Cost-effectiveness of splenectomy versus intravenous gamma globulin in treatment of chronic immune thrombocytopenic purpura in childhood

One year follow-up of children and adolescents with chronic immune thrombocytopenic purpura (ITP) treated with rituximab

BACKGROUND

We previously showed in a prospective study that rituximab appears to be effective in some children and adolescents with severe chronic immune thrombocytopenia. Eleven of 36 patients achieved and maintained platelet counts over 50,000/mm(3) within the first 12 weeks. These patients were followed for the next year.

METHODS

Platelet counts were monitored monthly and all subsequent bleeding manifestations and need for further treatment was noted.

RESULTS

Eight of the 11 initial responders maintained a platelet count over 150,000/mm(3) without further treatment intervention. Three patients had a late relapse. One initial non-responder achieved a remission after 16 weeks, and two additional patients maintained platelet counts around 50,000/mm(3) without the need for further intervention.

CONCLUSIONS

Rituximab resulted in sustained efficacy with platelet counts of 50,000/mm(3) or higher in 11 of 36 patients (31%).

A GPIIb/IIIa bioreactor for specific treatment of immune thrombocytopenic purpura, an autoimmune disease. Preparation, in vitro characterization, and preliminary proof-of-concept animal studies

Immune thrombocytopenic purpura (ITP) is an autoimmune disease that affects thousands of Americans each year. The resulting thrombocytopenia, which develops from destruction of platelets (PLT) by anti-PLT autoantibodies (APAb), is often associated with hemorrhagic complications. Existing therapies are not effective and are associated with significant morbidity. Recently, a new treatment modality using plasmapheresis with a Protein-A column has shown some clinical promise. Yet, although this method would remove the pathogenic APAb, it would also deplete protective antibodies, thereby weakening the body's self-defense system. Because about 80% of patients with ITP develop APAb against the GPIIb/IIIa antigens on PLT, a novel approach of attaching a GPIIb/IIIa-linked bioreactor with an extracorporeal circuit is suggested herein to achieve highly effective/specific APAb removal and overcome shortcomings of plasmapheresis in treating ITP. A hollow fiber-based bioreactor device was fabricated, and GPIIb/IIIa antigens were immobilized onto the inner lumens of the hollow fibers by using the epichlorohydrin activation method. An optimized bioreactor containing a loading of 1.63 mg GPIIb/IIIa/g fibers and adsorption capacity of 1.9 mg 7E3/g fibers was developed. Preliminary proof-of-concept investigation using a 7E3-induced thrombocytopenic rat model (which mimicked clinical ITP) was carried out. A complete (100%) return of PLT counts to their initial levels was observed in rats within 6 h after the GPIIb/IIIa bioreactor treatment. In addition, a rapid restoration of WBC counts in the treated rats was also found. These preliminary findings shed light of promise of using the GPIIb/IIIa bioreactor approach in achieving highly improved ITP therapy.

The economic impact of intermittent high-dose intravenous versus oral corticosteroid treatment of juvenile dermatomyositis

OBJECTIVE

To perform a cost-identification and cost-effectiveness analysis comparing oral corticosteroids (OCS) with high-dose intermittent intravenous corticosteroid (IVCS) regimens in the treatment of juvenile dermatomyositis (JDM).

METHODS

Children previously diagnosed and treated for JDM (without myositis-specific or myositis-associated autoantibodies) at a single medical center by a single provider were identified. Two treatment protocols were compared: OCS and IVCS. Data on initial disease severity, time to remission, resource use, and costs generated were collected from patient records. Incremental cost-effectiveness ratios (ICE) were constructed.

RESULTS

Patients treated with IVCS achieved median remission 2 years earlier at median increased cost of $13,736. The ICE ratio comparing IVCS to OCS is $6,868 per year of disease avoided.

CONCLUSION

This study suggests that, although IVCS treatments are costly, they are cost-effective.

Initial bone marrow aspiration in childhood idiopathic thrombocytopenia: decision analysis

PURPOSE

Bone marrow aspiration (BMA) is routinely performed before starting steroid therapy in children with idiopathic thrombocytopenia, primarily to rule out leukemia.

METHODS

A decision tree for the initial management of a child older than age 6 months, presenting with idiopathic thrombocytopenia, without blasts on the peripheral smear was constructed. The three strategies are: 1) initial BMA in all patients; 2) initial BMA only in patients at high risk; and 3) empiric therapy for all patients without initial BMA. High-risk criteria include any of: platelet count >50 x 10(9)/L; hemoglobin <100 g/L (age younger than 12 months) or <110 g/L (age older than 12 months): white blood cell count <5 x 10(9)/L (younger than 6 years) or <4 x 10(9)/L (older than 6 years); or absolute neutrophil count <1.5 x 10(9)/L (younger than 6 years) or <2 x 10(9)/L (older than 6 years). The results are expressed as quality-adjusted life years (QALYs), a measure that estimates the overall life expectancy in years for patients receiving a particular treatment strategy, corrected for the patient's quality of life.

RESULTS

The base case results are: 1) BMA all = 69.649 QALYs; 2) high-risk BMA = 69.652 QALYs; and 3) empiric therapy = 69.644 QALYs. These results indicate a three-way toss-up because there is less than a 4-day quality-adjusted difference (0.01) between strategies.

CONCLUSION

This study indicates that the initial BMA does not significantly change the overall QALYs of a child presenting with thrombocytopenia and, consequently, is not mandatory in every patient before starting steroids.

Splenectomy-sparing strategies for the treatment and long-term maintenance of chronic idiopathic (immune) thrombocytopenic purpura

Patients with idiopathic thrombocytopenic purpura (ITP) have vulnerability to additional bleeding, leaving them susceptible to severe hemorrhaging. Low platelet counts contribute to this rare, but significant outcome, but may not be the sole determinant. Although the only current treatment of ITP felt to be curative is surgical removal of the spleen, the long-term outcome for these patients is not well defined. Our group Investigated the use of Intravenous gamma-globulin in the treatment of children with chronic ITP as a means to defer splenectomy. A variation of this approach uses anti-D to block splenic macrophages with antibody-coated red blood cells. There may be a correlation between response to anti-D and response to splenectomy in adults with ITP. Because the long-term results of splenectomy are not well defined, additional clinical studies are warranted. Questions requiring further study Include whether repeated Infusions of anti-D could allow the postponement and ultimate avoidance of splenectomy and whether the role of anti-D may be for pregnant women who are not readily eligible for splenectomy. Such an analysis should include information on the long-term outcome of splenectomy as well as information on whether patients have a durable improvement. Such studies about the potential outcomes of splenectomy and of avoidance of splenectomy will help identify new treatment strategies that may help to eliminate the need for this procedure in patients with chronic ITP.

Treatment options for chronic immune (idiopathic) thrombocytopenia purpura in children

Immune (idiopathic) thrombocytopenic purpura (ITP) in children is usually acute and self-limiting, but may become chronic in 10% to 30% of patients. Salient issues in the treatment of childhood chronic ITP (cITP) include the following: the choice of immunomodulatory agent; the child's desire for unrestricted physical activity; interventions to avoid or defer splenectomy; and, finally, choosing when (and how) to perform splenectomy. Treatment for children with cITP during childhood usually is extrapolated from that for acute ITP. Treatment with pooled intravenous immunoglobulin (IVIg) and anti-D immunoglobulin often gives an acute response followed by a predictable decay of platelet count. Corticosteroids usually lead to a platelet increase; however, the associated adverse effects of chronic usage are generally unsatisfactory for most children and adolescents. With pulsed, high-dose corticosteroids, a durable platelet response is the exception, not the rule. More aggressive immunosuppression is usually reserved for patients who are symptomatic and refractory to the above treatments, Including splenectomy. Although the estimated success rate ranges from 70% to 90%, the long-term outcome of splenectomy in children with cITP in not well described. In addition, the risk of fatal postsplenectomy infections is significant. A familiar initial strategy among pediatric hematologists thus involves deferral of splenectomy with the reasonable possibility of spontaneous recovery. Corticosteroids, anti-D, and IVIg are effective, temporizing medical alternatives to splenectomy in treating cITP in children. Quality-of-life measurements in children with cITP may help to stimulate the development of new approaches.

Use of anti-D in immune thrombocytopenic purpura as a means to prevent splenectomy: case reports from two University Hospital Medical Centers

Presented here are 16 case studies of adults with immune (idiopathic) thrombocytopenic purpura (ITP); 5 were treated at Hackensack University Medical Center (HUMC), Hackensack, NJ, and 11 were treated at the Allegheny University Hospital (AUH), Medical College of Pennsylvania. Four of the 5 patients at HUMC had initial transient responses to intravenous immunoglobulin G (IVIg) therapy and required large doses of corticosteroids to maintain platelet counts over 50,000 microL. One elderly patient with systemic lupus erythematosus (SLE) had been treated unsuccessfully with corticosteroids and immunosuppressants to maintain her platelet count over 50,000 microL. All 5 patients were given 1 or 2 doses of anti-D at 50 microg/kg, leading to complete resolution of ITP. Following anti-D therapy, patients were tapered off corticosteroids and currently remain in complete remission with platelet counts over 100,000/ microL. The mechanism of action of anti-D in ITP remains unclear and requires further study. Treatment of the 11 patients at AUH began with corticosteroids, which resulted in no durable therapeutic response. Anti-D was then given at 50 microg/kg, and this provoked an excellent response with a prompt recovery of platelet levels to 100,000/ microL, after which active treatment was halted. Patients were monitored by direct office visit every 3 months unless a clinical indication required an earlier return. If the patient's platelets dropped below 100,000/ microL, they were first given prednisone. As of the last follow-up, all 11 patients remain stable and no patients have required splenectomy.

Mapping the evidence base of pathology

Evidence-based medicine (EBM) is a paradigm that is beginning to exert an influence in related fields such as surgery, general practice, psychiatry, and now pathology. For example, a survey has shown that 70 per cent of therapeutic interventions in clinical haematology delivered in a district general hospital were based on research-derived evidence. A prerequisite to evidence-based pathology is availability of, and access to, the evidence base. As a discipline, pathology has certain characteristics that makes information retrieval more challenging. Nevertheless, a number of evidence-seeking techniques can be utilized to maximize the chances of success: focusing the question, use of an evidence-seeking protocol, and application of methodological filters. A number of key information sources are reviewed for their usefulness and a comparison is made with the yield from the World Wide Web. Conclusions are drawn from an example of the evidence-seeking process based on a clinical scenario involving immune thrombocytopenic purpura.

Decision analysis in surgery

BACKGROUND

The technique of decision analysis is often applied to clinical policy and economic issues in surgery. Because surgeons may be unfamiliar with such work, this article catalogues decision analysis studies in the surgical specialties.

METHODS

We reviewed the medical literature (1966 to 1994) to identify surgical decision analysis studies and to assess trends over time. Each article was categorized according to the type of journal (surgical, other clinical, or technical) in which it was published and content, including surgical specialty, clinical topic, article focus (individual patient decision making, clinical policy, or cost-effectiveness), and primary findings.

RESULTS

Publication rates of surgical decision analysis have increased dramatically over time. Of the 86 total studies only six were published before 1980. In contrast, 44 studies appeared between 1990 and 1994. Although 77% were published in nonsurgical journals, decision analyses have begun to appear more regularly in surgical forums. Studies addressing all of the surgical specialties were found, although more than one half addressed topics in general surgery (34%) or cardiothoracic surgery (22%). The most frequent topics were gallstones (11 articles), head and neck cancer (five articles), coronary artery disease (four articles), and cerebral arteriovenous malformations (four articles). Articles focusing on clinical policy (i.e., those assessing surgical efficacy for broad groups of patients) now account for large majority of published decision analyses.

CONCLUSIONS

The use of decision analysis in surgery is growing steadily. Because decision analysis is being used to influence clinical policy, it is important for surgeons to be aware of these studies and to be able to review them critically.

Intravenous immunoglobulin in rheumatic disease

With the advent of numerous commercial preparations of intravenous immunoglobulin preparations since 1981, it is now possible to administer these preparations in significant quantities to cause elevation of serum immunoglobulin levels both in patients with antibody-deficient states and in those with normal circulating immunoglobulin levels. This led to a report of dramatic improvement of thrombocytopenia in a child with agammaglobulinemia following the use of intravenous immunoglobulin preparations for recurrent infections, and further studies in both children and adults with associated symptoms suggested therapeutic efficacy of intravenous immunoglobulin preparations in controlling autoimmune symptoms.

Uses of intravenous gammaglobulin in immune hematologic disease

In summary, for intravenous gammaglobulin use of ITP in children and adults, it is clear that intravenous gammaglobulin is an effective way to increase the platelet count acutely and this will be faster than or as fast as any other therapy. However, there is no proven curative effect of IV gammaglobulin. Its use in situations requiring a rapid increase in the platelet count seems secure as does its use in children with chronic ITP. The latter however and the treatment of HIV-ITP may find IVIG treatment largely replaced in the future by IV Anti-D(10) which is currently experimental. The use of a viral inactivated form of IVIG currently seems mandatory to avoid post-transmission hepatitis.

Seventeen years of experience with chronic idiopathic thrombocytopenic purpura in childhood. Is therapy always better?

Between 1975 and 1992 450 children with idiopathic thrombocytopenic purpura (ITP) were diagnosed, and of those 100 (22%) developed the chronic form of the disease. Approximately half the patients with chronic ITP presented with mild to moderate hemorrhagic manifestations at the onset of purpura (30 cases) and/or later during the course of the disease (25 cases). The incidence of intracranial hemorrhage was 1%, and the mortality rate due to overwhelming septicemia after splenectomy was also 1%. Overall one-third of the patients received no therapy; two-thirds of them went into spontaneous remission within 8 months to 8 years from the onset of ITP. Steroids given in conventional or high doses (51 cases) achieved a transient (if any) rise in platelet count, but in no case were steroids curative. Remission related to intravenous immune globulin (IVIG) therapy was noticed in 38.5% of the children (10 of 26) after variable courses. The response rate to splenectomy was 95.0%. Ultimately the long-term outcome in children with chronic ITP was as follows: remission, 58 cases (spontaneous, 30; after IVIG therapy, 10; after splenectomy, 18); hemostatic platelet values, 22 cases (spontaneous, 16; after IVIG, 5; after splenectomy, 1). Thirteen children were lost in follow-up, and 7 remain thrombocytopenic but asymptomatic. These data indicate that chronic ITP in childhood runs a benign course in most cases and may remit with or without therapy even several years from onset. Therefore, therapeutic intervention has to be individualized, and splenectomy, which is not always safe, should be reserved for problematic cases that fail to respond to conventional therapeutic modalities.

A multicenter study of the treatment of childhood chronic idiopathic thrombocytopenic purpura with anti-D

We evaluated the effects of the intravenous administration of anti-D, an immune globulin directed at the D antigen on erythrocytes that is purified from plasma from sensitized persons, on patients with idiopathic thrombocytopenic purpura. To determine the most effective dose, the duration of response, and the side effects of this therapy in children, we performed a multicenter cohort study of escalating doses of intravenously administered anti-D in children aged 1 to 18 years with chronic idiopathic thrombocytopenic purpura, defined as idiopathic thrombocytopenic purpura persisting for more than 6 months with a platelet count of less than 50 x 10(9) cells/L. Twenty-five Rh-positive children received increasing doses of anti-D as follows: day 1, 25 micrograms/kg; day 2, 25 micrograms/kg; day 7, 35 micrograms/kg; day 14, 45 micrograms/kg; and day 21, 55 micrograms/kg. Administration of anti-D was stopped after day 21 or when the platelet count rose to greater than 150 x 10(9) cells/L or the hemoglobin level was 100 gm/L. Platelet count was less than 50 x 10(9) cells/L in all children before treatment. A response was defined as an increase in the platelet count to more than 50 x 10(9)/L and a doubling of the pretreatment platelet count. Of 25 children, 23 (92%) had responses by day 7 of the initial treatment protocol. Eighteen children (72%) had platelet counts greater than 150 x 10(9) cells/L by day 7 after two doses of anti-D. Median duration of response was 5 weeks (range 1 to 24 weeks). Average drop in hemoglobin level was 13.7 gm/L; in one child (a nonresponder) hemoglobin value fell to less than 100 gm/L. No other untoward side effects were seen. Of the 23 children who responded, 21 were retreated with one dose of anti-D when platelet counts returned to baseline values of less than 50 x 10(9) cells/L; all but three of the children who underwent retreatment showed a response the second time. Sixteen children continued to receive intermittent anti-D therapy after completion of the study, and all continued to have excellent responses. We conclude that anti-D is a safe, effective, and relatively inexpensive therapy for childhood chronic idiopathic thrombocytopenic purpura.

Use of intravenous immune globulin therapy: an overview

The intravenous immune globulin (IGIV) preparations are reviewed with respect to method of preparation, pharmacokinetics, clinical uses (with emphasis on the labeled indications), and adverse reactions; a brief review of the immune system also is provided. IGIV preparations are approved for the treatment of hypogammaglobulinemia, recurrent bacterial infections due to B-cell chronic lymphocytic leukemia, and idiopathic thrombocytopenic purpura (ITP). The mechanism of action in the first two indications is passive replacement of antibodies, but in ITP the mechanism is not clearly established. The clinical literature on the use of IGIV for these indications is summarized. In patients with ITP, platelet counts return to safe levels and the number of infections is reduced in patients with primary humoral immunodeficiency treated with IGIV. The use of IGIV in pregnant women and premature infants is controversial. Adverse reactions are primarily related to infusion rate, activation of complement, and anaphylactic reactions to a component of the product. There is minimal to no risk of viral transmission with IGIV therapy. IGIV also has been administered safely on an outpatient or homecare basis. This has led to a feeling of greater control by patients over their chronic illness. Other uses of IGIV are under investigation. As our understanding of the immune system and the pharmacology of immune globulin increases, the uses of IGIV will expand.

Alternation of two doses of intravenous gammaglobulin in the maintenance treatment of patients with immune thrombocytopenic purpura: more is not always better

Intravenous infusion of gammaglobulin (IVGG) has been shown to be effective in the maintenance treatment of children and adults with immune thrombocytopenic purpura (ITP). The objective of this treatment is not to increase the platelet count into the normal range but rather to keep the platelet count above a safe level, usually 20,000-30,000/microliters. This use requires periodic infusion whenever the platelet count falls. The dose of gammaglobulin in previous studies was 1 gm/kg/infusion in the majority of patients. This study compared doses of 0.5 and 1.0 gm/kg/infusion by alternating the two doses in the maintenance treatment of 11 patients with ITP. There was no significant difference in the duration of response following single IVGG infusion between these two doses. This finding suggests that there is no advantage to the greater dose of IVGG and will substantially lower the cost of as well as facilitating IVGG maintenance treatment. It was not possible to determine whether a lower dose would impact adversely on the curative potential of IVGG. This effect of IVGG has never been proved and, if it exists, may be mediated by a different mechanism from the acute platelet response.

Thrombocytopenia in newborns, infants, and children

There are many causes of thrombocytopenia in infants and children. With experience, they can be readily identified and appropriate treatment instituted, if required. Particular attention should be paid to the well baby with unexplained thrombocytopenia, as alloimmune thrombocytopenia is the most common cause of intracranial hemorrhage due to thrombocytopenia and can be prevented if identified and treated early on. Autoimmune thrombocytopenia of childhood is generally benign, but children may require careful management until spontaneous resolution occurs. Human immunodeficiency virus infection should be looked for in these patients.

High dose intravenous gammaglobulins in autoimmune disorders: mode of action and therapeutic uses

Gammaglobulins administered intramuscularly have been used for more than 40 years to treat antibody deficiency states. In the last decade intravenous preparations were developed. They do not aggregate and contain IgG molecules with intact recognition and effector functions. These compounds are safe and only minor side effects were reported even when high doses were given. While studying their effect when given in high doses to hypogammaglobulinemic patients, an accidental finding was observed regarding their beneficial effect in idiopathic thrombocytopenic purpura (ITP). This observation led to many studies looking at the effect of high dose gammaglobulin in several other autoimmune diseases. While the effect in acute ITP is well established, there are encouraging reports in respect to the effect of intravenous gammaglobulin in many other disorders, but no final conclusion can be drawn due to the small numbers of cases studied. The mechanism by which intravenous gammaglobulin exerts its function is still unclear. It may work through the Fc receptor in the reticuloendothelial system, as an immunoregulator agent or interact in the idiotype-antiidiotype network. Intravenous gammaglobulin seems to be an important therapeutic tool in a large number of autoimmune disorders of various etiologies.