The term ‘NRBC’ – ‘nucleated red blood cells’ – refers to precursor cells of the red blood cell lineage which still contain a nucleus. In healthy adults and older children, NRBC can only be found in blood-building bone marrow where they mature. Their appearance in peripheral blood points to extramedullary erythropoiesis or disruption of the blood - bone marrow barrier. Both possible scenarios can only be found in the course of a severe disease.
Thrombocytopenia is a disorder in which there is an abnormally low amount of platelets. It can be life threatening and its detection and precise count is extremely important. The immature platelet fraction (IPF parameter) measures young, reticulated platelets in peripheral Blood, revealing if the bone marrow is producing or not.
The treatment of immune thrombocytopenia (ITP) can be challenging. The immature platelet count (IPF) can be used in ITP as a supportive information to assess whether the treatment mechanism is having an effect: To have a supportive parameter to answer the clinical question as to whether the observed increase in the platelet count is due to increased platelet production or inhibition of antibody-mediated platelet destruction. Due to the higher reactivity and haemostatic potential of immature platelets, an increased immature platelet count was also found to be associated with a lower risk of bleeding with severely thrombocytopenic patients.
A short introduction to the concepts of metrological traceability and measurement uncertainty is given in the article for readers who are not familiar with them. It also includes a short description of the steps needed to evaluate uncertainty. The article further explains how traceability is assured for the Sysmex haematology calibrators and describes how the uncertainty of these calibrators was evaluated.
PLT counts alone do not reveal the underlying aetiology of thrombocytopenia. The causes of thrombocytopenia can be due to decreased platelet production in bone marrow or an increased destruction/consumption of platelets in peripheral blood. The IPF is a diagnostic parameter that can support treating physicians when determining the cause of thrombocytopenia based on the aetiology of various congenital and acquired thrombocytopenic states, as described in this white paper.