Original scientific paper

Studies on in vitro hemolysis and utility of corrective formulas for reporting results on hemolyzed specimens

Giuseppe Lippi orcid.org/0000-0001-9523-9054 ; U.O. Diagnostica Ematochimica, Dipartimento di Patologia e Medicina di Laboratorio, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
Paola Avanzini ; U.O. Diagnostica Ematochimica, Dipartimento di Patologia e Medicina di Laboratorio, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
Fernanda Pavesi ; U.O. Diagnostica Ematochimica, Dipartimento di Patologia e Medicina di Laboratorio, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
Mirco Bardi ; U.O. Diagnostica Ematochimica, Dipartimento di Patologia e Medicina di Laboratorio, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
Luigi Ippolito ; U.O. Diagnostica Ematochimica, Dipartimento di Patologia e Medicina di Laboratorio, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
Rosalia Aloe ; U.O. Diagnostica Ematochimica, Dipartimento di Patologia e Medicina di Laboratorio, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
Emmanuel J Favaloro ; Department of Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), Westmead Hospital, NSW, Australia

Abstract

Introduction: Spuriously hemolyzed specimens are the most common preanalytical problems in clini-cal laboratories. Corrective formulas have been proposed to allow the laboratory to release test re-sults on these specimens. This study aimed to assess the influence of spurious hemolysis and reliability of corrective formulas.
Materials and methods: Blood collected into lithium heparin vacuum tubes was divided in aliquots and subjected to mechanical injury by aspiration with an insulin syringe equipped with a thin needle (30 gauge). Each aliquot (numbered from “#0” to “#5”) was subjected to a growing number of passa-ges through the needle, from 0 to 5 times. After hematological testing, plasma was separated by cen-trifugation and assayed for lactate dehydrogenase (LD), aspartate aminotransferase (AST), potassi-um and hemolysis index (HI).
Results: Cell-free hemoglobin concentration gradually increased from aliquot #0 (HI: 0) to #5 (HI: 76±22, cell-free hemoglobin č 37.0 g/L). A highly significant inverse correlation was observed between HI and red blood cell count (RBC), hematocrit, mean corpuscular volume (MCV), LD, AST, potassium, whereas the correlation was negative with mean corpuscular hemoglobin (MCH). No cor-relation was found with hemoglobin, platelet count and glucose. A trend towards decrease was also observed for white blood cells count. The ANCOVA comparison of analyte-specific regression lines from the five subjects studied revealed significant differences for all parameters except potassium. In all circumstances the sy,x of these equations however exceeded the allowable clinical bias.
Conclusions: Mechanical injury of blood, as it might arise from preanalytical problems, occurs dishomogeneously, so that corrective formulas are unreliable and likely misleading.

Keywords

hemolysis; hemolyzed specimens; interference; preanalytical variability

Hrčak ID:

72951

URI

https://hrcak.srce.hr/72951

Publication date:

15.10.2011.

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