Immature platelet fraction as a useful marker in the etiological determination of thrombocytopenia

Abstract

Background: The aetiology of thrombocytopenia is important in treatment and management of the condition. Most platelet parameters that are routinely analysed in the diagnostic laboratory have not proven useful in identifying the aetiology while specialised assays suffer from poor standardisation and lack of agreement between laboratories. The immature platelet fraction (IPF), which indirectly provides a measure of bone marrow function is showing promise as a valuable marker of thrombopoietic responses. Objectives: To determine whether the IPF could effectively identify specific underlying aetiologies of thrombocytopenia in a large thrombocytopenic cohort, to allow for quicker, more effective management of the condition. Patients and Methods: The IPF was analysed in a large cohort of 637 thrombocytopenic patients and 171 healthy control patients on the Sysmex XN 10 haematology analyser using the specialised fluorescence optical analysis. The thrombocytopenic patients were divided into six cohorts based on aetiology. Results: The IPF%, was significantly higher in cases of increased platelet consumption (median=9.55, min=1.1, max= 77.9), or pseudothrombocytopenia (median=13.1, min=0.4, max=28.8) compared with control (median=4.2, min=1.3, max=12.8). Furthermore, the IPF% was also able to identify idiopathic thrombocytopenic purpura (ITP) (P<0.05) (median=13.4, min=2.8, max=77.9) from other causes of increased platelet consumptive disorders (Infection; median=6.4, min=1.1, max=21.6; haemorrhage, median=8.9, min=1.2, max=20.2). Conclusion: Using this large thrombocytopenic cohort, the IPF% has been shown to be of significant diagnostic value, providing a useful rapid test in the aetiological investigation of platelet disorders.

Platelet variability index: a measure of platelet count fluctuations in patients with immune thrombocytopenia

“…In that study, a high immature platelet fraction (>8.45%) could discriminate between ITP and other causes of thrombocytopenia, with a sensitivity of 80.4% and specificity of 79.9% (28). Similar findings have been reported in adults (29,30). Platelet activation has also been compared between groups of patients with thrombocytopenic syndromes.…”

Immature Platelet Dynamics in Immune-Mediated Thrombocytopenic States

“…Regrettably, this study lacks A-IPC data analysis and determination if immature platelet counts were comparable with stratification according to platelet count (39). Despite this, recent data indicates that as ITP patients respond to treatment (40), specific changes in A-IPCs identify those with the disease (8). Based on these results, potentially helpful clinical scoring models that include immature platelet counts and favor ITP as a diagnosis have been proposed (2,33), that take into consideration the high positive predictive value of these A-IPC changes (41).…”

“…Pathologically both higher platelet destruction that results in decreased platelet counts and potentially impaired thrombopoiesis influence risk of bleeding (31). Thus it should be of interest that reports appear to suggest that bone marrow attempts to compensate for platelet destruction by markedly increasing %-IPF to cope with the consumptive/destructive process (2,8,21,30,(32)(33)(34); that these increases appear higher in those with chronic ITP (35); and that these dynamics may help risk stratify patients at risk of bleeding since they appear to have a higher preponderance of immature platelets (32,36,37). Notably, the magnitude of these compensatory increases in patients with ITP may be conveyed in a more consistent manner by looking at A-IPC at presentation (38).…”

“…One of these markers, readily obtainable in modern automated hematology analyzers with fluorescence capability, is the immature platelet fraction (%-IPF) and specifically the absolute immature platelet count (A-IPC). Regardless of how the acronyms are presented in the literature, such as designation of either immature or reticulated platelets, it has become more evident that this is an important variable when discerning processes leading to a thrombocytopenic state which has long been overlooked in clinical practice (3)(4)(5)(6)(7)(8).…”

Immature Platelet Fraction in Thrombocytopenic Patients

“…They can be distinguished from mature platelets by their RNA content and their larger size [1]. IPF has been reported significantly higher in cases of increased platelet consumption [2] and reduced in bone marrow failure cases, highlighting the thrombopoiesis activity in the bone marrow. [3] By understanding the value, clinicians can use it in determining whether or not the invasive examination is needed and more importantly avoiding unnecessary platelet transfusion.…”