Development and internal validation of a clinical prediction model for the diagnosis of immune thrombocytopenia

Abstract

Background Immune thrombocytopenia (ITP) is a diagnosis of exclusion that can resemble other thrombocytopenic disorders. Objectives To develop a clinical prediction model (CPM) for the diagnosis of ITP to aid hematogists in investigating patients presenting with undifferentiated thrombocytopenia. Methods We designed a CPM for ITP diagnosis at the time of the initial hematology consultation using penalized logistic regression based on data from patients with thrombocytopenia enrolled in the McMaster ITP registry (n = 523) called the Predict‐ITP Tool. The case definition for ITP was a platelet count less than 100 × 109/L and a platelet count response after high‐dose corticosteroids or intravenous immune globulin, defined as the achievement of a platelet count above 50 × 109/L and at least a doubling of baseline. Internal validation was done using bootstrap resampling. Model discrimination was assessed by the c‐statistic, and calibration was assessed by the calibration slope, calibration‐in‐the‐large, and calibration plot. Results The final model included the following variables: (1) platelet count variability (based on three or more platelet count values), (2) lowest platelet count value, (3) maximum mean platelet volume, and (4) history of major bleeding (defined by the ITP bleeding scale). The optimism‐corrected c‐statistic was 0.83, the calibration slope was 0.88, and calibration‐in‐the‐large for all performance measures was <0.001 with standard error <0.001, indicating good discrimination and excellent calibration. Conclusions The Predict‐ITP Tool can estimate the likelihood of ITP for a given patient with thrombocytopenia at the time of the initial hematology consultation. The tool had high predictive accuracy for the diagnosis of ITP.

A prospective cohort study to identify clinical diagnostic and prognostic markers of primary immune thrombocytopenia in dogs

“…Thrombocytopenia severity also aids diagnosis of ITP in humans, with enhanced accuracy of clinical predictive models that include the lowest platelet count. 47 …”

“…Thrombocytopenia severity also aids diagnosis of ITP in humans, with enhanced accuracy of clinical predictive models that include the lowest platelet count. 47 The residual circulating platelets of dogs with pITP and sITP had decreased expression of platelet membrane antigens CD61 and CD9.…”

Therapeutic Outcomes of High Dose-Dexamethasone versus Prednisolone + Azathioprine, Rituximab, Eltrombopag, and Romiplostim Strategies in Persistent, Chronic, Refractory, and Relapsed Immune Thrombocytopenia Patients

“…Recent studies have highlighted the role of apoptosis in controlling platelet lifespan and survival in chronic ITP patients [ 2 ]. TPO-RAs have been suggested to reduce platelet apoptosis [ 30 ], and their immunomodulatory activity on monocyte/macrophage plasticity further supports the findings of this study [ 30 ].…”

“…Based on the results of recent works, using ELTRO may be beneficial in chronic and refractory ITP patients [31]. HD-DXM showed a higher overall response rate in chronic ITP patients than in persistent ITP patients, likely due to its role in reducing apoptosis and increasing PLT counts [2]. Although the overall response to RTX was relatively high (64.7% and 56.2%), the sustained response was not encouraging in chronic and refractory ITP patients (18.1% and 22.2%).…”

“…Primary immune thrombocytopenia (ITP) is an autoimmune hemorrhage disorder characterized by impairment of platelet production and immunological abnormalities resulting in platelet destruction [ 1 ]. Severe internal bleeding can occur as a consequence [ 2 , 3 ]. ITP affects approximately 1 in every 20,000 individuals, with females being more affected than males [ 4 , 5 , 6 ].…”