In the past 10 years, we have observed 112 cases of EDTA-dependent pseudothrombocytopenia (PTCP) due to in vitro platelet clumping at room temperature. 93 patients had antiplatelet antibodies (48 IgM, 30 IgG, 3 IgA, and 12 had two different isotypes concomitantly).
In 20% of patients, the presence of IgM antibodies characteristically accompanied platelet agglutination also at 37°C, and in citrated blood.
The phenomenon was not age or sex related, nor was it associated with any particular pathology or use of specific drugs, and was present in both healthy subjects and patients with various diseases.
Flow cytofluorimetric analysis of CD5-positive B cells, which are responsible for autoantibody production, did not demonstrate any changes in the percentage and absolute number of this lymphocyte subset.
Average follow-up was 5 years (6 months-10 years) ; however, previous clinical records disclosed that PTCP was present for more than 15 years in four cases, and more than 20 years in three others, with no clinical manifestation of disease.
This study confirms that EDTA-dependent PTCP is a phenomenon related to the presence of natural autoantibodies with antiplatelet activity, devoid of pathological significance.
Its clinical interest resides in the need for its prompt and certain recognition in order to avoid unnecessary examinations and therapeutic interventions.
Mots-clés Pascal : Thrombopénie, Diagnostic erreur, Autoanticorps, Anticorps, Agrégation, EDTA, Epidémiologie, Etude longitudinale, In vitro, Homme, Thrombocyte, Hémopathie, Pseudothrombopénie
Mots-clés Pascal anglais : Thrombocytopenia, Error diagnostic, Autoantibody, Antibody, Aggregation, EDTA, Epidemiology, Follow up study, In vitro, Human, Platelet, Hemopathy
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 95-0550291
Code Inist : 002B19C. Création : 01/03/1996.