Impact of immunological platelet counting (by the platelet/RBC ratio) on haematological practice

Abstract

With the increasing availability of flow cytometers within haematology laboratories, a number of different groups began to investigate the applicability of this technology to accurately enumerate platelets and other cells within whole blood, with the ultimate aim of replacing manual counting reference methods. Six years ago, different candidate flow cytometric immunological platelet counting procedures were reviewed by the International Council for Standardisation in Haematology (ICSH) expert panel on cytometry. The ICSH panel identified all the variables and problems associated with this methodology that enabled an International Society of Laboratory Haematology (ISLH) task force panel to rapidly develop, evolve, and test a new candidate consensus reference method using the platelet/red blood cell (RBC) ratio for platelet counting (1,2). The detailed methodology was published and has been available to the scientific community for a number of years. To our knowledge, many laboratories and instrument manufacturers are successfully using the method without any significant problems. Exact details on how to perform this methodology are provided in the original publications and in a more recent review of platelet counting methodologies (1-3). The intended utility of this method was never to develop a routine alternative counting method except in a few rare clinical cases and for comparative research-based studies but to provide the most accurate means to determine the values of calibrants and quality control (QC) materials in the laboratory. In this review, we discuss the impact of this methodology on haematological practice, e.g., the QC of the accuracy of platelet counting in thrombocytopenia and its potential impact on platelet transfusion decision making.

A novel method to estimate platelet counts from peripheral smears: A study comparing a new method of platelet estimation with existing methods.

“…This method measures the platelet count based on platelet/ RBC ratio and total RBC count. This method has been found to be very accurate [13] . But the procedure involves the detection of fluorescent labeled platelets in a fluorescence flow-cytometer which cannot be performed routinely in developing countries due to the costs involved.…”

Comparative evaluation of platelet counts in two hematology analyzers and potential effects on prophylactic platelet transfusion decisions

“…Various authors have demonstrated excellent precision and accuracy of this method, as well as excellent correlation with the ICSH dual‐color immunofluorescence method . It is possibly even more precise than the reference method . For now, this method is the only immunologic PLT method available for routine use.…”

“…A fully automated modification of this immunoplatelet method using CD61 antibodies is available in the Abbott CELL‐DYN Sapphire analyzer . Various authors have demonstrated excellent precision and accuracy of this method, as well as excellent correlation with the ICSH dual‐color immunofluorescence method . It is possibly even more precise than the reference method .…”

“…In view of the known methodologic challenges in patients with thrombocytopenia, we also investigated the potential impact of inaccuracy of these PLT methods at various transfusion trigger thresholds for prophylactic PLT transfusions. This subject has been studied previously, but not with the Sysmex XN analyzer . Since the use of this new analyzer is rapidly growing, we believe that it is of interest documenting the performance of this analyzer's three PLT technologies in this respect.…”

Valutazione del sistema Cellavision DM-96 nell’analisi della formula leucocitaria e nel conteggio piastrinico

“…In questo ambito la citofluorimetria rappresenta l'esame di riferimento, ma per costi elevati e complessità analitiche non è ancora utilizzata nelle routine estese [3].…”