DETERMINATION OF ERYTHROCYTIC PARAMETERS IN CASE OF EXTREMELY SEVERE AGGLUTINATION ASSOCIATED TO HEMOLYSIS

Introduction

Several conditions lead to abnormal determination of blood count parameters by the automated hematology analyzers resulting in spurious counts. Namely, hemolysis/agglutination results in increased Mean Corpuscular Hemoglobin Concentration (MCHC) which induces an analytical alarm that needs corrective action to ensure delivery of reliable results. 

Clinical Case

A 92 year-old female presented at the ER with complaints of pain and multiple skin lesions in her legs and hands. She had a previous diagnosis of Auto-Immune Hemolytic Anemia by Cold Antibodies, Cryoglobulinemia type II, Raynaud Phenomenon, Lupus and Systemic Sclerosis. A blood count was requested and performed in the hematology analyser Sysmex© XE-2100 revealing several spurious determinations: RBC: 0.71×1012/L; Hgb: 10.1 g/dL; Hct: 7.1%; MCV:100 fl; MCH: 142 pg; MCHC: 142 g/dL. It was then noted that the sample showed agglutination so severe it seemed to be clotted. Following the routine protocol, the sample was warmed at 37ºC for 1 hour. After this period the blood count was repeated at the Sysmex© XE-5000, still showing spurious determinations. It was warmed for another hour and immediately after analyzed this time by fluorescence flow cytometry on the RET/PLT-O channel in order to determine the Red Blood Cells-Optical (RBC-O) and Hemoglobin- Optical (Hgb-O). The Hematocrit was determined using the micro-hematocrit method. A blood smear was performed confirming the agglutination.

All other erythrocytic parameters were thus re-calculated using these values and delivered as follows: RBC: 2.89×1012/L; Hgb: 9.1 g/dL; Hct: 29.1%; MCV:101 fl; MCH: 31.5 pg; MCHC: 31.2 g/dL.

Discussion:

The degree of red blood cell agglutination in this case was so severe that in almost all the visits to the hospital for the past 12 years, the sample had been assumed to be either clotted or only a part of the blood count was delivered. As it has been suggested by some authors, analyzing the sample on the RET/PLT-O channel provides a count by fluorescence flow cytometry which allows the delivery of appropriate and full results for the erythrocytic parameters of the blood count.

Declaração de Conflitos de Interesses

O autor responsável pela submissão do resumo intitulado DETERMINATION OF ERYTHROCYTIC PARAMETERS IN CASE OF EXTREMELY SEVERE AGGLUTINATION ASSOCIATED TO HEMOLYSIS e todos os coautores, declaram que NÃO POSSUEM CONFLITO DE INTERESSES de ordem pessoal, comercial, acadêmico, político ou financeiro no mesmo.