English 
Italian Informazioni inaspettate dall’esame emocromocitometrico: variante emoglobinica Hb Leiden rilevata tramite un analizzatore ematologico
Unexpected information from a blood count test: a hemoglobin variant, Hb Leiden, detected with a hematology analyzer
AUTORI
1Dipartimento di Medicina di Laboratorio, Policlinico “Tor Vergata”, Roma
2Dipartimento di Medicina Sperimentale, Università “Tor Vergata”, Roma
Questo lavoro è stato in parte presentato al 52° Congresso Nazionale SIBioC, 6-8 Ottobre 2020, Virtual Edition, nella Sessione Casi Cinici
ABSTRACT
Unexpected information from a blood count test: a hemoglobin variant, Hb Leiden, detected with a hematology analyzer
Hemoglobin variants are abnormal forms of hemoglobin that may cause hematological disorders. The variants can be (or not) associated with normal hematology parameters. We were able to identify a hemoglobin variant in a 56-year-old Italian Caucasian male using a hematology analyzer.
A routine complete blood count was performed on the Sysmex XN-9000 analyzer for a patient presenting at the Emergency Department with dizziness. Unusual morphological alarms were reported by the analyzer. The microscopy observation of the peripheral blood smear showed a significant number of contracted ed cells and target red cells. Differential count cytograms showed changes in the distribution of the cell clusters and a reduction in the fluorescence signal. In the hypothesis that these alterations were caused by a hemoglobin variant, a HPLC test was performed and a variant in the D/E zone was detected. Molecular analysis confirmed the presence of a variant identified as Hb Leiden. We were thus able to demonstrate the importance to correlate instrumental alarms with validation rules to detect variants in cases where clinical evidence was lacking. The introduction of a new validation rule that automatically activates reticulocyte count and peripheral blood smear in case of specific instrumental alarms is highly advisable.