Abstract Number: PB0888
Meeting: ISTH 2021 Congress
Theme: Platelet Disorders, von Willebrand Disease and Thrombotic Microangiopathies » Platelet Function Disorders, Acquired
Background: Acquired δ-Storage pool disorder(SPD) is frequently associated with myelodysplastic syndrome/myeloproliferative neoplasms(MDS/MPN) possibly resulting from chromosomal alterations in megakaryocyte lineage causing decreased dense granules production. Patients with MPN may also have acquired Factor V deficiency either due to Factor V adsorption on myeloid-megakaryocyte mass, hepatic synthetic dysfunction or inhibitors. Acquired SPD and factor deficiency may co-exist in patients with MDS/MPN, timely diagnosis of both being essential to offer appropriate therapeutic intervention at the time of bleeding.
Aims: To describe co-existence of acquired δ-SPD and acquired factor V deficiency in a 14 years old child with MDS/MPN.
Methods: Informed consent was taken from parents. ISTH-Bleeding Assessment Tool(BAT) was used to objectively score the bleeding symptoms. Complete blood counts(CBC), Prothrombin Time(PT), Activated Partial thromboplastin time(APTT), mixing studies, Fibrinogen, Modified Ivy’s bleeding time(BT), Closure time on Platelet function analyzer-200 (PFA-200), Ristocetin cofactor assay(vWF:RCo), light transmission aggregometry(LTA), lumi-aggregometry, mepacrine uptake/release assay, CD63 expression after agonist stimulation by flow cytometry and one-stage clot-based factor assays were performed.
Results: Patient had elevated BAT score of 4 with recent onset epistaxis and ecchymosis. CBC revealed low hemoglobin(6.9gm/dl), elevated WBC count(76.4 x 109/L), mild thrombocytopenia(83×109/L) with myeloid left shift, increased blasts(9%), hypogranular myeloids and platelet anisocytosis(Figure1). Bone marrow examination was consistent with MDS/MPN with cytogenetics showing monosomy 7. PT and APTT were prolonged, correcting on mixing studies. Factor V was mildly reduced(20%) while other coagulation factors and vWF:RCo were normal. Although BT, PFA-200 closure time and LTA were normal, lumi-aggregometry showed absent ATP release. Markedly reduced Mepacrine uptake/release(Figure2) and markedly reduced CD63 expression upon convulxin stimulation confirmed the diagnosis of δ-SPD.
Peripheral smear showing blast, myelocyte, hypogranular myeloid, platelet anisocytosis and anisogranularity
Mepacrine Uptake / Release Assay showing markedly reduced Mepacrine uptake/ release for the patient as compared to the control
Conclusions: Acquired δ-SPD may co-exist with acquired factor V deficiency in patients with MDS/MPN. Hence, lumi-aggregometry and mepacrine uptake/release assay should be performed in patients with MDS/MPN having bleeding symptoms despite normal screening tests for primary hemostasis and normal LTA.
To cite this abstract in AMA style:
Dave R, Mammen J, Geevar T, Rasalam J, Vijayan R, Samuel A, Singh S, Nair S, Mathew L. Acquired δ-Storage Pool Disorder Co-existing with Acquired Factor V Deficiency in Myelodysplastic Syndrome / Myeloproliferative Neoplasm [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/acquired-%ce%b4-storage-pool-disorder-co-existing-with-acquired-factor-v-deficiency-in-myelodysplastic-syndrome-myeloproliferative-neoplasm/. Accessed September 29, 2023.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/acquired-%ce%b4-storage-pool-disorder-co-existing-with-acquired-factor-v-deficiency-in-myelodysplastic-syndrome-myeloproliferative-neoplasm/