Anti-beta2-glycoprotein I in childhood immune thrombocytopenic purpura

Non-Criteria Manifestations of Juvenile Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder mainly characterised by increased risks of thrombosis and pregnancy morbidity and persistent positive test results for antiphospholipid antibodies (aPLs). The criteria for diagnosing juvenile APS have yet to be validated, while the Sydney classification criteria do not contain several non-thrombotic clinical manifestations associated with the presence of aPLs. As such, difficulties have been encountered in the diagnosis of patients who have no certain thrombotic occlusions. Moreover, extra-criteria manifestations (i.e., clinical manifestations not listed in the classification criteria), including neurologic manifestations (chorea, myelitis and migraine), haematologic manifestations (thrombocytopenia and haemolytic anaemia), livedo reticularis, nephropathy and valvular heart disease have been reported, which suggests that the clinical spectrum of aPL-related manifestations extends beyond that indicated in the classification criteria. Studies have demonstrated that more than 40% of children with aPLs demonstrated non-thrombotic aPL-related clinical manifestations alone. Moreover, our results showed that the pathogenesis of non-criteria manifestations is characterised by “APS vasculopathy”. The present review introduces the characteristics and findings of non-criteria manifestations observed in juvenile APS.

Modeling and Simulation Support Eltrombopag Dosing in Pediatric Patients With Immune Thrombocytopenia

Our objective was to support initial eltrombopag doses and dose titration based on modeling and simulation of plasma exposure and platelet count response in pediatric patients aged 1-17 years with previously treated chronic immune thrombocytopenia enrolled in two clinical studies. Data from 168 pediatric patients were used to develop a life-span population pharmacokinetic and pharmacodynamic model including three pharmacokinetic and four pharmacodynamic compartments enabling simulation of platelet counts for various starting doses and dose titration schedules. This work supported initial eltrombopag doses of 50 mg once daily (q.d.) for non-Asian patients aged ≥ 6 years and 25 mg q.d. for Asian patients, regardless of age, and for all patients aged 1-5 years, regardless of ethnic origin. Doses were escalated at 2-week intervals or reduced as needed according to each patient's platelet counts to both minimize the time to achieve target platelet counts and mitigate thrombocytosis. Clinicaltrials.gov Identifier: NCT00908037, NCT01520909.

Dural Venous Sinus Thrombosis and Pulmonary Embolism Following Immunoglobulin Treatment in Pediatric Patient With Immune Thrombocytopenic Purpura

Intravenous immunoglobulin (IVIG) is a widely used agent as the first choice of treatment of immune thrombocytopenic purpura (ITP). IVIG has several side effects, but it is a relatively safe treatment. Life-threatening thrombosis has been reported in adults and rarely in children. We report a case of a 14-year-old boy with dural venous sinus thrombosis and pulmonary embolism after treatment with IVIG for ITP. The patient was treated with low-molecular-weight heparin followed by warfarin and the symptoms were recovered. If a patient with ITP shows mental change or respiratory difficulty, we should consider thrombosis as well as hemorrhage.

Incidence of Antiphospholipid Antibodies in Patients With Immune Thrombocytopenia and Correlation With Treatment With Steroids in North Indian Population

Introduction:

Antiphospholipid antibodies (APLAs) have been variably reported in 14% to 75% of patients with immune thrombocytopenia (ITP). There is lack of Indian data on incidence of APLA in ITP.

Objective:

We studied the incidence of APLA in patients with pediatric and adult Indian ITP.

Materials and Methods:

We prospectively studied 100 patients including acute (n = 37), persistent (n = 13), and chronic (n = 50) ITP. Male to female ratio was 1.22:1. Median age was 18 years (1.5-56). All patients underwent investigations for lupus anticoagulant (LA), anticardiolipin (aCL) immunoglobulin G (IgG) and IgM antibodies, and anti-β2 glycoprotein 1 (β2GP1) IgG and IgM antibodies. Patients with secondary ITP were excluded. Bleeding manifestations were recorded. Patients with acute and persistent ITP were assessed for steroid response. Response rates were compared between APLA-positive and APLA-negative patients.

Results:

Antiphospholipid antibodies were detected in ∼12% of patients with ITP: 8.1% (3 of 37) in acute, 0% (0 of 13) in persistent, and 18% (9 of 50) in chronic ITP. Anti-β2GP1 antibodies were most frequent (9%). Only 2 patients each were positive for anti-aCL antibodies and LA. Although platelet counts were significantly higher in APLA-positive patients, there was no significant difference in bleeding between the APLA-positive versus APLA-negative patients with ITP. There was also no significant difference in steroid response between APLA-positive and APLA-negative patients with acute/persistent ITP. In the short follow-up (median 8 months), none of the APLA-positive patients developed thrombosis.

Conclusions:

Incidence of APLA in Indian population was lower than reported in the West, which indicates that not all patients of ITP need to be subjected to these manifestations upfront at diagnosis.