39%). For patients with anemia/ transfusion-dependency, Hb improved ≥2g/dL &/or transfusion requirement decreased by half in 68% for a median of 13 months. For patients with thrombocytopenia, 66% improved platelet count by >30×10^9/L for a median of 18 months. No patient had deterioration in Hb or Plt post-splenectomy not otherwise explained by disease or concomitant therapy. Complications occurred in 58% patients with the most common being thrombocytosis >1000×10^9/L (17%), venous thrombosis (16%), pneumonia (10%), abdominal collection (9%), leucocytosis >150×10^9/L (6%), painful hepatomegaly (4%) and bleeding (3%). Sites of thrombosis were: 10 portal vein, 3 Budd-Chiari, 3 DVT/PE, 2 splenic vein and 1 SVC obstruction; 2 patients had multiple thrombosis sites. Patients with baseline platelets ≥150×10^9/L were more likely to develop platelets >1000×10^9/L postoperatively (39% v 6%, p<0.001), who in turn were at an increased risk of venous thrombosis (32% v 13%, p=0.05). Median survival was 19 months: most patients died of progressive disease, with only six deaths attributable to surgery, and the occurrence of surgical complications had no impact on survival (p=0.45). In order to assess the impact of splenectomy on AML risk and survival of myelofibrosis patients, we compared outcomes between 53 study patients and 267 control (non-splenectomized) patients from the MD Anderson MPD database. Patient with features of pre-terminal disease (blasts ≥10%, abnormal chromosome 17 or severe cytopenia) were excluded from this analysis. In this comparison, splenectomized myelofibrosis patients experienced inferior survival (median 21 v 46 months, p<0.001), with the difference remaining significant (HR 1.6 p=0.02) after accounting for age, cytogenetics, blast%, monocyte count and Lille score in a multivariate analysis. AML risk was also increased in splenectomized patients, but occurred in only a minority of patients (23% at 4 yrs, v 13% for controls, p=0.01), and splenectomy was not an independent factor for AML development after accounting for peripheral blood blast% (HR 1.3, p=0.008) and Lille score (HR 2.2 p=0.005) in multivariate analysis. The requirement of splenectomy for disease control is an independent predictor of poor outcome in patients with myelofibrosis.

Should rituximab be used before or after splenectomy in patients with immune thrombocytopenic purpura?

The anti-CD20 monoclonal antibody rituximab has been used to treat patients with chronic immune thrombocytopenic purpura. This review discusses whether the optimal timing for this therapy is before splenectomy, or after failure of splenectomy. No study has directly compared rituximab to splenectomy in patients with chronic immune thrombocytopenic purpura. Rituximab produces an initial response in approximately 60% of cases, with no significant difference between splenectomized and nonsplenectomized patients. Long-term complete responses are observed in 15-20% of cases. Adverse events related to the drug were usually mild or moderate, with a low incidence of infections. Long-term safety data, however, are still lacking. Deaths have been reported for 2.9% of immune thrombocytopenic purpura cases treated with rituximab, but they could not be attributed to the study drug. Both the response rate and the response duration appear lower following rituximab than following splenectomy. Although the side effects may be fewer, there is insufficient evidence to support the replacement of splenectomy with rituximab as a second-line treatment of chronic immune thrombocytopenic purpura outside a clinical trial. At the present time, the use of immunotherapy before splenectomy can be recommended only in patients at high risk for splenectomy and in those not willing to undergo surgery.

Anti-D Immunoglobulin-induced Prolonged Intravascular Hemolysis and Neutropenia

Intravenous anti-D immunoglobulin (anti-D IVIG) is indicated for the treatment of immune thrombocytopenic purpura (ITP) in nonsplenectomized patients who are Rh(D)-positive. Recent reports have described episodes of intravascular hemolysis after anti-D IVIG. We report an adolescent boy with chronic ITP who required multiple transfusions of erythrocyte suspensions when intravascular hemolysis persisted for 6 months after anti-D IVIG treatment. He did not have hemolytic anemia before treatment. The features of our case suggest that pediatric patients treated with anti-D IVIG for ITP should be closely monitored for signs and symptoms of hemoglobinemia and/or hemoglobinuria, and clinically significant anemia. Our case proposes that persistence of immune hemolysis after this treatment may be related to presence of previously defined predisposing agents like tuberculosis and antituberculous therapy. Our observations suggest that steroid therapy can be effective in patients who developed prolonged hemolytic anemia and neutropenia after anti-D IVIG therapy.

Hemostatic alterations in splenectomized and non-splenectomized patients with β-thalassemia/hemoglobin E disease

β-Thalassemia/hemoglobin (Hb) E is a hereditary hemolytic anemia with varying degrees of severity. Severely affected patients are treated with blood transfusion and/or splenectomy in order to maintain an optimum level of hemoglobin for normal growth and physical activities. As thrombosis has been observed among splenectomized patients, we have investigated alterations in coagulation and fibrinolysis in β-thalassemia/Hb E patients. Plasma levels of prothrombin, fibrinogen, factors V, VII, VIII, IX and XI, protein C, protein S, thrombin activatable fibrinolysis inhibitor (TAFI) and prothrombin fragment 1 + 2 were determined in 61 patients (21 non-severe non-splenectomized, 18 severe non-splenectomized, 22 severe splenectomized) and 28 healthy individuals. Serum levels of D-dimer, ferritin, aspartate transaminase and alanine transaminase were also measured. All severe patients received regular blood transfusion. Prothrombin fragment 1 + 2 and D-dimer were significantly elevated in splenectomized patients compared to the healthy control subjects, whereas levels of proteins C, protein S, TAFI, fibrinogen, and factors V and VIII in the splenectomized groups were statistically lower than those in control group. There are no statistical differences for the other parameters measured between patients and controls. Coagulation tests showed only significantly reduction in TAFI and factor V and VIII levels in severe splenectomized group in comparison with severe non-splenectomized patients. These results demonstrate the existence of a low grade consumptive coagulopathy among blood-transfused splenectomized patients with severe clinical manifestations, indicating that these patients may have a higher risk for thrombosis than comparable patients with intact spleen.

Superior effect of intravenous anti‐D compared with IV gammaglobulin in the treatment of HIV‐thrombocytopenia: Results of a small, randomized prospective comparison

This small, prospective, randomized study compared increases in platelet counts and duration of response after intravenous gammaglobulin (IVIG) and IV anti-D in patients with HIV-related thrombocytopenia (HIV-TP). Nine Rh+, nonsplenectomized HIV-positive patients with thrombocytopenia were treated sequentially, in random order, with IVIG and IV anti-D in a cross over design, receiving each therapy for 3 months. Peak platelet counts and duration of effect after each treatment were compared. In addition, viral load measurements and CD4 counts were followed serially, as well as thrombopoietin levels. IV anti-D resulted in a mean peak platelet count of 77 x 10(9)/L compared to only 29 x 10(9)/L after IVIG (P = 0.07). The mean duration of response was significantly longer in patients treated with anti-D (41 days) compared to IVIG (19 days, P = 0.01). No consistent changes were seen in the CD4 counts or viral load measurements as a result of either therapy. Thrombopoietin levels were normal in all patients despite often severe thrombocytopenia. Anti-D was more efficacious than IVIG for the treatment of HIV-TP, confirming and extending previous results. Anti-D should be the first line therapy in HIV-positive, Rh+ patients, when antiretroviral agents are not indicated, not effective, or there is an urgent need to increase the platelet count.

Modification of CYP2E1 and CYP3A4 activities in haemoglobin E-beta thalassemia patients

Thalassemia disease is a genetic haemoglobinopathy usually associated with an iron overload and some degree of organ impairment. The impact of the disease on the drug metabolising enzyme cytochrome P450 (CYP) is not known. CYP2E1 and CYP3A4 are responsible for the metabolism of a large number of drugs and changes in their activities may have clinical consequences. Haemoglobin E-beta thalassemia paediatric, blood transfusion-dependent patients apparently without complications (n = 35) and healthy controls (n = 42) were recruited in this study. The ratios of plasma 6-hydroxychlorzoxazone to chlorzoxazone, and urinary 6-beta-hydroxycortisol (6beta-OHF) to cortisol were used as indices for CYP2E1 and CYP3A4 activities, respectively. Blood and plasma samples were assayed for parameters of clinical biochemistry, oxidants and antioxidants. There were significant increases in serum iron, protein carbonyl and lipid peroxidation in thalassemia patients, whereas there was a decrease in blood glutathione, but unchanged plasma nitric oxide metabolites. CYP2E1 activity in the patients was unchanged; however, when the patients were stratified by splenectomy status, CYP2E1 activity was increased in non-splenectomised patients in comparison with the controls and splenectomised subjects. On the other hand, 6beta-OHF/cortisol ratios increased markedly in patients associated with depressed growth hormone levels. There were no correlations between CYP2E1 activity and oxidant stress or antioxidant parameters. This report is the first demonstration that thalassemia major is associated with an alteration of CYP2E1 and CYP3A4 activities; this could modify the sensitivity of thalassemia patients to the toxic or therapeutic effects of drugs.

Dapsone as Second-Line Drug in Non-Splenectomized Patients with Chronic Idiopathic Thrombocytopenic Purpura (ITP): A Highly Cost Effective Option in a Developing Country.

The management of chronic refractory ITP continues to be a frustrating experience for the patients as well as treating hematologists. Many patients relapse after steroid therapy as well as splenectomy. Even though latter modality leaves them susceptible to life-threatening infections, without making them symptom free. Immunoglobulins and anti-D vaccine do show a good but brief response. Retuximab is a newer drug to be used in ITP, but it is out of reach for most of the patients in a developing country like India. Of late Dapsone has been seen to be an effective drug in such situations and probably acts through reticulo-endothelial blockade.We report the efficacy of Dapsone in 46 consecutively treated patients in our hospital, who had continued to be symptomatic despite adequate steroid therapy. They were chosen to be treated with Dapsone without being subjected to splenectomy. Their median age was 21 years(range : 8–46 years). The patients having associated connective tissue disorders were excluded. All the patients were screened for hemolytic tendency and splenectomy. Dapsone was started at an initial dose of 50 mg/day and escalated to100 mg/day, if the response was sub-optimal. Children received 25 mg/day initially and subsequent dose was adjusted to a minimal level required to achieve symptom free status. The aim of the therapy was to eliminate purpura rather than to achieve a particular level of platelet count. The duration of treatment ranged from six months to 48 months.36 patients (80%) showed an overall response with disappearance of purpura and a significant rise (> 40,000/cmm) in platelet count. Treatment was well tolerated and no adverse effects were encountered even though dose related hemolysis has been reported. The drug was continued in 36 responders for a median period of 32 months and they all continued to be asymptomatic throughout. The treatment was intentionally withdrawn in 12 responders, but thrombocytopenia recurred in all these patients. In our experience Dapsone provided an inexpensive and well tolerated alternative for patients with ITP who showed suboptimal response to steroid therapy. The splenectomy was successfully avoided in these patients. Its use is cost effective as well. Both these factors make this a great boon to the patients in a developing country. We recommend that all patients be started on Dapsone once they fail to show response to steroids. Splenectomy should be reserved for the patients who do not respond to Dapsone.

Variation of Serum Lipid Profile during Enzyme Replacement Therapy, in Patients with Type 1 Gauchers Disease.

Enzyme Replacement Therapy (ERT) has dramatically changed the clinical course and prognosis of patients with Gaucher disease. We have assessed the extent to which the recently defined Goals of Therapy (Pastores et al, Semin Hematol 41(suppl 5):4–14) in 9 major fields (anemia, thrombocytopenia, hepatomegaly, splenomegaly, skeletal pathology,biomarkers, pulmonary manifestations, growth and functional health and well being) were achieved in our cohort of patients with type I Gaucher disease. Fifty-seven patients (27 females, 30 males, median age at diagnosis 30 years (range 2–77 years) and at start of ERT 39 years (range 5–79 years) were assessed. The median period of ERT was 94 months (range 24–155 months). Patients on ERT for less than 2 years were excluded. Twenty five specific goals are defined within the 9 fields. The median overall success rate was 20 of 25 goals or 80% per patient (range 12–25 goals or 60–100%). The success rate for 9 goals was 100% ( normalization of hemoglobin 1 year post-splenectomy, no major bleeding 1 year after ERT start, doubling of baseline platelet count in severely thrombocytopenic patients 2 years after ERT start, maintenance of platelet count in non-thrombocytopenic patients, prevention of bone crises, reversion of hepatopulmonary syndrome and dependence on oxygen, amelioration of pulmonary hypertension and prevention of rapid deterioration of pulmonary disease and sudden death). Higher success rates were achieved for the goals related to thrombocytopenia (97.9%) and pulmonary manifestations (97%) although in the latter case the applicability was low. Lower success rates were achieved for the goals related to bone manifestations (78.7%). There was no significant difference in the success rate between males and females, splenectomised and non-splenectomised patients, and between patients treated less or more than 6 years. However patients started on ERT before the 40th year of age exhibited significantly higher success rate as compared to patients started after the 40th year (p=0.047) and there was a significant inverse correlation between overall success rate and patient's age at treatment start (r = − 0.437). Finally, the success rate was higher among double heterozygotes, carrying the N370S mutation, as compared to patients homozygous for the N370S mutation (89.2±9.6% vs. 80.2±12.9%, p=0.016).

Anti-D Immunglobulin in the Treatment of Childhood Chronic Idiopathic Thrombocytopenic Purpura.

Chronic idiopathic (immune) thrombocytopenic purpura (ITP) develops in approximately 20% of children with acute ITP. The therapies for chronic refractory ITP include splenectomy, steroids, intravenous immunoglobulin (Ig), anti-D Ig, monoclonal antibodies, danazol, chemotherapy, plasma exchange, and others. We report five 5 RhD-positive, pediatric, non-splenectomized patients with chronic immune thrombocytopenic purpura (ITP), treated with anti-D. Patients were refractory to steroids and high dose intravenous immunoglobulin (IVIG). The mean age of the patients was 10.5 years, duration of thrombocytopenia was more than 6 months, and the median platelet count was 6x 10(9)/l. Patients received a single intravenous dose of 75 microg/kg anti-D, and were monitored for response to treatment and adverse events. Complete blood cell and renal function tests were assessed at baseline and 1, 7, 14 and 28 days after infusion. By 24 hours after treatment two of patients had achieved a platelet count>20 x 10(9)/l. Mild headache, fever, or chills occurred in one patients and ameliorated with prednisone and acetaminophen premedication. None of the patients had more than 0.5 gm/dl fall in the hemoglobin level and renal dysfunction following anti-D infusion by day 1,7, 14, 28. A single 75 microg/kg dose of anti-D may increase the platelet count in some children with chronic resistant immune thrombocytopenic purpura with an acceptable safety profile. It is a valuable, safe, well tolerated, and cheap alternative to conventional chronic ITP treatments in selected non-splenectomized patients.

Efficacy and Safety of Rituximab in the Treatment of Refractory/Relapsed Idiopathic Thrombocytopenic Purpura (ITP): Results of a Meta-Analysis of 299 Patients.

Background: Rituximab is a chimeric monoclonal antibody (mAb) targeting CD20 antigen on neoplastic and normal B cells. In addition to its role in the treatment CD20-positive B-cell malignancies, rituximab has been approved for symptom management of rheumatoid arthritis. Expanding the use of rituximab in other autoimmune diseases remains investigational. The treatment of auto-antibody mediated platelet destruction in refractory ITP is challenging. Although a good response is seen in the majority of patients treated with steroids and/or splenectomy, relapses occur in half of the patients. A few uncontrolled studies have evaluated the use of rituximab for therapy of relapsed/refractory ITP.Objective: In order to define the efficacy and safety of rituximab in the treatment of patients with refractory/relapsed ITP we conducted a review of the current available literature and performed a meta-analysis.Materials and Methods: We conducted a MEDLINE literature search using Pub med, Ovid software for the key words rituximab, ITP and immune thrombocytopenia on all available published literature analyzed to date (Jan 2001 to June 30, 2006). Studies involving children (<18 years) were excluded and our search was limited to reports in English. References of each article were also searched for additional literature. Individual case reports with less than 5 patients were excluded. In addition, studies were analyzed for disease duration, rituximab toxicity, and characteristics of responders.Results: A total of 34 peer reviewed publications were identified after the electronic search that identified a total of 324 patients. Five abstracts and 14 full-length manuscripts were excluded from the analysis as they included < 5 patients/report. Thus, the meta-analysis consisted of 299 patients described in 15 reports. The mean age of the patients was 50 (39–49 years); about half (52%) had failed splenectomy; mean duration of ITP was 54.4 months. All patients received four weekly doses of rituximab at 375mg/m2. The overall response rate was 55%, of which 38% of the patients achieved a complete response (CR) that was defined as a platelet count of at least 100,000–150,000. In addition, 17% of the patients achieved a partial response (PR) (i.e. platelet count >50,000 and < 100,000). The median duration of response in CR patients was 74 weeks (24–120) and in PR patients was 55 weeks (12–160). Of 12 patients re-treated with rituximab: 7 had 2nd CR (duration 6 m to 4 yrs). CR in splenectomized patients (available from 5 studies, n=126) was higher (62%) than non-splenectomized patients. Initial rise in platelet count in early responders was seen as early as 7–14 days from initiation of therapy.Discussion: Treatment of relapsed or refractory ITP is based on retrospective studies and no specific guidelines exist. Rituximab-associated depletion of antibody producing B-cells and/or Fc receptor blockade by mAb results in objective responses in over half (55%) of the patients treated. Re-treatment is effective in a similar percentage of patients with durable response. Minimal toxicity with equivalent results to other immunosuppressants favors rituximab's use in patients with symptomatic refractory ITP. Prospective trials should further validate these results and potentially identify ITP patient characteristics prognostic for responsiveness to rituximab immunotherapy.

The Clinical and Direct Medical Cost Burden of Splenectomy among Managed Care Patients with Chronic Immune Thrombocytopenic Purpura (ITP).

Background: ITP is a serious chronic disease involving increased platelet destruction and impaired platelet production. Corticosteroids (CS) are used most commonly to treat ITP and are associated with reduction in quality of life. Splenectomy is used less frequently but is a bigger cost driver. Improved therapies for ITP are needed in view of these compromises.Objective: A retrospective database analysis assessed clinical and economic burdens of ITP in a managed care population, focusing on CS use and splenectomy.Methods: Patients with a diagnosis of ITP (ICD9-CM code 287.3) between July 1, 2000, and December 31, 2003, were included if they had continuous health plan enrollment 6 months prior to and 12 months after index ITP diagnosis, were aged ≥18 years, and had any ITP-related treatment. This analysis used data from the PharMetrics Integrated Medical and Pharmaceutical Database, which includes data on diagnoses (ICD-9-CM format), procedures (CPT-4 and HCPCS formats), prescriptions (classified by NDC and AHFS), amounts paid and charged, and dates of service for all claims from >45 million patients participating in 82 different managed care plans (80% commercial, 3% Medicaid, 1.7% Medicare Risk, with the remainder “other”).Results: A total of 770 patients met the study criteria. The mean age was 43.2 years (±14.9) and females accounted for approximately 64% (n=489) of patients. A majority of patients (n=632, 82%) had at least one claim for CS therapy during the 12-month follow-up, and 93% (n=718) received CS for an average of 59.2 (±90.8) days during the 18 months surrounding the index diagnosis; 12% of patients (n=90) received splenectomy within 12 months of index diagnosis. The average time from ITP diagnosis to splenectomy was 119 days (±97). The average annual cost of care per patient was $23,420, with 43% attributable to inpatient hospitalizations. Splenectomized patients incurred an average annual cost of care of $48,424 (±$62,034), compared with $20,110 (±$45,466) for nonsplenectomized patients. Inpatient hospitalizations were the primary cost driver in patients who had undergone splenectomy (39.6%) as well as in those who had not (43.8%). Total health care costs were higher 14 days postsplenectomy ($12,839) versus 14 days presplenectomy ($7,176); this was consistent for inpatient costs ($6,988 vs $4,708), outpatient costs ($834 vs $631) and other combined costs ($4,623 vs $1,178). Almost 90% of splenectomized patients also received CS; this percentage was also greater at 14 days postsplenectomy (48.9%) compared with 14 days presplenectomy (30%). Anti-rhesus D (anti-D) immunoglobulin was also administered more frequently post- versus presplenectomy (8.9% vs 1.1%); this is potentially important, as average annual costs were higher ($32,268 ± 43,704) for patients with anti-D rescue therapy than for those without ($21,718 ± 48,494).Conclusions: Splenectomized patients (n=90) were nearly 2.5 times more costly than nonsplenectomized patients (n=680), incurring almost $28,000 greater costs, and also showed increased CS use after versus before splenectomy. Additional subanalyses are underway to assess impact of treatment-specific costs in this ITP patient population. Prospectively designed studies are needed to reevaluate standards of care for ITP and long-term patient outcomes as new treatments for ITP are developed.

The Effect of Tumor Necrosis Factor (TNFα) Inhibition on Platelet Counts in Adults and Children with Persistent ITP.

Immune Thrombocytopenic Purpura (ITP) is hematologic disorder caused by autoimmune opsonization and premature destruction of platelets. Approximately 20% of children and the majority of adults will have a chronic course of ITP with antibody-mediated destruction of platelets and the inability to clear immune complexes. Pro-inflammatory cytokines IL-2, TNF-α and IFN-γ are secreted following a Th1 response and are elevated in patients with chronic ITP. Recent treatments for chronic ITP in adults and children have focused on quelling dysregulated T and B lymphocyte activity. We conducted a pilot clinical trial of etanercept, a fusion peptibody composed of the soluble TNF-α receptor and the Fc portion of Ig. Hematologic and immunologic responses were measured before, during (blood counts only) and after a 12-week regimen of 0.4mg/kg/dose (max dose 25 mg) of subcutaneous etanercept, given twice weekly. Only fixed-dose prednisone or danazol were allowed as concomitant ITP medications. Cytokine concentrations were measured pre- and post-treatment from plasma and cultured lymphocytes (unstimulated or PHA- [2.5ng/ml] stimulated). Sixteen patients (9 male, 7 female), with chronic ITP (8 post-splenectomy) an initial platelet concentration < 30 × 109/L were enrolled with data evaluable for 15. The mean age of the patients was 31 years (median 32, min/max 7/52 years). One patient withdrew due to dizziness thought related to the study drug. One patient developed autoimmune hemolytic anemia, was diagnosed with Evans syndrome at treatment week 3 and withdrew from the study. Otherwise, no severe or serious related adverse events were observed. Two patients had a complete platelet response (CR, plt count > 150 × 109/L at least 6 weeks post treatment), 6 had a partial response (PR, plt count > 30 × 109/L and double baseline plt count), one had a minimal response (MR, plt count > 30 × 109/L) and 5 had no platelet response (NR). Two of the patients with PR had a platelet count rise that lasted at least until the end of the 8 week post-treatment observation period. The platelet response rate in nonsplenectomized and splenectomized patients was 67% and 28%, respectively, p = 0.1. Concentrations of IL-1β, IL-4, IL-6, IL-10 IFN-γ and TGF-β, before and at the end of the 12-week treatment course, showed marked inter-patient variation and did not predict the platelet count outcome. Both patients that had a CR had a reduction in PHA-stimulated TNF-α of 33 and 30%, respectively. Others with NR to treatment had similar declines in TNF-α, however. Although the precise mechanism of action is unclear, etanercept treatment led to at least a partial platelet response in 50% of patients with persistent ITP and was well-tolerated.

MK-0457 Is a Novel Aurora Kinase and Janus Kinase 2 (JAK2) Inhibitor with Activity in Transformed JAK2-Positive Myeloproliferative Disease (MPD).

MK-0457 (VX-680) was developed as a small-molecule inhibitor of Aurora kinases A, B, and C (Ki,app = 0.66–18 nM). Recent screening for additional kinase activity shows that MK-0457 inhibits JAK-2 with an IC50 of 123 nM for wildtype JAK2 and 295 nM for the JAK2 V617F activating mutation. Based on these in vitro findings, eleven patients with documented JAK2-mutated myeloproliferative disorders (MPDs), including 2 patients with prior MPD progressing to AML, were treated with MK-0457 at either 20, 24 or 28 mg/m2/hr administered by a continuous 5-day intravenous infusion every 3 weeks. The age range was 37– 83 (median 64); 5 (45%) patients were male and performance status was 0 or 1 in 10 (91%) patients. Five (45%) patients were previously splenectomized and 2 (33%) of the non-splenectomized patients had splenomegaly present at baseline. Two (18%) patients had diploid cytogenetics, eight (73%) were pseudodiploid with varying abnormalities and one (9%) had a -17 abnormality. One patient with hepatosplenomegaly at enrollment experienced complete resolution of hepatomegaly and >50% reduction in splenomegaly with a single cycle of therapy. Of the 10 (91%) patients starting therapy with a normal or increased absolute neutrophil count (ANC), all experienced grade 3 or 4 neutropenia during the study period. Transient reductions in platelet counts of patients with normal or elevated baseline platelets were also seen. Six of 7 (86%) patients with serial JAK2 testing had gradual, yet steady reductions in percentage of PCR product with the V617F mutation. MK-0457 is worthy of further exploration at lower doses (20mg/m2/hr) which are more suitable for chronic administration in patients with less aggressive disease, in contrast to patients with AML transformation of JAK2-mutated MPD in which higher, more myelosuppressive doses may be warranted.

Rituximab (Anti-CD20 Monoclonal Antibody) in Children with Chronic Refractory Symptomatic Immune Thrombocytopenic Purpura: Efficacy and Safety of Treatment

This retrospective study investigated the effects of rituximab in 19 pediatric patients (15 girls and 4 boys) with chronic refractory symptomatic immune thrombocytopenic purpura (ITP). Patients received from 2 to 5 weekly infusions of rituximab (375 mg/m(2)); 15 patients were younger than 12 years when treated. The median follow-up time was 30 months (range, 9-43 months). The overall response rate was 68% (13/19 patients). Six responders relapsed at a median of 4.5 months (range, 3-8 months). Seven patients still displayed a platelet count >150,000/microL at a median of 33 months (range, 14-43 months) after rituximab treatment. Six of 15 patients treated with 4 or 5 weekly infusions and 1 of 4 patients treated with 2 or 3 infusions are still in remission. No difference was detected between splenectomized and nonsplenectomized patients. The duration of ITP disease at the time of treatment did not influence the response rate. Patients still in remission showed significantly lower levels of CD19+ cells after 4 and 6 months than nonresponding or relapsed patients (P < .05). No major infections were reported during follow-up. Our data show the efficacy and tolerability of rituximab in young children with refractory symptomatic ITP. Nonrelapsed patients showed a more prolonged B-cell depletion.