Association between Platelet-Associated Immunoglobulin G Levels and Response to Corticosteroid Therapy in Patients with Newly Diagnosed Immune Thrombocytopenia

Abstract

<b><i>Objective:</i></b> Platelet-associated immunoglobulin G (PA-IgG) refers to IgG attached to the surface of platelets, while the immature platelet fraction (IPF) reflects the state of platelet production in bone marrow. Since PA-IgG and IPF are increased in patients with immune thrombocytopenia (ITP), reflecting amounts of platelet antibodies and compensatory platelet production, respectively, we hypothesized that these laboratory findings may provide useful markers for predicting treatment response in patients with ITP. We therefore retrospectively investigated associations between levels of these markers at diagnosis and response to first-line therapy in patients with ITP. <b><i>Methods:</i></b> Forty-three patients diagnosed with ITP at Oita Kouseiren Tsurumi Hospital between May 2010 and November 2018 were included. Patients were divided into 2 groups based on response to corticosteroid as first-line therapy. Laboratory findings were compared between responders and nonresponders. <b><i>Results:</i></b> Median PA-IgG was 285 ng/10<sup>7</sup> cells (range, 45.5–18,200 ng/10<sup>7</sup> cells), and median IPF was 15.5% (range, 5.4–62.1%). Median levels were higher than the respective upper limits of normal range (PA-IgG, 0–46 ng/10<sup>7</sup> cells; IPF, 1.1–9.5%). First-line therapy was performed using standard-dose prednisolone (0.5–1.0 mg/kg/day) in 32 patients and high-dose dexamethasone (40 mg/day, 4 days) or methylprednisolone (125–1,000 mg/day, 3–4 days) in 11 patients. Twenty-four patients (55.8%) responded to first-line therapy. In univariate analysis, type of corticosteroid (<i>p</i> = 0.17) tended to differ between groups but did not differ significantly, and no difference in IPF level was apparent between responders (15.35%; range, 5.4–41.5%) and nonresponders (16.7%; range, 6.3–62.1%; <i>p</i> = 0.15). PA-IgG was significantly higher among nonresponders (430 ng/10<sup>7</sup> cells; range, 101–18,200 ng/10<sup>7</sup> cells) than among responders (254.5 ng/10<sup>7</sup> cells; range, 45.5–470 ng/10<sup>7</sup> cells; <i>p</i> = 0.004). Multivariate analysis revealed PA-IgG was independently associated with response to first-line therapy (odds ratio, 1.000; 95% confidence interval, 1.000–1.010; <i>p</i> = 0.029). <b><i>Conclusion:</i></b> Our data suggested that PA-IgG at diagnosis could offer a useful predictor of response to first-line corticosteroid therapy for ITP.

Gut microbiota alterations in children and their relationship with primary immune thrombocytopenia

“…IgG and IgM antiplatelet antibodies can be used to diagnose ITP ( 29 ). Studies have suggested that detection of PA-IgG may provide a useful predictor of the response to first-line corticosteroid therapy for ITP ( 30 ), Our research found that PLT and IgG were significantly negatively correlated, while IgG and phylum Bacteroidetes were significantly positively correlated ( P < 0.01), suggesting that antiplatelet antibodies may reflect changes in gut microbiota to a certain extent, and also that they may participate in the pathogenesis of ITP disease via IgG. On this basis, they may be used to judge diseases and guide treatment.…”

Suspected Immune Thrombocytopenic Purpura Induced by Lenalidomide for the Treatment of Myelodysplastic Syndrome with Deletion of Chromosome 5q: A Case Report

“…Fourth, the level of PAIgG was extremely high compared to that before treatment with LEN. Although the specificity of PAIgG for ITP is thought to be low (Kelton et al 1989;Gilli et al 2012), a recent study showed that PAIgG was significantly higher among non-responders to corticosteroids than among responders, indicating that high levels of PAIgG may have clinical significance in ITP (Saburi et al 2021). Fifth, LEN has been known to induce ITP, as described previously (Herold et al 2011;Pompa et al 2016;Meguri et al 2018;Forehand III et al 2020).…”