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Medline ® Abstract for Reference 11

of 'Acquired TTP: Clinical manifestations and diagnosis'

Hemolysis and schistocytosis in the emergency department: consider pseudothrombotic microangiopathy related to vitamin B12 deficiency.
Noël N, MaignéG, Tertian G, Anguel N, Monnet X, Michot JM, Goujard C, Lambotte O
QJM. 2013 Nov;106(11):1017-22. Epub 2013 Jul 10.
BACKGROUND: Hemolytic anemia with thrombocytopenia and schistocytosis is suggestive of thrombotic thrombocytopenic purpura (TTP). However, these features can occur in the context of vitamin B12 deficiency.
AIM: To identify simple means of distinguishing between TTP and pseudothrombotic microangiopathies related to vitamin B12 deficiency (pseudo-TMA) at the bedside.
DESIGN AND METHODS: Retrospective study of patients with pseudo-TMA compared with patients with TTP. The patients with pseudo-TMA were further compared with other cases of cobalamin deficiency, in order to detect factors associated with microangiopathic hemolysis during vitamin B12 deprivation.
RESULTS: Seven patients with pseudo-TMA were compared with six patients with TTP. The pseudo-TMA patients had higher median lactate dehydrogenase (LDH)levels (7310 vs. 1460 IU/l, P = 0.01), a higher platelet count (73 vs.12.5×10(9)/l, P = 0.0023), a lower reticulocyte count (13.1 vs. 265.5×10(9)/l, P = 0.0012) and a lower neutrophil count (1.3 vs. 5.1×10(9)/l, P = 0.0023). When compared with 21 patients with vitamin B12 deficiency and anemia (but no schistocytosis), the pseudo-TMA patients were more likely to present with pernicious anemia [7 out of 21 (33.3%) vs. 5 out of 7 (71.4%), respectively]and had lower vitamin B12 levels (105 vs. 45µmol/l, respectively). Vitamin supplementation led to hematological improvements in all pseudo-TMA patients.
CONCLUSION: In a context of mechanical hemolysis with thrombocytopenia in a patient admitted to the emergency department, very high LDH levels and a low reticulocyte count are strongly suggestive of pseudo-TMA and should prompt the physician to screen for cobalamin deficiency.
MD, PhD, Service de Médecine Interne, Hôpital Bicêtre, 78, rue du Général Leclerc, F-94275 Le Kremlin Bicêtre cedex, France. olivier.lambotte@bct.aphp.fr.