The study showed that ET patients compared to healthy individuals have an increased amount of reticulated platelets and increased aggregation potential. These findings might in part explain the increased thromboembolic risk in patients with ET. © 2018 International Clinical Cytometry Society.

Insufficient platelet inhibition has been reported in up to 40% of aspirin-treated patients, including patients with essential thrombocytosis. To maintain sufficient platelet inhibition, a shorter dosing interval with aspirin has been suggested. We aimed to investigate the antiplatelet effect of low-dose aspirin given twice-daily compared to standard once-daily dosing in patients with essential thrombocytosis. We included 22 patients, who were treated for 7 days with standard once-daily aspirin (75 mg once-daily) followed by 7 days treatment of twice-daily aspirin (37.5 mg twice-daily). The two regimens were separated by 14 days aspirin washout. Blood samples were obtained 1h and 24h/12h after the last pill intake in each regimen. The effect of aspirin was evaluated by: (1) platelet aggregation measured by whole blood impedance aggregometry (Multiplate® Analyser) using arachidonic acid (ASPItest 0.5 mM) as agonist and (2) serum thromboxane B levels determined using an enzyme-linked immunosorbent assay. The difference in platelet aggregation from 1h to the end of the dosing interval (24h/12h) was used to compare the two regimens. We demonstrated a significantly smaller difference in platelet aggregation in the twice-daily regimen compared to the once-daily: mean of difference = 228 AU*min (95% confidence interval (CI): 92-363, p < 0.01). In addition, a significantly smaller difference in thromboxane B was demonstrated in the twice-daily regimen compared to the once-daily regimen: mean of difference = 16.3 ng/mL (95% CI: 9.9-22.7, p < 0.01). In conclusion, twice-daily dosing with low-dose aspirin provides a more consistent platelet inhibition compared with standard once-daily dosing in patients with essential thrombocytosis.

Most patients cannot be included in randomized clinical trials. We report real-world outcomes of all Danish patients with multiple myeloma (MM) treated with daratumumab-based regimens until 1 January 2019. Methods Information of 635 patients treated with daratumumab was collected retrospectively and included lines of therapy (LOT), hematologic responses according to the International Myeloma Working Group recommendations, time to next treatment (TNT) and the cause of discontinuation of treatment. Baseline characteristics were acquired from the validated Danish Multiple Myeloma Registry (DMMR). Results Daratumumab was administrated as monotherapy (Da-mono) in 27.7%, in combination with immunomodulatory drugs (Da-IMiD) in 57.3%, in combination with proteasome inhibitors (Da-PI) in 11.2% and in other combinations (Da-other) in 3.8% of patients. The median number of lines of therapy given before daratumumab was 5 for Da-mono, 3 for Da-IMiD, 4 for Da-PI, and 2 for Da-other. In Da-mono, overall response rate (ORR) was 44.9% and median time to next treatment (mTNT) was 4.9 months. In Da-IMiD, ORR was 80.5%, and mTNT was 16.1 months. In Da-PI, OOR was 60.6% and mTNT was 5.3 months. In patients treated with Da-other, OOR was 54,2% and mTNT was 5.6 months. The use of daratumumab in early LOT was associated with longer TNT (p<0.0001). Patients with amplification 1q had outcome comparable to standard risk patients, while patients with t(4;14), t(14;16) or del17p had worse outcome (p = 0.0001). Multivariate analysis indicated that timing of treatment (timing of daratumumab in the sequence of all LOT that the patients received throughout the course of their disease) was the most important factor for outcome (p<0.0001). Conclusion The real-world outcomes of multiple myeloma patients treated with daratumumab are worse than the results of clinical trials. Outcomes achieved with daratumumab were best when daratumumab was used in combination with IMIDs and in early LOT. Patients with high-risk CA had worse outcomes, but patients with amp1q had similar outcomes to standard-risk patients.

Bleeding and thrombosis are well-known complications to hematological malignancies, and changes in fibrinolysis impact both these issues. In the present systematic review, we provide an overview and discussion of the current literature in regards to clinical manifestations, diagnosis, and treatment of altered fibrinolysis in patients suffering from hematological malignancies, beyond acute promyelocytic leukemia. We performed a systematic literature search employing the databases Pubmed, Embase, and Web of Science to identify original studies investigating fibrinolysis in hematological malignancies. Studies investigating fibrinolysis in acute promyelocytic leukemia or disseminated intravascular coagulation were excluded. We identified 32 studies fulfilling the inclusion criteria. A majority of the studies were published more than two decades ago, and none of the studies examined all available markers of fibrinolysis or used dynamic clot lysis assays. In acute leukemia L-asparaginase treatment induced a hypofibrinolytic state, and prior to chemotherapy there seemed to be little to no change in fibrinolysis. In studies examining fibrinolysis during chemotherapy results were ambiguous. Two studies examining multiple myeloma indicated hypofibrinolysis prior to chemotherapy, and in another plasma cell disease, amyloid light chain-amyloidosis, clear signs of hyperfibrinolysis were demonstrated. In myeloproliferative neoplasms, the studies reported signs of hypofibrinolysis, in line with the increased risk of thrombosis in this disease. Only one study regarding lymphoma was identified, which indicated no alterations in fibrinolysis. In conclusion, this systematic review demonstrated that only sparse, and mainly old, evidence exists on fibrinolysis in hematological malignancy. However, the published studies showed a tendency toward hypofibrinolysis in myeloproliferative disorders, an increased risk of hyperfibrinolysis, and bleeding in patients with AL-amyloidosis, whereas studies regarding acute leukemias were inconclusive except with regard to L-asparaginase treatment, which induced a hypofibrinolytic state.