Chronic idiopathic thrombocytopenic purpura

Fostamatinib effectiveness and safety for immune thrombocytopenia in clinical practice

ABSTRACT

Fostamatinib, a recently approved Syk inhibitor used in adult primary immune thrombocytopenia (ITP), has been shown to be safe and effective in this disorder. However, clinical trial results may not be similarly reproduced in clinical practice. Here, 138 patients with ITP (both primary and secondary) from 42 Spanish centers who had been treated with fostamatinib were evaluated prospectively and retrospectively. The median age of our cohort (55.8% women) was 66 years (interquartile range [IQR], 56-80). The median time since ITP diagnosis at fostamatinib initiation was 51 months (IQR, 10-166). The median number of therapies before fostamatinib initiation was 4 (IQR, 2-5), including eltrombopag (76.1%), romiplostim (57.2%), and IV immunoglobulins (44.2%). Fifty-eight patients (42.0%) had signs/symptoms of bleeding in the month before treatment initiation. Seventy-nine percent of patients responded to fostamatinib with 53.6% complete responses (platelet count > 100 × 109/L). Eighty-three patients (60.1%) received fostamatinib monotherapy, achieving a high response rate (85.4%). The proportion of time in response during the 27-month period examined was 83.3%. The median time to platelet response was 11 days (IQR, 7-21). Sixty-seven patients (48.5%) experienced adverse events, mainly grade 1 to 2; the commonest of which were diarrhea (n = 28) and hypertension (n = 21). One patient had deep venous thrombosis, and one patient developed acute myocardial infarction. Fostamatinib was shown to be effective with good safety profile in patients with primary and secondary ITP across a wide age spectrum in this real-world study.

The Roles and Challenges of Advanced Therapies in the Management of Refractory Immune Thrombocytopenia: A Case Report and Review of the Literature

The management of primary immune thrombocytopenia (ITP) is becoming a subject of interest as there appears to be treatment failure and resistance to modern conventional treatment, necessitating a more universal and goal-directed approach to management. Our patient is a 74-year-old male who was diagnosed with ITP six years ago and recently presented to the emergency department (ED) with complaints of melena stools and severe fatigue lasting for two days. Prior to the ED presentation, he had received multiple lines of treatment including splenectomy. On admission, the pathology after splenectomy showed a benign enlarged spleen with a focal area of intraparenchymal hemorrhage/rupture and changes compatible with ITP. He was managed with multiple platelet transfusions, IV methyl prednisone succinate, rituximab, and romiplostim. His platelet counts improved to 47,000, and he was discharged home on oral steroids with outpatient hematology follow-up. However, in a few weeks, his condition deteriorated, and he presented with an increased platelet count and further multiple complaints. Romiplostim was discontinued, and he was continued on prednisone 20 mg daily, after which he improved, and his platelet count reduced to 273,000 on 20 mg prednisone. This case calls attention to the need to review the role of combination therapy in treating refractory ITP and the prevention of complications of thrombocytosis secondary to advanced therapy. Treatment needs to be more streamlined, focused, and goal-directed. Escalation and de-escalation of treatment should be synchronized to prevent adverse complications from overtreating or undertreating.

Pharmacokinetics, Pharmacodynamics, Efficacy and Safety of a Romiplostim Biosimilar in Chronic Refractory Immune Thrombocytopenic Purpura (ITP) Patients

Romiplostim (Nplate®, Amgen Inc.) is an orphan drug approved for the treatment of chronic refractory immune thrombolytic purpura (ITP) in adult and pediatric patients. Limited availability of pharmacokinetic (PK) data and large inter- and intra-subject variability in PK and platelet response is a challenge in the clinical development of a romiplostim biosimilar. We compared pharmacokinetics (PK), pharmacodynamics (PD)/efficacy, and safety of a romiplostim biosimilar with Nplate in 24 patients with ITP following a single 3 μg/kg dose, and assessed efficacy of the romiplostim biosimilar at a titrated dose range of 1-5 μg/kg in 50 patients with ITP. The PK of the romiplostim biosimilar did not differ compared to the PK of Nplate, and PD/efficacy responses were similar between the products following the single dose. The romiplostim biosimilar showed historically comparable PD/efficacy with Nplate over 8 weeks when treated at the titrated dose range. It was well tolerated in both the studies.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12288-021-01431-y.

Neonatal Fc receptor in human immunity: Function and role in therapeutic intervention

The humoral immune response provides specific, long-lived protection against invading pathogens, via immunoglobulin production and other memory functions. IgG, the most abundant immunoglobulin isotype, has the longest half-life and protects against bacterial and viral infections. The neonatal Fc receptor (FcRn) transports IgG across barriers, for example, the placenta, enhancing fetal humoral immunity to levels similar to their mothers'. Importantly, FcRn, by protecting IgG from intracellular degradation, results in an approximately 21-day circulating IgG half-life and high plasma levels; similarly, FcRn recycles albumin and is the portal of entry for enteric cytopathic human orphan (echo) virus infection. Dysregulated immune responses may lead to antibodies against self-antigens (autoantibodies), resulting in organ-specific or systemic autoimmune diseases. Autoantibody-mediated diseases have been treated by nonspecific immunoglobulin-lowering/modulating therapies, including immunoadsorption, plasma exchange, and high-dose intravenous immunoglobulin. However, targeting FcRn with specific inhibitors results in reduction in only IgG levels. The effectiveness of FcRn inhibitors in autoimmune diseases, including myasthenia gravis and immune thrombocytopenia, provides further evidence that IgG is a primary driver in these autoantibody-mediated diseases. We describe the role of FcRn in human biology, including insights that clinical testing of FcRn inhibitors have provided into FcRn biology and autoimmune disease mechanisms, allowing fact-based speculation on their therapeutic potential.

Long-term sustained response to fostamatinib in two patients with chronic refractory immune thrombocytopenia (ITP)

Care of patients with chronic immune thrombocytopenia (ITP) who are refractory to available treatments can be quite challenging. Fostamatinib, an oral Syk inhibitor, is the newest FDA-approved agent for ITP. Phase 3 clinical trials demonstrated an overall response in 43% of patients treated with fostamatinib and use for two years has been reported. Herein, we report two patients with long histories of ITP without lasting responses to numerous first-, second- and third-line therapies with prolonged responses to ongoing fostamatinib. This shows that patients unresponsive to other agents may respond to fostamatinib and can have sustained benefit.

Flow cytometry and immune thrombocytopenic purpura

Although Immune thrombocytopenic purpura is a common disorder that family physicians, internists and hematologists face in their everyday practice, its diagnosis rests only on "exclusion" and its therapy is based on algorithms where "trial and error" is the rule. Flow cytometry, if simplified and standardized, could provide a quicker and better diagnostic accuracy. Studies of the lymphocyte subset using flow cytometry and more elaborate immune studies are paving the way for a better understanding of the disease and in identification of prognostic markers. Such studies may even help stratify the first-line therapy responder and assist in the use of the arsenal of immune suppressive therapy with better precision.

Distinct alterations of CD68+CD163+ M2-like macrophages and myeloid-derived suppressor cells in newly diagnosed primary immune thrombocytopenia with or without CR after high-dose dexamethasone treatment

Background

Although impaired myeloid-derived suppressor cells (MDSCs) recently have been studied in immune thrombocytopenia (ITP), another myeloid-derived cell population signified as M2 macrophages has not been investigated properly in ITP patients. In the present study, we intended to determine the features of circulating M2-like macrophages, to examine its relationship with MDSCs, and to explore their prognostic values in ITP.

Methods

Peripheral blood mononuclear cells from healthy controls and primary ITP patients were isolated to test the circulating M2-like macrophages and MDSCs. The circulating M2-like macrophage population defined as CD68⁺CD163⁺ and circulating MDSC population as CD11b⁺CD33⁺HLA-DR⁻ were determined by flow cytometry. Plasma inflammatory cytokines were measured by multiplex ELISA.

Results

The percentages of MDSCs were found to be expanded in newly diagnosed patients of ITP, especially among those of the complete response (CR) group (p < 0.0001). Positive linear correlation was verified between percentages of M2-like macrophages and MDSCs. The same correlation was also determined in the CR group. After treatment, the percentages of M2-like macrophages and MDSCs were both increased significantly in CR group, while those patients among the PR + NR group manifested a significant numeric decrease of MDSCs but only a moderate decrease in M2-like macrophages. MIP-1α/CCL3 was negatively correlated with M2-like macrophages while MCP-1 possessed a positive correlation with M2-like macrophages, eotaxin-1/CCL11 was negatively correlated with MDSCs and interleukin-1β (IL-1β) was found to be negatively correlated with both M2-like macrophages and MDSCs.

Conclusions

The present findings indicated critical roles of both circulating M2-like macrophages and MDSCs in ITP. The positive correlation between them might be related to inflammatory factors-mediated bidirectional interactions or partially due to their similar background patterns during differentiation. MIP-1α/CCL3, MCP-1, eotaxin-1/CCL11 and IL-1β might play a critical role in the expansion of both M2 macrophages and MDSCs population in ITP patients, which deserves further investigation.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1424-8) contains supplementary material, which is available to authorized users.

FC gamma receptor polymorphisms in patients with immune thrombocytopenia

INTRODUCTION

Immune thrombocytopenia (ITP) is an autoimmune blood disease of unknown etiology. The aim of our study was to investigate a possible role of FCGR2A and FCGR3A polymorphisms in the development of primary ITP.

METHODS

We analyzed 125 adult patients with ITP and 120 healthy controls. Genotyping was performed by using PCR-RFLP methods.

RESULTS

Our results showed significantly higher frequency of high-affinity FCGR3A-158V allele in patients with ITP compared with control subjects (47.2% versus 37.5%; p = 0.037). We did not find significant differences in the genotype distribution or allele frequencies for FCGR2A-131H/R between patients and controls, p = 0.652 and p = 0.478. In the groups of patients with unresponsive and responsive ITP we found significantly different genotype distribution and allele frequencies for FCGR3A, p = 0.036 and p = 0.008 respectively. There was no significant difference in genotype and allele frequencies for FCGR2A between these two groups of patients. Our results confirmed that the combination of high-affinity FCGR2A-131H and FCGR3A-158V allele was more common in patients with ITP than in controls (55% versus 40%; p = 0.024).

CONCLUSION

Our results suggest possible role of FCGR3A polymorphism in the etiology, development and clinical outcome of ITP, but larger prospective studies are needed to confirm these results.

[A prospective study of the efficacy and safety of maintenance therapy with recombinant human thrombopoietin in patients with primary immune thrombocytopenia: a multicenter study]

Objective: To evaluate the efficacy and safety of maintenance therapy with reduced dose of rhTPO in the patients with primary immune thrombocytopenia (ITP) who attained stable platelet (PLT) counts after daily administration of rhTPO. Methods: Treatment was started with a daily administration of rhTPO (300 U/kg) for 2 consecutive weeks. Patients who attained stable PLT≥50×10(9)/L were enrolled to maintenance therapy starting with every other day administration of rhTPO, then adjusted dose interval to maintain platelet count (30-100) ×10(9)/L. Results: A total of 91 eligible patients were enrolled. Fourteen patients discontinued the study due to noncompliance (12/14) and investigator decision (2/14) . Among 77 patients who completed the study, 38 patients with the administration of rhTPO at every other day or less could maintain PLT≥30×10(9)/L for 12 weeks. The percentage of patients with a platelet response (PLT≥30×10(9)/L) at 4(th) week, 8(th) week and 12(th) week of maintain therapy was 92.6% (63/68) , 82.7% (43/52) and 85.0% (34/40) , respectively. Median platelet counts remained in the range of (70-124) ×10(9)/L. The overall incidence of rhTPO-related adverse events was 7.7%. All the adverse events were generally mild. Conclusion: Extending the dose interval of rhTPO is feasible to maintain stable platelet count in the patients with ITP, but the optimal dose interval is uncertain and might vary with individuals.

Thrombocytopenia

Thrombocytopenia is a commonly encountered hematologic problem in inpatient and ambulatory medicine. The many underlying mechanisms of thrombocytopenia include pseudothrombocytopenia, splenic sequestration, and marrow underproduction and destruction. This article presents the known causes of thrombocytopenia, a framework for evaluation, and brief descriptions of management in a case-based format.

Abnormalities of the bone marrow immune microenvironment in patients with immune thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired autoimmune disease. Although antiplatelet antibodies are considered as the primary immunologic defect in these patients, dysfunctional cellular immunity is also important in the pathophysiology of ITP. Peripheral T cell abnormalities have been demonstrated in patients with ITP; however, whether the impaired bone marrow (BM) microenvironment, specifically the BM immune microenvironment, is involved in the pathogenesis of ITP remains unknown. In this study, the compartments of the BM immune microenvironment and BM vascular microenvironment were analyzed in 26 untreated patients with ITP and 26 healthy donors (HD). Subsets of T cells in the BM immune microenvironment, including Th1, Th2, Tc1, Tc2, Th17, and Treg cells, were analyzed via flow cytometry. BM endothelial cells and perivascular cells, which are key elements of the vascular microenvironment, were analyzed via flow cytometry as well as hematoxylin-eosin (H&E) and immunohistochemical (IHC) staining in situ. Elements of the BM vascular microenvironment were found to be normal in patients with ITP, but abnormal characteristics of the BM immune microenvironment, including excessive polarization in Th1, Tc1, and Th17 cells and a remarkable decrease in Treg cells, were observed in patients with ITP. Therefore, a deregulated T cell response in the BM microenvironment might play an important role in the pathogenesis of ITP.

Identifying the characteristics, natural behavioral pattern, and response to therapy in ITP in a multi-center population in Sri Lanka

OBJECTIVE

To describe some selected characteristics of immune thrombocytopenia (ITP) such as presentation, the disease pattern, treatment options, and response to therapy and side effects to common therapeutic options.

METHODS

A group of 72 patients diagnosed as ITP were studied over a period of 5 years in two main centers in Sri Lanka. Characteristics of the disease such as presentation, the disease pattern, treatment options, and response to therapy and side effects to common therapeutic options were studied.

RESULTS

The ages of the patients ranged from 12 to 71 years but the majority (64.2%) were between 20 and 45 years. In 47 (65.3%) the average platelet count at presentation was below 30 × 10(9)/l and in these patients there was a significant increase in bleeding manifestations. Sixty-nine patients were given steroids as the initial treatment and all had responded initially. Time to respond ranged from 3 to 30 days with an average of 11 days. Twenty-four patients developed steroid-related side effects. In 24 patients second-line treatment options such as dapsone, azathioprine, and danazole were given but a satisfactory response to them could not be demonstrated.

DISCUSSION

The heterogeneous behavioral patterns of the disease with patients who are having the same platelet count (<30 × 10(9)/l) were observed and this revealed that ITP needs an individualized approach regardless of the platelet count of the patient. A close follow-up of the patients revealed that the patient's understanding of the disease and ability to identify the warning signs resulted in less intervention with drugs which lead to many harmful long-term side effects.

Plasma Levels of Interleukin 12 Family Cytokines and Their Relevant Cytokines in Adult Patients with Chronic Immune Thrombocytopenia before and after High-Dose Dexamethasome Treatment

OBJECTIVE

We aimed to investigate the expression of interleukin 12 (IL-12) family cytokines (IL-12, IL-23, IL-27 and IL-35) and their relevant cytokines (IFN-γ, IL-4, IL-17A and IL-10) in patients with chronic immune thrombocytopenia (cITP) as well as the effect of high-dose dexamethasone (HD-DXM) treatment on this expression.

MATERIALS AND METHODS

DXM was administered orally at a dose of 40 mg per day for 4 consecutive days to 38 patients with cITP. We measured the plasma levels of IL-12p70, IL-23, IL-27, IFN-γ, IL-4 and IL-17A before and after treatment and also in 36 matched healthy controls, by means of FlowCytomix™ technology. The plasma levels of IL-10 and IL-35 were measured by enzyme-linked immunosorbent assay.

RESULTS

Significantly higher plasma levels of IL-12p70, IL-23, IL-27, IFN-γ and IL-17A were observed in cITP patients than in controls (p < 0.01), and after HD-DXM treatment, these levels decreased significantly (p < 0.01). However, significantly lower plasma levels of IL-4, IL-10 and IL-35 were observed in cITP patients than in controls (p < 0.01); after the HD-DXM treatment, these levels had increased significantly in the cITP patients (p < 0.01). Moreover, the cytokine levels of patients who attained a complete response returned to the levels of normal controls (p > 0.05) but were not corrected in the patients who had no response (p < 0.01).

CONCLUSIONS

The patients with cITP had abnormal expression of the IL-12 family cytokines and their relevant cytokines levels, and HD-DXM treatment corrected the derangement of plasma cytokines. Measuring cytokine levels may help in the clinical assessment of cITP.

Foxp3 methylation status in children with primary immune thrombocytopenia

AIM

To investigate the status of DNA methylation in the Foxp3 promoter in pediatric ITP patients and assess the role of DNA methylation of Treg cells in the pathogenesis of ITP.

METHODS

Quantitative DNA methylation levels of Foxp3 promoter in pediatric ITP patients were detected by MassARRAY EpiTYPER. Methylation levels of Foxp3 promoter were analyzed in ITP patients and normal controls.

RESULTS

Significantly higher expression of CpG-2, CpG-3 and CpG-11.12 was observed in ITP patients compared to the controls. A subgroup analysis revealed that persistent and chronic ITP patients exhibited significantly higher CpG-6 expression than in the subgroup of newly diagnosed ITP patients. All patients who represented newly diagnosed ITP at admission were reclassified at later follow-up. In this follow-up subgroup analysis, there were significantly higher levels of CpG-6 in the persistent ITP group than that in the newly diagnosed ITP group.

CONCLUSIONS

Our results indicate that defective Treg cell activity identified in ITP might be partially mediated through hypermethylation of CpG sites in the promoter region of Foxp3.

A cost-effectiveness study of intravenous immunoglobulin in childhood idiopathic thrombocytopenia purpura patients with life-threatening bleeding

BACKGROUND

Although the international guideline recommends intravenous immunoglobulin (IVIG) as the first-line treatment for childhood idiopathic thrombocytopenia purpura (ITP) with life-threatening bleeding, ITP patients may not be able to access IVIG because of the limitation in health benefit packages especially in developing countries. There remains an important policy question as to whether IVIG used as a first-line treatment is worth the money spent. Thus, the objective of this study was to perform a cost-effectiveness analysis of adding IVIG to the standard treatment of platelet transfusion and corticosteroids, for the treatment of childhood ITP with life-threatening bleeding in the context of Thailand.

METHODS

A cost-effectiveness analysis using a hybrid model consisting of a decision tree and Markov models was conducted with a societal perspective. The effectiveness and utility parameters were determined by systematic reviews, while costs and mortality parameters were determined using a retrospective electronic hospital database analysis. All costs were presented in 2012 US$. The discount rate of 3 % was applied for both costs and outcomes. One-way and probabilistic sensitivity analyses were also performed.

RESULTS

The incremental cost-effectiveness ratio (ICER) was $3,172 per quality-adjusted life-year gained ($/QALY) for the addition of IVIG versus standard treatment alone. The probability of response to corticosteroids was the most influential parameter on ICER. According to the willingness-to-pay of Thailand, of approximately $3,861/QALY, the probability of IVIG being cost effective was 33 %.

CONCLUSIONS

The addition of IVIG to standard treatment in the treatment of childhood ITP with life-threatening bleeding is possibly a cost-effective intervention in Thailand. However, our findings were highly sensitive. Policy makers may consider our findings as part of the information for their decision making.

Long-term results of laparoscopic splenectomy in pediatric chronic immune thrombocytopenic purpura

Purpose

Laparoscopic splenectomy (LS) for pediatric chronic immune thrombocytopenic purpura (ITP) patients has recently become widespread. However, its long-term result is rarely reported in children.

Methods

We retrospectively analyzed the patients who underwent LS for pediatric chronic ITP from June 1998 to April 2007.

Results

There were 18 patients (14 male and 4 female) with mean age 9.5 ± 3.8 years. 14 complete response, 3 partial response, and 1 no response were occurred. During the 82-month median follow-up period, 9 patients maintained in a remission state without any additional treatment, and 9 patients relapsed. In a comparative analysis of the relapse group and no relapse group, hospital stays were longer in the relapse group and the preoperative platelet counts and platelet counts at 1 month post were lower in relapse group. A relapse-free survival among 17 patients who achieved partial or complete responses following LS showed 76.5%, 61.8%, and 33.0% at 1-, 5-, and 10-year following LS, respectively.

Conclusion

Although LS in pediatric chronic ITP patients had excellent results immediately after surgery, careful follow up is needed due to late relapse even when a complete response has been noted for several years.

Alterations in immune cell subsets and their cytokine secretion profile in childhood idiopathic thrombocytopenic purpura (ITP)

Immune thrombocytopenic purpura (ITP) is acquired autoimmune disease in children characterized by the breakdown of immune tolerance. This work is designed to explore the contribution of different lymphocyte subsets in acute and chronic ITP children. Imbalance in the T helper type 1 (Th1)/Th2 cytokine secretion profile was investigated. The frequency of T (CD3(+), CD4(+), CD8(+)) and B (CD19(+)) lymphocytes, natural killer (NK) (CD16(+) 56(+)) and regulatory T (T(reg)) [CD4(+) CD25(+high) forkhead box protein 3 (FoxP3)(+) ] cells was investigated by flow cytometry in 35 ITP children (15 acute and 20 chronic) and 10 healthy controls. Plasma levels of Th1 cytokines [interferon (IFN-γ) and tumour necrosis factor (TNF-α)] and Th2 [interleukin (IL)-4, IL-6 and IL-10)] cytokines were measured using enzyme-linked immunosorbent assay (ELISA). The percentage of Treg (P < 0·001) and natural killer (NK) (P < 0·001) cells were significantly decreased in ITP patients compared to healthy controls. A negative correlation was reported between the percentage of T(reg) cells and development of acute (r = -0·737; P < 0·01) and chronic (r = -0·515; P < 0·01) disease. All evaluated cytokines (IFN-γ, TNF-α, IL-4, IL-6 and IL-10) were elevated significantly in ITP patients (P < 0·001, P < 0·05, P < 0·05, P < 0·05 and P < 0·001, respectively) compared to controls. In conclusion, our data shed some light on the fundamental role of immune cells and their related cytokines in ITP patients. The loss of tolerance in ITP may contribute to the dysfunction of T(regs). Understanding the role of T cell subsets will permit a better control of autoimmunity through manipulation of their cytokine network.

Adult primary and secondary immune thrombocytopenic purpura: a comparative analysis of characteristics and clinical course

This study was conducted to compare the platelet count and the presence of bleeding manifestations at initial diagnosis of immune thrombocytopenic purpura (ITP) between patients with primary and secondary ITP. Medical records for 67 consecutive adult patients with ITP were reviewed retrospectively and the relevant data were abstracted. Thirty-eight (56.7%) patients were diagnosed as having primary ITP and 29 (43.3%) were considered to have secondary ITP. At the time of diagnosis, the median initial platelet count (median: 60 × 10(9)/L) for patients with secondary ITP was significantly (P < .005) higher than that for patients with primary ITP (median: 3.5 × 10(9)/L). Ecchymosis and/or purpura was observed in 4 (13.8%) patients with secondary ITP and in 33 (86.6%) patients with primary ITP (P value <.005). In conclusion, patients with secondary ITP had higher platelet count at diagnosis and were less likely to present with bleeding manifestations than those with primary ITP.

Multi-faceted role of naturally occurring autoantibodies in fighting pathogens

Naturally occurring antibodies (NAbs) play a vital role in the first line of defense against bacterial and viral infections. Most studies in mice and man have attributed this role to NAbs of the IgM isotype. However, there is also a significant amount of data on the anti-infectious function of NAbs of the IgG isotype. Most of these observations are derived from studies using a privileged source of NAbs, the pooled human IgG for intravenous application, IVIG. In addition to its use as a replacement in humoral immunodeficiencies, IVIG is extensively used in autoimmune and inflammatory diseases. The properties of NAbs, the principal components of IVIG, are considered crucial for their immune-regulatory properties, owing to their ability to recognize self-antigens and even autoantibodies. By virtue of these specificities for several cellular antigens, including exposed proteins that act as receptors for a variety of pathogens, certain NAbs in IVIG have a therapeutic role in preventing or modulating infections. We summarize in this chapter several examples that highlight the importance of NAbs in the control of certain bacterial and viral infections.

Successful treatment of steroid-refractory autoimmune thrombocytopenia associated with Castleman disease with anti-CD-20 antibody (rituximab)

Multicentric Castleman disease (MCD) is a lymphoproliferative disorder of incompletely understood etiology and with various clinical presentations. The best therapeutic option for this disease is not well established. MCD is known to be associated with autoimmune phenomena. A 70-year-old female patient of MCD with progressive nodal disease associated with autoimmune thrombocytopenia failed steroid treatment and showed a transient response to intravenous immunoglobulin. The patient achieved complete recovery of her platelet count and a very good response in nodal disease after 3 weekly doses of anti-CD-20 antibody (rituximab). Anti-CD20 antibody treatment could be a good therapeutic option for MCD, mainly when associated with immune-related disorders.

Management of severe refractory thrombocytopenia in dengue hemorrhagic fever with intravenous anti-D immune globulin

Dengue hemorrhagic fever (DHF) is a potentially lethal complication of dengue fever due to shock and/or bleeding. Bleeding in DHF is due to thrombocytopenia and/or coagulopathy. The authors present their experience of usage of intravenous anti-D in 5 children with DHF and severe refractory thrombocytopenia (<10,000/mm(3)). It was administered in a dose of 50 to 75 μg/kg. Mean platelet count was 6800/mm(3) before and 33,600, 44,600, and 79,000/mm(3) after intravenous anti-D administration at 24, 48, and 72 hours, respectively. Average drop in hemoglobin after administration of anti-D was 2.28 g/dL. Intravenous anti-D can possibly be a treatment option for refractory thrombocytopenia in DHF.

MicroRNAs in autoimmune disease

MicroRNAs (miRNAs) are non-coding, single-stranded small RNAs, usually 18-25 nucleotides long, have ability to regulate gene expression post-transcriptionally. miRNAs are highly homologous, conserved and are found in various living organisms including plants and animals. Present studies show that these small RNAs anticipate and are directly involved in many important physiological and pathological processes including growth, proliferation, maturation, metabolism, and inflammation among others. Evidences are accumulating that miRNAs play active role in directing immune responses and, therefore, might be involved in pathogenesis of autoimmune diseases. Recent studies have found that miRNAs are critical in proliferation, maturation and differentiation of T cells, B cells and, therefore, may affect the outcome of an immune response. In light of such understanding, this review briefly introduces miRNAs and discusses its role in the pathogenesis of various autoimmune diseases, as well as its potential as a biomarker and therapeutic target in the management of autoimmune diseases.

Evaluation of bleeding and thrombotic events during long-term use of romiplostim in patients with chronic immune thrombocytopenia (ITP)

BACKGROUND

Romiplostim is a peptibody protein that raises platelet counts during long-term treatment of patients with chronic immune thrombocytopenia (ITP). Clinical outcomes related to increased platelet counts include a reduced risk of bleeding and a potential risk of thrombosis.

OBJECTIVE

To evaluate bleeding and thrombotic events occurring in chronic ITP patients during two phase 3, randomized, placebo-controlled, 24-week studies of romiplostim and during subsequent treatment in an open-label extension study.

PATIENTS/METHODS

In the phase 3 trials, 125 patients were randomized to romiplostim or placebo; romiplostim dose was adjusted to maintain platelet counts of 50-200 x 10(9) L(-1). Patients who completed the phase 3 trials could enroll in the extension study in which all patients received romiplostim.

RESULTS

In the phase 3 trials, a significantly greater percentage of patients treated with placebo (34%) had bleeding adverse events of moderate or greater severity than did patients treated with romiplostim (15%, P = 0.018). In the extension study, the incidence of bleeding adverse events of moderate or greater severity decreased from 23% of patients in the first 24 weeks to 12% after 24-48 weeks, remaining < or = 6% thereafter. The exposure-adjusted incidence of thrombotic events was 0.1 per 100 patient-weeks in the phase 3 studies, and 0.08 per 100 patient-weeks in the extension study where patients received romiplostim for up to 144 additional weeks.

CONCLUSIONS

The incidence and severity of bleeding was decreased in chronic ITP patients treated with romiplostim compared with placebo, and the incidence of thrombotic events was not different between the two groups.

Assessment of immunogenicity of romiplostim in clinical studies with ITP subjects

Romiplostim is an Fc-peptide fusion protein that activates intracellular transcriptional pathways via the thrombopoietin (TPO) receptor leading to increased platelet production. Romiplostim has been engineered to have no amino acid sequence homology to endogenous TPO. Recombinant protein therapeutics can be at a risk of development of an antibody response that can impact efficacy and safety. Hence, a strategy to detect potential antibody formation to the drug and to related endogenous molecules can be useful. The immunogenicity assessment strategy involved both the detection and characterization of binding and neutralizing antibodies. The method for detection was based on a surface plasmon resonance biosensor platform using the Biacore 3000. Samples that tested positive for binding antibodies in the Biacore immunoassay were then tested in a neutralization assay. Serum samples from 225 subjects with immune thrombocytopenic purpura (ITP) dosed with romiplostim and 45 ITP subjects dosed with placebo were tested for romiplostim and TPO antibodies. Prior to romiplostim treatment, 17 subjects (7%) tested romiplostim antibody positive and 12 subjects (5%) tested TPO antibody positive for pre-existing binding antibodies. After romiplostim exposure, 11% of the subjects exhibited binding antibodies against romiplostim and 5% of the subjects with ITP showed binding antibodies against TPO. The antibodies against romiplostim did not cross-react with TPO and vice versa. No cases of anti-TPO neutralizing antibodies were detected in romiplostim-treated subjects. The incidence of anti-romiplostim neutralizing antibodies to romiplostim was 0.4% (one subject); this subject tested negative at the time of follow-up 4 months later. No impact on platelet profiles were apparent in subjects that had antibodies to romiplostim to date. In summary, administration of romiplostim in ITP subjects resulted in the development of a binding antibody response against romiplostim and TPO ligand. One subject developed a neutralizing antibody response to romiplostim that impacted the platelet counts of this subject. No neutralizing antibodies to endogenous TPO were observed.

Impact of ITP on physician visits and workplace productivity

OBJECTIVE

To assess the impact of immune thrombocytopenic purpura (ITP) on primary care and specialist visits and workplace productivity.

RESEARCH DESIGN AND METHODS

This was a cross-sectional, descriptive study comparing ITP patients to age- and gender-matched controls. Subjects completed a one-time web-based survey, which included questions on work loss, work productivity, and physician visits. ITP patients and controls were compared on these outcomes. For ITP patients, the relationship between work-related issues and physician visits with clinical characteristics (time since diagnosis, platelet count, number of treatments received, and an ITP-specific health-related quality of life measure, the ITP-PAQ) was explored.

RESULTS

A total of 1002 ITP patients and 1031 controls completed the survey. On average, ITP patients were 46 years old, diagnosed 9 years ago, and had platelet counts of 148 x 10(9)/L; 37% had undergone splenectomy. More ITP patients had primary care (20% vs. 11%) and specialist (28% vs. 11%) visits in the past month versus controls (p < or = 0.001). Higher proportions of ITP patients have ever taken sick leave (56% vs. 30%), and missed chore hours in the past week (18% vs. 13%) (p < or = 0.003). ITP patients scored significantly worse than controls on all six work productivity items. Patients diagnosed within the past year were more likely to have specialist visits and to miss chore hours versus those diagnosed less recently. Worse ITP-PAQ scores and more ITP-related treatments were related to more physician visits and worse work-related and productivity outcomes. Platelet count is not associated with these outcomes. The study is limited by the potential for biased samples due to recruitment approaches, the inherent issues of a cross-sectional study design and recall bias in questionnaire responses.

CONCLUSIONS

ITP was consistently associated with more physician visits and worse work and productivity outcomes. Future research should build on these findings by calculating a comprehensive cost-of-illness of ITP including both direct and indirect costs.

Characteristics of immune thrombocytopenic purpura: a guide for clinical practice

Immune (idiopathic) thrombocytopenic purpura (ITP) is an autoantibody-mediated condition characterized by an abnormally low number of platelets in the circulating blood. Originally, the cause of ITP was attributed to accelerated antibody-mediated platelet destruction where the rate of thrombopoiesis was inadequate to offset the increased rate of platelet destruction. However, new evidence has indicated that insufficient or inadequate platelet production is also responsible for low platelet counts, and research has focused on the development of treatments that increase platelet production. ITP affects both children and adults and can be either acute or chronic. To manage and treat ITP effectively, an exhaustive assessment of the signs and symptoms must be undertaken because the clinical manifestation of ITP can be highly variable among patients. At the moment, the diagnostic approach in ITP is based largely on a process of exclusion due to the lack of available data regarding clinical and laboratory parameters. The diagnostic procedures used in children and adults are similar and involve collecting the patient's history and performing a physical examination. Laboratory investigations are kept simple in patients with suspected ITP and include a full blood count and peripheral blood smear. A number of specialized laboratory assays have been developed with varying degrees of success. There remains scope for improving and simplifying the diagnostic process to identify ITP.

Evaluation of bone marrow reticulin formation in chronic immune thrombocytopenia patients treated with romiplostim

Romiplostim is a thrombopoietin receptor agonist that increases platelet counts in patients with chronic immune thrombocytopenia (ITP). Thrombopoietin receptor agonists are reported to increase the risk for reticulin fiber deposition within bone marrow. This report describes bone marrow findings from romiplostim-treated rats, a retrospective analysis of reticulin observed in romiplostim ITP clinical trials, and a prospective clinical study of the effects of romiplostim on bone marrow morphology. In rats, romiplostim produced a dose-dependent increase in bone marrow fibrosis that resolved after treatment withdrawal. Of 271 ITP patients in romiplostim clinical trials, 10 were reported to have reticulin deposition; reticulin grade was increased in 4 of 5 patients with both pretreatment and on-treatment bone marrow results. Reticulin grade often decreased soon after romiplostim discontinuation. In the prospective study, reticulin grade during romiplostim treatment remained within the normal range for all patients and was increased in only 1 of 6 patients with pretreatment and on-treatment bone marrow results. This report suggests that romiplostim produces reversible, dose-dependent bone marrow changes in rats and produces modest increases in bone marrow reticulin in some ITP patients that decrease when therapy is discontinued. These studies were registered at www.clinicaltrials.gov as #NCT00102323, #NCT00102336, #NCT00861224, and #NCT00116688.

International consensus report on the investigation and management of primary immune thrombocytopenia

Previously published guidelines for the diagnosis and management of primary immune thrombocytopenia (ITP) require updating largely due to the introduction of new classes of therapeutic agents, and a greater understanding of the disease pathophysiology. However, treatment-related decisions still remain principally dependent on clinical expertise or patient preference rather than high-quality clinical trial evidence. This consensus document aims to report on new data and provide consensus-based recommendations relating to diagnosis and treatment of ITP in adults, in children, and during pregnancy. The inclusion of summary tables within this document, supported by information tables in the online appendices, is intended to aid in clinical decision making.

[The role of Helicobacter pylori infection in children with chronic immune thrombocytopenic purpura]

Helicobacter pylori infection has been associated with immune thrombocytopenic purpura in adults, however, the few studies concerning this issue showed conflicting results in the paediatric field. Therefore, authors prospectively investigated the incidence of Helicobacter pylori infection and the effect of Helicobacter pylori eradication on platelet count recovery in children with immune thrombocytopenic purpura.

PATIENTS AND METHODS

The study included 27 children with immune thrombocytopenic purpura (13 boys and 14 girls) with a median age of 8.2 years (range, 18 months-18 years). 38 healthy children (controls) were also enrolled (20 boys, 18 girls, median age, 9.6 years, range, 4-18 years). Helicobacter pylori infection was diagnosed using 13 C urea breath test. Eradication was assessed at 6 weeks following the end of the treatment by 13 C urea breath.

RESULTS

2 children out of 27 patients with immune thrombocytopenic purpura proved to be positive for Helicobacter pylori infection (7.7%) and were treated with combination therapy. Controls showed similar rate of Helicobacter pylori infection (3/38, 7.9%) in comparison to those with immune thrombocytopenic purpura. In the follow-up period (mean, 10 months, range, 6-14 months) platelets did not show any improvement in infected children following the eradication treatment and were identical to those of the uninfected patients. Eradication was successful in the 2 Helicobacter pylori infected patients with immune thrombocytopenic purpura.

CONCLUSION

The results do not suggest a pathogenetic role of Helicobacter pylori infection in the etiology of immune thrombocytopenic purpura. Screening of Helicobacter pylori infection among paediatric patients with immune thrombocytopenic purpura is not recommended.

Therapeutic approaches to secondary immune thrombocytopenic purpura

Secondary thrombocytopenia is similar to primary or idiopathic thrombocytopenia (ITP) in that it is characterized by reduced platelet production or increased platelet destruction resulting in platelet levels<60,000/microL. Thrombocytopenia can occur from secondary causes associated with chronic disorders or with disturbed immune function due to chronic infections, lymphoproliferative and myeloproliferative disorders, pregnancy, or autoimmune disorders. Diagnosis of secondary ITP in some cases is complex, and the thrombocytopenia can often be resolved by treating the underlying disorder to the extent this is possible. In most cases, treatment is focused on reducing platelet destruction, but, in some cases, treatment may also be directed at stimulating platelet production. The most problematic cases of thrombocytopenia may be seen in pregnant women. This review will address various agents and their utility in treating ITP from secondary causes; in addition, thrombocytopenia in pregnancy, ITP in immunodeficiency conditions, and drug-induced thrombocytopenia will be discussed. Unlike primary ITP, treatment often must be tailored to the specific circumstance underlying the secondary ITP, even if the condition itself is incurable.

Intravenous immunoglobulins in the treatment of dengue illness

Dengue infection causes significant morbidity and mortality worldwide. Therapeutic options for severe thrombocytopaenia and shock syndrome, the main causes of mortality, are limited. Careful fluid management is the mainstay of treatment. The immunological basis of the life-threatening manifestations of severe dengue together with the potentially beneficial immunomodulatory effects of intravenous immunoglobulins (IVIG) suggest a possible place for treatment with this expensive therapy. Trials so far have not shown significant benefit in terms of survival or improvement in clinical parameters with IVIG. However, evidence is very limited, and there is clearly a place for well-designed randomized controlled trials investigating the beneficial effects of IVIG in the various life-threatening manifestations of dengue.

Safety and efficacy of long-term treatment with romiplostim in thrombocytopenic patients with chronic ITP

Chronic immune thrombocytopenic purpura (ITP) is characterized by low platelet counts and mucocutaneous bleeding. In previous studies romiplostim (AMG531), a thrombopoiesis-stimulating protein, increased platelet counts in most patients with chronic ITP. This ongoing, long-term open-label, single-arm study investigated safety and efficacy in patients who completed a previous romiplostim study and had platelet counts less than or equal to 50 [corrected] x 10(9)/L. One hundred forty-two patients were treated for up to 156 weeks (mean, 69 weeks). Platelet responses (platelet count > or = 50 x 10(9)/L and double baseline) were observed in 87% of all patients and occurred on average 67% of the time in responding patients. In 77% of patients, the romiplostim dose remained within 2 microg/kg of their most frequent dose at least 90% of the time. Ninety patients (63%) received treatment by self-administration. Treatment-related serious adverse events were reported in 13 patients (9%). Bone marrow reticulin was observed in 8 patients; marrows were not routinely performed in this study, so the true incidence of this event cannot be determined. Severe bleeding events were reported in 12 patients (9%). Thrombotic events occurred in 7 patients (5%). In conclusion, romiplostim increased platelet counts in most patients for up to 156 weeks without tachyphylaxis and had an acceptable safety profile. (ClinicalTrials.gov Identifier NCT00116688).

A double antibody radioassay for the detection of platelet associated IgG

A double antibody radioimmunoassay has been developed for the detection of platelet associated IgG (PAIgG). The assay employs conventional radioassay technology and, as such, readily may be adopted by laboratories familiar with radioassay techniques. The assay is sensitive to 0.6 ng IgG and can be undertaken on 10(6)-10(7) platelets, or fewer in the case of thrombocytopenia with raised PAIgG. The assay can be completed within 2 working days. Normal PAIgG levels in EDTA blood were 0.8 to 5.7 micrograms IgG/10(9) platelets. However, normal levels depended upon the anticoagulant used for blood collection and were on average five-fold higher for blood taken into EDTA than for blood taken into ACD; normal range 0.1-1.2 micrograms/IgG 10(9) platelets. PAIgG was assayed on blood taken simultaneously into ACD and EDTA from 15 patients with chronic idiopathic thrombocytopenia (ITP). PAIgG was raised in 14 out of 15 EDTA samples, but in only 11 of 15 ACD samples. EDTA was therefore regarded as the anticoagulant of choice. A total of 20 of 23 (87%) patients with chronic ITP had PAIgG values above the normal range. The PAIgG in chronic ITP was weakly related to platelet count, weakly and inversely related to platelet volume, but was independent of serum IgG concentration.

Recruitment of T cells into bone marrow of ITP patients possibly due to elevated expression of VLA-4 and CX3CR1

In idiopathic thrombocytopenic purpura (ITP), platelets are destroyed in the spleen, liver, and bone marrow (BM) by autoantibodies and cytotoxic T cells. In a DNA microarray screen of peripheral blood T cells, we found that VLA-4, CX3CR1, and CXCR4, involved in T-cell homing, had increased expression in ITP patients compared with controls. However, we only found increased protein expression of VLA-4 on T cells from peripheral blood by flow cytometry. To address a possible recruitment of T cells into the organs involved in platelet destruction, we analyzed T cells in BM. In BM, T-cell surface expression of VLA-4 and CX3CR1 was increased in ITP patients compared with controls. Furthermore, the number of CD3(+) T cells in BM, but not in blood, was increased in ITP patients compared with controls. This finding was confirmed by immunohistochemistry of BM biopsies. The number of regulatory T cells (CD4(+)/CD25(bright)) was decreased in the BM of ITP patients, whereas Fas expression was increased. In conclusion, ITP is associated with accumulation and activation of T cells in the BM. Recruitment of T cells into the target organ (eg, BM) is plausible and may be facilitated through increased VLA-4 and CX3CR1 expression. These molecules might serve as new treatment targets in ITP.

Outcome of immunosuppressive therapy with Helicobacter pylori eradication therapy in patients with chronic idiopathic thrombocytopenic purpura

We initiated this study to investigate whether combining Helicobacter pylori eradication with immunosuppressive therapy provides an additional benefit to patients with idiopathic thrombocytopenic purpura (ITP) that has relapsed or has not responded to steroid and/or danazol therapy in patients who have H. pylori infection. Thirty- four patients with chronic ITP that had relapsed or failed to steroid and/or danazol therapy were assessed for H. pylori infection. Of the 21 confirmed cases, 12 patients were given H. pylori eradication therapy alone (EA), while 9 patients received eradication therapy combined with immunosuppressive therapy (EI). The response rate was not significantly different between patients in the EA and those in the EI group (41.7% in the EA group vs. 66.7% in the EI group, p=0.345). The median platelet count at 6 months after therapy was higher in the EI group patients (75 x 10(9)/L in the EI group patients vs. 18 x 10(9)/L in the EA group patients, p=0.028). The median response duration was also longer in the EI group patients (9 months in the EI group patients vs. 3 months in the EA group patients, p=0.049). These results show that a significant benefit is gained by the use of H. pylori eradication combined with immunosuppressive therapy over the use of eradication therapy alone for patients with chronic ITP.

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.

Efficacy of romiplostim in patients with chronic immune thrombocytopenic purpura: a double-blind randomised controlled trial

BACKGROUND

Chronic immune thrombocytopenic purpura (ITP) is characterised by accelerated platelet destruction and decreased platelet production. Short-term administration of the thrombopoiesis-stimulating protein, romiplostim, has been shown to increase platelet counts in most patients with chronic ITP. We assessed the long-term administration of romiplostim in splenectomised and non-splenectomised patients with ITP.

METHODS

In two parallel trials, 63 splenectomised and 62 non-splenectomised patients with ITP and a mean of three platelet counts 30x10(9)/L or less were randomly assigned 2:1 to subcutaneous injections of romiplostim (n=42 in splenectomised study and n=41 in non-splenectomised study) or placebo (n=21 in both studies) every week for 24 weeks. Doses of study drug were adjusted to maintain platelet counts of 50x10(9)/L to 200x10(9)/L. The primary objectives were to assess the efficacy of romiplostim as measured by a durable platelet response (platelet count > or =50x10(9)/L during 6 or more of the last 8 weeks of treatment) and treatment safety. Analysis was per protocol. These studies are registered with ClinicalTrials.gov, numbers NCT00102323 and NCT00102336.

FINDINGS

A durable platelet response was achieved by 16 of 42 splenectomised patients given romplostim versus none of 21 given placebo (difference in proportion of patients responding 38% [95% CI 23.4-52.8], p=0.0013), and by 25 of 41 non-splenectomised patients given romplostim versus one of 21 given placebo (56% [38.7-73.7], p<0.0001). The overall platelet response rate (either durable or transient platelet response) was noted in 88% (36/41) of non-splenectomised and 79% (33/42) of splenectomised patients given romiplostim compared with 14% (three of 21) of non-splenectomised and no splenectomised patients given placebo (p<0.0001). Patients given romiplostim achieved platelet counts of 50x10(9)/L or more on a mean of 13.8 (SE 0.9) weeks (mean 12.3 [1.2] weeks in splenectomised group vs 15.2 [1.2] weeks in non-splenectomised group) compared with 0.8 (0.4) weeks for those given placebo (0.2 [0.1] weeks vs 1.3 [0.8] weeks). 87% (20/23) of patients given romiplostim (12/12 splenectomised and eight of 11 non-splenectomised patients) reduced or discontinued concurrent therapy compared with 38% (six of 16) of those given placebo (one of six splenectomised and five of ten non-splenectomised patients). Adverse events were much the same in patients given romiplostim and placebo. No antibodies against romiplostim or thrombopoietin were detected.

INTERPRETATION

Romiplostim was well tolerated, and increased and maintained platelet counts in splenectomised and non-splenectomised patients with ITP. Many patients were able to reduce or discontinue other ITP medications. Stimulation of platelet production by romiplostim may provide a new therapeutic option for patients with ITP.

Helicobacter pylori-associated chronic idiopathic thrombocytopenic purpura and low molecular weight H. pylori proteins

We examined the association between Helicobacter pylori infection and chronic idiopathic thrombocytopenic purpura (cITP) to clarify the development of H. pylori-associated cITP. cITP patients were classified into 3 different groups: Hp-negative (HP-N); Hp-positive, completely or partially responsive to treatment (CR); and Hp-positive and unresponsive to treatment (NR). Reactivity of antibodies to H. pylori before and after eradication was examined by immunoblotting. We used immunoblotting with immunoprecipitation to establish whether platelets form complexes with H. pylori proteins and if these complexes react with patients' sera. CR group showed large (>50 kDa) and low molecular weight protein bands, especially of 36, 27 and 17-kDa. These low molecular weight bands were detected significantly more in the CR group compared to other groups. When healthy human platelets were incubated with H. pylori lysate, they aggregated with the lysate, indicating that complexes were formed between the platelets and the lysate. The complexes immunoprecipitated with anti-human thrombocyte antibodies, and showed a 17 kDa band in the CR, but not in other groups. At least 3 low molecular weight proteins of H. pylori were involved in H. pylori-associated cITP. Immunocomplexes consisting of platelets, low molecular weight proteins of H. pylori and anti-H. pylori antibodies may represent an extra mechanism in development of H. pylori- associated cITP.

A disease-specific measure of health-related quality of life for use in adults with immune thrombocytopenic purpura: its development and validation

Background

No validated disease-specific measures are available to assess health-related quality of life (HRQoL) in adult subjects with immune thrombocytopenic purpura (ITP). Therefore, we sought to develop and validate the ITP-Patient Assessment Questionnaire (ITP-PAQ) for adult subjects with ITP.

Methods

Information from literature reviews, focus groups with subjects, and clinicians were used to develop 50 ITP-PAQ items. Factor analyses were conducted to develop the scale structure and reduce the number of items. The final 44-item ITP-PAQ, which includes ten scales [Symptoms (S), Bother-Physical Health (B), Fatigue/Sleep (FT), Activity (A), Fear (FR), Psychological Health (PH), Work (W), Social Activity (SA), Women's Reproductive Health (RH), and Overall (QoL)], was self-administered to adult ITP subjects at baseline and 7–10 days later. Test-retest reliability, internal consistency reliability, construct and known groups validity of the final ITP-PAQ were evaluated.

Results

Seventy-three subjects with ITP completed the questionnaire twice. Test-retest reliability, as measured by the intra-class correlation, ranged from 0.52–0.90. Internal consistency reliability was demonstrated with Cronbach's alpha for all scales above the acceptable level of 0.70 (range: 0.71–0.92), except for RH (0.66). Construct validity, assessed by correlating ITP-PAQ scales with established measures (Short Form-36 v.1, SF-36 and Center for Epidemiologic Studies Depression Scale, CES-D), was demonstrated through moderate correlations between the ITP-PAQ SA and SF-36 Social Function scales (r = 0.67), and between ITP-PAQ PH and SF-36 Mental Health Scales (r = 0.63). Moderate to strong inter-scale correlations were reported between ITP-PAQ scales and the CES-D, except for the RH scale. Known groups validity was evaluated by comparing mean scores for groups that differed clinically. Statistically significant differences (p < 0.01) were observed when subjects were categorized by treatment status [S, FT, B, A, PH, and QoL, perceived effectiveness of ITP treatment [S], and time elapsed since ITP diagnosis [PH].

Conclusion

Results provide preliminary evidence of the reliability and validity of the ITP-PAQ in adult subjects with ITP. Further work should be conducted to assess the responsiveness and to estimate the minimal clinical important difference of the ITP-PAQ to more fully understand the impact of ITP and its treatments on HRQoL.

Reduced Cd4+Cd25+ T cells in patients with idiopathic thrombocytopenic purpura

Immunoregulatory CD4(+)CD25(+) T cells play an important role in the induction and maintenance of peripheral self-tolerance. These professional regulatory cells prevent the activation and proliferation of potentially autoreactive T cells that have escaped thymic deletion. Therefore, CD4(+)CD25(+) T cells are believed to possibly play an important role in pathogenic autoimmune diseases. We measured the count of CD4(+)CD25(+) T cells in 44 patients with idiopathic thrombocytopenic purpura (ITP), and the number of CD4(+)CD25(+) T cells and clinical features were then analyzed. By using a flow cytometric analysis, the number of CD4(+)CD25(+) T cells in the patients with ITP showed a very wide distribution in comparison to healthy volunteers. The number of CD4(+)CD25(+) T cells was significantly lower in the ITP patients in the severe phase, and in patients positive for anti-glycoprotein IIb-IIIa antibody. However, the number of those cells increased in the patients at the complete remission phase, especially after a splenectomy. The Foxp3 mRNA levels of peripheral blood mononuclear cells (PBMC) of ITP patients were higher with an improved platelet count than in those with a low platelet count. In addition, the Foxp3 mRNA levels closely correlated with the number of CD4(+)CD25(+) cells. These mechanisms remain to be fully elucidated, however, the count of CD4(+)CD25(+) T cells is considered to possibly be related to the severity of ITP.

Dengue illness: clinical features and pathogenesis

The incidence and geographical distribution of dengue has gradually increased during the past decade. This review is an update on dengue virus infections, based on our clinical and laboratory experiences in the Philippines and on other relevant literature. The differential diagnosis of this disease is discussed, especially for use by clinicians where dengue is not endemic. The complex pathogenesis of thrombocytopenia and increased vascular permeability in dengue illness is also discussed. Our recent data suggest that platelet-associated immunoglobulins involving anti-dengue virus activity play a pivotal role in the development of dengue hemorrhagic fever (DHF), as well as thrombocytopenia in secondary dengue virus infections. Further elucidation is needed on the involvement of platelet-associated immunoglobulins on the molecular mechanisms of thrombocytopenia and the increased vascular permeability.