The Diagnostic Value of Thrombopoietin Level Measurements in Thrombocytopenia

Abstract

SummaryIt has been reported that blood trombopoietin (TPO) levels can discriminate between thrombocytopenia due to increased platelet destruction and decreased platelet production. With our TPO ELISA and a glycocalicin ELISA we analysed a large group of patients in detail and could confirm and amplify the above notion in detail.TPO levels were determined in plasma from 178 clinically and serologically well-defined thrombocytopenic patients: 72 patients with idiopathic autoimmune thrombocytopenia (AITP), 29 patients with secondary AITP, 5 patients with amegakaryocytic thrombocytopenia and 72 patients who suffered from various diseases (46 in whom megakaryocyte deficiency was not and 26 in whom it was expected). In addition, we measured the level of glycocalicin as a marker of total body mass of platelets.In all patients with primary AITP and secondary AITP, TPO levels were within the normal range or in some (n = 7) cases only slightly increased. The level of glycocalicin was not significantly different from that of the controls (n = 95). The patients with amegakaryocytic thrombocytopenia had strongly elevated TPO levels and significantly decreased glycocalicin levels. Similarly, among the 72 thrombocytopenic patients with various disorders, elevated TPO levels were only found in patients in whom platelet production was depressed. The mean level of glycocalicin in these patients was decreased compared to that in controls and patients with AITP, but was not as low as in patients with amegakaryocytic thrombocytopenia.In conclusion, all patients with depressed platelet production had elevated levels of circulating TPO, whereas the TPO levels in patients with an immune-mediated thrombocytopenia were mostly within the normal range. Therefore, measurement of plasma TPO levels provides valuable diagnostic information for the analysis of thrombocytopenia in general.Moreover, treatment with TPO may be an option in AITP.

Fetal and Neonatal Thrombopoietin Levels in Alloimmune Thrombocytopenia

“…Trials are in progress to clarify the relative merits of each form of treatment, although, increasingly, it is desirable to avoid fetal sampling, if feasible. We and others detected normal or only slightly elevated Tpo levels in ITP patients (7)(8)(9)(10). We now find that Tpo levels in NAIT fetuses are also normal or only slightly elevated compared with levels in nonthrombocytopenic age-matched controls.…”

“…After binding, Tpo is eventually destroyed together with the platelets. We and others have shown the diagnostic value of measurement of plasma Tpo levels for discrimination between thrombocytopenia caused by megakaryocyte and platelet production failure (highly elevated Tpo levels) and thrombocytopenia caused by elevated platelet destruction observed in autoimmune thrombocytopenia (normal or only slightly elevated Tpo levels) (7)(8)(9)(10)(11). In the latter disorder, megakaryocyte numbers in the marrow are normal or increased, as is platelet production.…”

Immature Platelet Fraction: Establishment of a Reference Interval and Diagnostic Measure for Thrombocytopenia

“…These clearly showed that, under conditions of thrombocytopenia, the platelet RNA content correlated directly with megakaryocytic activity [9]. The parameters of platelet production and turnover rate have also been studied using platelet lifespan [14], glycocalicin index [15], and thrombopoietin level [16]. However, the platelet lifespan is not widely used because of problems associated with the manipulation of platelets and the use of radioactivity [17].…”

Superior effect of intravenous anti‐D compared with IV gammaglobulin in the treatment of HIV‐thrombocytopenia: Results of a small, randomized prospective comparison

“…The actual quantity of HIV in circulation was evaluated by estimation of plasma HIV-RNA levels using the polymerase chain reaction (Amplicor HIV-1 Monitor test, limit of detection: 400 HIV-1RNA copies/mL, Roche Diagnostics). TPO levels were measured by an enzyme-linked immunoabsorbent assay (ELISA) [20,21]. According to this method, serum TPO levels measured in 137 healthy donors ranged from 13.6 to 108 AU (2.5th-97.5th percentile; these levels average 3.4-fold higher than plasma TPO levels in the same individuals).…”