Detection of neoplastic cells in body fluid samples on the Sysmex UF-5000 analyzer

Thrombotic thrombocytopenic purpura (TTP) demands rapid initiation of therapeutic plasma exchange to avoid severe complications associated with it. ADAMTS13 activity <10% defines TTP, however, this is a send-out test at most institutions. We have previously reported our experience looking at absolute immature platelet counts (A-IPC) in TTP patients. Thus, we compared A-IPC on admission to the PLASMIC score to predict ADAMTS13 deficiency.Of seventy-two patients identified, 52 met inclusion criteria. All patients were suspected of new-onset TTP and had A-IPC on admission. Of these patients, 25/52 were later shown to have ADAMTS13 <10%, defined as TTP group, and 27/52 had ADAMTS13 >10% and are henceforth classified as non-TTP.Patients with TTP were found to have A-IPC below reference range (<1.5 × 109/L) and responded to therapy as shown by fold-increases in A-IPC (p < 0.0001), neither seen in non-TTP patients. A-IPC had a significant correlation with ADAMTS13 deficiency (p = 0.0001) with high sensitivity, specificity, positive and negative predictive values. Comparison of A-IPC to PLASMIC score indicated that the former identified all TTP patients compared to PLASMIC score even in patients obtaining scores of 4 and 5. Finally, Receiver Operating Characteristic curves showed A-IPC had area under the curve of 0.986.A-IPC below reference range and A-IPC fold-increases were only observed in TTP patients. There was strong association between A-IPC and ADAMTS13 deficiency and A-IPC predicted patients with ADAMTS13 deficiency. Future larger studies are needed to determine ways to apply findings in suspected TTP patients.