Idiopathic thrombocytopenic purpura in childhood: controversies and solutions

FcγRIIa and FcγRIIIa genes polymorphism in Egyptian children with primary immune thrombocytopenia

INTRODUCTION

Phagocytosis of autoantibody-sensitized coated platelets through Fc gamma receptors on phagocytic cells is an important mechanism of thrombocytopenia in primary immune thrombocytopenia (ITP).

OBJECTIVE

We aimed to investigate the contribution of the FcγRIIa and FcγRIIIa genes polymorphism to the risk of ITP and their association with disease characteristics in Egyptian children.

METHODS

A case control study was conducted on eighty children with primary ITP and eighty age and sex healthy matched subjects as a control group. The FcγRIIa and FcγRIIIa genes polymorphism was detected using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

We found that the FcγRIIa-131H and -131R allele frequencies were 51.3 % and 48.7%, respectively, in children with ITP, versus 75% and 25%, respectively, in controls (p = 0.002). The compound heterozygous HR genotype was significantly higher in ITP patients (p < 0.05). The FcγRIIIa-158F and -158V allele frequencies were 46.3% and 53.7%, respectively, in children with ITP, versus 70% and 30%, respectively, in controls (p = 0.002). The compound heterozygous VF genotype was significantly higher in ITP patients (p < 0.05). The combined HR/FV genotype was 47.5% in ITP patients, versus 10% in controls (p < 0.001). No significant difference was found between children with newly diagnosed ITP and those who developed chronic ITP, regarding the frequency distribution of the FcγRIIa and FcγRIIIa alleles and genotypes (p > 0.05).

CONCLUSION

There is a possible association of the FcγRIIa and FcγRIIIa genes polymorphism with the risk for, and genetic susceptibility to ITP in Egyptian children, but large-scale studies are still needed to support our findings.

Management strategies for newly diagnosed immune thrombocytopenia in Italian AIEOP Centres: do we overtreat? Data from a multicentre, prospective cohort study

BACKGROUND

The aim of the present study was to assess management strategies for immune thrombocytopenia (ITP) among Italian paediatric haematologists, and to compare these with those of recent international guidelines. Predictors of early remission or disease chronicity were also evaluated.

MATERIALS AND METHODS

During a period of 1 year, 205 children (age: 1 month-18 years) with newly diagnosed ITP were prospectively enrolled by 16 centres belonging to the Italian Association of Paediatric Haematology and Oncology (AIEOP). We collected the subjects demographic data, history, clinical symptoms, platelet count and treatment at presentation and at subsequent visits.

RESULTS

Of the 205 patients, 47 (23%) were initially managed with a wait-and-see approach. Compared to these patients, children administered platelet-enhancing therapies were significantly younger (median age: 4.75 vs 7.96 years; p<0.001) and had lower platelet counts. At the 3-month follow-up, 92/202 patients (46%) had persistent ITP. Recovery within 3 months was predicted by younger median age (5.3 vs 7.8 years; p<0.001), and recent viral infection (p<0.001) . At 1 year, 56 patients had chronic ITP, which was associated with older median age (7.54 vs 5.35 years; p<0.001), and a family history of autoimmunity (p<0.05; relative risk: 1.81; 95% confidence interval: 1.09-2.98). In total, 357 pharmacological treatments were recorded (216 intravenous immunoglobulins, 80 steroids). Response to intravenous immunoglobulins did not have an effect on remission rate at 12 months.

DISCUSSION

Pediatric hematologists in Italian Centre treat over three-quarters of patients with newly diagnosed ITP, despite recent international guidelines. Almost 80% of patients with mild clinical symptoms received pharmacological treatment at diagnosis, which was significantly associated with younger age. Chronicity at 12 months was not affected by different therapeutic approaches at diagnosis or response to therapy.

The clinical outcome of 260 pediatric ITP patients in one center

In the current study, clinical and laboratory findings and treatment modalities of children with acute and chronic immune thrombocytopenic purpura (ITP) were evaluated retrospectively. Our purpose was to determine clinical outcome of children with ITP and their responses to different treatment regimes. Total of 260 children with ITP were enrolled in the study. The mean age of patients was 76.8 ± 48.1 months. The therapy responses of high-dose methylprednisolone (HDMP; n = 134), standard dose methylprednisolone (n = 32), and intravenous immunoglobulin (IVIG; n = 15) treatments were similar. Two (0.8%) of the 260 ITP patients had intracranial bleeding. None of the patients died due to hemorrhage. Of all the patients with ITP, 191 (73.5%) completely resolved within 6 months after initiation of the disease and therefore they were diagnosed as acute ITP; 69 patients (26.5%) had progressed into chronic ITP. The therapy responses of HDMP, standard dose methylprednisolone, and IVIG treatments are similar.

Clinical features, treatment responses, and outcome of children with idiopathic thrombocytopenic purpura

The authors investigated demographics, clinical and laboratory features, treatment responses, and outcomes of 93 children (median age 5 years) admitted for idiopathic thrombocytopenic purpura (ITP). The therapy responses of high-dose methylprednisolone (HDMP) (n = 77) and intravenous immunoglobulin (IVIG) (n = 10) treatments were similar. None of the patients with hemorrhage died. Fifteen patients (16.1%) had progressed into chronic ITP. Seven infants had a probable relationship with vaccination; none of these infants progressed into chronic ITP. In conclusion, the overall prognosis in childhood ITP is good. The therapy responses of HDMP and IVIG treatments are similar. Also, ITP cases who havw vaccination history have a benign course.

Controversies in the diagnosis and management of childhood acute immune thrombocytopenic purpura

Acute immune thrombocytopenic purpura (ITP) occurs most commonly in young children who present with severe isolated thrombocytopenia and purpura. A marrow examination is not required unless glucocorticoids are used, lest treatment mask incipient acute lymphoblastic leukemia, but controversy exists here. The recommendations for evaluation and management remain controversial, since prospective controlled trials have not been done. There is some consensus based on experience and empiric data. Almost all children with acute ITP will recover completely without therapy. Although the various treatments may increase the platelet count, they do not influence the outcome of the illness, may increase cost, and cause significant side effects. Therefore, careful observation may be the best management option for the patient with ITP, in the absence of severe bleeding. The data available relevant to these issues are discussed.

A benchmark analysis of the achievement of therapeutic goals for type 1 Gaucher disease patients treated with imiglucerase

To assess the extent to which patients with type 1 Gaucher disease (GD1) receiving individualized enzyme replacement therapy with imiglucerase attain six defined therapeutic goals. One hundred and ninety-five GD1 patients enrolled in the ICGG Gaucher Registry, all of whom had data available for hemoglobin, platelet count, liver volume, spleen volume, bone pain, and bone crises at first infusion and after 4 years of therapy with imiglucerase, were evaluated for achievement of published therapeutic goals. The proportion of patients who met all six therapeutic goals increased from 2.1% at first infusion to 41.5% at 4 years; > or =5 goals from 12.8% to 76.9%; > or =4 goals from 37.4% to 92.8%; > or =3 goals from 70.8% to 99.0%; and > or =2 goals from 95.4% to 99.5%. All patients met at least one goal at first infusion and after 4 years of treatment. The proportion of patients meeting specific therapeutic goals increased for all parameters between first infusion and 4 years of therapy: platelet count (24.6%-79.5%), spleen volume (25.6%-78.5%), liver volume (45.6%-90.8%), bone pain (62.6-70.3%), hemoglobin (68.2-91.8%), and bone crises (91.8-99.0%). On average, patients who received higher doses of imiglucerase achieved a greater number of therapeutic goals. This analysis provides a benchmark for evaluating the utility of a disease management approach for GD1 based on monitoring achievement of therapeutic goals after treatment with imiglucerase.

Immune thrombocytopenic purpura

Immune thrombocytopenic purpura (ITP) is the commonest cause of sudden onset thrombocytopenia in a healthy child. The condition is frequently preceded by a viral infection. The hematological parameters are essentially normal except a low platelet count. Bone marrow examination is not routinely indicated except in specific situations. The pros and cons of drug treatment have been discussed as the disease is benign with excellent prognosis in majority of the cases. The various treatment options including low and high dose steroids, intravenous immunoglobulins and anti D have been discussed at length with other modalities of treatment and role of splenectomy. Current therapeutic options with rituximab and other drugs for stimulating platelet production in chronic cases have also been included in discussion.

A population-based, multisite cohort study of the predictors of chronic idiopathic thrombocytopenic purpura in children

OBJECTIVE

The objective of this study was to identify risk factors for developing chronic idiopathic thrombocytopenic purpura in a cohort of pediatric patients with idiopathic thrombocytopenic purpura.

METHODS

We conducted a retrospective cohort analysis of 259 children who were diagnosed with idiopathic thrombocytopenic purpura between 1991 and 2000 at 1 of 8 managed care organizations that comprise the Vaccine Safety Datalink. We reviewed the charts of 595 potential patients with idiopathic thrombocytopenic purpura from the 8 Vaccine Safety Datalink sites and excluded patients with known causes of thrombocytopenia. Chronic idiopathic thrombocytopenic purpura was defined as having thrombocytopenia for 6 months beyond the initial diagnosis. The risk for developing chronic idiopathic thrombocytopenic purpura was assessed using simple and multivariable analyses.

RESULTS

Of the 259 cases of idiopathic thrombocytopenic purpura, 197 (76%) were acute, 60 (23%) were chronic, and 2 (1%) could not be determined. Among the acute cases, the mean duration of illness was 22 days. There was 1 serious bleeding outcome in the cohort. In multivariable regression analysis, the patients with chronic illness were older, less likely to present with mucosal bleeding, less likely to have had an acute illness before diagnosis, and more likely to present with a platelet count > 20,000/microL than children with acute idiopathic thrombocytopenic purpura. In particular, children whose illness was diagnosed at > or = 10 years of age and who had platelet counts > or = 20,000/microL had an approximate fivefold risk for progressing to chronic disease when compared with children who presented at < or = 2 years of age with platelet counts < 20,000/microL.

CONCLUSIONS

Although idiopathic thrombocytopenic purpura tends to be a benign and self-limited condition, acute and chronic idiopathic thrombocytopenic purpura seem to be distinct illnesses defined by age, platelet count, bleeding symptoms, and the presence of acute illness before diagnosis. Physicians should be aware of these differences when advising their patients and families.

Immune thrombocytopenic purpura

Immune thrombocytopenic purpura (ITP) is an autoantibody-mediated thrombocytopenic disorder in which accelerated destruction of platelets occurs; platelet production may also be impaired by these antibodies. ITP is characterized by mucocutaneous bleeding. Rarely, more severe hemorrhages, such as intracranial hemorrhage, may occur. Traditional therapies, such as steroids, immunoglobulin therapy, and splenectomy, generally reduce peripheral destruction of platelets. More recently, with a better understanding of the immunopathologic mechanisms underlying thrombocytopenia, several new treatments have been developed, including thrombopoietic agents, specific inhibitors of Fcgamma receptor (FcgammaR) signaling, and B-cell depletion therapies. This article outlines current understanding of the epidemiology, etiology, diagnosis, and treatment of ITP. The focus is on recent pathophysiologic insights and areas of potential controversy in which studies are ongoing.